Re: Alternates and push
From: Junio C Hamano <hidden>
Date: 2016-06-15 22:45:19
Theodore Tso [off-list ref] writes:
One way that wouldn't break backwards compatibility would be to use $D/refs if it exists, but if it isn't, fall back to existing behavior (which is to say, only use the refs in the repository, not in the borrowed repository/object store). Is there a reason why this would be problematic?
This does not answer "is this safe enough change?" question, but the code to implement this should look like this (Area expert Daniel CC'ed). Makefile | 2 +- receive-pack.c => builtin-receive-pack.c | 60 ++++++++++++++++++++++++++++- builtin.h | 1 + cache.h | 2 + git.c | 1 + sha1_file.c | 10 +++++ 6 files changed, 72 insertions(+), 4 deletions(-)
diff --git c/Makefile w/Makefile
index dfed7ba..badf27a 100644
--- c/Makefile
+++ w/Makefile@@ -294,7 +294,6 @@ PROGRAMS += git-mktag$X PROGRAMS += git-mktree$X PROGRAMS += git-pack-redundant$X PROGRAMS += git-patch-id$X -PROGRAMS += git-receive-pack$X PROGRAMS += git-send-pack$X PROGRAMS += git-show-index$X PROGRAMS += git-unpack-file$X
@@ -543,6 +542,7 @@ BUILTIN_OBJS += builtin-prune-packed.o BUILTIN_OBJS += builtin-prune.o BUILTIN_OBJS += builtin-push.o BUILTIN_OBJS += builtin-read-tree.o +BUILTIN_OBJS += builtin-receive-pack.o BUILTIN_OBJS += builtin-reflog.o BUILTIN_OBJS += builtin-remote.o BUILTIN_OBJS += builtin-rerere.o
diff --git c/receive-pack.c w/builtin-receive-pack.c
similarity index 88%
rename from receive-pack.c
rename to builtin-receive-pack.c
index b81678a..c9bb722 100644
--- c/receive-pack.c
+++ w/builtin-receive-pack.c@@ -6,6 +6,8 @@ #include "exec_cmd.h" #include "commit.h" #include "object.h" +#include "remote.h" +#include "transport.h" static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
@@ -462,14 +464,64 @@ static int delete_only(struct command *cmd) return 1; } -int main(int argc, char **argv) +/* Need to move this to path.c or somewhere, and remove the same from builtin-clone.c */ +static int is_directory(const char *path) +{ + struct stat buf; + + return !stat(path, &buf) && S_ISDIR(buf.st_mode); +} + +static int add_refs_from_alternate(struct alternate_object_database *e, void *unused) +{ + char *other = xstrdup(make_absolute_path(e->base)); + size_t len = strlen(other); + struct remote *remote; + struct transport *transport; + const struct ref *extra; + struct strbuf buf = STRBUF_INIT; + + while (other[len-1] == '/') + other[--len] = '\0'; + if (len < 8 || memcmp(other + len - 8, "/objects", 8)) + return 0; + /* Is this a git repository with refs? */ + memcpy(other + len - 8, "/refs", 6); + if (!is_directory(other)) + return 0; + other[len - 8] = '\0'; + remote = remote_get(other); + transport = transport_get(remote, other); + for (extra = transport_get_remote_refs(transport); + extra; + extra = extra->next) { + /* + * Make sure this is named uniquely but with invalid name, so + * that we can catch the other end trying to do anything funky + * with it. + */ + strbuf_reset(&buf); + strbuf_addf(&buf, "refs/borrowed-ref/%s", extra->name); + add_extra_ref(buf.buf, extra->old_sha1, 0); + } + transport_disconnect(transport); + free(other); + return 0; +} + +static void add_alternate_refs(void) +{ + foreach_alt_odb(add_refs_from_alternate, NULL); +} + +int cmd_receive_pack(int argc, const char **argv, const char *prefix) { int i; char *dir = NULL; argv++; for (i = 1; i < argc; i++) { - char *arg = *argv++; + const char *arg = *argv++; if (*arg == '-') { /* Do flag handling here */
@@ -477,7 +529,7 @@ int main(int argc, char **argv) } if (dir) usage(receive_pack_usage); - dir = arg; + dir = xstrdup(arg); } if (!dir) usage(receive_pack_usage);
@@ -497,7 +549,9 @@ int main(int argc, char **argv) else if (0 <= receive_unpack_limit) unpack_limit = receive_unpack_limit; + add_alternate_refs(); write_head_info(); + clear_extra_refs(); /* EOF */ packet_flush(1);
diff --git c/builtin.h w/builtin.h
index f3502d3..ade9a12 100644
--- c/builtin.h
+++ w/builtin.h@@ -78,6 +78,7 @@ extern int cmd_prune(int argc, const char **argv, const char *prefix); extern int cmd_prune_packed(int argc, const char **argv, const char *prefix); extern int cmd_push(int argc, const char **argv, const char *prefix); extern int cmd_read_tree(int argc, const char **argv, const char *prefix); +extern int cmd_receive_pack(int argc, const char **argv, const char *prefix); extern int cmd_reflog(int argc, const char **argv, const char *prefix); extern int cmd_remote(int argc, const char **argv, const char *prefix); extern int cmd_config(int argc, const char **argv, const char *prefix);
diff --git c/cache.h w/cache.h
index de8c2b6..ddea8d1 100644
--- c/cache.h
+++ w/cache.h@@ -640,6 +640,8 @@ extern struct alternate_object_database { } *alt_odb_list; extern void prepare_alt_odb(void); extern void add_to_alternates_file(const char *reference); +typedef int alt_odb_fn(struct alternate_object_database *, void *); +extern void foreach_alt_odb(alt_odb_fn, void*); struct pack_window { struct pack_window *next;
diff --git c/git.c w/git.c
index fdb0f71..bf1ac1b 100644
--- c/git.c
+++ w/git.c@@ -328,6 +328,7 @@ static void handle_internal_command(int argc, const char **argv) { "prune-packed", cmd_prune_packed, RUN_SETUP }, { "push", cmd_push, RUN_SETUP }, { "read-tree", cmd_read_tree, RUN_SETUP }, + { "receive-pack", cmd_receive_pack }, { "reflog", cmd_reflog, RUN_SETUP }, { "remote", cmd_remote, RUN_SETUP }, { "repo-config", cmd_config },
diff --git c/sha1_file.c w/sha1_file.c
index 9ee1ed1..6bd0ef0 100644
--- c/sha1_file.c
+++ w/sha1_file.c@@ -394,6 +394,16 @@ void add_to_alternates_file(const char *reference) link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0); } +void foreach_alt_odb(alt_odb_fn fn, void *cb) +{ + struct alternate_object_database *ent; + + prepare_alt_odb(); + for (ent = alt_odb_list; ent; ent = ent->next) + if (fn(ent, cb)) + return; +} + void prepare_alt_odb(void) { const char *alt;