Make the pack-refs interfaces usable from outside

This just basically creates a "pack_refs()" function that could be used by
anybody. You pass it in the flags you want as a bitmask (PACK_REFS_ALL and
PACK_REFS_PRUNE), and it will do all the heavy lifting.

Of course, it's still static, and it's all in the builtin-pack-refs.c
file, so it's not actually visible to the outside, but the next step would
be to just move it all to a library file (probably refs.c) and expose it.

Then we could easily make "git gc" do this too.

While I did it, I also made it check the return value of the fflush and
fsync stage, to make sure that we don't overwrite the old packed-refs file
with something that got truncated due to write errors!

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/builtin-pack-refs.c b/builtin-pack-refs.c
index d080e30d67a913529d46e0da169faa4b0be75580..1952950c9a4bf13dc728bb8d6a79493dad36df06 100644 (file)
--- a/builtin-pack-refs.c
+++ b/builtin-pack-refs.c
@@ -12,9 +12,11 @@ struct ref_to_prune {
        char name[FLEX_ARRAY];
 };
 
+#define PACK_REFS_PRUNE        0x0001
+#define PACK_REFS_ALL  0x0002
+
 struct pack_refs_cb_data {
-       int prune;
-       int all;
+       unsigned int flags;
        struct ref_to_prune *ref_to_prune;
        FILE *refs_file;
 };
@@ -39,7 +41,7 @@ static int handle_one_ref(const char *path, const unsigned char *sha1,
        is_tag_ref = !prefixcmp(path, "refs/tags/");
 
        /* ALWAYS pack refs that were already packed or are tags */
-       if (!cb->all && !is_tag_ref && !(flags & REF_ISPACKED))
+       if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref && !(flags & REF_ISPACKED))
                return 0;
 
        fprintf(cb->refs_file, "%s %s\n", sha1_to_hex(sha1), path);
@@ -53,7 +55,7 @@ static int handle_one_ref(const char *path, const unsigned char *sha1,
                }
        }
 
-       if (cb->prune && !do_not_prune(flags)) {
+       if ((cb->flags & PACK_REFS_PRUNE) && !do_not_prune(flags)) {
                int namelen = strlen(path) + 1;
                struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
                hashcpy(n->sha1, sha1);
@@ -85,26 +87,51 @@ static void prune_refs(struct ref_to_prune *r)
 
 static struct lock_file packed;
 
-int cmd_pack_refs(int argc, const char **argv, const char *prefix)
+static int pack_refs(unsigned int flags)
 {
-       int fd, i;
+       int fd;
        struct pack_refs_cb_data cbdata;
 
        memset(&cbdata, 0, sizeof(cbdata));
+       cbdata.flags = flags;
+
+       fd = hold_lock_file_for_update(&packed, git_path("packed-refs"), 1);
+       cbdata.refs_file = fdopen(fd, "w");
+       if (!cbdata.refs_file)
+               die("unable to create ref-pack file structure (%s)",
+                   strerror(errno));
+
+       /* perhaps other traits later as well */
+       fprintf(cbdata.refs_file, "# pack-refs with: peeled \n");
+
+       for_each_ref(handle_one_ref, &cbdata);
+       if (fflush(cbdata.refs_file) || fsync(fd) || fclose(cbdata.refs_file))
+               die("failed to write ref-pack file (%s)", strerror(errno));
+       if (commit_lock_file(&packed) < 0)
+               die("unable to overwrite old ref-pack file (%s)", strerror(errno));
+       if (cbdata.flags & PACK_REFS_PRUNE)
+               prune_refs(cbdata.ref_to_prune);
+       return 0;
+}
 
-       cbdata.prune = 1;
+int cmd_pack_refs(int argc, const char **argv, const char *prefix)
+{
+       int i;
+       unsigned int flags;
+
+       flags = PACK_REFS_PRUNE;
        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
                if (!strcmp(arg, "--prune")) {
-                       cbdata.prune = 1; /* now the default */
+                       flags |= PACK_REFS_PRUNE; /* now the default */
                        continue;
                }
                if (!strcmp(arg, "--no-prune")) {
-                       cbdata.prune = 0;
+                       flags &= ~PACK_REFS_PRUNE;
                        continue;
                }
                if (!strcmp(arg, "--all")) {
-                       cbdata.all = 1;
+                       flags |= PACK_REFS_ALL;
                        continue;
                }
                /* perhaps other parameters later... */
@@ -113,22 +140,5 @@ int cmd_pack_refs(int argc, const char **argv, const char *prefix)
        if (i != argc)
                usage(builtin_pack_refs_usage);
 
-       fd = hold_lock_file_for_update(&packed, git_path("packed-refs"), 1);
-       cbdata.refs_file = fdopen(fd, "w");
-       if (!cbdata.refs_file)
-               die("unable to create ref-pack file structure (%s)",
-                   strerror(errno));
-
-       /* perhaps other traits later as well */
-       fprintf(cbdata.refs_file, "# pack-refs with: peeled \n");
-
-       for_each_ref(handle_one_ref, &cbdata);
-       fflush(cbdata.refs_file);
-       fsync(fd);
-       fclose(cbdata.refs_file);
-       if (commit_lock_file(&packed) < 0)
-               die("unable to overwrite old ref-pack file (%s)", strerror(errno));
-       if (cbdata.prune)
-               prune_refs(cbdata.ref_to_prune);
-       return 0;
+       return pack_refs(flags);
 }