1 files changed, 248 insertions, 0 deletions
diff --git a/server-info.c b/server-info.c
new file mode 100644
index 0000000000..05bce7da3b
--- /dev/null
+++ b/server-info.c
@@ -0,0 +1,248 @@
+#include "cache.h"
+#include "refs.h"
+#include "object.h"
+#include "commit.h"
+#include "tag.h"
+
+/* refs */
+static FILE *info_ref_fp;
+
+static int add_info_ref(const char *path, const unsigned char *sha1)
+{
+	struct object *o = parse_object(sha1);
+
+	fprintf(info_ref_fp, "%s	%s\n", sha1_to_hex(sha1), path);
+	if (o->type == tag_type) {
+		o = deref_tag(o, path, 0);
+		if (o)
+			fprintf(info_ref_fp, "%s	%s^{}\n",
+				sha1_to_hex(o->sha1), path);
+	}
+	return 0;
+}
+
+static int update_info_refs(int force)
+{
+	char *path0 = strdup(git_path("info/refs"));
+	int len = strlen(path0);
+	char *path1 = xmalloc(len + 2);
+
+	strcpy(path1, path0);
+	strcpy(path1 + len, "+");
+
+	safe_create_leading_directories(path0);
+	info_ref_fp = fopen(path1, "w");
+	if (!info_ref_fp)
+		return error("unable to update %s", path0);
+	for_each_ref(add_info_ref);
+	fclose(info_ref_fp);
+	rename(path1, path0);
+	free(path0);
+	free(path1);
+	return 0;
+}
+
+/* packs */
+static struct pack_info {
+	struct packed_git *p;
+	int old_num;
+	int new_num;
+	int nr_alloc;
+	int nr_heads;
+	unsigned char (*head)[20];
+} **info;
+static int num_pack;
+static const char *objdir;
+static int objdirlen;
+
+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;
+		/* skip "/pack/" after ".git/objects" */
+		if (!strcmp(p->pack_name + objdirlen + 6, 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 *line, int old_cnt)
+{
+	struct pack_info *i = find_pack_by_name(line + 2);
+	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;
+	char line[1000];
+	int old_cnt = 0;
+
+	fp = fopen(infofile, "r");
+	if (!fp)
+		return 1; /* nonexisting is not an error. */
+
+	while (fgets(line, sizeof(line), fp)) {
+		int len = strlen(line);
+		if (line[len-1] == '\n')
+			line[--len] = 0;
+
+		if (!len)
+			continue;
+
+		switch (line[0]) {
+		case 'P': /* P name */
+			if (parse_pack_def(line, old_cnt++))
+				goto out_stale;
+			break;
+		case 'D': /* we used to emit D but that was misguided. */
+			goto out_stale;
+			break;
+		case 'T': /* we used to emit T but nobody uses it. */
+			goto out_stale;
+			break;
+		default:
+			error("unrecognized: %s", line);
+			break;
+		}
+	}
+	fclose(fp);
+	return 0;
+ out_stale:
+	fclose(fp);
+	return 1;
+}
+
+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 = 0;
+
+	objdir = get_object_directory();
+	objdirlen = strlen(objdir);
+
+	prepare_packed_git();
+	for (p = packed_git; p; p = p->next) {
+		/* we ignore things on alternate path since they are
+		 * not available to the pullers in general.
+		 */
+		if (!p->pack_local)
+			continue;
+		i++;
+	}
+	num_pack = i;
+	info = xcalloc(num_pack, sizeof(struct pack_info *));
+	for (i = 0, p = packed_git; p; p = p->next) {
+		if (!p->pack_local)
+			continue;
+		info[i] = xcalloc(1, sizeof(struct pack_info));
+		info[i]->p = p;
+		info[i]->old_num = -1;
+		i++;
+	}
+
+	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;
+			info[i]->nr_heads = 0;
+		}
+	}
+
+	/* renumber them */
+	qsort(info, num_pack, sizeof(info[0]), compare_info);
+	for (i = 0; i < num_pack; i++)
+		info[i]->new_num = i;
+}
+
+static void write_pack_info_file(FILE *fp)
+{
+	int i;
+	for (i = 0; i < num_pack; i++)
+		fprintf(fp, "P %s\n", info[i]->p->pack_name + objdirlen + 6);
+	fputc('\n', fp);
+}
+
+static int update_info_packs(int force)
+{
+	char infofile[PATH_MAX];
+	char name[PATH_MAX];
+	int namelen;
+	FILE *fp;
+
+	namelen = sprintf(infofile, "%s/info/packs", get_object_directory());
+	strcpy(name, infofile);
+	strcpy(name + namelen, "+");
+
+	init_pack_info(infofile, force);
+
+	safe_create_leading_directories(name);
+	fp = fopen(name, "w");
+	if (!fp)
+		return error("cannot open %s", name);
+	write_pack_info_file(fp);
+	fclose(fp);
+	rename(name, infofile);
+	return 0;
+}
+
+/* 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(git_path("info/rev-cache"));
+
+	return errs;
+}