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-rw-r--r--xdiff-interface.c333
-rw-r--r--xdiff-interface.h74
-rw-r--r--xdiff/xdiff.h153
-rw-r--r--xdiff/xdiffi.c1089
-rw-r--r--xdiff/xdiffi.h62
-rw-r--r--xdiff/xemit.c330
-rw-r--r--xdiff/xemit.h36
-rw-r--r--xdiff/xhistogram.c370
-rw-r--r--xdiff/xinclude.h36
-rw-r--r--xdiff/xmacros.h71
-rw-r--r--xdiff/xmerge.c739
-rw-r--r--xdiff/xpatience.c373
-rw-r--r--xdiff/xprepare.c461
-rw-r--r--xdiff/xprepare.h34
-rw-r--r--xdiff/xtypes.h67
-rw-r--r--xdiff/xutils.c451
-rw-r--r--xdiff/xutils.h48
17 files changed, 4727 insertions, 0 deletions
diff --git a/xdiff-interface.c b/xdiff-interface.c
new file mode 100644
index 0000000..adcea10
--- /dev/null
+++ b/xdiff-interface.c
@@ -0,0 +1,333 @@
+#include "git-compat-util.h"
+#include "config.h"
+#include "hex.h"
+#include "object-store-ll.h"
+#include "strbuf.h"
+#include "xdiff-interface.h"
+#include "xdiff/xtypes.h"
+#include "xdiff/xdiffi.h"
+#include "xdiff/xemit.h"
+#include "xdiff/xmacros.h"
+#include "xdiff/xutils.h"
+
+struct xdiff_emit_state {
+ xdiff_emit_hunk_fn hunk_fn;
+ xdiff_emit_line_fn line_fn;
+ void *consume_callback_data;
+ struct strbuf remainder;
+};
+
+static int xdiff_out_hunk(void *priv_,
+ long old_begin, long old_nr,
+ long new_begin, long new_nr,
+ const char *func, long funclen)
+{
+ struct xdiff_emit_state *priv = priv_;
+
+ if (priv->remainder.len)
+ BUG("xdiff emitted hunk in the middle of a line");
+
+ priv->hunk_fn(priv->consume_callback_data,
+ old_begin, old_nr, new_begin, new_nr,
+ func, funclen);
+ return 0;
+}
+
+static int consume_one(void *priv_, char *s, unsigned long size)
+{
+ struct xdiff_emit_state *priv = priv_;
+ char *ep;
+ while (size) {
+ unsigned long this_size;
+ int ret;
+ ep = memchr(s, '\n', size);
+ this_size = (ep == NULL) ? size : (ep - s + 1);
+ ret = priv->line_fn(priv->consume_callback_data, s, this_size);
+ if (ret)
+ return ret;
+ size -= this_size;
+ s += this_size;
+ }
+ return 0;
+}
+
+static int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
+{
+ struct xdiff_emit_state *priv = priv_;
+ int i;
+ int stop = 0;
+
+ if (!priv->line_fn)
+ return 0;
+
+ for (i = 0; i < nbuf; i++) {
+ if (stop)
+ return 1;
+ if (mb[i].ptr[mb[i].size-1] != '\n') {
+ /* Incomplete line */
+ strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
+ continue;
+ }
+
+ /* we have a complete line */
+ if (!priv->remainder.len) {
+ stop = consume_one(priv, mb[i].ptr, mb[i].size);
+ continue;
+ }
+ strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
+ stop = consume_one(priv, priv->remainder.buf, priv->remainder.len);
+ strbuf_reset(&priv->remainder);
+ }
+ if (stop)
+ return -1;
+ if (priv->remainder.len) {
+ stop = consume_one(priv, priv->remainder.buf, priv->remainder.len);
+ strbuf_reset(&priv->remainder);
+ }
+ if (stop)
+ return -1;
+ return 0;
+}
+
+/*
+ * Trim down common substring at the end of the buffers,
+ * but end on a complete line.
+ */
+static void trim_common_tail(mmfile_t *a, mmfile_t *b)
+{
+ const int blk = 1024;
+ long trimmed = 0, recovered = 0;
+ char *ap = a->size ? a->ptr + a->size : a->ptr;
+ char *bp = b->size ? b->ptr + b->size : b->ptr;
+ long smaller = (a->size < b->size) ? a->size : b->size;
+
+ while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
+ trimmed += blk;
+ ap -= blk;
+ bp -= blk;
+ }
+
+ while (recovered < trimmed)
+ if (ap[recovered++] == '\n')
+ break;
+ a->size -= trimmed - recovered;
+ b->size -= trimmed - recovered;
+}
+
+int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
+{
+ mmfile_t a = *mf1;
+ mmfile_t b = *mf2;
+
+ if (mf1->size > MAX_XDIFF_SIZE || mf2->size > MAX_XDIFF_SIZE)
+ return -1;
+
+ if (!xecfg->ctxlen && !(xecfg->flags & XDL_EMIT_FUNCCONTEXT))
+ trim_common_tail(&a, &b);
+
+ return xdl_diff(&a, &b, xpp, xecfg, xecb);
+}
+
+int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
+ xdiff_emit_hunk_fn hunk_fn,
+ xdiff_emit_line_fn line_fn,
+ void *consume_callback_data,
+ xpparam_t const *xpp, xdemitconf_t const *xecfg)
+{
+ int ret;
+ struct xdiff_emit_state state;
+ xdemitcb_t ecb;
+
+ memset(&state, 0, sizeof(state));
+ state.hunk_fn = hunk_fn;
+ state.line_fn = line_fn;
+ state.consume_callback_data = consume_callback_data;
+ memset(&ecb, 0, sizeof(ecb));
+ if (hunk_fn)
+ ecb.out_hunk = xdiff_out_hunk;
+ ecb.out_line = xdiff_outf;
+ ecb.priv = &state;
+ strbuf_init(&state.remainder, 0);
+ ret = xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
+ strbuf_release(&state.remainder);
+ return ret;
+}
+
+int read_mmfile(mmfile_t *ptr, const char *filename)
+{
+ struct stat st;
+ FILE *f;
+ size_t sz;
+
+ if (stat(filename, &st))
+ return error_errno("Could not stat %s", filename);
+ if (!(f = fopen(filename, "rb")))
+ return error_errno("Could not open %s", filename);
+ sz = xsize_t(st.st_size);
+ ptr->ptr = xmalloc(sz ? sz : 1);
+ if (sz && fread(ptr->ptr, sz, 1, f) != 1) {
+ fclose(f);
+ return error("Could not read %s", filename);
+ }
+ fclose(f);
+ ptr->size = sz;
+ return 0;
+}
+
+void read_mmblob(mmfile_t *ptr, const struct object_id *oid)
+{
+ unsigned long size;
+ enum object_type type;
+
+ if (oideq(oid, null_oid())) {
+ ptr->ptr = xstrdup("");
+ ptr->size = 0;
+ return;
+ }
+
+ ptr->ptr = repo_read_object_file(the_repository, oid, &type, &size);
+ if (!ptr->ptr || type != OBJ_BLOB)
+ die("unable to read blob object %s", oid_to_hex(oid));
+ ptr->size = size;
+}
+
+#define FIRST_FEW_BYTES 8000
+int buffer_is_binary(const char *ptr, unsigned long size)
+{
+ if (FIRST_FEW_BYTES < size)
+ size = FIRST_FEW_BYTES;
+ return !!memchr(ptr, 0, size);
+}
+
+struct ff_regs {
+ int nr;
+ struct ff_reg {
+ regex_t re;
+ int negate;
+ } *array;
+};
+
+static long ff_regexp(const char *line, long len,
+ char *buffer, long buffer_size, void *priv)
+{
+ struct ff_regs *regs = priv;
+ regmatch_t pmatch[2];
+ int i;
+ int result;
+
+ /* Exclude terminating newline (and cr) from matching */
+ if (len > 0 && line[len-1] == '\n') {
+ if (len > 1 && line[len-2] == '\r')
+ len -= 2;
+ else
+ len--;
+ }
+
+ for (i = 0; i < regs->nr; i++) {
+ struct ff_reg *reg = regs->array + i;
+ if (!regexec_buf(&reg->re, line, len, 2, pmatch, 0)) {
+ if (reg->negate)
+ return -1;
+ break;
+ }
+ }
+ if (regs->nr <= i)
+ return -1;
+ i = pmatch[1].rm_so >= 0 ? 1 : 0;
+ line += pmatch[i].rm_so;
+ result = pmatch[i].rm_eo - pmatch[i].rm_so;
+ if (result > buffer_size)
+ result = buffer_size;
+ while (result > 0 && (isspace(line[result - 1])))
+ result--;
+ memcpy(buffer, line, result);
+ return result;
+}
+
+void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
+{
+ int i;
+ struct ff_regs *regs;
+
+ xecfg->find_func = ff_regexp;
+ regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
+ for (i = 0, regs->nr = 1; value[i]; i++)
+ if (value[i] == '\n')
+ regs->nr++;
+ ALLOC_ARRAY(regs->array, regs->nr);
+ for (i = 0; i < regs->nr; i++) {
+ struct ff_reg *reg = regs->array + i;
+ const char *ep, *expression;
+ char *buffer = NULL;
+
+ if (!value)
+ BUG("mismatch between line count and parsing");
+ ep = strchr(value, '\n');
+
+ reg->negate = (*value == '!');
+ if (reg->negate && i == regs->nr - 1)
+ die("Last expression must not be negated: %s", value);
+ if (*value == '!')
+ value++;
+ if (ep)
+ expression = buffer = xstrndup(value, ep - value);
+ else
+ expression = value;
+ if (regcomp(&reg->re, expression, cflags))
+ die("Invalid regexp to look for hunk header: %s", expression);
+ free(buffer);
+ value = ep ? ep + 1 : NULL;
+ }
+}
+
+void xdiff_clear_find_func(xdemitconf_t *xecfg)
+{
+ if (xecfg->find_func) {
+ int i;
+ struct ff_regs *regs = xecfg->find_func_priv;
+
+ for (i = 0; i < regs->nr; i++)
+ regfree(&regs->array[i].re);
+ free(regs->array);
+ free(regs);
+ xecfg->find_func = NULL;
+ xecfg->find_func_priv = NULL;
+ }
+}
+
+unsigned long xdiff_hash_string(const char *s, size_t len, long flags)
+{
+ return xdl_hash_record(&s, s + len, flags);
+}
+
+int xdiff_compare_lines(const char *l1, long s1,
+ const char *l2, long s2, long flags)
+{
+ return xdl_recmatch(l1, s1, l2, s2, flags);
+}
+
+int git_xmerge_style = -1;
+
+int git_xmerge_config(const char *var, const char *value,
+ const struct config_context *ctx, void *cb)
+{
+ if (!strcmp(var, "merge.conflictstyle")) {
+ if (!value)
+ die("'%s' is not a boolean", var);
+ if (!strcmp(value, "diff3"))
+ git_xmerge_style = XDL_MERGE_DIFF3;
+ else if (!strcmp(value, "zdiff3"))
+ git_xmerge_style = XDL_MERGE_ZEALOUS_DIFF3;
+ else if (!strcmp(value, "merge"))
+ git_xmerge_style = 0;
+ /*
+ * Please update _git_checkout() in
+ * git-completion.bash when you add new merge config
+ */
+ else
+ die("unknown style '%s' given for '%s'",
+ value, var);
+ return 0;
+ }
+ return git_default_config(var, value, ctx, cb);
+}
diff --git a/xdiff-interface.h b/xdiff-interface.h
new file mode 100644
index 0000000..e6f80df
--- /dev/null
+++ b/xdiff-interface.h
@@ -0,0 +1,74 @@
+#ifndef XDIFF_INTERFACE_H
+#define XDIFF_INTERFACE_H
+
+#include "hash-ll.h"
+#include "xdiff/xdiff.h"
+
+/*
+ * xdiff isn't equipped to handle content over a gigabyte;
+ * we make the cutoff 1GB - 1MB to give some breathing
+ * room for constant-sized additions (e.g., merge markers)
+ */
+#define MAX_XDIFF_SIZE (1024UL * 1024 * 1023)
+
+/**
+ * The `xdiff_emit_line_fn` function can return 1 to abort early, or 0
+ * to continue processing. Note that doing so is an all-or-nothing
+ * affair, as returning 1 will return all the way to the top-level,
+ * e.g. the xdi_diff_outf() call to generate the diff.
+ *
+ * Thus returning 1 means you won't be getting any more diff lines. If
+ * you need something in-between those two options you'll to use
+ * `xdl_emit_hunk_consume_func_t` and implement your own version of
+ * xdl_emit_diff().
+ *
+ * We may extend the interface in the future to understand other more
+ * granular return values. While you should return 1 to exit early,
+ * doing so will currently make your early return indistinguishable
+ * from an error internal to xdiff, xdiff itself will see that
+ * non-zero return and translate it to -1.
+ *
+ * See "diff_grep" in diffcore-pickaxe.c for a trick to work around
+ * this, i.e. using the "consume_callback_data" to note the desired
+ * early return.
+ */
+typedef int (*xdiff_emit_line_fn)(void *, char *, unsigned long);
+typedef void (*xdiff_emit_hunk_fn)(void *data,
+ long old_begin, long old_nr,
+ long new_begin, long new_nr,
+ const char *func, long funclen);
+
+int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *ecb);
+int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
+ xdiff_emit_hunk_fn hunk_fn,
+ xdiff_emit_line_fn line_fn,
+ void *consume_callback_data,
+ xpparam_t const *xpp, xdemitconf_t const *xecfg);
+int read_mmfile(mmfile_t *ptr, const char *filename);
+void read_mmblob(mmfile_t *ptr, const struct object_id *oid);
+int buffer_is_binary(const char *ptr, unsigned long size);
+
+void xdiff_set_find_func(xdemitconf_t *xecfg, const char *line, int cflags);
+void xdiff_clear_find_func(xdemitconf_t *xecfg);
+struct config_context;
+int git_xmerge_config(const char *var, const char *value,
+ const struct config_context *ctx, void *cb);
+extern int git_xmerge_style;
+
+/*
+ * Compare the strings l1 with l2 which are of size s1 and s2 respectively.
+ * Returns 1 if the strings are deemed equal, 0 otherwise.
+ * The `flags` given as XDF_WHITESPACE_FLAGS determine how white spaces
+ * are treated for the comparison.
+ */
+int xdiff_compare_lines(const char *l1, long s1,
+ const char *l2, long s2, long flags);
+
+/*
+ * Returns a hash of the string s of length len.
+ * The `flags` given as XDF_WHITESPACE_FLAGS determine how white spaces
+ * are treated for the hash.
+ */
+unsigned long xdiff_hash_string(const char *s, size_t len, long flags);
+
+#endif
diff --git a/xdiff/xdiff.h b/xdiff/xdiff.h
new file mode 100644
index 0000000..bb56b23
--- /dev/null
+++ b/xdiff/xdiff.h
@@ -0,0 +1,153 @@
+/*
+ * LibXDiff by Davide Libenzi ( File Differential Library )
+ * Copyright (C) 2003 Davide Libenzi
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XDIFF_H)
+#define XDIFF_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* #ifdef __cplusplus */
+
+/* xpparm_t.flags */
+#define XDF_NEED_MINIMAL (1 << 0)
+
+#define XDF_IGNORE_WHITESPACE (1 << 1)
+#define XDF_IGNORE_WHITESPACE_CHANGE (1 << 2)
+#define XDF_IGNORE_WHITESPACE_AT_EOL (1 << 3)
+#define XDF_IGNORE_CR_AT_EOL (1 << 4)
+#define XDF_WHITESPACE_FLAGS (XDF_IGNORE_WHITESPACE | \
+ XDF_IGNORE_WHITESPACE_CHANGE | \
+ XDF_IGNORE_WHITESPACE_AT_EOL | \
+ XDF_IGNORE_CR_AT_EOL)
+
+#define XDF_IGNORE_BLANK_LINES (1 << 7)
+
+#define XDF_PATIENCE_DIFF (1 << 14)
+#define XDF_HISTOGRAM_DIFF (1 << 15)
+#define XDF_DIFF_ALGORITHM_MASK (XDF_PATIENCE_DIFF | XDF_HISTOGRAM_DIFF)
+#define XDF_DIFF_ALG(x) ((x) & XDF_DIFF_ALGORITHM_MASK)
+
+#define XDF_INDENT_HEURISTIC (1 << 23)
+
+/* xdemitconf_t.flags */
+#define XDL_EMIT_FUNCNAMES (1 << 0)
+#define XDL_EMIT_NO_HUNK_HDR (1 << 1)
+#define XDL_EMIT_FUNCCONTEXT (1 << 2)
+
+/* merge simplification levels */
+#define XDL_MERGE_MINIMAL 0
+#define XDL_MERGE_EAGER 1
+#define XDL_MERGE_ZEALOUS 2
+#define XDL_MERGE_ZEALOUS_ALNUM 3
+
+/* merge favor modes */
+#define XDL_MERGE_FAVOR_OURS 1
+#define XDL_MERGE_FAVOR_THEIRS 2
+#define XDL_MERGE_FAVOR_UNION 3
+
+/* merge output styles */
+#define XDL_MERGE_DIFF3 1
+#define XDL_MERGE_ZEALOUS_DIFF3 2
+
+typedef struct s_mmfile {
+ char *ptr;
+ long size;
+} mmfile_t;
+
+typedef struct s_mmbuffer {
+ char *ptr;
+ long size;
+} mmbuffer_t;
+
+typedef struct s_xpparam {
+ unsigned long flags;
+
+ /* -I<regex> */
+ regex_t **ignore_regex;
+ size_t ignore_regex_nr;
+
+ /* See Documentation/diff-options.txt. */
+ char **anchors;
+ size_t anchors_nr;
+} xpparam_t;
+
+typedef struct s_xdemitcb {
+ void *priv;
+ int (*out_hunk)(void *,
+ long old_begin, long old_nr,
+ long new_begin, long new_nr,
+ const char *func, long funclen);
+ int (*out_line)(void *, mmbuffer_t *, int);
+} xdemitcb_t;
+
+typedef long (*find_func_t)(const char *line, long line_len, char *buffer, long buffer_size, void *priv);
+
+typedef int (*xdl_emit_hunk_consume_func_t)(long start_a, long count_a,
+ long start_b, long count_b,
+ void *cb_data);
+
+typedef struct s_xdemitconf {
+ long ctxlen;
+ long interhunkctxlen;
+ unsigned long flags;
+ find_func_t find_func;
+ void *find_func_priv;
+ xdl_emit_hunk_consume_func_t hunk_func;
+} xdemitconf_t;
+
+typedef struct s_bdiffparam {
+ long bsize;
+} bdiffparam_t;
+
+
+#define xdl_malloc(x) xmalloc(x)
+#define xdl_calloc(n, sz) xcalloc(n, sz)
+#define xdl_free(ptr) free(ptr)
+#define xdl_realloc(ptr,x) xrealloc(ptr,x)
+
+void *xdl_mmfile_first(mmfile_t *mmf, long *size);
+long xdl_mmfile_size(mmfile_t *mmf);
+
+int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+ xdemitconf_t const *xecfg, xdemitcb_t *ecb);
+
+typedef struct s_xmparam {
+ xpparam_t xpp;
+ int marker_size;
+ int level;
+ int favor;
+ int style;
+ const char *ancestor; /* label for orig */
+ const char *file1; /* label for mf1 */
+ const char *file2; /* label for mf2 */
+} xmparam_t;
+
+#define DEFAULT_CONFLICT_MARKER_SIZE 7
+
+int xdl_merge(mmfile_t *orig, mmfile_t *mf1, mmfile_t *mf2,
+ xmparam_t const *xmp, mmbuffer_t *result);
+
+#ifdef __cplusplus
+}
+#endif /* #ifdef __cplusplus */
+
+#endif /* #if !defined(XDIFF_H) */
diff --git a/xdiff/xdiffi.c b/xdiff/xdiffi.c
new file mode 100644
index 0000000..344c2df
--- /dev/null
+++ b/xdiff/xdiffi.c
@@ -0,0 +1,1089 @@
+/*
+ * LibXDiff by Davide Libenzi ( File Differential Library )
+ * Copyright (C) 2003 Davide Libenzi
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#include "xinclude.h"
+
+#define XDL_MAX_COST_MIN 256
+#define XDL_HEUR_MIN_COST 256
+#define XDL_LINE_MAX (long)((1UL << (CHAR_BIT * sizeof(long) - 1)) - 1)
+#define XDL_SNAKE_CNT 20
+#define XDL_K_HEUR 4
+
+typedef struct s_xdpsplit {
+ long i1, i2;
+ int min_lo, min_hi;
+} xdpsplit_t;
+
+/*
+ * See "An O(ND) Difference Algorithm and its Variations", by Eugene Myers.
+ * Basically considers a "box" (off1, off2, lim1, lim2) and scan from both
+ * the forward diagonal starting from (off1, off2) and the backward diagonal
+ * starting from (lim1, lim2). If the K values on the same diagonal crosses
+ * returns the furthest point of reach. We might encounter expensive edge cases
+ * using this algorithm, so a little bit of heuristic is needed to cut the
+ * search and to return a suboptimal point.
+ */
+static long xdl_split(unsigned long const *ha1, long off1, long lim1,
+ unsigned long const *ha2, long off2, long lim2,
+ long *kvdf, long *kvdb, int need_min, xdpsplit_t *spl,
+ xdalgoenv_t *xenv) {
+ long dmin = off1 - lim2, dmax = lim1 - off2;
+ long fmid = off1 - off2, bmid = lim1 - lim2;
+ long odd = (fmid - bmid) & 1;
+ long fmin = fmid, fmax = fmid;
+ long bmin = bmid, bmax = bmid;
+ long ec, d, i1, i2, prev1, best, dd, v, k;
+
+ /*
+ * Set initial diagonal values for both forward and backward path.
+ */
+ kvdf[fmid] = off1;
+ kvdb[bmid] = lim1;
+
+ for (ec = 1;; ec++) {
+ int got_snake = 0;
+
+ /*
+ * We need to extend the diagonal "domain" by one. If the next
+ * values exits the box boundaries we need to change it in the
+ * opposite direction because (max - min) must be a power of
+ * two.
+ *
+ * Also we initialize the external K value to -1 so that we can
+ * avoid extra conditions in the check inside the core loop.
+ */
+ if (fmin > dmin)
+ kvdf[--fmin - 1] = -1;
+ else
+ ++fmin;
+ if (fmax < dmax)
+ kvdf[++fmax + 1] = -1;
+ else
+ --fmax;
+
+ for (d = fmax; d >= fmin; d -= 2) {
+ if (kvdf[d - 1] >= kvdf[d + 1])
+ i1 = kvdf[d - 1] + 1;
+ else
+ i1 = kvdf[d + 1];
+ prev1 = i1;
+ i2 = i1 - d;
+ for (; i1 < lim1 && i2 < lim2 && ha1[i1] == ha2[i2]; i1++, i2++);
+ if (i1 - prev1 > xenv->snake_cnt)
+ got_snake = 1;
+ kvdf[d] = i1;
+ if (odd && bmin <= d && d <= bmax && kvdb[d] <= i1) {
+ spl->i1 = i1;
+ spl->i2 = i2;
+ spl->min_lo = spl->min_hi = 1;
+ return ec;
+ }
+ }
+
+ /*
+ * We need to extend the diagonal "domain" by one. If the next
+ * values exits the box boundaries we need to change it in the
+ * opposite direction because (max - min) must be a power of
+ * two.
+ *
+ * Also we initialize the external K value to -1 so that we can
+ * avoid extra conditions in the check inside the core loop.
+ */
+ if (bmin > dmin)
+ kvdb[--bmin - 1] = XDL_LINE_MAX;
+ else
+ ++bmin;
+ if (bmax < dmax)
+ kvdb[++bmax + 1] = XDL_LINE_MAX;
+ else
+ --bmax;
+
+ for (d = bmax; d >= bmin; d -= 2) {
+ if (kvdb[d - 1] < kvdb[d + 1])
+ i1 = kvdb[d - 1];
+ else
+ i1 = kvdb[d + 1] - 1;
+ prev1 = i1;
+ i2 = i1 - d;
+ for (; i1 > off1 && i2 > off2 && ha1[i1 - 1] == ha2[i2 - 1]; i1--, i2--);
+ if (prev1 - i1 > xenv->snake_cnt)
+ got_snake = 1;
+ kvdb[d] = i1;
+ if (!odd && fmin <= d && d <= fmax && i1 <= kvdf[d]) {
+ spl->i1 = i1;
+ spl->i2 = i2;
+ spl->min_lo = spl->min_hi = 1;
+ return ec;
+ }
+ }
+
+ if (need_min)
+ continue;
+
+ /*
+ * If the edit cost is above the heuristic trigger and if
+ * we got a good snake, we sample current diagonals to see
+ * if some of them have reached an "interesting" path. Our
+ * measure is a function of the distance from the diagonal
+ * corner (i1 + i2) penalized with the distance from the
+ * mid diagonal itself. If this value is above the current
+ * edit cost times a magic factor (XDL_K_HEUR) we consider
+ * it interesting.
+ */
+ if (got_snake && ec > xenv->heur_min) {
+ for (best = 0, d = fmax; d >= fmin; d -= 2) {
+ dd = d > fmid ? d - fmid: fmid - d;
+ i1 = kvdf[d];
+ i2 = i1 - d;
+ v = (i1 - off1) + (i2 - off2) - dd;
+
+ if (v > XDL_K_HEUR * ec && v > best &&
+ off1 + xenv->snake_cnt <= i1 && i1 < lim1 &&
+ off2 + xenv->snake_cnt <= i2 && i2 < lim2) {
+ for (k = 1; ha1[i1 - k] == ha2[i2 - k]; k++)
+ if (k == xenv->snake_cnt) {
+ best = v;
+ spl->i1 = i1;
+ spl->i2 = i2;
+ break;
+ }
+ }
+ }
+ if (best > 0) {
+ spl->min_lo = 1;
+ spl->min_hi = 0;
+ return ec;
+ }
+
+ for (best = 0, d = bmax; d >= bmin; d -= 2) {
+ dd = d > bmid ? d - bmid: bmid - d;
+ i1 = kvdb[d];
+ i2 = i1 - d;
+ v = (lim1 - i1) + (lim2 - i2) - dd;
+
+ if (v > XDL_K_HEUR * ec && v > best &&
+ off1 < i1 && i1 <= lim1 - xenv->snake_cnt &&
+ off2 < i2 && i2 <= lim2 - xenv->snake_cnt) {
+ for (k = 0; ha1[i1 + k] == ha2[i2 + k]; k++)
+ if (k == xenv->snake_cnt - 1) {
+ best = v;
+ spl->i1 = i1;
+ spl->i2 = i2;
+ break;
+ }
+ }
+ }
+ if (best > 0) {
+ spl->min_lo = 0;
+ spl->min_hi = 1;
+ return ec;
+ }
+ }
+
+ /*
+ * Enough is enough. We spent too much time here and now we
+ * collect the furthest reaching path using the (i1 + i2)
+ * measure.
+ */
+ if (ec >= xenv->mxcost) {
+ long fbest, fbest1, bbest, bbest1;
+
+ fbest = fbest1 = -1;
+ for (d = fmax; d >= fmin; d -= 2) {
+ i1 = XDL_MIN(kvdf[d], lim1);
+ i2 = i1 - d;
+ if (lim2 < i2)
+ i1 = lim2 + d, i2 = lim2;
+ if (fbest < i1 + i2) {
+ fbest = i1 + i2;
+ fbest1 = i1;
+ }
+ }
+
+ bbest = bbest1 = XDL_LINE_MAX;
+ for (d = bmax; d >= bmin; d -= 2) {
+ i1 = XDL_MAX(off1, kvdb[d]);
+ i2 = i1 - d;
+ if (i2 < off2)
+ i1 = off2 + d, i2 = off2;
+ if (i1 + i2 < bbest) {
+ bbest = i1 + i2;
+ bbest1 = i1;
+ }
+ }
+
+ if ((lim1 + lim2) - bbest < fbest - (off1 + off2)) {
+ spl->i1 = fbest1;
+ spl->i2 = fbest - fbest1;
+ spl->min_lo = 1;
+ spl->min_hi = 0;
+ } else {
+ spl->i1 = bbest1;
+ spl->i2 = bbest - bbest1;
+ spl->min_lo = 0;
+ spl->min_hi = 1;
+ }
+ return ec;
+ }
+ }
+}
+
+
+/*
+ * Rule: "Divide et Impera" (divide & conquer). Recursively split the box in
+ * sub-boxes by calling the box splitting function. Note that the real job
+ * (marking changed lines) is done in the two boundary reaching checks.
+ */
+int xdl_recs_cmp(diffdata_t *dd1, long off1, long lim1,
+ diffdata_t *dd2, long off2, long lim2,
+ long *kvdf, long *kvdb, int need_min, xdalgoenv_t *xenv) {
+ unsigned long const *ha1 = dd1->ha, *ha2 = dd2->ha;
+
+ /*
+ * Shrink the box by walking through each diagonal snake (SW and NE).
+ */
+ for (; off1 < lim1 && off2 < lim2 && ha1[off1] == ha2[off2]; off1++, off2++);
+ for (; off1 < lim1 && off2 < lim2 && ha1[lim1 - 1] == ha2[lim2 - 1]; lim1--, lim2--);
+
+ /*
+ * If one dimension is empty, then all records on the other one must
+ * be obviously changed.
+ */
+ if (off1 == lim1) {
+ char *rchg2 = dd2->rchg;
+ long *rindex2 = dd2->rindex;
+
+ for (; off2 < lim2; off2++)
+ rchg2[rindex2[off2]] = 1;
+ } else if (off2 == lim2) {
+ char *rchg1 = dd1->rchg;
+ long *rindex1 = dd1->rindex;
+
+ for (; off1 < lim1; off1++)
+ rchg1[rindex1[off1]] = 1;
+ } else {
+ xdpsplit_t spl;
+ spl.i1 = spl.i2 = 0;
+
+ /*
+ * Divide ...
+ */
+ if (xdl_split(ha1, off1, lim1, ha2, off2, lim2, kvdf, kvdb,
+ need_min, &spl, xenv) < 0) {
+
+ return -1;
+ }
+
+ /*
+ * ... et Impera.
+ */
+ if (xdl_recs_cmp(dd1, off1, spl.i1, dd2, off2, spl.i2,
+ kvdf, kvdb, spl.min_lo, xenv) < 0 ||
+ xdl_recs_cmp(dd1, spl.i1, lim1, dd2, spl.i2, lim2,
+ kvdf, kvdb, spl.min_hi, xenv) < 0) {
+
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+
+int xdl_do_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+ xdfenv_t *xe) {
+ long ndiags;
+ long *kvd, *kvdf, *kvdb;
+ xdalgoenv_t xenv;
+ diffdata_t dd1, dd2;
+ int res;
+
+ if (xdl_prepare_env(mf1, mf2, xpp, xe) < 0)
+ return -1;
+
+ if (XDF_DIFF_ALG(xpp->flags) == XDF_PATIENCE_DIFF) {
+ res = xdl_do_patience_diff(xpp, xe);
+ goto out;
+ }
+
+ if (XDF_DIFF_ALG(xpp->flags) == XDF_HISTOGRAM_DIFF) {
+ res = xdl_do_histogram_diff(xpp, xe);
+ goto out;
+ }
+
+ /*
+ * Allocate and setup K vectors to be used by the differential
+ * algorithm.
+ *
+ * One is to store the forward path and one to store the backward path.
+ */
+ ndiags = xe->xdf1.nreff + xe->xdf2.nreff + 3;
+ if (!XDL_ALLOC_ARRAY(kvd, 2 * ndiags + 2)) {
+
+ xdl_free_env(xe);
+ return -1;
+ }
+ kvdf = kvd;
+ kvdb = kvdf + ndiags;
+ kvdf += xe->xdf2.nreff + 1;
+ kvdb += xe->xdf2.nreff + 1;
+
+ xenv.mxcost = xdl_bogosqrt(ndiags);
+ if (xenv.mxcost < XDL_MAX_COST_MIN)
+ xenv.mxcost = XDL_MAX_COST_MIN;
+ xenv.snake_cnt = XDL_SNAKE_CNT;
+ xenv.heur_min = XDL_HEUR_MIN_COST;
+
+ dd1.nrec = xe->xdf1.nreff;
+ dd1.ha = xe->xdf1.ha;
+ dd1.rchg = xe->xdf1.rchg;
+ dd1.rindex = xe->xdf1.rindex;
+ dd2.nrec = xe->xdf2.nreff;
+ dd2.ha = xe->xdf2.ha;
+ dd2.rchg = xe->xdf2.rchg;
+ dd2.rindex = xe->xdf2.rindex;
+
+ res = xdl_recs_cmp(&dd1, 0, dd1.nrec, &dd2, 0, dd2.nrec,
+ kvdf, kvdb, (xpp->flags & XDF_NEED_MINIMAL) != 0,
+ &xenv);
+ xdl_free(kvd);
+ out:
+ if (res < 0)
+ xdl_free_env(xe);
+
+ return res;
+}
+
+
+static xdchange_t *xdl_add_change(xdchange_t *xscr, long i1, long i2, long chg1, long chg2) {
+ xdchange_t *xch;
+
+ if (!(xch = (xdchange_t *) xdl_malloc(sizeof(xdchange_t))))
+ return NULL;
+
+ xch->next = xscr;
+ xch->i1 = i1;
+ xch->i2 = i2;
+ xch->chg1 = chg1;
+ xch->chg2 = chg2;
+ xch->ignore = 0;
+
+ return xch;
+}
+
+
+static int recs_match(xrecord_t *rec1, xrecord_t *rec2)
+{
+ return (rec1->ha == rec2->ha);
+}
+
+/*
+ * If a line is indented more than this, get_indent() just returns this value.
+ * This avoids having to do absurd amounts of work for data that are not
+ * human-readable text, and also ensures that the output of get_indent fits
+ * within an int.
+ */
+#define MAX_INDENT 200
+
+/*
+ * Return the amount of indentation of the specified line, treating TAB as 8
+ * columns. Return -1 if line is empty or contains only whitespace. Clamp the
+ * output value at MAX_INDENT.
+ */
+static int get_indent(xrecord_t *rec)
+{
+ long i;
+ int ret = 0;
+
+ for (i = 0; i < rec->size; i++) {
+ char c = rec->ptr[i];
+
+ if (!XDL_ISSPACE(c))
+ return ret;
+ else if (c == ' ')
+ ret += 1;
+ else if (c == '\t')
+ ret += 8 - ret % 8;
+ /* ignore other whitespace characters */
+
+ if (ret >= MAX_INDENT)
+ return MAX_INDENT;
+ }
+
+ /* The line contains only whitespace. */
+ return -1;
+}
+
+/*
+ * If more than this number of consecutive blank rows are found, just return
+ * this value. This avoids requiring O(N^2) work for pathological cases, and
+ * also ensures that the output of score_split fits in an int.
+ */
+#define MAX_BLANKS 20
+
+/* Characteristics measured about a hypothetical split position. */
+struct split_measurement {
+ /*
+ * Is the split at the end of the file (aside from any blank lines)?
+ */
+ int end_of_file;
+
+ /*
+ * How much is the line immediately following the split indented (or -1
+ * if the line is blank):
+ */
+ int indent;
+
+ /*
+ * How many consecutive lines above the split are blank?
+ */
+ int pre_blank;
+
+ /*
+ * How much is the nearest non-blank line above the split indented (or
+ * -1 if there is no such line)?
+ */
+ int pre_indent;
+
+ /*
+ * How many lines after the line following the split are blank?
+ */
+ int post_blank;
+
+ /*
+ * How much is the nearest non-blank line after the line following the
+ * split indented (or -1 if there is no such line)?
+ */
+ int post_indent;
+};
+
+struct split_score {
+ /* The effective indent of this split (smaller is preferred). */
+ int effective_indent;
+
+ /* Penalty for this split (smaller is preferred). */
+ int penalty;
+};
+
+/*
+ * Fill m with information about a hypothetical split of xdf above line split.
+ */
+static void measure_split(const xdfile_t *xdf, long split,
+ struct split_measurement *m)
+{
+ long i;
+
+ if (split >= xdf->nrec) {
+ m->end_of_file = 1;
+ m->indent = -1;
+ } else {
+ m->end_of_file = 0;
+ m->indent = get_indent(xdf->recs[split]);
+ }
+
+ m->pre_blank = 0;
+ m->pre_indent = -1;
+ for (i = split - 1; i >= 0; i--) {
+ m->pre_indent = get_indent(xdf->recs[i]);
+ if (m->pre_indent != -1)
+ break;
+ m->pre_blank += 1;
+ if (m->pre_blank == MAX_BLANKS) {
+ m->pre_indent = 0;
+ break;
+ }
+ }
+
+ m->post_blank = 0;
+ m->post_indent = -1;
+ for (i = split + 1; i < xdf->nrec; i++) {
+ m->post_indent = get_indent(xdf->recs[i]);
+ if (m->post_indent != -1)
+ break;
+ m->post_blank += 1;
+ if (m->post_blank == MAX_BLANKS) {
+ m->post_indent = 0;
+ break;
+ }
+ }
+}
+
+/*
+ * The empirically-determined weight factors used by score_split() below.
+ * Larger values means that the position is a less favorable place to split.
+ *
+ * Note that scores are only ever compared against each other, so multiplying
+ * all of these weight/penalty values by the same factor wouldn't change the
+ * heuristic's behavior. Still, we need to set that arbitrary scale *somehow*.
+ * In practice, these numbers are chosen to be large enough that they can be
+ * adjusted relative to each other with sufficient precision despite using
+ * integer math.
+ */
+
+/* Penalty if there are no non-blank lines before the split */
+#define START_OF_FILE_PENALTY 1
+
+/* Penalty if there are no non-blank lines after the split */
+#define END_OF_FILE_PENALTY 21
+
+/* Multiplier for the number of blank lines around the split */
+#define TOTAL_BLANK_WEIGHT (-30)
+
+/* Multiplier for the number of blank lines after the split */
+#define POST_BLANK_WEIGHT 6
+
+/*
+ * Penalties applied if the line is indented more than its predecessor
+ */
+#define RELATIVE_INDENT_PENALTY (-4)
+#define RELATIVE_INDENT_WITH_BLANK_PENALTY 10
+
+/*
+ * Penalties applied if the line is indented less than both its predecessor and
+ * its successor
+ */
+#define RELATIVE_OUTDENT_PENALTY 24
+#define RELATIVE_OUTDENT_WITH_BLANK_PENALTY 17
+
+/*
+ * Penalties applied if the line is indented less than its predecessor but not
+ * less than its successor
+ */
+#define RELATIVE_DEDENT_PENALTY 23
+#define RELATIVE_DEDENT_WITH_BLANK_PENALTY 17
+
+/*
+ * We only consider whether the sum of the effective indents for splits are
+ * less than (-1), equal to (0), or greater than (+1) each other. The resulting
+ * value is multiplied by the following weight and combined with the penalty to
+ * determine the better of two scores.
+ */
+#define INDENT_WEIGHT 60
+
+/*
+ * How far do we slide a hunk at most?
+ */
+#define INDENT_HEURISTIC_MAX_SLIDING 100
+
+/*
+ * Compute a badness score for the hypothetical split whose measurements are
+ * stored in m. The weight factors were determined empirically using the tools
+ * and corpus described in
+ *
+ * https://github.com/mhagger/diff-slider-tools
+ *
+ * Also see that project if you want to improve the weights based on, for
+ * example, a larger or more diverse corpus.
+ */
+static void score_add_split(const struct split_measurement *m, struct split_score *s)
+{
+ /*
+ * A place to accumulate penalty factors (positive makes this index more
+ * favored):
+ */
+ int post_blank, total_blank, indent, any_blanks;
+
+ if (m->pre_indent == -1 && m->pre_blank == 0)
+ s->penalty += START_OF_FILE_PENALTY;
+
+ if (m->end_of_file)
+ s->penalty += END_OF_FILE_PENALTY;
+
+ /*
+ * Set post_blank to the number of blank lines following the split,
+ * including the line immediately after the split:
+ */
+ post_blank = (m->indent == -1) ? 1 + m->post_blank : 0;
+ total_blank = m->pre_blank + post_blank;
+
+ /* Penalties based on nearby blank lines: */
+ s->penalty += TOTAL_BLANK_WEIGHT * total_blank;
+ s->penalty += POST_BLANK_WEIGHT * post_blank;
+
+ if (m->indent != -1)
+ indent = m->indent;
+ else
+ indent = m->post_indent;
+
+ any_blanks = (total_blank != 0);
+
+ /* Note that the effective indent is -1 at the end of the file: */
+ s->effective_indent += indent;
+
+ if (indent == -1) {
+ /* No additional adjustments needed. */
+ } else if (m->pre_indent == -1) {
+ /* No additional adjustments needed. */
+ } else if (indent > m->pre_indent) {
+ /*
+ * The line is indented more than its predecessor.
+ */
+ s->penalty += any_blanks ?
+ RELATIVE_INDENT_WITH_BLANK_PENALTY :
+ RELATIVE_INDENT_PENALTY;
+ } else if (indent == m->pre_indent) {
+ /*
+ * The line has the same indentation level as its predecessor.
+ * No additional adjustments needed.
+ */
+ } else {
+ /*
+ * The line is indented less than its predecessor. It could be
+ * the block terminator of the previous block, but it could
+ * also be the start of a new block (e.g., an "else" block, or
+ * maybe the previous block didn't have a block terminator).
+ * Try to distinguish those cases based on what comes next:
+ */
+ if (m->post_indent != -1 && m->post_indent > indent) {
+ /*
+ * The following line is indented more. So it is likely
+ * that this line is the start of a block.
+ */
+ s->penalty += any_blanks ?
+ RELATIVE_OUTDENT_WITH_BLANK_PENALTY :
+ RELATIVE_OUTDENT_PENALTY;
+ } else {
+ /*
+ * That was probably the end of a block.
+ */
+ s->penalty += any_blanks ?
+ RELATIVE_DEDENT_WITH_BLANK_PENALTY :
+ RELATIVE_DEDENT_PENALTY;
+ }
+ }
+}
+
+static int score_cmp(struct split_score *s1, struct split_score *s2)
+{
+ /* -1 if s1.effective_indent < s2->effective_indent, etc. */
+ int cmp_indents = ((s1->effective_indent > s2->effective_indent) -
+ (s1->effective_indent < s2->effective_indent));
+
+ return INDENT_WEIGHT * cmp_indents + (s1->penalty - s2->penalty);
+}
+
+/*
+ * Represent a group of changed lines in an xdfile_t (i.e., a contiguous group
+ * of lines that was inserted or deleted from the corresponding version of the
+ * file). We consider there to be such a group at the beginning of the file, at
+ * the end of the file, and between any two unchanged lines, though most such
+ * groups will usually be empty.
+ *
+ * If the first line in a group is equal to the line following the group, then
+ * the group can be slid down. Similarly, if the last line in a group is equal
+ * to the line preceding the group, then the group can be slid up. See
+ * group_slide_down() and group_slide_up().
+ *
+ * Note that loops that are testing for changed lines in xdf->rchg do not need
+ * index bounding since the array is prepared with a zero at position -1 and N.
+ */
+struct xdlgroup {
+ /*
+ * The index of the first changed line in the group, or the index of
+ * the unchanged line above which the (empty) group is located.
+ */
+ long start;
+
+ /*
+ * The index of the first unchanged line after the group. For an empty
+ * group, end is equal to start.
+ */
+ long end;
+};
+
+/*
+ * Initialize g to point at the first group in xdf.
+ */
+static void group_init(xdfile_t *xdf, struct xdlgroup *g)
+{
+ g->start = g->end = 0;
+ while (xdf->rchg[g->end])
+ g->end++;
+}
+
+/*
+ * Move g to describe the next (possibly empty) group in xdf and return 0. If g
+ * is already at the end of the file, do nothing and return -1.
+ */
+static inline int group_next(xdfile_t *xdf, struct xdlgroup *g)
+{
+ if (g->end == xdf->nrec)
+ return -1;
+
+ g->start = g->end + 1;
+ for (g->end = g->start; xdf->rchg[g->end]; g->end++)
+ ;
+
+ return 0;
+}
+
+/*
+ * Move g to describe the previous (possibly empty) group in xdf and return 0.
+ * If g is already at the beginning of the file, do nothing and return -1.
+ */
+static inline int group_previous(xdfile_t *xdf, struct xdlgroup *g)
+{
+ if (g->start == 0)
+ return -1;
+
+ g->end = g->start - 1;
+ for (g->start = g->end; xdf->rchg[g->start - 1]; g->start--)
+ ;
+
+ return 0;
+}
+
+/*
+ * If g can be slid toward the end of the file, do so, and if it bumps into a
+ * following group, expand this group to include it. Return 0 on success or -1
+ * if g cannot be slid down.
+ */
+static int group_slide_down(xdfile_t *xdf, struct xdlgroup *g)
+{
+ if (g->end < xdf->nrec &&
+ recs_match(xdf->recs[g->start], xdf->recs[g->end])) {
+ xdf->rchg[g->start++] = 0;
+ xdf->rchg[g->end++] = 1;
+
+ while (xdf->rchg[g->end])
+ g->end++;
+
+ return 0;
+ } else {
+ return -1;
+ }
+}
+
+/*
+ * If g can be slid toward the beginning of the file, do so, and if it bumps
+ * into a previous group, expand this group to include it. Return 0 on success
+ * or -1 if g cannot be slid up.
+ */
+static int group_slide_up(xdfile_t *xdf, struct xdlgroup *g)
+{
+ if (g->start > 0 &&
+ recs_match(xdf->recs[g->start - 1], xdf->recs[g->end - 1])) {
+ xdf->rchg[--g->start] = 1;
+ xdf->rchg[--g->end] = 0;
+
+ while (xdf->rchg[g->start - 1])
+ g->start--;
+
+ return 0;
+ } else {
+ return -1;
+ }
+}
+
+/*
+ * Move back and forward change groups for a consistent and pretty diff output.
+ * This also helps in finding joinable change groups and reducing the diff
+ * size.
+ */
+int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo, long flags) {
+ struct xdlgroup g, go;
+ long earliest_end, end_matching_other;
+ long groupsize;
+
+ group_init(xdf, &g);
+ group_init(xdfo, &go);
+
+ while (1) {
+ /*
+ * If the group is empty in the to-be-compacted file, skip it:
+ */
+ if (g.end == g.start)
+ goto next;
+
+ /*
+ * Now shift the change up and then down as far as possible in
+ * each direction. If it bumps into any other changes, merge
+ * them.
+ */
+ do {
+ groupsize = g.end - g.start;
+
+ /*
+ * Keep track of the last "end" index that causes this
+ * group to align with a group of changed lines in the
+ * other file. -1 indicates that we haven't found such
+ * a match yet:
+ */
+ end_matching_other = -1;
+
+ /* Shift the group backward as much as possible: */
+ while (!group_slide_up(xdf, &g))
+ if (group_previous(xdfo, &go))
+ BUG("group sync broken sliding up");
+
+ /*
+ * This is this highest that this group can be shifted.
+ * Record its end index:
+ */
+ earliest_end = g.end;
+
+ if (go.end > go.start)
+ end_matching_other = g.end;
+
+ /* Now shift the group forward as far as possible: */
+ while (1) {
+ if (group_slide_down(xdf, &g))
+ break;
+ if (group_next(xdfo, &go))
+ BUG("group sync broken sliding down");
+
+ if (go.end > go.start)
+ end_matching_other = g.end;
+ }
+ } while (groupsize != g.end - g.start);
+
+ /*
+ * If the group can be shifted, then we can possibly use this
+ * freedom to produce a more intuitive diff.
+ *
+ * The group is currently shifted as far down as possible, so
+ * the heuristics below only have to handle upwards shifts.
+ */
+
+ if (g.end == earliest_end) {
+ /* no shifting was possible */
+ } else if (end_matching_other != -1) {
+ /*
+ * Move the possibly merged group of changes back to
+ * line up with the last group of changes from the
+ * other file that it can align with.
+ */
+ while (go.end == go.start) {
+ if (group_slide_up(xdf, &g))
+ BUG("match disappeared");
+ if (group_previous(xdfo, &go))
+ BUG("group sync broken sliding to match");
+ }
+ } else if (flags & XDF_INDENT_HEURISTIC) {
+ /*
+ * Indent heuristic: a group of pure add/delete lines
+ * implies two splits, one between the end of the
+ * "before" context and the start of the group, and
+ * another between the end of the group and the
+ * beginning of the "after" context. Some splits are
+ * aesthetically better and some are worse. We compute
+ * a badness "score" for each split, and add the scores
+ * for the two splits to define a "score" for each
+ * position that the group can be shifted to. Then we
+ * pick the shift with the lowest score.
+ */
+ long shift, best_shift = -1;
+ struct split_score best_score;
+
+ shift = earliest_end;
+ if (g.end - groupsize - 1 > shift)
+ shift = g.end - groupsize - 1;
+ if (g.end - INDENT_HEURISTIC_MAX_SLIDING > shift)
+ shift = g.end - INDENT_HEURISTIC_MAX_SLIDING;
+ for (; shift <= g.end; shift++) {
+ struct split_measurement m;
+ struct split_score score = {0, 0};
+
+ measure_split(xdf, shift, &m);
+ score_add_split(&m, &score);
+ measure_split(xdf, shift - groupsize, &m);
+ score_add_split(&m, &score);
+ if (best_shift == -1 ||
+ score_cmp(&score, &best_score) <= 0) {
+ best_score.effective_indent = score.effective_indent;
+ best_score.penalty = score.penalty;
+ best_shift = shift;
+ }
+ }
+
+ while (g.end > best_shift) {
+ if (group_slide_up(xdf, &g))
+ BUG("best shift unreached");
+ if (group_previous(xdfo, &go))
+ BUG("group sync broken sliding to blank line");
+ }
+ }
+
+ next:
+ /* Move past the just-processed group: */
+ if (group_next(xdf, &g))
+ break;
+ if (group_next(xdfo, &go))
+ BUG("group sync broken moving to next group");
+ }
+
+ if (!group_next(xdfo, &go))
+ BUG("group sync broken at end of file");
+
+ return 0;
+}
+
+
+int xdl_build_script(xdfenv_t *xe, xdchange_t **xscr) {
+ xdchange_t *cscr = NULL, *xch;
+ char *rchg1 = xe->xdf1.rchg, *rchg2 = xe->xdf2.rchg;
+ long i1, i2, l1, l2;
+
+ /*
+ * Trivial. Collects "groups" of changes and creates an edit script.
+ */
+ for (i1 = xe->xdf1.nrec, i2 = xe->xdf2.nrec; i1 >= 0 || i2 >= 0; i1--, i2--)
+ if (rchg1[i1 - 1] || rchg2[i2 - 1]) {
+ for (l1 = i1; rchg1[i1 - 1]; i1--);
+ for (l2 = i2; rchg2[i2 - 1]; i2--);
+
+ if (!(xch = xdl_add_change(cscr, i1, i2, l1 - i1, l2 - i2))) {
+ xdl_free_script(cscr);
+ return -1;
+ }
+ cscr = xch;
+ }
+
+ *xscr = cscr;
+
+ return 0;
+}
+
+
+void xdl_free_script(xdchange_t *xscr) {
+ xdchange_t *xch;
+
+ while ((xch = xscr) != NULL) {
+ xscr = xscr->next;
+ xdl_free(xch);
+ }
+}
+
+static int xdl_call_hunk_func(xdfenv_t *xe UNUSED, xdchange_t *xscr, xdemitcb_t *ecb,
+ xdemitconf_t const *xecfg)
+{
+ xdchange_t *xch, *xche;
+
+ for (xch = xscr; xch; xch = xche->next) {
+ xche = xdl_get_hunk(&xch, xecfg);
+ if (!xch)
+ break;
+ if (xecfg->hunk_func(xch->i1, xche->i1 + xche->chg1 - xch->i1,
+ xch->i2, xche->i2 + xche->chg2 - xch->i2,
+ ecb->priv) < 0)
+ return -1;
+ }
+ return 0;
+}
+
+static void xdl_mark_ignorable_lines(xdchange_t *xscr, xdfenv_t *xe, long flags)
+{
+ xdchange_t *xch;
+
+ for (xch = xscr; xch; xch = xch->next) {
+ int ignore = 1;
+ xrecord_t **rec;
+ long i;
+
+ rec = &xe->xdf1.recs[xch->i1];
+ for (i = 0; i < xch->chg1 && ignore; i++)
+ ignore = xdl_blankline(rec[i]->ptr, rec[i]->size, flags);
+
+ rec = &xe->xdf2.recs[xch->i2];
+ for (i = 0; i < xch->chg2 && ignore; i++)
+ ignore = xdl_blankline(rec[i]->ptr, rec[i]->size, flags);
+
+ xch->ignore = ignore;
+ }
+}
+
+static int record_matches_regex(xrecord_t *rec, xpparam_t const *xpp) {
+ regmatch_t regmatch;
+ int i;
+
+ for (i = 0; i < xpp->ignore_regex_nr; i++)
+ if (!regexec_buf(xpp->ignore_regex[i], rec->ptr, rec->size, 1,
+ &regmatch, 0))
+ return 1;
+
+ return 0;
+}
+
+static void xdl_mark_ignorable_regex(xdchange_t *xscr, const xdfenv_t *xe,
+ xpparam_t const *xpp)
+{
+ xdchange_t *xch;
+
+ for (xch = xscr; xch; xch = xch->next) {
+ xrecord_t **rec;
+ int ignore = 1;
+ long i;
+
+ /*
+ * Do not override --ignore-blank-lines.
+ */
+ if (xch->ignore)
+ continue;
+
+ rec = &xe->xdf1.recs[xch->i1];
+ for (i = 0; i < xch->chg1 && ignore; i++)
+ ignore = record_matches_regex(rec[i], xpp);
+
+ rec = &xe->xdf2.recs[xch->i2];
+ for (i = 0; i < xch->chg2 && ignore; i++)
+ ignore = record_matches_regex(rec[i], xpp);
+
+ xch->ignore = ignore;
+ }
+}
+
+int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+ xdemitconf_t const *xecfg, xdemitcb_t *ecb) {
+ xdchange_t *xscr;
+ xdfenv_t xe;
+ emit_func_t ef = xecfg->hunk_func ? xdl_call_hunk_func : xdl_emit_diff;
+
+ if (xdl_do_diff(mf1, mf2, xpp, &xe) < 0) {
+
+ return -1;
+ }
+ if (xdl_change_compact(&xe.xdf1, &xe.xdf2, xpp->flags) < 0 ||
+ xdl_change_compact(&xe.xdf2, &xe.xdf1, xpp->flags) < 0 ||
+ xdl_build_script(&xe, &xscr) < 0) {
+
+ xdl_free_env(&xe);
+ return -1;
+ }
+ if (xscr) {
+ if (xpp->flags & XDF_IGNORE_BLANK_LINES)
+ xdl_mark_ignorable_lines(xscr, &xe, xpp->flags);
+
+ if (xpp->ignore_regex)
+ xdl_mark_ignorable_regex(xscr, &xe, xpp);
+
+ if (ef(&xe, xscr, ecb, xecfg) < 0) {
+
+ xdl_free_script(xscr);
+ xdl_free_env(&xe);
+ return -1;
+ }
+ xdl_free_script(xscr);
+ }
+ xdl_free_env(&xe);
+
+ return 0;
+}
diff --git a/xdiff/xdiffi.h b/xdiff/xdiffi.h
new file mode 100644
index 0000000..126c9d8
--- /dev/null
+++ b/xdiff/xdiffi.h
@@ -0,0 +1,62 @@
+/*
+ * LibXDiff by Davide Libenzi ( File Differential Library )
+ * Copyright (C) 2003 Davide Libenzi
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XDIFFI_H)
+#define XDIFFI_H
+
+
+typedef struct s_diffdata {
+ long nrec;
+ unsigned long const *ha;
+ long *rindex;
+ char *rchg;
+} diffdata_t;
+
+typedef struct s_xdalgoenv {
+ long mxcost;
+ long snake_cnt;
+ long heur_min;
+} xdalgoenv_t;
+
+typedef struct s_xdchange {
+ struct s_xdchange *next;
+ long i1, i2;
+ long chg1, chg2;
+ int ignore;
+} xdchange_t;
+
+
+
+int xdl_recs_cmp(diffdata_t *dd1, long off1, long lim1,
+ diffdata_t *dd2, long off2, long lim2,
+ long *kvdf, long *kvdb, int need_min, xdalgoenv_t *xenv);
+int xdl_do_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+ xdfenv_t *xe);
+int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo, long flags);
+int xdl_build_script(xdfenv_t *xe, xdchange_t **xscr);
+void xdl_free_script(xdchange_t *xscr);
+int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
+ xdemitconf_t const *xecfg);
+int xdl_do_patience_diff(xpparam_t const *xpp, xdfenv_t *env);
+int xdl_do_histogram_diff(xpparam_t const *xpp, xdfenv_t *env);
+
+#endif /* #if !defined(XDIFFI_H) */
diff --git a/xdiff/xemit.c b/xdiff/xemit.c
new file mode 100644
index 0000000..75f0fe4
--- /dev/null
+++ b/xdiff/xemit.c
@@ -0,0 +1,330 @@
+/*
+ * LibXDiff by Davide Libenzi ( File Differential Library )
+ * Copyright (C) 2003 Davide Libenzi
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#include "xinclude.h"
+
+static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec) {
+
+ *rec = xdf->recs[ri]->ptr;
+
+ return xdf->recs[ri]->size;
+}
+
+
+static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb) {
+ long size, psize = strlen(pre);
+ char const *rec;
+
+ size = xdl_get_rec(xdf, ri, &rec);
+ if (xdl_emit_diffrec(rec, size, pre, psize, ecb) < 0) {
+
+ return -1;
+ }
+
+ return 0;
+}
+
+
+/*
+ * Starting at the passed change atom, find the latest change atom to be included
+ * inside the differential hunk according to the specified configuration.
+ * Also advance xscr if the first changes must be discarded.
+ */
+xdchange_t *xdl_get_hunk(xdchange_t **xscr, xdemitconf_t const *xecfg)
+{
+ xdchange_t *xch, *xchp, *lxch;
+ long max_common = 2 * xecfg->ctxlen + xecfg->interhunkctxlen;
+ long max_ignorable = xecfg->ctxlen;
+ unsigned long ignored = 0; /* number of ignored blank lines */
+
+ /* remove ignorable changes that are too far before other changes */
+ for (xchp = *xscr; xchp && xchp->ignore; xchp = xchp->next) {
+ xch = xchp->next;
+
+ if (xch == NULL ||
+ xch->i1 - (xchp->i1 + xchp->chg1) >= max_ignorable)
+ *xscr = xch;
+ }
+
+ if (!*xscr)
+ return NULL;
+
+ lxch = *xscr;
+
+ for (xchp = *xscr, xch = xchp->next; xch; xchp = xch, xch = xch->next) {
+ long distance = xch->i1 - (xchp->i1 + xchp->chg1);
+ if (distance > max_common)
+ break;
+
+ if (distance < max_ignorable && (!xch->ignore || lxch == xchp)) {
+ lxch = xch;
+ ignored = 0;
+ } else if (distance < max_ignorable && xch->ignore) {
+ ignored += xch->chg2;
+ } else if (lxch != xchp &&
+ xch->i1 + ignored - (lxch->i1 + lxch->chg1) > max_common) {
+ break;
+ } else if (!xch->ignore) {
+ lxch = xch;
+ ignored = 0;
+ } else {
+ ignored += xch->chg2;
+ }
+ }
+
+ return lxch;
+}
+
+
+static long def_ff(const char *rec, long len, char *buf, long sz)
+{
+ if (len > 0 &&
+ (isalpha((unsigned char)*rec) || /* identifier? */
+ *rec == '_' || /* also identifier? */
+ *rec == '$')) { /* identifiers from VMS and other esoterico */
+ if (len > sz)
+ len = sz;
+ while (0 < len && isspace((unsigned char)rec[len - 1]))
+ len--;
+ memcpy(buf, rec, len);
+ return len;
+ }
+ return -1;
+}
+
+static long match_func_rec(xdfile_t *xdf, xdemitconf_t const *xecfg, long ri,
+ char *buf, long sz)
+{
+ const char *rec;
+ long len = xdl_get_rec(xdf, ri, &rec);
+ if (!xecfg->find_func)
+ return def_ff(rec, len, buf, sz);
+ return xecfg->find_func(rec, len, buf, sz, xecfg->find_func_priv);
+}
+
+static int is_func_rec(xdfile_t *xdf, xdemitconf_t const *xecfg, long ri)
+{
+ char dummy[1];
+ return match_func_rec(xdf, xecfg, ri, dummy, sizeof(dummy)) >= 0;
+}
+
+struct func_line {
+ long len;
+ char buf[80];
+};
+
+static long get_func_line(xdfenv_t *xe, xdemitconf_t const *xecfg,
+ struct func_line *func_line, long start, long limit)
+{
+ long l, size, step = (start > limit) ? -1 : 1;
+ char *buf, dummy[1];
+
+ buf = func_line ? func_line->buf : dummy;
+ size = func_line ? sizeof(func_line->buf) : sizeof(dummy);
+
+ for (l = start; l != limit && 0 <= l && l < xe->xdf1.nrec; l += step) {
+ long len = match_func_rec(&xe->xdf1, xecfg, l, buf, size);
+ if (len >= 0) {
+ if (func_line)
+ func_line->len = len;
+ return l;
+ }
+ }
+ return -1;
+}
+
+static int is_empty_rec(xdfile_t *xdf, long ri)
+{
+ const char *rec;
+ long len = xdl_get_rec(xdf, ri, &rec);
+
+ while (len > 0 && XDL_ISSPACE(*rec)) {
+ rec++;
+ len--;
+ }
+ return !len;
+}
+
+int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
+ xdemitconf_t const *xecfg) {
+ long s1, s2, e1, e2, lctx;
+ xdchange_t *xch, *xche;
+ long funclineprev = -1;
+ struct func_line func_line = { 0 };
+
+ for (xch = xscr; xch; xch = xche->next) {
+ xdchange_t *xchp = xch;
+ xche = xdl_get_hunk(&xch, xecfg);
+ if (!xch)
+ break;
+
+pre_context_calculation:
+ s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
+ s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
+
+ if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) {
+ long fs1, i1 = xch->i1;
+
+ /* Appended chunk? */
+ if (i1 >= xe->xdf1.nrec) {
+ long i2 = xch->i2;
+
+ /*
+ * We don't need additional context if
+ * a whole function was added.
+ */
+ while (i2 < xe->xdf2.nrec) {
+ if (is_func_rec(&xe->xdf2, xecfg, i2))
+ goto post_context_calculation;
+ i2++;
+ }
+
+ /*
+ * Otherwise get more context from the
+ * pre-image.
+ */
+ i1 = xe->xdf1.nrec - 1;
+ }
+
+ fs1 = get_func_line(xe, xecfg, NULL, i1, -1);
+ while (fs1 > 0 && !is_empty_rec(&xe->xdf1, fs1 - 1) &&
+ !is_func_rec(&xe->xdf1, xecfg, fs1 - 1))
+ fs1--;
+ if (fs1 < 0)
+ fs1 = 0;
+ if (fs1 < s1) {
+ s2 = XDL_MAX(s2 - (s1 - fs1), 0);
+ s1 = fs1;
+
+ /*
+ * Did we extend context upwards into an
+ * ignored change?
+ */
+ while (xchp != xch &&
+ xchp->i1 + xchp->chg1 <= s1 &&
+ xchp->i2 + xchp->chg2 <= s2)
+ xchp = xchp->next;
+
+ /* If so, show it after all. */
+ if (xchp != xch) {
+ xch = xchp;
+ goto pre_context_calculation;
+ }
+ }
+ }
+
+ post_context_calculation:
+ lctx = xecfg->ctxlen;
+ lctx = XDL_MIN(lctx, xe->xdf1.nrec - (xche->i1 + xche->chg1));
+ lctx = XDL_MIN(lctx, xe->xdf2.nrec - (xche->i2 + xche->chg2));
+
+ e1 = xche->i1 + xche->chg1 + lctx;
+ e2 = xche->i2 + xche->chg2 + lctx;
+
+ if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) {
+ long fe1 = get_func_line(xe, xecfg, NULL,
+ xche->i1 + xche->chg1,
+ xe->xdf1.nrec);
+ while (fe1 > 0 && is_empty_rec(&xe->xdf1, fe1 - 1))
+ fe1--;
+ if (fe1 < 0)
+ fe1 = xe->xdf1.nrec;
+ if (fe1 > e1) {
+ e2 = XDL_MIN(e2 + (fe1 - e1), xe->xdf2.nrec);
+ e1 = fe1;
+ }
+
+ /*
+ * Overlap with next change? Then include it
+ * in the current hunk and start over to find
+ * its new end.
+ */
+ if (xche->next) {
+ long l = XDL_MIN(xche->next->i1,
+ xe->xdf1.nrec - 1);
+ if (l - xecfg->ctxlen <= e1 ||
+ get_func_line(xe, xecfg, NULL, l, e1) < 0) {
+ xche = xche->next;
+ goto post_context_calculation;
+ }
+ }
+ }
+
+ /*
+ * Emit current hunk header.
+ */
+
+ if (xecfg->flags & XDL_EMIT_FUNCNAMES) {
+ get_func_line(xe, xecfg, &func_line,
+ s1 - 1, funclineprev);
+ funclineprev = s1 - 1;
+ }
+ if (!(xecfg->flags & XDL_EMIT_NO_HUNK_HDR) &&
+ xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2,
+ func_line.buf, func_line.len, ecb) < 0)
+ return -1;
+
+ /*
+ * Emit pre-context.
+ */
+ for (; s2 < xch->i2; s2++)
+ if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0)
+ return -1;
+
+ for (s1 = xch->i1, s2 = xch->i2;; xch = xch->next) {
+ /*
+ * Merge previous with current change atom.
+ */
+ for (; s1 < xch->i1 && s2 < xch->i2; s1++, s2++)
+ if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0)
+ return -1;
+
+ /*
+ * Removes lines from the first file.
+ */
+ for (s1 = xch->i1; s1 < xch->i1 + xch->chg1; s1++)
+ if (xdl_emit_record(&xe->xdf1, s1, "-", ecb) < 0)
+ return -1;
+
+ /*
+ * Adds lines from the second file.
+ */
+ for (s2 = xch->i2; s2 < xch->i2 + xch->chg2; s2++)
+ if (xdl_emit_record(&xe->xdf2, s2, "+", ecb) < 0)
+ return -1;
+
+ if (xch == xche)
+ break;
+ s1 = xch->i1 + xch->chg1;
+ s2 = xch->i2 + xch->chg2;
+ }
+
+ /*
+ * Emit post-context.
+ */
+ for (s2 = xche->i2 + xche->chg2; s2 < e2; s2++)
+ if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0)
+ return -1;
+ }
+
+ return 0;
+}
diff --git a/xdiff/xemit.h b/xdiff/xemit.h
new file mode 100644
index 0000000..1b9887e
--- /dev/null
+++ b/xdiff/xemit.h
@@ -0,0 +1,36 @@
+/*
+ * LibXDiff by Davide Libenzi ( File Differential Library )
+ * Copyright (C) 2003 Davide Libenzi
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XEMIT_H)
+#define XEMIT_H
+
+
+typedef int (*emit_func_t)(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
+ xdemitconf_t const *xecfg);
+
+xdchange_t *xdl_get_hunk(xdchange_t **xscr, xdemitconf_t const *xecfg);
+int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
+ xdemitconf_t const *xecfg);
+
+
+
+#endif /* #if !defined(XEMIT_H) */
diff --git a/xdiff/xhistogram.c b/xdiff/xhistogram.c
new file mode 100644
index 0000000..16a8fe2
--- /dev/null
+++ b/xdiff/xhistogram.c
@@ -0,0 +1,370 @@
+/*
+ * Copyright (C) 2010, Google Inc.
+ * and other copyright owners as documented in JGit's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials provided
+ * with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ * names of its contributors may be used to endorse or promote
+ * products derived from this software without specific prior
+ * written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "xinclude.h"
+
+#define MAX_PTR UINT_MAX
+#define MAX_CNT UINT_MAX
+
+#define LINE_END(n) (line##n + count##n - 1)
+#define LINE_END_PTR(n) (*line##n + *count##n - 1)
+
+struct histindex {
+ struct record {
+ unsigned int ptr, cnt;
+ struct record *next;
+ } **records, /* an occurrence */
+ **line_map; /* map of line to record chain */
+ chastore_t rcha;
+ unsigned int *next_ptrs;
+ unsigned int table_bits,
+ records_size,
+ line_map_size;
+
+ unsigned int max_chain_length,
+ key_shift,
+ ptr_shift;
+
+ unsigned int cnt,
+ has_common;
+
+ xdfenv_t *env;
+ xpparam_t const *xpp;
+};
+
+struct region {
+ unsigned int begin1, end1;
+ unsigned int begin2, end2;
+};
+
+#define LINE_MAP(i, a) (i->line_map[(a) - i->ptr_shift])
+
+#define NEXT_PTR(index, ptr) \
+ (index->next_ptrs[(ptr) - index->ptr_shift])
+
+#define CNT(index, ptr) \
+ ((LINE_MAP(index, ptr))->cnt)
+
+#define REC(env, s, l) \
+ (env->xdf##s.recs[l - 1])
+
+static int cmp_recs(xrecord_t *r1, xrecord_t *r2)
+{
+ return r1->ha == r2->ha;
+
+}
+
+#define CMP(i, s1, l1, s2, l2) \
+ (cmp_recs(REC(i->env, s1, l1), REC(i->env, s2, l2)))
+
+#define TABLE_HASH(index, side, line) \
+ XDL_HASHLONG((REC(index->env, side, line))->ha, index->table_bits)
+
+static int scanA(struct histindex *index, int line1, int count1)
+{
+ unsigned int ptr, tbl_idx;
+ unsigned int chain_len;
+ struct record **rec_chain, *rec;
+
+ for (ptr = LINE_END(1); line1 <= ptr; ptr--) {
+ tbl_idx = TABLE_HASH(index, 1, ptr);
+ rec_chain = index->records + tbl_idx;
+ rec = *rec_chain;
+
+ chain_len = 0;
+ while (rec) {
+ if (CMP(index, 1, rec->ptr, 1, ptr)) {
+ /*
+ * ptr is identical to another element. Insert
+ * it onto the front of the existing element
+ * chain.
+ */
+ NEXT_PTR(index, ptr) = rec->ptr;
+ rec->ptr = ptr;
+ /* cap rec->cnt at MAX_CNT */
+ rec->cnt = XDL_MIN(MAX_CNT, rec->cnt + 1);
+ LINE_MAP(index, ptr) = rec;
+ goto continue_scan;
+ }
+
+ rec = rec->next;
+ chain_len++;
+ }
+
+ if (chain_len == index->max_chain_length)
+ return -1;
+
+ /*
+ * This is the first time we have ever seen this particular
+ * element in the sequence. Construct a new chain for it.
+ */
+ if (!(rec = xdl_cha_alloc(&index->rcha)))
+ return -1;
+ rec->ptr = ptr;
+ rec->cnt = 1;
+ rec->next = *rec_chain;
+ *rec_chain = rec;
+ LINE_MAP(index, ptr) = rec;
+
+continue_scan:
+ ; /* no op */
+ }
+
+ return 0;
+}
+
+static int try_lcs(struct histindex *index, struct region *lcs, int b_ptr,
+ int line1, int count1, int line2, int count2)
+{
+ unsigned int b_next = b_ptr + 1;
+ struct record *rec = index->records[TABLE_HASH(index, 2, b_ptr)];
+ unsigned int as, ae, bs, be, np, rc;
+ int should_break;
+
+ for (; rec; rec = rec->next) {
+ if (rec->cnt > index->cnt) {
+ if (!index->has_common)
+ index->has_common = CMP(index, 1, rec->ptr, 2, b_ptr);
+ continue;
+ }
+
+ as = rec->ptr;
+ if (!CMP(index, 1, as, 2, b_ptr))
+ continue;
+
+ index->has_common = 1;
+ for (;;) {
+ should_break = 0;
+ np = NEXT_PTR(index, as);
+ bs = b_ptr;
+ ae = as;
+ be = bs;
+ rc = rec->cnt;
+
+ while (line1 < as && line2 < bs
+ && CMP(index, 1, as - 1, 2, bs - 1)) {
+ as--;
+ bs--;
+ if (1 < rc)
+ rc = XDL_MIN(rc, CNT(index, as));
+ }
+ while (ae < LINE_END(1) && be < LINE_END(2)
+ && CMP(index, 1, ae + 1, 2, be + 1)) {
+ ae++;
+ be++;
+ if (1 < rc)
+ rc = XDL_MIN(rc, CNT(index, ae));
+ }
+
+ if (b_next <= be)
+ b_next = be + 1;
+ if (lcs->end1 - lcs->begin1 < ae - as || rc < index->cnt) {
+ lcs->begin1 = as;
+ lcs->begin2 = bs;
+ lcs->end1 = ae;
+ lcs->end2 = be;
+ index->cnt = rc;
+ }
+
+ if (np == 0)
+ break;
+
+ while (np <= ae) {
+ np = NEXT_PTR(index, np);
+ if (np == 0) {
+ should_break = 1;
+ break;
+ }
+ }
+
+ if (should_break)
+ break;
+
+ as = np;
+ }
+ }
+ return b_next;
+}
+
+static int fall_back_to_classic_diff(xpparam_t const *xpp, xdfenv_t *env,
+ int line1, int count1, int line2, int count2)
+{
+ xpparam_t xpparam;
+
+ memset(&xpparam, 0, sizeof(xpparam));
+ xpparam.flags = xpp->flags & ~XDF_DIFF_ALGORITHM_MASK;
+
+ return xdl_fall_back_diff(env, &xpparam,
+ line1, count1, line2, count2);
+}
+
+static inline void free_index(struct histindex *index)
+{
+ xdl_free(index->records);
+ xdl_free(index->line_map);
+ xdl_free(index->next_ptrs);
+ xdl_cha_free(&index->rcha);
+}
+
+static int find_lcs(xpparam_t const *xpp, xdfenv_t *env,
+ struct region *lcs,
+ int line1, int count1, int line2, int count2)
+{
+ int b_ptr;
+ int ret = -1;
+ struct histindex index;
+
+ memset(&index, 0, sizeof(index));
+
+ index.env = env;
+ index.xpp = xpp;
+
+ index.records = NULL;
+ index.line_map = NULL;
+ /* in case of early xdl_cha_free() */
+ index.rcha.head = NULL;
+
+ index.table_bits = xdl_hashbits(count1);
+ index.records_size = 1 << index.table_bits;
+ if (!XDL_CALLOC_ARRAY(index.records, index.records_size))
+ goto cleanup;
+
+ index.line_map_size = count1;
+ if (!XDL_CALLOC_ARRAY(index.line_map, index.line_map_size))
+ goto cleanup;
+
+ if (!XDL_CALLOC_ARRAY(index.next_ptrs, index.line_map_size))
+ goto cleanup;
+
+ /* lines / 4 + 1 comes from xprepare.c:xdl_prepare_ctx() */
+ if (xdl_cha_init(&index.rcha, sizeof(struct record), count1 / 4 + 1) < 0)
+ goto cleanup;
+
+ index.ptr_shift = line1;
+ index.max_chain_length = 64;
+
+ if (scanA(&index, line1, count1))
+ goto cleanup;
+
+ index.cnt = index.max_chain_length + 1;
+
+ for (b_ptr = line2; b_ptr <= LINE_END(2); )
+ b_ptr = try_lcs(&index, lcs, b_ptr, line1, count1, line2, count2);
+
+ if (index.has_common && index.max_chain_length < index.cnt)
+ ret = 1;
+ else
+ ret = 0;
+
+cleanup:
+ free_index(&index);
+ return ret;
+}
+
+static int histogram_diff(xpparam_t const *xpp, xdfenv_t *env,
+ int line1, int count1, int line2, int count2)
+{
+ struct region lcs;
+ int lcs_found;
+ int result;
+redo:
+ result = -1;
+
+ if (count1 <= 0 && count2 <= 0)
+ return 0;
+
+ if (LINE_END(1) >= MAX_PTR)
+ return -1;
+
+ if (!count1) {
+ while(count2--)
+ env->xdf2.rchg[line2++ - 1] = 1;
+ return 0;
+ } else if (!count2) {
+ while(count1--)
+ env->xdf1.rchg[line1++ - 1] = 1;
+ return 0;
+ }
+
+ memset(&lcs, 0, sizeof(lcs));
+ lcs_found = find_lcs(xpp, env, &lcs, line1, count1, line2, count2);
+ if (lcs_found < 0)
+ goto out;
+ else if (lcs_found)
+ result = fall_back_to_classic_diff(xpp, env, line1, count1, line2, count2);
+ else {
+ if (lcs.begin1 == 0 && lcs.begin2 == 0) {
+ while (count1--)
+ env->xdf1.rchg[line1++ - 1] = 1;
+ while (count2--)
+ env->xdf2.rchg[line2++ - 1] = 1;
+ result = 0;
+ } else {
+ result = histogram_diff(xpp, env,
+ line1, lcs.begin1 - line1,
+ line2, lcs.begin2 - line2);
+ if (result)
+ goto out;
+ /*
+ * result = histogram_diff(xpp, env,
+ * lcs.end1 + 1, LINE_END(1) - lcs.end1,
+ * lcs.end2 + 1, LINE_END(2) - lcs.end2);
+ * but let's optimize tail recursion ourself:
+ */
+ count1 = LINE_END(1) - lcs.end1;
+ line1 = lcs.end1 + 1;
+ count2 = LINE_END(2) - lcs.end2;
+ line2 = lcs.end2 + 1;
+ goto redo;
+ }
+ }
+out:
+ return result;
+}
+
+int xdl_do_histogram_diff(xpparam_t const *xpp, xdfenv_t *env)
+{
+ return histogram_diff(xpp, env,
+ env->xdf1.dstart + 1, env->xdf1.dend - env->xdf1.dstart + 1,
+ env->xdf2.dstart + 1, env->xdf2.dend - env->xdf2.dstart + 1);
+}
diff --git a/xdiff/xinclude.h b/xdiff/xinclude.h
new file mode 100644
index 0000000..a4285ac
--- /dev/null
+++ b/xdiff/xinclude.h
@@ -0,0 +1,36 @@
+/*
+ * LibXDiff by Davide Libenzi ( File Differential Library )
+ * Copyright (C) 2003 Davide Libenzi
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XINCLUDE_H)
+#define XINCLUDE_H
+
+#include "git-compat-util.h"
+#include "xmacros.h"
+#include "xdiff.h"
+#include "xtypes.h"
+#include "xutils.h"
+#include "xprepare.h"
+#include "xdiffi.h"
+#include "xemit.h"
+
+
+#endif /* #if !defined(XINCLUDE_H) */
diff --git a/xdiff/xmacros.h b/xdiff/xmacros.h
new file mode 100644
index 0000000..8487bb3
--- /dev/null
+++ b/xdiff/xmacros.h
@@ -0,0 +1,71 @@
+/*
+ * LibXDiff by Davide Libenzi ( File Differential Library )
+ * Copyright (C) 2003 Davide Libenzi
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XMACROS_H)
+#define XMACROS_H
+
+
+
+
+#define XDL_MIN(a, b) ((a) < (b) ? (a): (b))
+#define XDL_MAX(a, b) ((a) > (b) ? (a): (b))
+#define XDL_ABS(v) ((v) >= 0 ? (v): -(v))
+#define XDL_ISDIGIT(c) ((c) >= '0' && (c) <= '9')
+#define XDL_ISSPACE(c) (isspace((unsigned char)(c)))
+#define XDL_ADDBITS(v,b) ((v) + ((v) >> (b)))
+#define XDL_MASKBITS(b) ((1UL << (b)) - 1)
+#define XDL_HASHLONG(v,b) (XDL_ADDBITS((unsigned long)(v), b) & XDL_MASKBITS(b))
+#define XDL_LE32_PUT(p, v) \
+do { \
+ unsigned char *__p = (unsigned char *) (p); \
+ *__p++ = (unsigned char) (v); \
+ *__p++ = (unsigned char) ((v) >> 8); \
+ *__p++ = (unsigned char) ((v) >> 16); \
+ *__p = (unsigned char) ((v) >> 24); \
+} while (0)
+#define XDL_LE32_GET(p, v) \
+do { \
+ unsigned char const *__p = (unsigned char const *) (p); \
+ (v) = (unsigned long) __p[0] | ((unsigned long) __p[1]) << 8 | \
+ ((unsigned long) __p[2]) << 16 | ((unsigned long) __p[3]) << 24; \
+} while (0)
+
+/* Allocate an array of nr elements, returns NULL on failure */
+#define XDL_ALLOC_ARRAY(p, nr) \
+ ((p) = SIZE_MAX / sizeof(*(p)) >= (size_t)(nr) \
+ ? xdl_malloc((nr) * sizeof(*(p))) \
+ : NULL)
+
+/* Allocate an array of nr zeroed out elements, returns NULL on failure */
+#define XDL_CALLOC_ARRAY(p, nr) ((p) = xdl_calloc(nr, sizeof(*(p))))
+
+/*
+ * Ensure array p can accommodate at least nr elements, growing the
+ * array and updating alloc (which is the number of allocated
+ * elements) as necessary. Frees p and returns -1 on failure, returns
+ * 0 on success
+ */
+#define XDL_ALLOC_GROW(p, nr, alloc) \
+ (-!((nr) <= (alloc) || \
+ ((p) = xdl_alloc_grow_helper((p), (nr), &(alloc), sizeof(*(p))))))
+
+#endif /* #if !defined(XMACROS_H) */
diff --git a/xdiff/xmerge.c b/xdiff/xmerge.c
new file mode 100644
index 0000000..af40c88
--- /dev/null
+++ b/xdiff/xmerge.c
@@ -0,0 +1,739 @@
+/*
+ * LibXDiff by Davide Libenzi ( File Differential Library )
+ * Copyright (C) 2003-2006 Davide Libenzi, Johannes E. Schindelin
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#include "xinclude.h"
+
+typedef struct s_xdmerge {
+ struct s_xdmerge *next;
+ /*
+ * 0 = conflict,
+ * 1 = no conflict, take first,
+ * 2 = no conflict, take second.
+ * 3 = no conflict, take both.
+ */
+ int mode;
+ /*
+ * These point at the respective postimages. E.g. <i1,chg1> is
+ * how side #1 wants to change the common ancestor; if there is no
+ * overlap, lines before i1 in the postimage of side #1 appear
+ * in the merge result as a region touched by neither side.
+ */
+ long i1, i2;
+ long chg1, chg2;
+ /*
+ * These point at the preimage; of course there is just one
+ * preimage, that is from the shared common ancestor.
+ */
+ long i0;
+ long chg0;
+} xdmerge_t;
+
+static int xdl_append_merge(xdmerge_t **merge, int mode,
+ long i0, long chg0,
+ long i1, long chg1,
+ long i2, long chg2)
+{
+ xdmerge_t *m = *merge;
+ if (m && (i1 <= m->i1 + m->chg1 || i2 <= m->i2 + m->chg2)) {
+ if (mode != m->mode)
+ m->mode = 0;
+ m->chg0 = i0 + chg0 - m->i0;
+ m->chg1 = i1 + chg1 - m->i1;
+ m->chg2 = i2 + chg2 - m->i2;
+ } else {
+ m = xdl_malloc(sizeof(xdmerge_t));
+ if (!m)
+ return -1;
+ m->next = NULL;
+ m->mode = mode;
+ m->i0 = i0;
+ m->chg0 = chg0;
+ m->i1 = i1;
+ m->chg1 = chg1;
+ m->i2 = i2;
+ m->chg2 = chg2;
+ if (*merge)
+ (*merge)->next = m;
+ *merge = m;
+ }
+ return 0;
+}
+
+static int xdl_cleanup_merge(xdmerge_t *c)
+{
+ int count = 0;
+ xdmerge_t *next_c;
+
+ /* were there conflicts? */
+ for (; c; c = next_c) {
+ if (c->mode == 0)
+ count++;
+ next_c = c->next;
+ free(c);
+ }
+ return count;
+}
+
+static int xdl_merge_cmp_lines(xdfenv_t *xe1, int i1, xdfenv_t *xe2, int i2,
+ int line_count, long flags)
+{
+ int i;
+ xrecord_t **rec1 = xe1->xdf2.recs + i1;
+ xrecord_t **rec2 = xe2->xdf2.recs + i2;
+
+ for (i = 0; i < line_count; i++) {
+ int result = xdl_recmatch(rec1[i]->ptr, rec1[i]->size,
+ rec2[i]->ptr, rec2[i]->size, flags);
+ if (!result)
+ return -1;
+ }
+ return 0;
+}
+
+static int xdl_recs_copy_0(int use_orig, xdfenv_t *xe, int i, int count, int needs_cr, int add_nl, char *dest)
+{
+ xrecord_t **recs;
+ int size = 0;
+
+ recs = (use_orig ? xe->xdf1.recs : xe->xdf2.recs) + i;
+
+ if (count < 1)
+ return 0;
+
+ for (i = 0; i < count; size += recs[i++]->size)
+ if (dest)
+ memcpy(dest + size, recs[i]->ptr, recs[i]->size);
+ if (add_nl) {
+ i = recs[count - 1]->size;
+ if (i == 0 || recs[count - 1]->ptr[i - 1] != '\n') {
+ if (needs_cr) {
+ if (dest)
+ dest[size] = '\r';
+ size++;
+ }
+
+ if (dest)
+ dest[size] = '\n';
+ size++;
+ }
+ }
+ return size;
+}
+
+static int xdl_recs_copy(xdfenv_t *xe, int i, int count, int needs_cr, int add_nl, char *dest)
+{
+ return xdl_recs_copy_0(0, xe, i, count, needs_cr, add_nl, dest);
+}
+
+static int xdl_orig_copy(xdfenv_t *xe, int i, int count, int needs_cr, int add_nl, char *dest)
+{
+ return xdl_recs_copy_0(1, xe, i, count, needs_cr, add_nl, dest);
+}
+
+/*
+ * Returns 1 if the i'th line ends in CR/LF (if it is the last line and
+ * has no eol, the preceding line, if any), 0 if it ends in LF-only, and
+ * -1 if the line ending cannot be determined.
+ */
+static int is_eol_crlf(xdfile_t *file, int i)
+{
+ long size;
+
+ if (i < file->nrec - 1)
+ /* All lines before the last *must* end in LF */
+ return (size = file->recs[i]->size) > 1 &&
+ file->recs[i]->ptr[size - 2] == '\r';
+ if (!file->nrec)
+ /* Cannot determine eol style from empty file */
+ return -1;
+ if ((size = file->recs[i]->size) &&
+ file->recs[i]->ptr[size - 1] == '\n')
+ /* Last line; ends in LF; Is it CR/LF? */
+ return size > 1 &&
+ file->recs[i]->ptr[size - 2] == '\r';
+ if (!i)
+ /* The only line has no eol */
+ return -1;
+ /* Determine eol from second-to-last line */
+ return (size = file->recs[i - 1]->size) > 1 &&
+ file->recs[i - 1]->ptr[size - 2] == '\r';
+}
+
+static int is_cr_needed(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m)
+{
+ int needs_cr;
+
+ /* Match post-images' preceding, or first, lines' end-of-line style */
+ needs_cr = is_eol_crlf(&xe1->xdf2, m->i1 ? m->i1 - 1 : 0);
+ if (needs_cr)
+ needs_cr = is_eol_crlf(&xe2->xdf2, m->i2 ? m->i2 - 1 : 0);
+ /* Look at pre-image's first line, unless we already settled on LF */
+ if (needs_cr)
+ needs_cr = is_eol_crlf(&xe1->xdf1, 0);
+ /* If still undecided, use LF-only */
+ return needs_cr < 0 ? 0 : needs_cr;
+}
+
+static int fill_conflict_hunk(xdfenv_t *xe1, const char *name1,
+ xdfenv_t *xe2, const char *name2,
+ const char *name3,
+ int size, int i, int style,
+ xdmerge_t *m, char *dest, int marker_size)
+{
+ int marker1_size = (name1 ? strlen(name1) + 1 : 0);
+ int marker2_size = (name2 ? strlen(name2) + 1 : 0);
+ int marker3_size = (name3 ? strlen(name3) + 1 : 0);
+ int needs_cr = is_cr_needed(xe1, xe2, m);
+
+ if (marker_size <= 0)
+ marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
+
+ /* Before conflicting part */
+ size += xdl_recs_copy(xe1, i, m->i1 - i, 0, 0,
+ dest ? dest + size : NULL);
+
+ if (!dest) {
+ size += marker_size + 1 + needs_cr + marker1_size;
+ } else {
+ memset(dest + size, '<', marker_size);
+ size += marker_size;
+ if (marker1_size) {
+ dest[size] = ' ';
+ memcpy(dest + size + 1, name1, marker1_size - 1);
+ size += marker1_size;
+ }
+ if (needs_cr)
+ dest[size++] = '\r';
+ dest[size++] = '\n';
+ }
+
+ /* Postimage from side #1 */
+ size += xdl_recs_copy(xe1, m->i1, m->chg1, needs_cr, 1,
+ dest ? dest + size : NULL);
+
+ if (style == XDL_MERGE_DIFF3 || style == XDL_MERGE_ZEALOUS_DIFF3) {
+ /* Shared preimage */
+ if (!dest) {
+ size += marker_size + 1 + needs_cr + marker3_size;
+ } else {
+ memset(dest + size, '|', marker_size);
+ size += marker_size;
+ if (marker3_size) {
+ dest[size] = ' ';
+ memcpy(dest + size + 1, name3, marker3_size - 1);
+ size += marker3_size;
+ }
+ if (needs_cr)
+ dest[size++] = '\r';
+ dest[size++] = '\n';
+ }
+ size += xdl_orig_copy(xe1, m->i0, m->chg0, needs_cr, 1,
+ dest ? dest + size : NULL);
+ }
+
+ if (!dest) {
+ size += marker_size + 1 + needs_cr;
+ } else {
+ memset(dest + size, '=', marker_size);
+ size += marker_size;
+ if (needs_cr)
+ dest[size++] = '\r';
+ dest[size++] = '\n';
+ }
+
+ /* Postimage from side #2 */
+ size += xdl_recs_copy(xe2, m->i2, m->chg2, needs_cr, 1,
+ dest ? dest + size : NULL);
+ if (!dest) {
+ size += marker_size + 1 + needs_cr + marker2_size;
+ } else {
+ memset(dest + size, '>', marker_size);
+ size += marker_size;
+ if (marker2_size) {
+ dest[size] = ' ';
+ memcpy(dest + size + 1, name2, marker2_size - 1);
+ size += marker2_size;
+ }
+ if (needs_cr)
+ dest[size++] = '\r';
+ dest[size++] = '\n';
+ }
+ return size;
+}
+
+static int xdl_fill_merge_buffer(xdfenv_t *xe1, const char *name1,
+ xdfenv_t *xe2, const char *name2,
+ const char *ancestor_name,
+ int favor,
+ xdmerge_t *m, char *dest, int style,
+ int marker_size)
+{
+ int size, i;
+
+ for (size = i = 0; m; m = m->next) {
+ if (favor && !m->mode)
+ m->mode = favor;
+
+ if (m->mode == 0)
+ size = fill_conflict_hunk(xe1, name1, xe2, name2,
+ ancestor_name,
+ size, i, style, m, dest,
+ marker_size);
+ else if (m->mode & 3) {
+ /* Before conflicting part */
+ size += xdl_recs_copy(xe1, i, m->i1 - i, 0, 0,
+ dest ? dest + size : NULL);
+ /* Postimage from side #1 */
+ if (m->mode & 1) {
+ int needs_cr = is_cr_needed(xe1, xe2, m);
+
+ size += xdl_recs_copy(xe1, m->i1, m->chg1, needs_cr, (m->mode & 2),
+ dest ? dest + size : NULL);
+ }
+ /* Postimage from side #2 */
+ if (m->mode & 2)
+ size += xdl_recs_copy(xe2, m->i2, m->chg2, 0, 0,
+ dest ? dest + size : NULL);
+ } else
+ continue;
+ i = m->i1 + m->chg1;
+ }
+ size += xdl_recs_copy(xe1, i, xe1->xdf2.nrec - i, 0, 0,
+ dest ? dest + size : NULL);
+ return size;
+}
+
+static int recmatch(xrecord_t *rec1, xrecord_t *rec2, unsigned long flags)
+{
+ return xdl_recmatch(rec1->ptr, rec1->size,
+ rec2->ptr, rec2->size, flags);
+}
+
+/*
+ * Remove any common lines from the beginning and end of the conflicted region.
+ */
+static void xdl_refine_zdiff3_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
+ xpparam_t const *xpp)
+{
+ xrecord_t **rec1 = xe1->xdf2.recs, **rec2 = xe2->xdf2.recs;
+ for (; m; m = m->next) {
+ /* let's handle just the conflicts */
+ if (m->mode)
+ continue;
+
+ while(m->chg1 && m->chg2 &&
+ recmatch(rec1[m->i1], rec2[m->i2], xpp->flags)) {
+ m->chg1--;
+ m->chg2--;
+ m->i1++;
+ m->i2++;
+ }
+ while (m->chg1 && m->chg2 &&
+ recmatch(rec1[m->i1 + m->chg1 - 1],
+ rec2[m->i2 + m->chg2 - 1], xpp->flags)) {
+ m->chg1--;
+ m->chg2--;
+ }
+ }
+}
+
+/*
+ * Sometimes, changes are not quite identical, but differ in only a few
+ * lines. Try hard to show only these few lines as conflicting.
+ */
+static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
+ xpparam_t const *xpp)
+{
+ for (; m; m = m->next) {
+ mmfile_t t1, t2;
+ xdfenv_t xe;
+ xdchange_t *xscr, *x;
+ int i1 = m->i1, i2 = m->i2;
+
+ /* let's handle just the conflicts */
+ if (m->mode)
+ continue;
+
+ /* no sense refining a conflict when one side is empty */
+ if (m->chg1 == 0 || m->chg2 == 0)
+ continue;
+
+ /*
+ * This probably does not work outside git, since
+ * we have a very simple mmfile structure.
+ */
+ t1.ptr = (char *)xe1->xdf2.recs[m->i1]->ptr;
+ t1.size = xe1->xdf2.recs[m->i1 + m->chg1 - 1]->ptr
+ + xe1->xdf2.recs[m->i1 + m->chg1 - 1]->size - t1.ptr;
+ t2.ptr = (char *)xe2->xdf2.recs[m->i2]->ptr;
+ t2.size = xe2->xdf2.recs[m->i2 + m->chg2 - 1]->ptr
+ + xe2->xdf2.recs[m->i2 + m->chg2 - 1]->size - t2.ptr;
+ if (xdl_do_diff(&t1, &t2, xpp, &xe) < 0)
+ return -1;
+ if (xdl_change_compact(&xe.xdf1, &xe.xdf2, xpp->flags) < 0 ||
+ xdl_change_compact(&xe.xdf2, &xe.xdf1, xpp->flags) < 0 ||
+ xdl_build_script(&xe, &xscr) < 0) {
+ xdl_free_env(&xe);
+ return -1;
+ }
+ if (!xscr) {
+ /* If this happens, the changes are identical. */
+ xdl_free_env(&xe);
+ m->mode = 4;
+ continue;
+ }
+ x = xscr;
+ m->i1 = xscr->i1 + i1;
+ m->chg1 = xscr->chg1;
+ m->i2 = xscr->i2 + i2;
+ m->chg2 = xscr->chg2;
+ while (xscr->next) {
+ xdmerge_t *m2 = xdl_malloc(sizeof(xdmerge_t));
+ if (!m2) {
+ xdl_free_env(&xe);
+ xdl_free_script(x);
+ return -1;
+ }
+ xscr = xscr->next;
+ m2->next = m->next;
+ m->next = m2;
+ m = m2;
+ m->mode = 0;
+ m->i1 = xscr->i1 + i1;
+ m->chg1 = xscr->chg1;
+ m->i2 = xscr->i2 + i2;
+ m->chg2 = xscr->chg2;
+ }
+ xdl_free_env(&xe);
+ xdl_free_script(x);
+ }
+ return 0;
+}
+
+static int line_contains_alnum(const char *ptr, long size)
+{
+ while (size--)
+ if (isalnum((unsigned char)*(ptr++)))
+ return 1;
+ return 0;
+}
+
+static int lines_contain_alnum(xdfenv_t *xe, int i, int chg)
+{
+ for (; chg; chg--, i++)
+ if (line_contains_alnum(xe->xdf2.recs[i]->ptr,
+ xe->xdf2.recs[i]->size))
+ return 1;
+ return 0;
+}
+
+/*
+ * This function merges m and m->next, marking everything between those hunks
+ * as conflicting, too.
+ */
+static void xdl_merge_two_conflicts(xdmerge_t *m)
+{
+ xdmerge_t *next_m = m->next;
+ m->chg1 = next_m->i1 + next_m->chg1 - m->i1;
+ m->chg2 = next_m->i2 + next_m->chg2 - m->i2;
+ m->next = next_m->next;
+ free(next_m);
+}
+
+/*
+ * If there are less than 3 non-conflicting lines between conflicts,
+ * it appears simpler -- because it takes up less (or as many) lines --
+ * if the lines are moved into the conflicts.
+ */
+static int xdl_simplify_non_conflicts(xdfenv_t *xe1, xdmerge_t *m,
+ int simplify_if_no_alnum)
+{
+ int result = 0;
+
+ if (!m)
+ return result;
+ for (;;) {
+ xdmerge_t *next_m = m->next;
+ int begin, end;
+
+ if (!next_m)
+ return result;
+
+ begin = m->i1 + m->chg1;
+ end = next_m->i1;
+
+ if (m->mode != 0 || next_m->mode != 0 ||
+ (end - begin > 3 &&
+ (!simplify_if_no_alnum ||
+ lines_contain_alnum(xe1, begin, end - begin)))) {
+ m = next_m;
+ } else {
+ result++;
+ xdl_merge_two_conflicts(m);
+ }
+ }
+}
+
+/*
+ * level == 0: mark all overlapping changes as conflict
+ * level == 1: mark overlapping changes as conflict only if not identical
+ * level == 2: analyze non-identical changes for minimal conflict set
+ * level == 3: analyze non-identical changes for minimal conflict set, but
+ * treat hunks not containing any letter or number as conflicting
+ *
+ * returns < 0 on error, == 0 for no conflicts, else number of conflicts
+ */
+static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1,
+ xdfenv_t *xe2, xdchange_t *xscr2,
+ xmparam_t const *xmp, mmbuffer_t *result)
+{
+ xdmerge_t *changes, *c;
+ xpparam_t const *xpp = &xmp->xpp;
+ const char *const ancestor_name = xmp->ancestor;
+ const char *const name1 = xmp->file1;
+ const char *const name2 = xmp->file2;
+ int i0, i1, i2, chg0, chg1, chg2;
+ int level = xmp->level;
+ int style = xmp->style;
+ int favor = xmp->favor;
+
+ /*
+ * XDL_MERGE_DIFF3 does not attempt to refine conflicts by looking
+ * at common areas of sides 1 & 2, because the base (side 0) does
+ * not match and is being shown. Similarly, simplification of
+ * non-conflicts is also skipped due to the skipping of conflict
+ * refinement.
+ *
+ * XDL_MERGE_ZEALOUS_DIFF3, on the other hand, will attempt to
+ * refine conflicts looking for common areas of sides 1 & 2.
+ * However, since the base is being shown and does not match,
+ * it will only look for common areas at the beginning or end
+ * of the conflict block. Since XDL_MERGE_ZEALOUS_DIFF3's
+ * conflict refinement is much more limited in this fashion, the
+ * conflict simplification will be skipped.
+ */
+ if (style == XDL_MERGE_DIFF3 || style == XDL_MERGE_ZEALOUS_DIFF3) {
+ /*
+ * "diff3 -m" output does not make sense for anything
+ * more aggressive than XDL_MERGE_EAGER.
+ */
+ if (XDL_MERGE_EAGER < level)
+ level = XDL_MERGE_EAGER;
+ }
+
+ c = changes = NULL;
+
+ while (xscr1 && xscr2) {
+ if (!changes)
+ changes = c;
+ if (xscr1->i1 + xscr1->chg1 < xscr2->i1) {
+ i0 = xscr1->i1;
+ i1 = xscr1->i2;
+ i2 = xscr2->i2 - xscr2->i1 + xscr1->i1;
+ chg0 = xscr1->chg1;
+ chg1 = xscr1->chg2;
+ chg2 = xscr1->chg1;
+ if (xdl_append_merge(&c, 1,
+ i0, chg0, i1, chg1, i2, chg2)) {
+ xdl_cleanup_merge(changes);
+ return -1;
+ }
+ xscr1 = xscr1->next;
+ continue;
+ }
+ if (xscr2->i1 + xscr2->chg1 < xscr1->i1) {
+ i0 = xscr2->i1;
+ i1 = xscr1->i2 - xscr1->i1 + xscr2->i1;
+ i2 = xscr2->i2;
+ chg0 = xscr2->chg1;
+ chg1 = xscr2->chg1;
+ chg2 = xscr2->chg2;
+ if (xdl_append_merge(&c, 2,
+ i0, chg0, i1, chg1, i2, chg2)) {
+ xdl_cleanup_merge(changes);
+ return -1;
+ }
+ xscr2 = xscr2->next;
+ continue;
+ }
+ if (level == XDL_MERGE_MINIMAL || xscr1->i1 != xscr2->i1 ||
+ xscr1->chg1 != xscr2->chg1 ||
+ xscr1->chg2 != xscr2->chg2 ||
+ xdl_merge_cmp_lines(xe1, xscr1->i2,
+ xe2, xscr2->i2,
+ xscr1->chg2, xpp->flags)) {
+ /* conflict */
+ int off = xscr1->i1 - xscr2->i1;
+ int ffo = off + xscr1->chg1 - xscr2->chg1;
+
+ i0 = xscr1->i1;
+ i1 = xscr1->i2;
+ i2 = xscr2->i2;
+ if (off > 0) {
+ i0 -= off;
+ i1 -= off;
+ }
+ else
+ i2 += off;
+ chg0 = xscr1->i1 + xscr1->chg1 - i0;
+ chg1 = xscr1->i2 + xscr1->chg2 - i1;
+ chg2 = xscr2->i2 + xscr2->chg2 - i2;
+ if (ffo < 0) {
+ chg0 -= ffo;
+ chg1 -= ffo;
+ } else
+ chg2 += ffo;
+ if (xdl_append_merge(&c, 0,
+ i0, chg0, i1, chg1, i2, chg2)) {
+ xdl_cleanup_merge(changes);
+ return -1;
+ }
+ }
+
+ i1 = xscr1->i1 + xscr1->chg1;
+ i2 = xscr2->i1 + xscr2->chg1;
+
+ if (i1 >= i2)
+ xscr2 = xscr2->next;
+ if (i2 >= i1)
+ xscr1 = xscr1->next;
+ }
+ while (xscr1) {
+ if (!changes)
+ changes = c;
+ i0 = xscr1->i1;
+ i1 = xscr1->i2;
+ i2 = xscr1->i1 + xe2->xdf2.nrec - xe2->xdf1.nrec;
+ chg0 = xscr1->chg1;
+ chg1 = xscr1->chg2;
+ chg2 = xscr1->chg1;
+ if (xdl_append_merge(&c, 1,
+ i0, chg0, i1, chg1, i2, chg2)) {
+ xdl_cleanup_merge(changes);
+ return -1;
+ }
+ xscr1 = xscr1->next;
+ }
+ while (xscr2) {
+ if (!changes)
+ changes = c;
+ i0 = xscr2->i1;
+ i1 = xscr2->i1 + xe1->xdf2.nrec - xe1->xdf1.nrec;
+ i2 = xscr2->i2;
+ chg0 = xscr2->chg1;
+ chg1 = xscr2->chg1;
+ chg2 = xscr2->chg2;
+ if (xdl_append_merge(&c, 2,
+ i0, chg0, i1, chg1, i2, chg2)) {
+ xdl_cleanup_merge(changes);
+ return -1;
+ }
+ xscr2 = xscr2->next;
+ }
+ if (!changes)
+ changes = c;
+ /* refine conflicts */
+ if (style == XDL_MERGE_ZEALOUS_DIFF3) {
+ xdl_refine_zdiff3_conflicts(xe1, xe2, changes, xpp);
+ } else if (XDL_MERGE_ZEALOUS <= level &&
+ (xdl_refine_conflicts(xe1, xe2, changes, xpp) < 0 ||
+ xdl_simplify_non_conflicts(xe1, changes,
+ XDL_MERGE_ZEALOUS < level) < 0)) {
+ xdl_cleanup_merge(changes);
+ return -1;
+ }
+ /* output */
+ if (result) {
+ int marker_size = xmp->marker_size;
+ int size = xdl_fill_merge_buffer(xe1, name1, xe2, name2,
+ ancestor_name,
+ favor, changes, NULL, style,
+ marker_size);
+ result->ptr = xdl_malloc(size);
+ if (!result->ptr) {
+ xdl_cleanup_merge(changes);
+ return -1;
+ }
+ result->size = size;
+ xdl_fill_merge_buffer(xe1, name1, xe2, name2,
+ ancestor_name, favor, changes,
+ result->ptr, style, marker_size);
+ }
+ return xdl_cleanup_merge(changes);
+}
+
+int xdl_merge(mmfile_t *orig, mmfile_t *mf1, mmfile_t *mf2,
+ xmparam_t const *xmp, mmbuffer_t *result)
+{
+ xdchange_t *xscr1 = NULL, *xscr2 = NULL;
+ xdfenv_t xe1, xe2;
+ int status = -1;
+ xpparam_t const *xpp = &xmp->xpp;
+
+ result->ptr = NULL;
+ result->size = 0;
+
+ if (xdl_do_diff(orig, mf1, xpp, &xe1) < 0)
+ return -1;
+
+ if (xdl_do_diff(orig, mf2, xpp, &xe2) < 0)
+ goto free_xe1; /* avoid double free of xe2 */
+
+ if (xdl_change_compact(&xe1.xdf1, &xe1.xdf2, xpp->flags) < 0 ||
+ xdl_change_compact(&xe1.xdf2, &xe1.xdf1, xpp->flags) < 0 ||
+ xdl_build_script(&xe1, &xscr1) < 0)
+ goto out;
+
+ if (xdl_change_compact(&xe2.xdf1, &xe2.xdf2, xpp->flags) < 0 ||
+ xdl_change_compact(&xe2.xdf2, &xe2.xdf1, xpp->flags) < 0 ||
+ xdl_build_script(&xe2, &xscr2) < 0)
+ goto out;
+
+ if (!xscr1) {
+ result->ptr = xdl_malloc(mf2->size);
+ if (!result->ptr)
+ goto out;
+ status = 0;
+ memcpy(result->ptr, mf2->ptr, mf2->size);
+ result->size = mf2->size;
+ } else if (!xscr2) {
+ result->ptr = xdl_malloc(mf1->size);
+ if (!result->ptr)
+ goto out;
+ status = 0;
+ memcpy(result->ptr, mf1->ptr, mf1->size);
+ result->size = mf1->size;
+ } else {
+ status = xdl_do_merge(&xe1, xscr1,
+ &xe2, xscr2,
+ xmp, result);
+ }
+ out:
+ xdl_free_script(xscr1);
+ xdl_free_script(xscr2);
+
+ xdl_free_env(&xe2);
+ free_xe1:
+ xdl_free_env(&xe1);
+
+ return status;
+}
diff --git a/xdiff/xpatience.c b/xdiff/xpatience.c
new file mode 100644
index 0000000..a2d8955
--- /dev/null
+++ b/xdiff/xpatience.c
@@ -0,0 +1,373 @@
+/*
+ * LibXDiff by Davide Libenzi ( File Differential Library )
+ * Copyright (C) 2003-2016 Davide Libenzi, Johannes E. Schindelin
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+#include "xinclude.h"
+
+/*
+ * The basic idea of patience diff is to find lines that are unique in
+ * both files. These are intuitively the ones that we want to see as
+ * common lines.
+ *
+ * The maximal ordered sequence of such line pairs (where ordered means
+ * that the order in the sequence agrees with the order of the lines in
+ * both files) naturally defines an initial set of common lines.
+ *
+ * Now, the algorithm tries to extend the set of common lines by growing
+ * the line ranges where the files have identical lines.
+ *
+ * Between those common lines, the patience diff algorithm is applied
+ * recursively, until no unique line pairs can be found; these line ranges
+ * are handled by the well-known Myers algorithm.
+ */
+
+#define NON_UNIQUE ULONG_MAX
+
+/*
+ * This is a hash mapping from line hash to line numbers in the first and
+ * second file.
+ */
+struct hashmap {
+ int nr, alloc;
+ struct entry {
+ unsigned long hash;
+ /*
+ * 0 = unused entry, 1 = first line, 2 = second, etc.
+ * line2 is NON_UNIQUE if the line is not unique
+ * in either the first or the second file.
+ */
+ unsigned long line1, line2;
+ /*
+ * "next" & "previous" are used for the longest common
+ * sequence;
+ * initially, "next" reflects only the order in file1.
+ */
+ struct entry *next, *previous;
+
+ /*
+ * If 1, this entry can serve as an anchor. See
+ * Documentation/diff-options.txt for more information.
+ */
+ unsigned anchor : 1;
+ } *entries, *first, *last;
+ /* were common records found? */
+ unsigned long has_matches;
+ xdfenv_t *env;
+ xpparam_t const *xpp;
+};
+
+static int is_anchor(xpparam_t const *xpp, const char *line)
+{
+ int i;
+ for (i = 0; i < xpp->anchors_nr; i++) {
+ if (!strncmp(line, xpp->anchors[i], strlen(xpp->anchors[i])))
+ return 1;
+ }
+ return 0;
+}
+
+/* The argument "pass" is 1 for the first file, 2 for the second. */
+static void insert_record(xpparam_t const *xpp, int line, struct hashmap *map,
+ int pass)
+{
+ xrecord_t **records = pass == 1 ?
+ map->env->xdf1.recs : map->env->xdf2.recs;
+ xrecord_t *record = records[line - 1];
+ /*
+ * After xdl_prepare_env() (or more precisely, due to
+ * xdl_classify_record()), the "ha" member of the records (AKA lines)
+ * is _not_ the hash anymore, but a linearized version of it. In
+ * other words, the "ha" member is guaranteed to start with 0 and
+ * the second record's ha can only be 0 or 1, etc.
+ *
+ * So we multiply ha by 2 in the hope that the hashing was
+ * "unique enough".
+ */
+ int index = (int)((record->ha << 1) % map->alloc);
+
+ while (map->entries[index].line1) {
+ if (map->entries[index].hash != record->ha) {
+ if (++index >= map->alloc)
+ index = 0;
+ continue;
+ }
+ if (pass == 2)
+ map->has_matches = 1;
+ if (pass == 1 || map->entries[index].line2)
+ map->entries[index].line2 = NON_UNIQUE;
+ else
+ map->entries[index].line2 = line;
+ return;
+ }
+ if (pass == 2)
+ return;
+ map->entries[index].line1 = line;
+ map->entries[index].hash = record->ha;
+ map->entries[index].anchor = is_anchor(xpp, map->env->xdf1.recs[line - 1]->ptr);
+ if (!map->first)
+ map->first = map->entries + index;
+ if (map->last) {
+ map->last->next = map->entries + index;
+ map->entries[index].previous = map->last;
+ }
+ map->last = map->entries + index;
+ map->nr++;
+}
+
+/*
+ * This function has to be called for each recursion into the inter-hunk
+ * parts, as previously non-unique lines can become unique when being
+ * restricted to a smaller part of the files.
+ *
+ * It is assumed that env has been prepared using xdl_prepare().
+ */
+static int fill_hashmap(xpparam_t const *xpp, xdfenv_t *env,
+ struct hashmap *result,
+ int line1, int count1, int line2, int count2)
+{
+ result->xpp = xpp;
+ result->env = env;
+
+ /* We know exactly how large we want the hash map */
+ result->alloc = count1 * 2;
+ if (!XDL_CALLOC_ARRAY(result->entries, result->alloc))
+ return -1;
+
+ /* First, fill with entries from the first file */
+ while (count1--)
+ insert_record(xpp, line1++, result, 1);
+
+ /* Then search for matches in the second file */
+ while (count2--)
+ insert_record(xpp, line2++, result, 2);
+
+ return 0;
+}
+
+/*
+ * Find the longest sequence with a smaller last element (meaning a smaller
+ * line2, as we construct the sequence with entries ordered by line1).
+ */
+static int binary_search(struct entry **sequence, int longest,
+ struct entry *entry)
+{
+ int left = -1, right = longest;
+
+ while (left + 1 < right) {
+ int middle = left + (right - left) / 2;
+ /* by construction, no two entries can be equal */
+ if (sequence[middle]->line2 > entry->line2)
+ right = middle;
+ else
+ left = middle;
+ }
+ /* return the index in "sequence", _not_ the sequence length */
+ return left;
+}
+
+/*
+ * The idea is to start with the list of common unique lines sorted by
+ * the order in file1. For each of these pairs, the longest (partial)
+ * sequence whose last element's line2 is smaller is determined.
+ *
+ * For efficiency, the sequences are kept in a list containing exactly one
+ * item per sequence length: the sequence with the smallest last
+ * element (in terms of line2).
+ */
+static int find_longest_common_sequence(struct hashmap *map, struct entry **res)
+{
+ struct entry **sequence;
+ int longest = 0, i;
+ struct entry *entry;
+
+ /*
+ * If not -1, this entry in sequence must never be overridden.
+ * Therefore, overriding entries before this has no effect, so
+ * do not do that either.
+ */
+ int anchor_i = -1;
+
+ if (!XDL_ALLOC_ARRAY(sequence, map->nr))
+ return -1;
+
+ for (entry = map->first; entry; entry = entry->next) {
+ if (!entry->line2 || entry->line2 == NON_UNIQUE)
+ continue;
+ i = binary_search(sequence, longest, entry);
+ entry->previous = i < 0 ? NULL : sequence[i];
+ ++i;
+ if (i <= anchor_i)
+ continue;
+ sequence[i] = entry;
+ if (entry->anchor) {
+ anchor_i = i;
+ longest = anchor_i + 1;
+ } else if (i == longest) {
+ longest++;
+ }
+ }
+
+ /* No common unique lines were found */
+ if (!longest) {
+ *res = NULL;
+ xdl_free(sequence);
+ return 0;
+ }
+
+ /* Iterate starting at the last element, adjusting the "next" members */
+ entry = sequence[longest - 1];
+ entry->next = NULL;
+ while (entry->previous) {
+ entry->previous->next = entry;
+ entry = entry->previous;
+ }
+ *res = entry;
+ xdl_free(sequence);
+ return 0;
+}
+
+static int match(struct hashmap *map, int line1, int line2)
+{
+ xrecord_t *record1 = map->env->xdf1.recs[line1 - 1];
+ xrecord_t *record2 = map->env->xdf2.recs[line2 - 1];
+ return record1->ha == record2->ha;
+}
+
+static int patience_diff(xpparam_t const *xpp, xdfenv_t *env,
+ int line1, int count1, int line2, int count2);
+
+static int walk_common_sequence(struct hashmap *map, struct entry *first,
+ int line1, int count1, int line2, int count2)
+{
+ int end1 = line1 + count1, end2 = line2 + count2;
+ int next1, next2;
+
+ for (;;) {
+ /* Try to grow the line ranges of common lines */
+ if (first) {
+ next1 = first->line1;
+ next2 = first->line2;
+ while (next1 > line1 && next2 > line2 &&
+ match(map, next1 - 1, next2 - 1)) {
+ next1--;
+ next2--;
+ }
+ } else {
+ next1 = end1;
+ next2 = end2;
+ }
+ while (line1 < next1 && line2 < next2 &&
+ match(map, line1, line2)) {
+ line1++;
+ line2++;
+ }
+
+ /* Recurse */
+ if (next1 > line1 || next2 > line2) {
+ if (patience_diff(map->xpp, map->env,
+ line1, next1 - line1,
+ line2, next2 - line2))
+ return -1;
+ }
+
+ if (!first)
+ return 0;
+
+ while (first->next &&
+ first->next->line1 == first->line1 + 1 &&
+ first->next->line2 == first->line2 + 1)
+ first = first->next;
+
+ line1 = first->line1 + 1;
+ line2 = first->line2 + 1;
+
+ first = first->next;
+ }
+}
+
+static int fall_back_to_classic_diff(struct hashmap *map,
+ int line1, int count1, int line2, int count2)
+{
+ xpparam_t xpp;
+
+ memset(&xpp, 0, sizeof(xpp));
+ xpp.flags = map->xpp->flags & ~XDF_DIFF_ALGORITHM_MASK;
+
+ return xdl_fall_back_diff(map->env, &xpp,
+ line1, count1, line2, count2);
+}
+
+/*
+ * Recursively find the longest common sequence of unique lines,
+ * and if none was found, ask xdl_do_diff() to do the job.
+ *
+ * This function assumes that env was prepared with xdl_prepare_env().
+ */
+static int patience_diff(xpparam_t const *xpp, xdfenv_t *env,
+ int line1, int count1, int line2, int count2)
+{
+ struct hashmap map;
+ struct entry *first;
+ int result = 0;
+
+ /* trivial case: one side is empty */
+ if (!count1) {
+ while(count2--)
+ env->xdf2.rchg[line2++ - 1] = 1;
+ return 0;
+ } else if (!count2) {
+ while(count1--)
+ env->xdf1.rchg[line1++ - 1] = 1;
+ return 0;
+ }
+
+ memset(&map, 0, sizeof(map));
+ if (fill_hashmap(xpp, env, &map,
+ line1, count1, line2, count2))
+ return -1;
+
+ /* are there any matching lines at all? */
+ if (!map.has_matches) {
+ while(count1--)
+ env->xdf1.rchg[line1++ - 1] = 1;
+ while(count2--)
+ env->xdf2.rchg[line2++ - 1] = 1;
+ xdl_free(map.entries);
+ return 0;
+ }
+
+ result = find_longest_common_sequence(&map, &first);
+ if (result)
+ goto out;
+ if (first)
+ result = walk_common_sequence(&map, first,
+ line1, count1, line2, count2);
+ else
+ result = fall_back_to_classic_diff(&map,
+ line1, count1, line2, count2);
+ out:
+ xdl_free(map.entries);
+ return result;
+}
+
+int xdl_do_patience_diff(xpparam_t const *xpp, xdfenv_t *env)
+{
+ return patience_diff(xpp, env, 1, env->xdf1.nrec, 1, env->xdf2.nrec);
+}
diff --git a/xdiff/xprepare.c b/xdiff/xprepare.c
new file mode 100644
index 0000000..c84549f
--- /dev/null
+++ b/xdiff/xprepare.c
@@ -0,0 +1,461 @@
+/*
+ * LibXDiff by Davide Libenzi ( File Differential Library )
+ * Copyright (C) 2003 Davide Libenzi
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#include "xinclude.h"
+
+
+#define XDL_KPDIS_RUN 4
+#define XDL_MAX_EQLIMIT 1024
+#define XDL_SIMSCAN_WINDOW 100
+#define XDL_GUESS_NLINES1 256
+#define XDL_GUESS_NLINES2 20
+
+
+typedef struct s_xdlclass {
+ struct s_xdlclass *next;
+ unsigned long ha;
+ char const *line;
+ long size;
+ long idx;
+ long len1, len2;
+} xdlclass_t;
+
+typedef struct s_xdlclassifier {
+ unsigned int hbits;
+ long hsize;
+ xdlclass_t **rchash;
+ chastore_t ncha;
+ xdlclass_t **rcrecs;
+ long alloc;
+ long count;
+ long flags;
+} xdlclassifier_t;
+
+
+
+
+static int xdl_init_classifier(xdlclassifier_t *cf, long size, long flags);
+static void xdl_free_classifier(xdlclassifier_t *cf);
+static int xdl_classify_record(unsigned int pass, xdlclassifier_t *cf, xrecord_t **rhash,
+ unsigned int hbits, xrecord_t *rec);
+static int xdl_prepare_ctx(unsigned int pass, mmfile_t *mf, long narec, xpparam_t const *xpp,
+ xdlclassifier_t *cf, xdfile_t *xdf);
+static void xdl_free_ctx(xdfile_t *xdf);
+static int xdl_clean_mmatch(char const *dis, long i, long s, long e);
+static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2);
+static int xdl_trim_ends(xdfile_t *xdf1, xdfile_t *xdf2);
+static int xdl_optimize_ctxs(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2);
+
+
+
+
+static int xdl_init_classifier(xdlclassifier_t *cf, long size, long flags) {
+ cf->flags = flags;
+
+ cf->hbits = xdl_hashbits((unsigned int) size);
+ cf->hsize = 1 << cf->hbits;
+
+ if (xdl_cha_init(&cf->ncha, sizeof(xdlclass_t), size / 4 + 1) < 0) {
+
+ return -1;
+ }
+ if (!XDL_CALLOC_ARRAY(cf->rchash, cf->hsize)) {
+
+ xdl_cha_free(&cf->ncha);
+ return -1;
+ }
+
+ cf->alloc = size;
+ if (!XDL_ALLOC_ARRAY(cf->rcrecs, cf->alloc)) {
+
+ xdl_free(cf->rchash);
+ xdl_cha_free(&cf->ncha);
+ return -1;
+ }
+
+ cf->count = 0;
+
+ return 0;
+}
+
+
+static void xdl_free_classifier(xdlclassifier_t *cf) {
+
+ xdl_free(cf->rcrecs);
+ xdl_free(cf->rchash);
+ xdl_cha_free(&cf->ncha);
+}
+
+
+static int xdl_classify_record(unsigned int pass, xdlclassifier_t *cf, xrecord_t **rhash,
+ unsigned int hbits, xrecord_t *rec) {
+ long hi;
+ char const *line;
+ xdlclass_t *rcrec;
+
+ line = rec->ptr;
+ hi = (long) XDL_HASHLONG(rec->ha, cf->hbits);
+ for (rcrec = cf->rchash[hi]; rcrec; rcrec = rcrec->next)
+ if (rcrec->ha == rec->ha &&
+ xdl_recmatch(rcrec->line, rcrec->size,
+ rec->ptr, rec->size, cf->flags))
+ break;
+
+ if (!rcrec) {
+ if (!(rcrec = xdl_cha_alloc(&cf->ncha))) {
+
+ return -1;
+ }
+ rcrec->idx = cf->count++;
+ if (XDL_ALLOC_GROW(cf->rcrecs, cf->count, cf->alloc))
+ return -1;
+ cf->rcrecs[rcrec->idx] = rcrec;
+ rcrec->line = line;
+ rcrec->size = rec->size;
+ rcrec->ha = rec->ha;
+ rcrec->len1 = rcrec->len2 = 0;
+ rcrec->next = cf->rchash[hi];
+ cf->rchash[hi] = rcrec;
+ }
+
+ (pass == 1) ? rcrec->len1++ : rcrec->len2++;
+
+ rec->ha = (unsigned long) rcrec->idx;
+
+ hi = (long) XDL_HASHLONG(rec->ha, hbits);
+ rec->next = rhash[hi];
+ rhash[hi] = rec;
+
+ return 0;
+}
+
+
+static int xdl_prepare_ctx(unsigned int pass, mmfile_t *mf, long narec, xpparam_t const *xpp,
+ xdlclassifier_t *cf, xdfile_t *xdf) {
+ unsigned int hbits;
+ long nrec, hsize, bsize;
+ unsigned long hav;
+ char const *blk, *cur, *top, *prev;
+ xrecord_t *crec;
+ xrecord_t **recs;
+ xrecord_t **rhash;
+ unsigned long *ha;
+ char *rchg;
+ long *rindex;
+
+ ha = NULL;
+ rindex = NULL;
+ rchg = NULL;
+ rhash = NULL;
+ recs = NULL;
+
+ if (xdl_cha_init(&xdf->rcha, sizeof(xrecord_t), narec / 4 + 1) < 0)
+ goto abort;
+ if (!XDL_ALLOC_ARRAY(recs, narec))
+ goto abort;
+
+ hbits = xdl_hashbits((unsigned int) narec);
+ hsize = 1 << hbits;
+ if (!XDL_CALLOC_ARRAY(rhash, hsize))
+ goto abort;
+
+ nrec = 0;
+ if ((cur = blk = xdl_mmfile_first(mf, &bsize))) {
+ for (top = blk + bsize; cur < top; ) {
+ prev = cur;
+ hav = xdl_hash_record(&cur, top, xpp->flags);
+ if (XDL_ALLOC_GROW(recs, nrec + 1, narec))
+ goto abort;
+ if (!(crec = xdl_cha_alloc(&xdf->rcha)))
+ goto abort;
+ crec->ptr = prev;
+ crec->size = (long) (cur - prev);
+ crec->ha = hav;
+ recs[nrec++] = crec;
+ if (xdl_classify_record(pass, cf, rhash, hbits, crec) < 0)
+ goto abort;
+ }
+ }
+
+ if (!XDL_CALLOC_ARRAY(rchg, nrec + 2))
+ goto abort;
+
+ if ((XDF_DIFF_ALG(xpp->flags) != XDF_PATIENCE_DIFF) &&
+ (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF)) {
+ if (!XDL_ALLOC_ARRAY(rindex, nrec + 1))
+ goto abort;
+ if (!XDL_ALLOC_ARRAY(ha, nrec + 1))
+ goto abort;
+ }
+
+ xdf->nrec = nrec;
+ xdf->recs = recs;
+ xdf->hbits = hbits;
+ xdf->rhash = rhash;
+ xdf->rchg = rchg + 1;
+ xdf->rindex = rindex;
+ xdf->nreff = 0;
+ xdf->ha = ha;
+ xdf->dstart = 0;
+ xdf->dend = nrec - 1;
+
+ return 0;
+
+abort:
+ xdl_free(ha);
+ xdl_free(rindex);
+ xdl_free(rchg);
+ xdl_free(rhash);
+ xdl_free(recs);
+ xdl_cha_free(&xdf->rcha);
+ return -1;
+}
+
+
+static void xdl_free_ctx(xdfile_t *xdf) {
+
+ xdl_free(xdf->rhash);
+ xdl_free(xdf->rindex);
+ xdl_free(xdf->rchg - 1);
+ xdl_free(xdf->ha);
+ xdl_free(xdf->recs);
+ xdl_cha_free(&xdf->rcha);
+}
+
+
+int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+ xdfenv_t *xe) {
+ long enl1, enl2, sample;
+ xdlclassifier_t cf;
+
+ memset(&cf, 0, sizeof(cf));
+
+ /*
+ * For histogram diff, we can afford a smaller sample size and
+ * thus a poorer estimate of the number of lines, as the hash
+ * table (rhash) won't be filled up/grown. The number of lines
+ * (nrecs) will be updated correctly anyway by
+ * xdl_prepare_ctx().
+ */
+ sample = (XDF_DIFF_ALG(xpp->flags) == XDF_HISTOGRAM_DIFF
+ ? XDL_GUESS_NLINES2 : XDL_GUESS_NLINES1);
+
+ enl1 = xdl_guess_lines(mf1, sample) + 1;
+ enl2 = xdl_guess_lines(mf2, sample) + 1;
+
+ if (xdl_init_classifier(&cf, enl1 + enl2 + 1, xpp->flags) < 0)
+ return -1;
+
+ if (xdl_prepare_ctx(1, mf1, enl1, xpp, &cf, &xe->xdf1) < 0) {
+
+ xdl_free_classifier(&cf);
+ return -1;
+ }
+ if (xdl_prepare_ctx(2, mf2, enl2, xpp, &cf, &xe->xdf2) < 0) {
+
+ xdl_free_ctx(&xe->xdf1);
+ xdl_free_classifier(&cf);
+ return -1;
+ }
+
+ if ((XDF_DIFF_ALG(xpp->flags) != XDF_PATIENCE_DIFF) &&
+ (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF) &&
+ xdl_optimize_ctxs(&cf, &xe->xdf1, &xe->xdf2) < 0) {
+
+ xdl_free_ctx(&xe->xdf2);
+ xdl_free_ctx(&xe->xdf1);
+ xdl_free_classifier(&cf);
+ return -1;
+ }
+
+ xdl_free_classifier(&cf);
+
+ return 0;
+}
+
+
+void xdl_free_env(xdfenv_t *xe) {
+
+ xdl_free_ctx(&xe->xdf2);
+ xdl_free_ctx(&xe->xdf1);
+}
+
+
+static int xdl_clean_mmatch(char const *dis, long i, long s, long e) {
+ long r, rdis0, rpdis0, rdis1, rpdis1;
+
+ /*
+ * Limits the window the is examined during the similar-lines
+ * scan. The loops below stops when dis[i - r] == 1 (line that
+ * has no match), but there are corner cases where the loop
+ * proceed all the way to the extremities by causing huge
+ * performance penalties in case of big files.
+ */
+ if (i - s > XDL_SIMSCAN_WINDOW)
+ s = i - XDL_SIMSCAN_WINDOW;
+ if (e - i > XDL_SIMSCAN_WINDOW)
+ e = i + XDL_SIMSCAN_WINDOW;
+
+ /*
+ * Scans the lines before 'i' to find a run of lines that either
+ * have no match (dis[j] == 0) or have multiple matches (dis[j] > 1).
+ * Note that we always call this function with dis[i] > 1, so the
+ * current line (i) is already a multimatch line.
+ */
+ for (r = 1, rdis0 = 0, rpdis0 = 1; (i - r) >= s; r++) {
+ if (!dis[i - r])
+ rdis0++;
+ else if (dis[i - r] == 2)
+ rpdis0++;
+ else
+ break;
+ }
+ /*
+ * If the run before the line 'i' found only multimatch lines, we
+ * return 0 and hence we don't make the current line (i) discarded.
+ * We want to discard multimatch lines only when they appear in the
+ * middle of runs with nomatch lines (dis[j] == 0).
+ */
+ if (rdis0 == 0)
+ return 0;
+ for (r = 1, rdis1 = 0, rpdis1 = 1; (i + r) <= e; r++) {
+ if (!dis[i + r])
+ rdis1++;
+ else if (dis[i + r] == 2)
+ rpdis1++;
+ else
+ break;
+ }
+ /*
+ * If the run after the line 'i' found only multimatch lines, we
+ * return 0 and hence we don't make the current line (i) discarded.
+ */
+ if (rdis1 == 0)
+ return 0;
+ rdis1 += rdis0;
+ rpdis1 += rpdis0;
+
+ return rpdis1 * XDL_KPDIS_RUN < (rpdis1 + rdis1);
+}
+
+
+/*
+ * Try to reduce the problem complexity, discard records that have no
+ * matches on the other file. Also, lines that have multiple matches
+ * might be potentially discarded if they happear in a run of discardable.
+ */
+static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2) {
+ long i, nm, nreff, mlim;
+ xrecord_t **recs;
+ xdlclass_t *rcrec;
+ char *dis, *dis1, *dis2;
+
+ if (!XDL_CALLOC_ARRAY(dis, xdf1->nrec + xdf2->nrec + 2))
+ return -1;
+ dis1 = dis;
+ dis2 = dis1 + xdf1->nrec + 1;
+
+ if ((mlim = xdl_bogosqrt(xdf1->nrec)) > XDL_MAX_EQLIMIT)
+ mlim = XDL_MAX_EQLIMIT;
+ for (i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart]; i <= xdf1->dend; i++, recs++) {
+ rcrec = cf->rcrecs[(*recs)->ha];
+ nm = rcrec ? rcrec->len2 : 0;
+ dis1[i] = (nm == 0) ? 0: (nm >= mlim) ? 2: 1;
+ }
+
+ if ((mlim = xdl_bogosqrt(xdf2->nrec)) > XDL_MAX_EQLIMIT)
+ mlim = XDL_MAX_EQLIMIT;
+ for (i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart]; i <= xdf2->dend; i++, recs++) {
+ rcrec = cf->rcrecs[(*recs)->ha];
+ nm = rcrec ? rcrec->len1 : 0;
+ dis2[i] = (nm == 0) ? 0: (nm >= mlim) ? 2: 1;
+ }
+
+ for (nreff = 0, i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart];
+ i <= xdf1->dend; i++, recs++) {
+ if (dis1[i] == 1 ||
+ (dis1[i] == 2 && !xdl_clean_mmatch(dis1, i, xdf1->dstart, xdf1->dend))) {
+ xdf1->rindex[nreff] = i;
+ xdf1->ha[nreff] = (*recs)->ha;
+ nreff++;
+ } else
+ xdf1->rchg[i] = 1;
+ }
+ xdf1->nreff = nreff;
+
+ for (nreff = 0, i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart];
+ i <= xdf2->dend; i++, recs++) {
+ if (dis2[i] == 1 ||
+ (dis2[i] == 2 && !xdl_clean_mmatch(dis2, i, xdf2->dstart, xdf2->dend))) {
+ xdf2->rindex[nreff] = i;
+ xdf2->ha[nreff] = (*recs)->ha;
+ nreff++;
+ } else
+ xdf2->rchg[i] = 1;
+ }
+ xdf2->nreff = nreff;
+
+ xdl_free(dis);
+
+ return 0;
+}
+
+
+/*
+ * Early trim initial and terminal matching records.
+ */
+static int xdl_trim_ends(xdfile_t *xdf1, xdfile_t *xdf2) {
+ long i, lim;
+ xrecord_t **recs1, **recs2;
+
+ recs1 = xdf1->recs;
+ recs2 = xdf2->recs;
+ for (i = 0, lim = XDL_MIN(xdf1->nrec, xdf2->nrec); i < lim;
+ i++, recs1++, recs2++)
+ if ((*recs1)->ha != (*recs2)->ha)
+ break;
+
+ xdf1->dstart = xdf2->dstart = i;
+
+ recs1 = xdf1->recs + xdf1->nrec - 1;
+ recs2 = xdf2->recs + xdf2->nrec - 1;
+ for (lim -= i, i = 0; i < lim; i++, recs1--, recs2--)
+ if ((*recs1)->ha != (*recs2)->ha)
+ break;
+
+ xdf1->dend = xdf1->nrec - i - 1;
+ xdf2->dend = xdf2->nrec - i - 1;
+
+ return 0;
+}
+
+
+static int xdl_optimize_ctxs(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2) {
+
+ if (xdl_trim_ends(xdf1, xdf2) < 0 ||
+ xdl_cleanup_records(cf, xdf1, xdf2) < 0) {
+
+ return -1;
+ }
+
+ return 0;
+}
diff --git a/xdiff/xprepare.h b/xdiff/xprepare.h
new file mode 100644
index 0000000..947d9fc
--- /dev/null
+++ b/xdiff/xprepare.h
@@ -0,0 +1,34 @@
+/*
+ * LibXDiff by Davide Libenzi ( File Differential Library )
+ * Copyright (C) 2003 Davide Libenzi
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XPREPARE_H)
+#define XPREPARE_H
+
+
+
+int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+ xdfenv_t *xe);
+void xdl_free_env(xdfenv_t *xe);
+
+
+
+#endif /* #if !defined(XPREPARE_H) */
diff --git a/xdiff/xtypes.h b/xdiff/xtypes.h
new file mode 100644
index 0000000..8442bd4
--- /dev/null
+++ b/xdiff/xtypes.h
@@ -0,0 +1,67 @@
+/*
+ * LibXDiff by Davide Libenzi ( File Differential Library )
+ * Copyright (C) 2003 Davide Libenzi
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XTYPES_H)
+#define XTYPES_H
+
+
+
+typedef struct s_chanode {
+ struct s_chanode *next;
+ long icurr;
+} chanode_t;
+
+typedef struct s_chastore {
+ chanode_t *head, *tail;
+ long isize, nsize;
+ chanode_t *ancur;
+ chanode_t *sncur;
+ long scurr;
+} chastore_t;
+
+typedef struct s_xrecord {
+ struct s_xrecord *next;
+ char const *ptr;
+ long size;
+ unsigned long ha;
+} xrecord_t;
+
+typedef struct s_xdfile {
+ chastore_t rcha;
+ long nrec;
+ unsigned int hbits;
+ xrecord_t **rhash;
+ long dstart, dend;
+ xrecord_t **recs;
+ char *rchg;
+ long *rindex;
+ long nreff;
+ unsigned long *ha;
+} xdfile_t;
+
+typedef struct s_xdfenv {
+ xdfile_t xdf1, xdf2;
+} xdfenv_t;
+
+
+
+#endif /* #if !defined(XTYPES_H) */
diff --git a/xdiff/xutils.c b/xdiff/xutils.c
new file mode 100644
index 0000000..9e36f24
--- /dev/null
+++ b/xdiff/xutils.c
@@ -0,0 +1,451 @@
+/*
+ * LibXDiff by Davide Libenzi ( File Differential Library )
+ * Copyright (C) 2003 Davide Libenzi
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#include "xinclude.h"
+
+
+long xdl_bogosqrt(long n) {
+ long i;
+
+ /*
+ * Classical integer square root approximation using shifts.
+ */
+ for (i = 1; n > 0; n >>= 2)
+ i <<= 1;
+
+ return i;
+}
+
+
+int xdl_emit_diffrec(char const *rec, long size, char const *pre, long psize,
+ xdemitcb_t *ecb) {
+ int i = 2;
+ mmbuffer_t mb[3];
+
+ mb[0].ptr = (char *) pre;
+ mb[0].size = psize;
+ mb[1].ptr = (char *) rec;
+ mb[1].size = size;
+ if (size > 0 && rec[size - 1] != '\n') {
+ mb[2].ptr = (char *) "\n\\ No newline at end of file\n";
+ mb[2].size = strlen(mb[2].ptr);
+ i++;
+ }
+ if (ecb->out_line(ecb->priv, mb, i) < 0) {
+
+ return -1;
+ }
+
+ return 0;
+}
+
+void *xdl_mmfile_first(mmfile_t *mmf, long *size)
+{
+ *size = mmf->size;
+ return mmf->ptr;
+}
+
+
+long xdl_mmfile_size(mmfile_t *mmf)
+{
+ return mmf->size;
+}
+
+
+int xdl_cha_init(chastore_t *cha, long isize, long icount) {
+
+ cha->head = cha->tail = NULL;
+ cha->isize = isize;
+ cha->nsize = icount * isize;
+ cha->ancur = cha->sncur = NULL;
+ cha->scurr = 0;
+
+ return 0;
+}
+
+
+void xdl_cha_free(chastore_t *cha) {
+ chanode_t *cur, *tmp;
+
+ for (cur = cha->head; (tmp = cur) != NULL;) {
+ cur = cur->next;
+ xdl_free(tmp);
+ }
+}
+
+
+void *xdl_cha_alloc(chastore_t *cha) {
+ chanode_t *ancur;
+ void *data;
+
+ if (!(ancur = cha->ancur) || ancur->icurr == cha->nsize) {
+ if (!(ancur = (chanode_t *) xdl_malloc(sizeof(chanode_t) + cha->nsize))) {
+
+ return NULL;
+ }
+ ancur->icurr = 0;
+ ancur->next = NULL;
+ if (cha->tail)
+ cha->tail->next = ancur;
+ if (!cha->head)
+ cha->head = ancur;
+ cha->tail = ancur;
+ cha->ancur = ancur;
+ }
+
+ data = (char *) ancur + sizeof(chanode_t) + ancur->icurr;
+ ancur->icurr += cha->isize;
+
+ return data;
+}
+
+long xdl_guess_lines(mmfile_t *mf, long sample) {
+ long nl = 0, size, tsize = 0;
+ char const *data, *cur, *top;
+
+ if ((cur = data = xdl_mmfile_first(mf, &size))) {
+ for (top = data + size; nl < sample && cur < top; ) {
+ nl++;
+ if (!(cur = memchr(cur, '\n', top - cur)))
+ cur = top;
+ else
+ cur++;
+ }
+ tsize += (long) (cur - data);
+ }
+
+ if (nl && tsize)
+ nl = xdl_mmfile_size(mf) / (tsize / nl);
+
+ return nl + 1;
+}
+
+int xdl_blankline(const char *line, long size, long flags)
+{
+ long i;
+
+ if (!(flags & XDF_WHITESPACE_FLAGS))
+ return (size <= 1);
+
+ for (i = 0; i < size && XDL_ISSPACE(line[i]); i++)
+ ;
+
+ return (i == size);
+}
+
+/*
+ * Have we eaten everything on the line, except for an optional
+ * CR at the very end?
+ */
+static int ends_with_optional_cr(const char *l, long s, long i)
+{
+ int complete = s && l[s-1] == '\n';
+
+ if (complete)
+ s--;
+ if (s == i)
+ return 1;
+ /* do not ignore CR at the end of an incomplete line */
+ if (complete && s == i + 1 && l[i] == '\r')
+ return 1;
+ return 0;
+}
+
+int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
+{
+ int i1, i2;
+
+ if (s1 == s2 && !memcmp(l1, l2, s1))
+ return 1;
+ if (!(flags & XDF_WHITESPACE_FLAGS))
+ return 0;
+
+ i1 = 0;
+ i2 = 0;
+
+ /*
+ * -w matches everything that matches with -b, and -b in turn
+ * matches everything that matches with --ignore-space-at-eol,
+ * which in turn matches everything that matches with --ignore-cr-at-eol.
+ *
+ * Each flavor of ignoring needs different logic to skip whitespaces
+ * while we have both sides to compare.
+ */
+ if (flags & XDF_IGNORE_WHITESPACE) {
+ goto skip_ws;
+ while (i1 < s1 && i2 < s2) {
+ if (l1[i1++] != l2[i2++])
+ return 0;
+ skip_ws:
+ while (i1 < s1 && XDL_ISSPACE(l1[i1]))
+ i1++;
+ while (i2 < s2 && XDL_ISSPACE(l2[i2]))
+ i2++;
+ }
+ } else if (flags & XDF_IGNORE_WHITESPACE_CHANGE) {
+ while (i1 < s1 && i2 < s2) {
+ if (XDL_ISSPACE(l1[i1]) && XDL_ISSPACE(l2[i2])) {
+ /* Skip matching spaces and try again */
+ while (i1 < s1 && XDL_ISSPACE(l1[i1]))
+ i1++;
+ while (i2 < s2 && XDL_ISSPACE(l2[i2]))
+ i2++;
+ continue;
+ }
+ if (l1[i1++] != l2[i2++])
+ return 0;
+ }
+ } else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL) {
+ while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) {
+ i1++;
+ i2++;
+ }
+ } else if (flags & XDF_IGNORE_CR_AT_EOL) {
+ /* Find the first difference and see how the line ends */
+ while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) {
+ i1++;
+ i2++;
+ }
+ return (ends_with_optional_cr(l1, s1, i1) &&
+ ends_with_optional_cr(l2, s2, i2));
+ }
+
+ /*
+ * After running out of one side, the remaining side must have
+ * nothing but whitespace for the lines to match. Note that
+ * ignore-whitespace-at-eol case may break out of the loop
+ * while there still are characters remaining on both lines.
+ */
+ if (i1 < s1) {
+ while (i1 < s1 && XDL_ISSPACE(l1[i1]))
+ i1++;
+ if (s1 != i1)
+ return 0;
+ }
+ if (i2 < s2) {
+ while (i2 < s2 && XDL_ISSPACE(l2[i2]))
+ i2++;
+ return (s2 == i2);
+ }
+ return 1;
+}
+
+static unsigned long xdl_hash_record_with_whitespace(char const **data,
+ char const *top, long flags) {
+ unsigned long ha = 5381;
+ char const *ptr = *data;
+ int cr_at_eol_only = (flags & XDF_WHITESPACE_FLAGS) == XDF_IGNORE_CR_AT_EOL;
+
+ for (; ptr < top && *ptr != '\n'; ptr++) {
+ if (cr_at_eol_only) {
+ /* do not ignore CR at the end of an incomplete line */
+ if (*ptr == '\r' &&
+ (ptr + 1 < top && ptr[1] == '\n'))
+ continue;
+ }
+ else if (XDL_ISSPACE(*ptr)) {
+ const char *ptr2 = ptr;
+ int at_eol;
+ while (ptr + 1 < top && XDL_ISSPACE(ptr[1])
+ && ptr[1] != '\n')
+ ptr++;
+ at_eol = (top <= ptr + 1 || ptr[1] == '\n');
+ if (flags & XDF_IGNORE_WHITESPACE)
+ ; /* already handled */
+ else if (flags & XDF_IGNORE_WHITESPACE_CHANGE
+ && !at_eol) {
+ ha += (ha << 5);
+ ha ^= (unsigned long) ' ';
+ }
+ else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL
+ && !at_eol) {
+ while (ptr2 != ptr + 1) {
+ ha += (ha << 5);
+ ha ^= (unsigned long) *ptr2;
+ ptr2++;
+ }
+ }
+ continue;
+ }
+ ha += (ha << 5);
+ ha ^= (unsigned long) *ptr;
+ }
+ *data = ptr < top ? ptr + 1: ptr;
+
+ return ha;
+}
+
+unsigned long xdl_hash_record(char const **data, char const *top, long flags) {
+ unsigned long ha = 5381;
+ char const *ptr = *data;
+
+ if (flags & XDF_WHITESPACE_FLAGS)
+ return xdl_hash_record_with_whitespace(data, top, flags);
+
+ for (; ptr < top && *ptr != '\n'; ptr++) {
+ ha += (ha << 5);
+ ha ^= (unsigned long) *ptr;
+ }
+ *data = ptr < top ? ptr + 1: ptr;
+
+ return ha;
+}
+
+unsigned int xdl_hashbits(unsigned int size) {
+ unsigned int val = 1, bits = 0;
+
+ for (; val < size && bits < CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++);
+ return bits ? bits: 1;
+}
+
+
+int xdl_num_out(char *out, long val) {
+ char *ptr, *str = out;
+ char buf[32];
+
+ ptr = buf + sizeof(buf) - 1;
+ *ptr = '\0';
+ if (val < 0) {
+ *--ptr = '-';
+ val = -val;
+ }
+ for (; val && ptr > buf; val /= 10)
+ *--ptr = "0123456789"[val % 10];
+ if (*ptr)
+ for (; *ptr; ptr++, str++)
+ *str = *ptr;
+ else
+ *str++ = '0';
+ *str = '\0';
+
+ return str - out;
+}
+
+static int xdl_format_hunk_hdr(long s1, long c1, long s2, long c2,
+ const char *func, long funclen,
+ xdemitcb_t *ecb) {
+ int nb = 0;
+ mmbuffer_t mb;
+ char buf[128];
+
+ memcpy(buf, "@@ -", 4);
+ nb += 4;
+
+ nb += xdl_num_out(buf + nb, c1 ? s1: s1 - 1);
+
+ if (c1 != 1) {
+ memcpy(buf + nb, ",", 1);
+ nb += 1;
+
+ nb += xdl_num_out(buf + nb, c1);
+ }
+
+ memcpy(buf + nb, " +", 2);
+ nb += 2;
+
+ nb += xdl_num_out(buf + nb, c2 ? s2: s2 - 1);
+
+ if (c2 != 1) {
+ memcpy(buf + nb, ",", 1);
+ nb += 1;
+
+ nb += xdl_num_out(buf + nb, c2);
+ }
+
+ memcpy(buf + nb, " @@", 3);
+ nb += 3;
+ if (func && funclen) {
+ buf[nb++] = ' ';
+ if (funclen > sizeof(buf) - nb - 1)
+ funclen = sizeof(buf) - nb - 1;
+ memcpy(buf + nb, func, funclen);
+ nb += funclen;
+ }
+ buf[nb++] = '\n';
+
+ mb.ptr = buf;
+ mb.size = nb;
+ if (ecb->out_line(ecb->priv, &mb, 1) < 0)
+ return -1;
+ return 0;
+}
+
+int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
+ const char *func, long funclen,
+ xdemitcb_t *ecb) {
+ if (!ecb->out_hunk)
+ return xdl_format_hunk_hdr(s1, c1, s2, c2, func, funclen, ecb);
+ if (ecb->out_hunk(ecb->priv,
+ c1 ? s1 : s1 - 1, c1,
+ c2 ? s2 : s2 - 1, c2,
+ func, funclen) < 0)
+ return -1;
+ return 0;
+}
+
+int xdl_fall_back_diff(xdfenv_t *diff_env, xpparam_t const *xpp,
+ int line1, int count1, int line2, int count2)
+{
+ /*
+ * This probably does not work outside Git, since
+ * we have a very simple mmfile structure.
+ *
+ * Note: ideally, we would reuse the prepared environment, but
+ * the libxdiff interface does not (yet) allow for diffing only
+ * ranges of lines instead of the whole files.
+ */
+ mmfile_t subfile1, subfile2;
+ xdfenv_t env;
+
+ subfile1.ptr = (char *)diff_env->xdf1.recs[line1 - 1]->ptr;
+ subfile1.size = diff_env->xdf1.recs[line1 + count1 - 2]->ptr +
+ diff_env->xdf1.recs[line1 + count1 - 2]->size - subfile1.ptr;
+ subfile2.ptr = (char *)diff_env->xdf2.recs[line2 - 1]->ptr;
+ subfile2.size = diff_env->xdf2.recs[line2 + count2 - 2]->ptr +
+ diff_env->xdf2.recs[line2 + count2 - 2]->size - subfile2.ptr;
+ if (xdl_do_diff(&subfile1, &subfile2, xpp, &env) < 0)
+ return -1;
+
+ memcpy(diff_env->xdf1.rchg + line1 - 1, env.xdf1.rchg, count1);
+ memcpy(diff_env->xdf2.rchg + line2 - 1, env.xdf2.rchg, count2);
+
+ xdl_free_env(&env);
+
+ return 0;
+}
+
+void* xdl_alloc_grow_helper(void *p, long nr, long *alloc, size_t size)
+{
+ void *tmp = NULL;
+ size_t n = ((LONG_MAX - 16) / 2 >= *alloc) ? 2 * *alloc + 16 : LONG_MAX;
+ if (nr > n)
+ n = nr;
+ if (SIZE_MAX / size >= n)
+ tmp = xdl_realloc(p, n * size);
+ if (tmp) {
+ *alloc = n;
+ } else {
+ xdl_free(p);
+ *alloc = 0;
+ }
+ return tmp;
+}
diff --git a/xdiff/xutils.h b/xdiff/xutils.h
new file mode 100644
index 0000000..fd0bba9
--- /dev/null
+++ b/xdiff/xutils.h
@@ -0,0 +1,48 @@
+/*
+ * LibXDiff by Davide Libenzi ( File Differential Library )
+ * Copyright (C) 2003 Davide Libenzi
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#if !defined(XUTILS_H)
+#define XUTILS_H
+
+
+
+long xdl_bogosqrt(long n);
+int xdl_emit_diffrec(char const *rec, long size, char const *pre, long psize,
+ xdemitcb_t *ecb);
+int xdl_cha_init(chastore_t *cha, long isize, long icount);
+void xdl_cha_free(chastore_t *cha);
+void *xdl_cha_alloc(chastore_t *cha);
+long xdl_guess_lines(mmfile_t *mf, long sample);
+int xdl_blankline(const char *line, long size, long flags);
+int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags);
+unsigned long xdl_hash_record(char const **data, char const *top, long flags);
+unsigned int xdl_hashbits(unsigned int size);
+int xdl_num_out(char *out, long val);
+int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
+ const char *func, long funclen, xdemitcb_t *ecb);
+int xdl_fall_back_diff(xdfenv_t *diff_env, xpparam_t const *xpp,
+ int line1, int count1, int line2, int count2);
+
+/* Do not call this function, use XDL_ALLOC_GROW instead */
+void* xdl_alloc_grow_helper(void* p, long nr, long* alloc, size_t size);
+
+#endif /* #if !defined(XUTILS_H) */
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-06 02:16:46 +0000