From fb9040cc83540fff9d05c8056433a4aa05b8a7c2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 4 Jul 2005 15:29:17 -0700 Subject: [PATCH] Make git-fetch-pack and git-upload-pack negotiate needs/haves fully Now the only piece missing is actually generating the pack-file. --- fetch-pack.c | 71 ++++++++++++++++++++++++++++++++++++++++++++------- upload-pack.c | 55 ++++++++++++++++++++++++++++++++++++++- 2 files changed, 116 insertions(+), 10 deletions(-) diff --git a/fetch-pack.c b/fetch-pack.c index e9035a1dc..151c1ff6b 100644 --- a/fetch-pack.c +++ b/fetch-pack.c @@ -1,4 +1,5 @@ #include "cache.h" +#include "refs.h" #include "pkt-line.h" static const char fetch_pack_usage[] = "git-fetch-pack [host:]directory [heads]* < mycommitlist"; @@ -22,11 +23,13 @@ static int get_ack(int fd, unsigned char *result_sha1) die("git-fetch_pack: expected ACK/NAK, got '%s'", line); } -static int find_common(int fd[2], unsigned char *result_sha1) +static int find_common(int fd[2], unsigned char *result_sha1, unsigned char *remote) { static char line[1000]; int count = 0, flushes = 0; + packet_write(fd[1], "want %s\n", sha1_to_hex(remote)); + packet_flush(fd[1]); while (fgets(line, sizeof(line), stdin) != NULL) { unsigned char sha1[20]; if (get_sha1_hex(line, sha1)) @@ -57,8 +60,47 @@ static int find_common(int fd[2], unsigned char *result_sha1) return -1; } -static int get_remote_heads(int fd, int nr_match, char **match) +static int get_old_sha1(const char *refname, unsigned char *sha1) +{ + static char pathname[PATH_MAX]; + const char *git_dir; + int fd, ret; + + git_dir = gitenv(GIT_DIR_ENVIRONMENT) ? : DEFAULT_GIT_DIR_ENVIRONMENT; + snprintf(pathname, sizeof(pathname), "%s/%s", git_dir, refname); + fd = open(pathname, O_RDONLY); + ret = -1; + if (fd >= 0) { + char buffer[60]; + if (read(fd, buffer, sizeof(buffer)) >= 40) + ret = get_sha1_hex(buffer, sha1); + close(fd); + } + return ret; +} + +static int check_ref(const char *refname, const unsigned char *sha1) { + unsigned char mysha1[20]; + char oldhex[41]; + + if (get_old_sha1(refname, mysha1) < 0) + memset(mysha1, 0, 20); + + if (!memcmp(sha1, mysha1, 20)) { + printf("%s: unchanged\n", refname); + return 0; + } + + memcpy(oldhex, sha1_to_hex(mysha1), 41); + printf("%s: %s (%s)\n", refname, sha1_to_hex(sha1), oldhex); + return 1; +} + +static int get_remote_heads(int fd, int nr_match, char **match, unsigned char *result) +{ + int count = 0; + for (;;) { static char line[1000]; unsigned char sha1[20]; @@ -75,20 +117,31 @@ static int get_remote_heads(int fd, int nr_match, char **match) refname = line+41; if (nr_match && !path_match(refname, nr_match, match)) continue; - printf("%s %s\n", sha1_to_hex(sha1), refname); + if (check_ref(refname, sha1)) { + count++; + memcpy(result, sha1, 20); + } } - return 0; + return count; } static int fetch_pack(int fd[2], int nr_match, char **match) { - unsigned char sha1[20]; + unsigned char sha1[20], remote[20]; + int heads; - get_remote_heads(fd[0], nr_match, match); - if (find_common(fd, sha1) < 0) + heads = get_remote_heads(fd[0], nr_match, match, remote); + if (heads != 1) { + packet_flush(fd[1]); + die(heads ? "multiple remote heads" : "no matching remote head"); + } + if (find_common(fd, sha1, remote) < 0) die("git-fetch-pack: no common commits"); - printf("common commit: %s\n", sha1_to_hex(sha1)); - return 0; + close(fd[1]); + dup2(fd[0], 0); + close(fd[0]); + execlp("git-unpack-objects", "git-unpack-objects", NULL); + die("git-unpack-objects exec failed"); } int main(int argc, char **argv) diff --git a/upload-pack.c b/upload-pack.c index 18b8e1a6c..b454c9e11 100644 --- a/upload-pack.c +++ b/upload-pack.c @@ -4,11 +4,37 @@ static const char upload_pack_usage[] = "git-upload-pack "; +#define MAX_HAS (16) +#define MAX_NEEDS (16) +static int nr_has = 0, nr_needs = 0; +static unsigned char has_sha1[MAX_HAS][20]; +static unsigned char needs_sha1[MAX_NEEDS][20]; + +static void create_pack_file(void) +{ + /* + * Here, we should do + * + * git-rev-list --objects needs_sha1 --not has_sha1 | + * git-pack-objects --stdout + * + * but we don't. + */ +} + static int got_sha1(char *hex, unsigned char *sha1) { + int nr; if (get_sha1_hex(hex, sha1)) die("git-upload-pack: expected SHA1 object, got '%s'", hex); - return has_sha1_file(sha1); + if (!has_sha1_file(sha1)) + return 0; + nr = nr_has; + if (nr < MAX_HAS) { + memcpy(has_sha1[nr], sha1, 20); + nr_has = nr+1; + } + return 1; } static int get_common_commits(void) @@ -55,6 +81,29 @@ static int get_common_commits(void) return 0; } +static int receive_needs(void) +{ + static char line[1000]; + int len, needs; + + needs = 0; + for (;;) { + len = packet_read_line(0, line, sizeof(line)); + if (!len) + return needs; + + /* + * This is purely theoretical right now: git-fetch-pack only + * ever asks for a single HEAD + */ + if (needs >= MAX_NEEDS) + die("I'm only doing a max of %d requests", MAX_NEEDS); + if (strncmp("want ", line, 5) || get_sha1_hex(line+5, needs_sha1[needs])) + die("git-upload-pack: protocol error, expected to get sha, not '%s'", line); + needs++; + } +} + static int send_ref(const char *refname, const unsigned char *sha1) { packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname); @@ -65,7 +114,11 @@ static int upload_pack(void) { for_each_ref(send_ref); packet_flush(1); + nr_needs = receive_needs(); + if (!nr_needs) + return 0; get_common_commits(); + create_pack_file(); return 0; } -- 2.30.2