summaryrefslogtreecommitdiffstats
path: root/server-info.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 14:47:53 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 14:47:53 +0000
commitc8bae7493d2f2910b57f13ded012e86bdcfb0532 (patch)
tree24e09d9f84dec336720cf393e156089ca2835791 /server-info.c
parentInitial commit. (diff)
downloadgit-c8bae7493d2f2910b57f13ded012e86bdcfb0532.tar.xz
git-c8bae7493d2f2910b57f13ded012e86bdcfb0532.zip
Adding upstream version 1:2.39.2.upstream/1%2.39.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'server-info.c')
-rw-r--r--server-info.c369
1 files changed, 369 insertions, 0 deletions
diff --git a/server-info.c b/server-info.c
new file mode 100644
index 0000000..0ec6c0c
--- /dev/null
+++ b/server-info.c
@@ -0,0 +1,369 @@
+#include "cache.h"
+#include "dir.h"
+#include "repository.h"
+#include "refs.h"
+#include "object.h"
+#include "commit.h"
+#include "tag.h"
+#include "packfile.h"
+#include "object-store.h"
+#include "strbuf.h"
+
+struct update_info_ctx {
+ FILE *cur_fp;
+ FILE *old_fp; /* becomes NULL if it differs from cur_fp */
+ struct strbuf cur_sb;
+ struct strbuf old_sb;
+};
+
+static void uic_mark_stale(struct update_info_ctx *uic)
+{
+ fclose(uic->old_fp);
+ uic->old_fp = NULL;
+}
+
+static int uic_is_stale(const struct update_info_ctx *uic)
+{
+ return uic->old_fp == NULL;
+}
+
+__attribute__((format (printf, 2, 3)))
+static int uic_printf(struct update_info_ctx *uic, const char *fmt, ...)
+{
+ va_list ap;
+ int ret = -1;
+
+ va_start(ap, fmt);
+
+ if (uic_is_stale(uic)) {
+ ret = vfprintf(uic->cur_fp, fmt, ap);
+ } else {
+ ssize_t r;
+ struct strbuf *cur = &uic->cur_sb;
+ struct strbuf *old = &uic->old_sb;
+
+ strbuf_reset(cur);
+ strbuf_vinsertf(cur, 0, fmt, ap);
+
+ strbuf_reset(old);
+ strbuf_grow(old, cur->len);
+ r = fread(old->buf, 1, cur->len, uic->old_fp);
+ if (r != cur->len || memcmp(old->buf, cur->buf, r))
+ uic_mark_stale(uic);
+
+ if (fwrite(cur->buf, 1, cur->len, uic->cur_fp) == cur->len)
+ ret = 0;
+ }
+
+ va_end(ap);
+
+ return ret;
+}
+
+/*
+ * Create the file "path" by writing to a temporary file and renaming
+ * it into place. The contents of the file come from "generate", which
+ * should return non-zero if it encounters an error.
+ */
+static int update_info_file(char *path,
+ int (*generate)(struct update_info_ctx *),
+ int force)
+{
+ char *tmp = mkpathdup("%s_XXXXXX", path);
+ int ret = -1;
+ int fd = -1;
+ FILE *to_close;
+ struct update_info_ctx uic = {
+ .cur_fp = NULL,
+ .old_fp = NULL,
+ .cur_sb = STRBUF_INIT,
+ .old_sb = STRBUF_INIT
+ };
+
+ safe_create_leading_directories(path);
+ fd = git_mkstemp_mode(tmp, 0666);
+ if (fd < 0)
+ goto out;
+ to_close = uic.cur_fp = fdopen(fd, "w");
+ if (!uic.cur_fp)
+ goto out;
+ fd = -1;
+
+ /* no problem on ENOENT and old_fp == NULL, it's stale, now */
+ if (!force)
+ uic.old_fp = fopen_or_warn(path, "r");
+
+ /*
+ * uic_printf will compare incremental comparison against old_fp
+ * and mark uic as stale if needed
+ */
+ ret = generate(&uic);
+ if (ret)
+ goto out;
+
+ /* new file may be shorter than the old one, check here */
+ if (!uic_is_stale(&uic)) {
+ struct stat st;
+ long new_len = ftell(uic.cur_fp);
+ int old_fd = fileno(uic.old_fp);
+
+ if (new_len < 0) {
+ ret = -1;
+ goto out;
+ }
+ if (fstat(old_fd, &st) || (st.st_size != (size_t)new_len))
+ uic_mark_stale(&uic);
+ }
+
+ uic.cur_fp = NULL;
+ if (fclose(to_close))
+ goto out;
+
+ if (uic_is_stale(&uic)) {
+ if (adjust_shared_perm(tmp) < 0)
+ goto out;
+ if (rename(tmp, path) < 0)
+ goto out;
+ } else {
+ unlink(tmp);
+ }
+ ret = 0;
+
+out:
+ if (ret) {
+ error_errno("unable to update %s", path);
+ if (uic.cur_fp)
+ fclose(uic.cur_fp);
+ else if (fd >= 0)
+ close(fd);
+ unlink(tmp);
+ }
+ free(tmp);
+ if (uic.old_fp)
+ fclose(uic.old_fp);
+ strbuf_release(&uic.old_sb);
+ strbuf_release(&uic.cur_sb);
+ return ret;
+}
+
+static int add_info_ref(const char *path, const struct object_id *oid,
+ int flag UNUSED,
+ void *cb_data)
+{
+ struct update_info_ctx *uic = cb_data;
+ struct object *o = parse_object(the_repository, oid);
+ if (!o)
+ return -1;
+
+ if (uic_printf(uic, "%s %s\n", oid_to_hex(oid), path) < 0)
+ return -1;
+
+ if (o->type == OBJ_TAG) {
+ o = deref_tag(the_repository, o, path, 0);
+ if (o)
+ if (uic_printf(uic, "%s %s^{}\n",
+ oid_to_hex(&o->oid), path) < 0)
+ return -1;
+ }
+ return 0;
+}
+
+static int generate_info_refs(struct update_info_ctx *uic)
+{
+ return for_each_ref(add_info_ref, uic);
+}
+
+static int update_info_refs(int force)
+{
+ char *path = git_pathdup("info/refs");
+ int ret = update_info_file(path, generate_info_refs, force);
+ free(path);
+ return ret;
+}
+
+/* packs */
+static struct pack_info {
+ struct packed_git *p;
+ int old_num;
+ int new_num;
+} **info;
+static int num_pack;
+
+static struct pack_info *find_pack_by_name(const char *name)
+{
+ int i;
+ for (i = 0; i < num_pack; i++) {
+ struct packed_git *p = info[i]->p;
+ if (!strcmp(pack_basename(p), name))
+ return info[i];
+ }
+ return NULL;
+}
+
+/* Returns non-zero when we detect that the info in the
+ * old file is useless.
+ */
+static int parse_pack_def(const char *packname, int old_cnt)
+{
+ struct pack_info *i = find_pack_by_name(packname);
+ if (i) {
+ i->old_num = old_cnt;
+ return 0;
+ }
+ else {
+ /* The file describes a pack that is no longer here */
+ return 1;
+ }
+}
+
+/* Returns non-zero when we detect that the info in the
+ * old file is useless.
+ */
+static int read_pack_info_file(const char *infofile)
+{
+ FILE *fp;
+ struct strbuf line = STRBUF_INIT;
+ int old_cnt = 0;
+ int stale = 1;
+
+ fp = fopen_or_warn(infofile, "r");
+ if (!fp)
+ return 1; /* nonexistent is not an error. */
+
+ while (strbuf_getline(&line, fp) != EOF) {
+ const char *arg;
+
+ if (!line.len)
+ continue;
+
+ if (skip_prefix(line.buf, "P ", &arg)) {
+ /* P name */
+ if (parse_pack_def(arg, old_cnt++))
+ goto out_stale;
+ } else if (line.buf[0] == 'D') {
+ /* we used to emit D but that was misguided. */
+ goto out_stale;
+ } else if (line.buf[0] == 'T') {
+ /* we used to emit T but nobody uses it. */
+ goto out_stale;
+ } else {
+ error("unrecognized: %s", line.buf);
+ }
+ }
+ stale = 0;
+
+ out_stale:
+ strbuf_release(&line);
+ fclose(fp);
+ return stale;
+}
+
+static int compare_info(const void *a_, const void *b_)
+{
+ struct pack_info *const *a = a_;
+ struct pack_info *const *b = b_;
+
+ if (0 <= (*a)->old_num && 0 <= (*b)->old_num)
+ /* Keep the order in the original */
+ return (*a)->old_num - (*b)->old_num;
+ else if (0 <= (*a)->old_num)
+ /* Only A existed in the original so B is obviously newer */
+ return -1;
+ else if (0 <= (*b)->old_num)
+ /* The other way around. */
+ return 1;
+
+ /* then it does not matter but at least keep the comparison stable */
+ if ((*a)->p == (*b)->p)
+ return 0;
+ else if ((*a)->p < (*b)->p)
+ return -1;
+ else
+ return 1;
+}
+
+static void init_pack_info(const char *infofile, int force)
+{
+ struct packed_git *p;
+ int stale;
+ int i;
+ size_t alloc = 0;
+
+ for (p = get_all_packs(the_repository); p; p = p->next) {
+ /* we ignore things on alternate path since they are
+ * not available to the pullers in general.
+ */
+ if (!p->pack_local || !file_exists(p->pack_name))
+ continue;
+
+ i = num_pack++;
+ ALLOC_GROW(info, num_pack, alloc);
+ CALLOC_ARRAY(info[i], 1);
+ info[i]->p = p;
+ info[i]->old_num = -1;
+ }
+
+ if (infofile && !force)
+ stale = read_pack_info_file(infofile);
+ else
+ stale = 1;
+
+ for (i = 0; i < num_pack; i++)
+ if (stale)
+ info[i]->old_num = -1;
+
+ /* renumber them */
+ QSORT(info, num_pack, compare_info);
+ for (i = 0; i < num_pack; i++)
+ info[i]->new_num = i;
+}
+
+static void free_pack_info(void)
+{
+ int i;
+ for (i = 0; i < num_pack; i++)
+ free(info[i]);
+ free(info);
+}
+
+static int write_pack_info_file(struct update_info_ctx *uic)
+{
+ int i;
+ for (i = 0; i < num_pack; i++) {
+ if (uic_printf(uic, "P %s\n", pack_basename(info[i]->p)) < 0)
+ return -1;
+ }
+ if (uic_printf(uic, "\n") < 0)
+ return -1;
+ return 0;
+}
+
+static int update_info_packs(int force)
+{
+ char *infofile = mkpathdup("%s/info/packs", get_object_directory());
+ int ret;
+
+ init_pack_info(infofile, force);
+ ret = update_info_file(infofile, write_pack_info_file, force);
+ free_pack_info();
+ free(infofile);
+ return ret;
+}
+
+/* public */
+int update_server_info(int force)
+{
+ /* We would add more dumb-server support files later,
+ * including index of available pack files and their
+ * intended audiences.
+ */
+ int errs = 0;
+
+ errs = errs | update_info_refs(force);
+ errs = errs | update_info_packs(force);
+
+ /* remove leftover rev-cache file if there is any */
+ unlink_or_warn(git_path("info/rev-cache"));
+
+ return errs;
+}