git-fetch-pack: avoid unnecessary zero packing

diff --git a/upload-pack.c b/upload-pack.c
index b454c9e11dbea4d023ec724252e14b4984bfba9b..83f5a35d2686401e9a70d7aafae07c88c7b6e936 100644 (file)
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -5,21 +5,74 @@
 static const char upload_pack_usage[] = "git-upload-pack <dir>";
 
 #define MAX_HAS (16)
-#define MAX_NEEDS (16)
+#define MAX_NEEDS (256)
 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 int strip(char *line, int len)
+{
+       if (len && line[len-1] == '\n')
+               line[--len] = 0;
+       return len;
+}
+
 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.
-        */
+       int fd[2];
+       pid_t pid;
+
+       if (pipe(fd) < 0)
+               die("git-upload-pack: unable to create pipe");
+       pid = fork();
+       if (pid < 0)
+               die("git-upload-pack: unable to fork git-rev-list");
+
+       if (!pid) {
+               int i;
+               int args;
+               char **argv;
+               char *buf;
+               char **p;
+
+               if (MAX_NEEDS <= nr_needs)
+                       args = nr_has + 10;
+               else
+                       args = nr_has + nr_needs + 5;
+               argv = xmalloc(args * sizeof(char *));
+               buf = xmalloc(args * 45);
+               p = argv;
+
+               dup2(fd[1], 1);
+               close(0);
+               close(fd[0]);
+               close(fd[1]);
+               *p++ = "git-rev-list";
+               *p++ = "--objects";
+               if (MAX_NEEDS <= nr_needs)
+                       *p++ = "--all";
+               else {
+                       for (i = 0; i < nr_needs; i++) {
+                               *p++ = buf;
+                               memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
+                               buf += 41;
+                       }
+               }
+               for (i = 0; i < nr_has; i++) {
+                       *p++ = buf;
+                       *buf++ = '^';
+                       memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
+                       buf += 41;
+               }
+               *p++ = NULL;
+               execvp("git-rev-list", argv);
+               die("git-upload-pack: unable to exec git-rev-list");
+       }
+       dup2(fd[0], 0);
+       close(fd[0]);
+       close(fd[1]);
+       execlp("git-pack-objects", "git-pack-objects", "--stdout", NULL);
+       die("git-upload-pack: unable to exec git-pack-objects");
 }
 
 static int got_sha1(char *hex, unsigned char *sha1)
@@ -50,8 +103,7 @@ static int get_common_commits(void)
                        packet_write(1, "NAK\n");
                        continue;
                }
-               if (line[len-1] == '\n')
-                       line[--len] = 0;
+               len = strip(line, len);
                if (!strncmp(line, "have ", 5)) {
                        if (got_sha1(line+5, sha1)) {
                                packet_write(1, "ACK %s\n", sha1_to_hex(sha1));
@@ -69,7 +121,8 @@ static int get_common_commits(void)
        for (;;) {
                len = packet_read_line(0, line, sizeof(line));
                if (!len)
-                       break;
+                       continue;
+               len = strip(line, len);
                if (!strncmp(line, "have ", 5)) {
                        got_sha1(line+5, sha1);
                        continue;
@@ -88,18 +141,24 @@ static int receive_needs(void)
 
        needs = 0;
        for (;;) {
+               unsigned char dummy[20], *sha1_buf;
                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);
+               sha1_buf = dummy;
+               if (needs == MAX_NEEDS) {
+                       fprintf(stderr,
+                               "warning: supporting only a max of %d requests. "
+                               "sending everything instead.\n",
+                               MAX_NEEDS);
+               }
+               else if (needs < MAX_NEEDS)
+                       sha1_buf = needs_sha1[needs];
+
+               if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
+                       die("git-upload-pack: protocol error, "
+                           "expected to get sha, not '%s'", line);
                needs++;
        }
 }
@@ -112,6 +171,7 @@ static int send_ref(const char *refname, const unsigned char *sha1)
 
 static int upload_pack(void)
 {
+       head_ref(send_ref);
        for_each_ref(send_ref);
        packet_flush(1);
        nr_needs = receive_needs();
@@ -128,12 +188,16 @@ int main(int argc, char **argv)
        if (argc != 2)
                usage(upload_pack_usage);
        dir = argv[1];
-       if (chdir(dir))
-               die("git-upload-pack unable to chdir to %s", dir);
+
+       /* chdir to the directory. If that fails, try appending ".git" */
+       if (chdir(dir) < 0) {
+               if (chdir(mkpath("%s.git", dir)) < 0)
+                       die("git-upload-pack unable to chdir to %s", dir);
+       }
        chdir(".git");
        if (access("objects", X_OK) || access("refs", X_OK))
                die("git-upload-pack: %s doesn't seem to be a git archive", dir);
-       setenv("GIT_DIR", ".", 1);
+       putenv("GIT_DIR=.");
        upload_pack();
        return 0;
 }