[PATCH] fetch-pack: start multi-head pulling.
From: Junio C Hamano <hidden>
Date: 2016-06-15 22:42:03
This is a beginning of resurrecting the multi-head pulling support for git-fetch-pack command. The git-fetch-script wrapper still only knows about fetching a single head, without renaming, so it is not very useful unless you directly call git-fetch-pack itself yet. It also fixes a longstanding obsolete description of how the command discovers the list of local commits. --- Linus, I need a bit of guidance from you about this one; an ancient commit 4f7770c87ce3c302e1639a7737a6d2531fe4b160 removed the multi-head support fetch-pack once had, labelling it as "a misguided attempt", and I would like to know if I am making the same misguided attempt again. This update actually makes clone-pack almost redundant. Documentation/git-fetch-pack.txt | 18 +++++------- fetch-pack.c | 56 +++++++++++++++++++++++++++----------- git-fetch-script | 4 +++ 3 files changed, 51 insertions(+), 27 deletions(-) 880df673e412bae9603782833d8a80a7c7c59769
diff --git a/Documentation/git-fetch-pack.txt b/Documentation/git-fetch-pack.txt
--- a/Documentation/git-fetch-pack.txt
+++ b/Documentation/git-fetch-pack.txt@@ -9,19 +9,19 @@ git-fetch-pack - Receive missing objects SYNOPSIS -------- -git-fetch-pack [-q] [--exec=<git-upload-pack>] [<host>:]<directory> [<head>...] < <commit-list> +git-fetch-pack [-q] [--exec=<git-upload-pack>] [<host>:]<directory> [<refs>...] DESCRIPTION ----------- Invokes 'git-upload-pack' on a potentially remote repository, and asks it to send objects missing from this repository, to update the named heads. The list of commits available locally -is fed from the standard input, to be sent to 'git-upload-pack' -running on the other end. +is found out by scanning local $GIT_DIR/refs/ and sent to +'git-upload-pack' running on the other end. -This command can be used only when the local side has a common -(ancestor) commit with the remote head that is being pulled -from. Use 'git-clone-pack' for that. +This command degenerates to download everything to complete the +asked refs from the remote side when the local side does not +have a common ancestor commit. OPTIONS
@@ -50,15 +50,11 @@ OPTIONS <directory>:: The repository to sync from. -<head>...:: +<refs>...:: The remote heads to update from. This is relative to $GIT_DIR (e.g. "HEAD", "refs/heads/master"). When unspecified, update from all heads the remote side has. - However the program refuses to work if more than one - remote head matches the specified heads. I am not sure - what this means... Help!!!!! - Author ------
diff --git a/fetch-pack.c b/fetch-pack.c
--- a/fetch-pack.c
+++ b/fetch-pack.c@@ -4,10 +4,13 @@ #include <sys/wait.h> static int quiet; -static const char fetch_pack_usage[] = "git-fetch-pack [-q] [--exec=upload-pack] [host:]directory [heads]* < mycommitlist"; +static int verbose; +static const char fetch_pack_usage[] = +"git-fetch-pack [-q] [-v] [--exec=upload-pack] [host:]directory <refs>..."; static const char *exec = "git-upload-pack"; -static int find_common(int fd[2], unsigned char *result_sha1, unsigned char *remote) +static int find_common(int fd[2], unsigned char *result_sha1, + struct ref *refs) { static char line[1000]; int count = 0, flushes = 0, retval;
@@ -16,7 +19,16 @@ static int find_common(int fd[2], unsign revs = popen("git-rev-list $(git-rev-parse --all)", "r"); if (!revs) die("unable to run 'git-rev-list'"); - packet_write(fd[1], "want %s\n", sha1_to_hex(remote)); + + while (refs) { + unsigned char *remote = refs->old_sha1; + if (verbose) + fprintf(stderr, + "want %s (%s)\n", sha1_to_hex(remote), + refs->name); + packet_write(fd[1], "want %s\n", sha1_to_hex(remote)); + refs = refs->next; + } packet_flush(fd[1]); flushes = 1; retval = -1;
@@ -25,6 +37,8 @@ static int find_common(int fd[2], unsign if (get_sha1_hex(line, sha1)) die("git-fetch-pack: expected object name, got crud"); packet_write(fd[1], "have %s\n", sha1_to_hex(sha1)); + if (verbose) + fprintf(stderr, "have %s\n", sha1_to_hex(sha1)); if (!(31 & ++count)) { packet_flush(fd[1]); flushes++;
@@ -38,6 +52,8 @@ static int find_common(int fd[2], unsign if (get_ack(fd[0], result_sha1)) { flushes = 0; retval = 0; + if (verbose) + fprintf(stderr, "got ack\n"); break; } flushes--;
@@ -45,19 +61,19 @@ static int find_common(int fd[2], unsign } pclose(revs); packet_write(fd[1], "done\n"); + if (verbose) + fprintf(stderr, "done\n"); while (flushes) { flushes--; - if (get_ack(fd[0], result_sha1)) + if (get_ack(fd[0], result_sha1)) { + if (verbose) + fprintf(stderr, "got ack\n"); return 0; + } } return retval; } -/* - * Eventually we'll want to be able to fetch multiple heads. - * - * Right now we'll just require a single match. - */ static int fetch_pack(int fd[2], int nr_match, char **match) { struct ref *ref;
@@ -70,12 +86,8 @@ static int fetch_pack(int fd[2], int nr_ packet_flush(fd[1]); die("no matching remote head"); } - if (ref->next) { - packet_flush(fd[1]); - die("multiple remote heads"); - } - if (find_common(fd, sha1, ref->old_sha1) < 0) - die("git-fetch-pack: no common commits"); + if (find_common(fd, sha1, ref) < 0) + fprintf(stderr, "warning: no common commits\n"); pid = fork(); if (pid < 0) die("git-fetch-pack: unable to fork off git-unpack-objects");
@@ -97,7 +109,11 @@ static int fetch_pack(int fd[2], int nr_ int code = WEXITSTATUS(status); if (code) die("git-unpack-objects died with error code %d", code); - puts(sha1_to_hex(ref->old_sha1)); + while (ref) { + printf("%s %s\n", + sha1_to_hex(ref->old_sha1), ref->name); + ref = ref->next; + } return 0; } if (WIFSIGNALED(status)) {
@@ -124,6 +140,14 @@ int main(int argc, char **argv) exec = arg + 7; continue; } + if (!strcmp("-q", arg)) { + quiet = 1; + continue; + } + if (!strcmp("-v", arg)) { + verbose = 1; + continue; + } usage(fetch_pack_usage); } dest = arg;
diff --git a/git-fetch-script b/git-fetch-script
--- a/git-fetch-script
+++ b/git-fetch-script@@ -31,6 +31,10 @@ rsync://*) ;; *) head=$(git-fetch-pack "$merge_repo" "$merge_head") + if h=`expr "$head" : '\([^ ][^ ]*\) '` + then + head=$h + fi ;; esac || exit 1