Sergey Vlasov, Andy Parkins and Alex Riesen all pointed out that it
is possible for a single invocation of receive-pack to be given more
refs than the OS might allow us to pass as command line parameters
to a single hook invocation.
We don't want to break these up into multiple invocations (like
xargs might do) as that makes it impossible for the pre-receive
hook to verify multiple related ref updates occur at the same time,
and it makes it harder for post-receive to send out a single batch
notification.
Instead we pass the reference data on a pipe connected to the
hook's stdin, supplying one ref per line to the hook. This way a
single hook invocation can obtain an infinite amount of ref data,
without bumping into any operating system limits.
Signed-off-by: Shawn O. Pearce <spearce@xxxxxxxxxxx>
---
Documentation/git-receive-pack.txt | 32 ++++++++++----------
receive-pack.c | 58 ++++++++++++++++++-----------------
t/t5401-update-hooks.sh | 30 ++++++++++--------
3 files changed, 62 insertions(+), 58 deletions(-)
diff --git a/Documentation/git-receive-pack.txt b/Documentation/git-receive-pack.txt
index 3cf5511..6914aa5 100644
--- a/Documentation/git-receive-pack.txt
+++ b/Documentation/git-receive-pack.txt
@@ -40,13 +40,13 @@ OPTIONS
pre-receive Hook
----------------
Before any ref is updated, if $GIT_DIR/hooks/pre-receive file exists
-and is executable, it will be invoked once, with three parameters
-per ref to be updated:
+and is executable, it will be invoked once with no parameters. The
+standard input of the hook will be one line per ref to be updated:
- $GIT_DIR/hooks/pre-receive (refname sha1-old sha1-new)+
+ sha1-old SP sha1-new SP refname LF
-The refname parameter is relative to $GIT_DIR; e.g. for the master
-head this is "refs/heads/master". The two sha1 arguments after
+The refname value is relative to $GIT_DIR; e.g. for the master
+head this is "refs/heads/master". The two sha1 values before
each refname are the object names for the refname before and after
the update. Refs to be created will have sha1-old equal to 0{40},
while refs to be deleted will have sha1-new equal to 0{40}, otherwise
@@ -86,13 +86,14 @@ post-receive Hook
-----------------
After all refs were updated (or attempted to be updated), if any
ref update was successful, and if $GIT_DIR/hooks/post-receive
-file exists and is executable, it will be invoke once with three
-parameters for each successfully updated ref:
+file exists and is executable, it will be invoke once with no
+parameters. The standard input of the hook will be one line
+for each successfully updated ref:
- $GIT_DIR/hooks/post-receive (refname sha1-old sha1-new)+
+ sha1-old SP sha1-new SP refname LF
-The refname parameter is relative to $GIT_DIR; e.g. for the master
-head this is "refs/heads/master". The two sha1 arguments after
+The refname value is relative to $GIT_DIR; e.g. for the master
+head this is "refs/heads/master". The two sha1 values before
each refname are the object names for the refname before and after
the update. Refs that were created will have sha1-old equal to
0{40}, while refs that were deleted will have sha1-new equal to
@@ -105,18 +106,17 @@ ref listing the commits pushed to the repository:
#!/bin/sh
# mail out commit update information.
- while test $# -gt 0
+ while read oval nval ref
do
- if expr "$2" : '0*$' >/dev/null
+ if expr "$oval" : '0*$' >/dev/null
then
echo "Created a new ref, with the following commits:"
- git-rev-list --pretty "$2"
+ git-rev-list --pretty "$nval"
else
echo "New commits:"
- git-rev-list --pretty "$3" "^$2"
+ git-rev-list --pretty "$nval" "^$oval"
fi |
- mail -s "Changes to ref $1" commit-list@mydomain
- shift; shift; shift; # discard this ref's args
+ mail -s "Changes to ref $ref" commit-list@mydomain
done
exit 0
diff --git a/receive-pack.c b/receive-pack.c
index 4d7170f..7cf5878 100644
--- a/receive-pack.c
+++ b/receive-pack.c
@@ -79,6 +79,8 @@ static int hook_status(int code, const char *hook_name)
return error("hook fork failed");
case -ERR_RUN_COMMAND_EXEC:
return error("hook execute failed");
+ case -ERR_RUN_COMMAND_PIPE:
+ return error("hook pipe failed");
case -ERR_RUN_COMMAND_WAITPID:
return error("waitpid failed");
case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
@@ -93,44 +95,44 @@ static int hook_status(int code, const char *hook_name)
}
}
-static int run_hook(const char *hook_name,
- struct command *first_cmd,
- int single)
+static int run_hook(const char *hook_name)
{
+ static char buf[sizeof(commands->old_sha1) * 2 + PATH_MAX + 4];
struct command *cmd;
- int argc, code;
- const char **argv;
+ struct child_process proc;
+ const char *argv[2];
+ int have_input = 0, code;
- for (argc = 0, cmd = first_cmd; cmd; cmd = cmd->next) {
+ for (cmd = commands; !have_input && cmd; cmd = cmd->next) {
if (!cmd->error_string)
- argc += 3;
- if (single)
- break;
+ have_input = 1;
}
- if (!argc || access(hook_name, X_OK) < 0)
+ if (!have_input || access(hook_name, X_OK) < 0)
return 0;
- argv = xmalloc(sizeof(*argv) * (2 + argc));
argv[0] = hook_name;
- for (argc = 1, cmd = first_cmd; cmd; cmd = cmd->next) {
+ argv[1] = NULL;
+
+ memset(&proc, 0, sizeof(proc));
+ proc.argv = argv;
+ proc.in = -1;
+ proc.stdout_to_stderr = 1;
+
+ code = start_command(&proc);
+ if (code)
+ return hook_status(code, hook_name);
+ for (cmd = commands; cmd; cmd = cmd->next) {
if (!cmd->error_string) {
- argv[argc++] = xstrdup(cmd->ref_name);
- argv[argc++] = xstrdup(sha1_to_hex(cmd->old_sha1));
- argv[argc++] = xstrdup(sha1_to_hex(cmd->new_sha1));
+ size_t n = snprintf(buf, sizeof(buf), "%s %s %s\n",
+ sha1_to_hex(cmd->old_sha1),
+ sha1_to_hex(cmd->new_sha1),
+ cmd->ref_name);
+ if (write_in_full(proc.in, buf, n) != n)
+ break;
}
- if (single)
- break;
}
- argv[argc] = NULL;
-
- code = run_command_v_opt(argv,
- RUN_COMMAND_NO_STDIN | RUN_COMMAND_STDOUT_TO_STDERR);
- while (--argc > 0)
- free((char*)argv[argc]);
- free(argv);
-
- return hook_status(code, hook_name);
+ return hook_status(finish_command(&proc), hook_name);
}
static int run_update_hook(struct command *cmd)
@@ -265,7 +267,7 @@ static void execute_commands(const char *unpacker_error)
return;
}
- if (run_hook(pre_receive_hook, commands, 0)) {
+ if (run_hook(pre_receive_hook)) {
while (cmd) {
cmd->error_string = "pre-receive hook declined";
cmd = cmd->next;
@@ -520,7 +522,7 @@ int main(int argc, char **argv)
unlink(pack_lockfile);
if (report_status)
report(unpack_status);
- run_hook(post_receive_hook, commands, 0);
+ run_hook(post_receive_hook);
run_update_post_hook(commands);
}
return 0;
diff --git a/t/t5401-update-hooks.sh b/t/t5401-update-hooks.sh
index c10721b..2d4b481 100755
--- a/t/t5401-update-hooks.sh
+++ b/t/t5401-update-hooks.sh
@@ -25,8 +25,8 @@ test_expect_success setup '
cat >victim/.git/hooks/pre-receive <<'EOF'
#!/bin/sh
-echo "$@" >>$GIT_DIR/pre-receive.args
-read x; printf "$x" >$GIT_DIR/pre-receive.stdin
+printf "$@" >>$GIT_DIR/pre-receive.args
+cat - >$GIT_DIR/pre-receive.stdin
echo STDOUT pre-receive
echo STDERR pre-receive >&2
EOF
@@ -44,8 +44,8 @@ chmod u+x victim/.git/hooks/update
cat >victim/.git/hooks/post-receive <<'EOF'
#!/bin/sh
-echo "$@" >>$GIT_DIR/post-receive.args
-read x; printf "$x" >$GIT_DIR/post-receive.stdin
+printf "$@" >>$GIT_DIR/post-receive.args
+cat - >$GIT_DIR/post-receive.stdin
echo STDOUT post-receive
echo STDERR post-receive >&2
EOF
@@ -80,11 +80,10 @@ test_expect_success 'hooks ran' '
test -f victim/.git/post-update.stdin
'
-test_expect_success 'pre-receive hook arguments' '
- echo \
- refs/heads/master $commit0 $commit1 \
- refs/heads/tofail $commit1 $commit0 \
- | diff - victim/.git/pre-receive.args
+test_expect_success 'pre-receive hook input' '
+ (echo $commit0 $commit1 refs/heads/master;
+ echo $commit1 $commit0 refs/heads/tofail
+ ) | diff - victim/.git/pre-receive.stdin
'
test_expect_success 'update hook arguments' '
@@ -93,9 +92,9 @@ test_expect_success 'update hook arguments' '
) | diff - victim/.git/update.args
'
-test_expect_success 'post-receive hook arguments' '
- echo refs/heads/master $commit0 $commit1 |
- git diff - victim/.git/post-receive.args
+test_expect_success 'post-receive hook input' '
+ echo $commit0 $commit1 refs/heads/master |
+ git diff - victim/.git/post-receive.stdin
'
test_expect_success 'post-update hook arguments' '
@@ -104,12 +103,15 @@ test_expect_success 'post-update hook arguments' '
'
test_expect_success 'all hook stdin is /dev/null' '
- ! test -s victim/.git/pre-receive.stdin &&
! test -s victim/.git/update.stdin &&
- ! test -s victim/.git/post-receive.stdin &&
! test -s victim/.git/post-update.stdin
'
+test_expect_success 'all *-receive hook args are empty' '
+ ! test -s victim/.git/pre-receive.args &&
+ ! test -s victim/.git/post-receive.args
+'
+
test_expect_failure 'send-pack produced no output' '
test -s send.out
'
--
1.5.0.3.942.g299f
-
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