When Git fetches a pack using dumb HTTP, it does at least 2 things
differently from when it fetches using fetch-pack or receive-pack: (1)
it reuses the server's name for the packfile (which incorporates a hash)
for the packfile, and (2) it does not create a .keep file to avoid race
conditions with repack.
A subsequent patch will allow downloading packs over HTTP(S) as part of
a fetch. These downloads will not necessarily be from a Git repository,
and thus may not have a hash as part of its name. Also, generating a
.keep file will be necessary to avoid race conditions with repack (until
the fetch has successfully written the new refs).
Thus, teach http to pass --stdin and --keep to index-pack, the former so
that we have no reliance on the server's name for the packfile, and the
latter so that we have the .keep file.
Signed-off-by: Jonathan Tan <jonathanta...@google.com>
---
This is part of the work of CDN offloading of fetch responses.
I have plans to use the http_pack_request suite of functions to
implement the part where we download from CDN over HTTP(S), but need
this change to be able to do so. I think it's better from the code
quality perspective to reuse these functions, but this necessitates a
behavior change in that we no longer use the filename as declared by the
server, so I'm sending this as RFC to see what the community thinks.
---
http-push.c | 7 ++++++-
http-walker.c | 5 ++++-
http.c | 42 ++++++++++++++++++++----------------------
http.h | 2 +-
4 files changed, 31 insertions(+), 25 deletions(-)
diff --git a/http-push.c b/http-push.c
index b22c7caea0..409b266b0c 100644
--- a/http-push.c
+++ b/http-push.c
@@ -586,11 +586,16 @@ static void finish_request(struct transfer_request
*request)
fprintf(stderr, "Unable to get pack file %s\n%s",
request->url, curl_errorstr);
} else {
+ char *lockfile;
+
preq = (struct http_pack_request *)request->userData;
if (preq) {
- if (finish_http_pack_request(preq) == 0)
+ if (finish_http_pack_request(preq,
+ &lockfile) == 0) {
+ unlink(lockfile);
fail = 0;
+ }
release_http_pack_request(preq);
}
}
diff --git a/http-walker.c b/http-walker.c
index 8ae5d76c6a..804dc82304 100644
--- a/http-walker.c
+++ b/http-walker.c
@@ -425,6 +425,7 @@ static int http_fetch_pack(struct walker *walker, struct
alt_base *repo, unsigne
int ret;
struct slot_results results;
struct http_pack_request *preq;
+ char *lockfile;
if (fetch_indices(walker, repo))
return -1;
@@ -457,7 +458,9 @@ static int http_fetch_pack(struct walker *walker, struct
alt_base *repo, unsigne
goto abort;
}
- ret = finish_http_pack_request(preq);
+ ret = finish_http_pack_request(preq, &lockfile);
+ if (!ret)
+ unlink(lockfile);
release_http_pack_request(preq);
if (ret)
return ret;
diff --git a/http.c b/http.c
index a32ad36ddf..5f8e602cd2 100644
--- a/http.c
+++ b/http.c
@@ -2200,13 +2200,13 @@ void release_http_pack_request(struct http_pack_request
*preq)
free(preq);
}
-int finish_http_pack_request(struct http_pack_request *preq)
+int finish_http_pack_request(struct http_pack_request *preq, char **lockfile)
{
struct packed_git **lst;
struct packed_git *p = preq->target;
- char *tmp_idx;
- size_t len;
struct child_process ip = CHILD_PROCESS_INIT;
+ int tmpfile_fd;
+ int ret = 0;
close_pack_index(p);
@@ -2218,35 +2218,33 @@ int finish_http_pack_request(struct http_pack_request
*preq)
lst = &((*lst)->next);
*lst = (*lst)->next;
- if (!strip_suffix(preq->tmpfile.buf, ".pack.temp", &len))
- BUG("pack tmpfile does not end in .pack.temp?");
- tmp_idx = xstrfmt("%.*s.idx.temp", (int)len, preq->tmpfile.buf);
+ tmpfile_fd = xopen(preq->tmpfile.buf, O_RDONLY);
argv_array_push(&ip.args, "index-pack");
- argv_array_pushl(&ip.args, "-o", tmp_idx, NULL);
- argv_array_push(&ip.args, preq->tmpfile.buf);
+ argv_array_push(&ip.args, "--stdin");
+ argv_array_pushf(&ip.args, "--keep=git %"PRIuMAX, (uintmax_t)getpid());
ip.git_cmd = 1;
- ip.no_stdin = 1;
- ip.no_stdout = 1;
+ ip.in = tmpfile_fd;
+ ip.out = -1;
- if (run_command(&ip)) {
- unlink(preq->tmpfile.buf);
- unlink(tmp_idx);
- free(tmp_idx);
- return -1;
+ if (start_command(&ip)) {
+ ret = -1;
+ goto cleanup;
}
- unlink(sha1_pack_index_name(p->sha1));
+ *lockfile = index_pack_lockfile(ip.out);
+ close(ip.out);
- if (finalize_object_file(preq->tmpfile.buf, sha1_pack_name(p->sha1))
- || finalize_object_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
- free(tmp_idx);
- return -1;
+ if (finish_command(&ip)) {
+ ret = -1;
+ goto cleanup;
}
install_packed_git(the_repository, p);
- free(tmp_idx);
- return 0;
+cleanup:
+ close(tmpfile_fd);
+ unlink(preq->tmpfile.buf);
+ return ret;
}
struct http_pack_request *new_http_pack_request(
diff --git a/http.h b/http.h
index 4eb4e808e5..20d1c85d0b 100644
--- a/http.h
+++ b/http.h
@@ -212,7 +212,7 @@ struct http_pack_request {
extern struct http_pack_request *new_http_pack_request(
struct packed_git *target, const char *base_url);
-extern int finish_http_pack_request(struct http_pack_request *preq);
+int finish_http_pack_request(struct http_pack_request *preq, char **lockfile);
extern void release_http_pack_request(struct http_pack_request *preq);
/* Helpers for fetching object */
--
2.19.0.271.gfe8321ec05.dirty
