Am 11.06.2015 um 20:59 schrieb Augie Fackler:
When developing server software, it's often helpful to save a potentially-bogus pack for later analysis. This makes that trivial, instead of painful.
When you develop server software, shouldn't you test drive the server via the bare metal protocol anyway? That *is* painful, but unavoidable because you must harden the server against any garbage that a potentially malicous client could throw at it. Restricting yourself to a well-behaved client such as fetch-pack is only half the deal.
That said, I do think that fetch-pack could learn a mode that makes it easier to debug the normal behavior of a server (if such a mode is missing currently).
What is the problem with the current fetch-pack implementation? Does it remove a bogus packfile after download? Does it abort during download when it detects a broken packfile? Does --keep not do what you need?
Instead of your approach (which forks off tee to dump a copy of the packfile), would it not be simpler to add an option --debug-pack (probably not the best name) that skips the cleanup step when a broken packfile is detected and prints the name of the downloaded packfile?
diff --git a/fetch-pack.c b/fetch-pack.c index a912935..fe6ba58 100644 --- a/fetch-pack.c +++ b/fetch-pack.c @@ -684,7 +684,7 @@ static int get_pack(struct fetch_pack_args *args, const char *argv[22]; char keep_arg[256]; char hdr_arg[256]; - const char **av, *cmd_name; + const char **av, *cmd_name, *savepath; int do_keep = args->keep_pack; struct child_process cmd = CHILD_PROCESS_INIT; int ret; @@ -708,9 +708,8 @@ static int get_pack(struct fetch_pack_args *args, cmd.argv = argv; av = argv; *hdr_arg = 0; + struct pack_header header; if (!args->keep_pack && unpack_limit) { - struct pack_header header; - if (read_pack_header(demux.out, &header)) die("protocol error: bad pack header"); snprintf(hdr_arg, sizeof(hdr_arg), @@ -762,7 +761,44 @@ static int get_pack(struct fetch_pack_args *args, *av++ = "--strict"; *av++ = NULL; - cmd.in = demux.out; + savepath = getenv("GIT_SAVE_FETCHED_PACK_TO"); + if (savepath) { + struct child_process cmd2 = CHILD_PROCESS_INIT; + const char *argv2[22]; + int pipefds[2]; + int e; + const char **av2; + cmd2.argv = argv2; + av2 = argv2; + *av2++ = "tee"; + if (*hdr_arg) { + /* hdr_arg being nonempty means we already read the + * pack header from demux, so we need to drop a pack + * header in place for tee to append to, otherwise + * we'll end up with a broken pack on disk. + */
/* * Write multi-line comments * like this (/* on its own line) */
+ int fp; + struct sha1file *s; + fp = open(savepath, O_CREAT | O_TRUNC | O_WRONLY, 0666); + s = sha1fd_throughput(fp, savepath, NULL); + sha1write(s, &header, sizeof(header)); + sha1flush(s);
Are you abusing sha1write() and sha1flush() to write a byte sequence to a file? Is write_in_full() not sufficient?
+ close(fp); + /* -a is supported by both GNU and BSD tee */ + *av2++ = "-a"; + } + *av2++ = savepath; + *av2++ = NULL; + cmd2.in = demux.out; + e = pipe(pipefds); + if (e != 0) + die("couldn't make pipe to save pack");
start_command() can create the pipe for you. Just say cmd2.out = -1.
+ cmd2.out = pipefds[1]; + cmd.in = pipefds[0]; + if (start_command(&cmd2)) + die("couldn't start tee to save a pack");
When you call start_command(), you must also call finish_command(). start_command() prints an error message for you; you don't have to do that (the start_command() in the context below is a bad example).
+ } else + cmd.in = demux.out; cmd.git_cmd = 1; if (start_command(&cmd)) die("fetch-pack: unable to fork off %s", cmd_name); diff --git a/t/t5551-http-fetch-smart.sh b/t/t5551-http-fetch-smart.sh index 58207d8..bf4640d 100755 --- a/t/t5551-http-fetch-smart.sh +++ b/t/t5551-http-fetch-smart.sh @@ -82,11 +82,23 @@ test_expect_success 'fetch changes via http' ' test_cmp file clone/file ' +test_expect_success 'fetch changes via http and save pack' ' + echo content >>file && + git commit -a -m two && + git push public && + GIT_SAVE_FETCHED_PACK_TO=saved.pack && + export GIT_SAVE_FETCHED_PACK_TO && + (cd clone && git pull) &&
This can be written as ( cd clone && GIT_SAVE_FETCHED_PACK_TO=../saved.pack git pull ) && without 'export'.
+ git index-pack clone/saved.pack +' + cat >exp <<EOF GET /smart/repo.git/info/refs?service=git-upload-pack HTTP/1.1 200 POST /smart/repo.git/git-upload-pack HTTP/1.1 200 GET /smart/repo.git/info/refs?service=git-upload-pack HTTP/1.1 200 POST /smart/repo.git/git-upload-pack HTTP/1.1 200 +GET /smart/repo.git/info/refs?service=git-upload-pack HTTP/1.1 200 +POST /smart/repo.git/git-upload-pack HTTP/1.1 200 EOF test_expect_success 'used upload-pack service' ' sed -e " diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh index bfdaf75..73f9e1c 100755 --- a/t/t5601-clone.sh +++ b/t/t5601-clone.sh @@ -40,6 +40,15 @@ test_expect_success C_LOCALE_OUTPUT 'output from clone' ' test $(grep Clon output | wc -l) = 1 ' +test_expect_success 'clone allows saving a pack' ' + rm -fr dst saved.pack && + GIT_SAVE_FETCHED_PACK_TO=saved.pack && + export GIT_SAVE_FETCHED_PACK_TO && + git clone -n "file://$(pwd)/src" dst >output 2>&1 &&
Same here.
+ test -e saved.pack && + git index-pack saved.pack +' + test_expect_success 'clone does not keep pack' ' rm -fr dst &&
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