1 files changed, 72 insertions, 0 deletions
diff --git a/xdiff-interface.h b/xdiff-interface.h
new file mode 100644
index 0000000..4301a7e
--- /dev/null
+++ b/xdiff-interface.h
@@ -0,0 +1,72 @@
+#ifndef XDIFF_INTERFACE_H
+#define XDIFF_INTERFACE_H
+
+#include "cache.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);
+int git_xmerge_config(const char *var, const char *value, 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