From 1fcc8ea55d9a126156c037a8c80dc256ceec0855 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 5 Jul 2005 15:45:37 -0700 Subject: [PATCH] Add "git-clone-pack" program to help with "git clone" --- Makefile | 2 +- clone-pack.c | 208 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 209 insertions(+), 1 deletion(-) create mode 100644 clone-pack.c diff --git a/Makefile b/Makefile index 233d24af..877d10b1 100644 --- a/Makefile +++ b/Makefile @@ -43,7 +43,7 @@ PROG= git-update-cache git-diff-files git-init-db git-write-tree \ git-get-tar-commit-id git-apply git-stripspace \ git-diff-stages git-rev-parse git-patch-id git-pack-objects \ git-unpack-objects git-verify-pack git-receive-pack git-send-pack \ - git-prune-packed git-fetch-pack git-upload-pack + git-prune-packed git-fetch-pack git-upload-pack git-clone-pack all: $(PROG) diff --git a/clone-pack.c b/clone-pack.c new file mode 100644 index 00000000..0337cecc --- /dev/null +++ b/clone-pack.c @@ -0,0 +1,208 @@ +#include "cache.h" +#include "refs.h" +#include "pkt-line.h" +#include + +static const char clone_pack_usage[] = "git-clone-pack [host:]directory [heads]*"; +static const char *exec = "git-upload-pack"; + +struct ref { + struct ref *next; + unsigned char sha1[20]; + char name[0]; +}; + +struct ref *get_remote_refs(int fd, int nr_match, char **match) +{ + struct ref *ref_list = NULL, **next_ref = &ref_list; + + for (;;) { + static char line[1000]; + unsigned char sha1[20]; + struct ref *ref; + char *refname; + int len; + + len = packet_read_line(fd, line, sizeof(line)); + if (!len) + break; + if (line[len-1] == '\n') + line[--len] = 0; + if (len < 42 || get_sha1_hex(line, sha1)) + die("git-fetch-pack: protocol error - expected ref descriptor, got '%s¤'", line); + refname = line+41; + len = len-40; + if (nr_match && !path_match(refname, nr_match, match)) + continue; + ref = xmalloc(sizeof(struct ref) + len); + ref->next = NULL; + memcpy(ref->sha1, sha1, 20); + memcpy(ref->name, refname, len); + *next_ref = ref; + next_ref = &ref->next; + } + return ref_list; +} + +static void clone_handshake(int fd[2], struct ref *ref) +{ + unsigned char sha1[20]; + + while (ref) { + packet_write(fd[1], "want %s\n", sha1_to_hex(ref->sha1)); + ref = ref->next; + } + packet_flush(fd[1]); + + /* We don't have nuttin' */ + packet_write(fd[1], "done\n"); + if (get_ack(fd[0], sha1)) + error("Huh! git-clone-pack got positive ack for %s", sha1_to_hex(sha1)); +} + +static int is_master(struct ref *ref) +{ + return !strcmp(ref->name, "refs/heads/master"); +} + +static void write_one_ref(struct ref *ref) +{ + char *path = git_path(ref->name); + int fd = open(path, O_CREAT | O_EXCL | O_WRONLY, 0666); + char *hex; + + if (fd < 0) + die("unable to create ref %s", ref->name); + hex = sha1_to_hex(ref->sha1); + hex[40] = '\n'; + if (write(fd, hex, 41) != 41) + die("unable to write ref %s", ref->name); + close(fd); +} + +static void write_refs(struct ref *ref) +{ + struct ref *head = NULL, *head_ptr, *master_ref; + char *head_path; + + if (!strcmp(ref->name, "HEAD")) { + head = ref; + ref = ref->next; + } + head_ptr = NULL; + master_ref = NULL; + while (ref) { + if (is_master(ref)) + master_ref = ref; + if (head && !memcmp(ref->sha1, head->sha1, 20)) { + if (!head_ptr || ref == master_ref) + head_ptr = ref; + } + write_one_ref(ref); + ref = ref->next; + } + if (!head) + return; + + head_path = git_path("HEAD"); + if (!head_ptr) { + /* + * If we had a master ref, and it wasn't HEAD, we need to undo the + * symlink, and write a standalone HEAD. Give a warning, because that's + * really really wrong. + */ + if (master_ref) { + error("HEAD doesn't point to any refs! Making standalone HEAD"); + unlink(head_path); + } + write_one_ref(head); + return; + } + + /* We reset to the master branch if it's available */ + if (master_ref) + return; + + /* + * Uhhuh. Other end didn't have master. We start HEAD off with + * the first branch with the same value. + */ + unlink(head_path); + if (symlink(head_ptr->name, head_path) < 0) + die("unable to link HEAD to %s", head_ptr->name); +} + +static int clone_pack(int fd[2], int nr_match, char **match) +{ + struct ref *refs; + int status; + pid_t pid; + + refs = get_remote_refs(fd[0], nr_match, match); + if (!refs) { + packet_flush(fd[1]); + die("no matching remote head"); + } + clone_handshake(fd, refs); + pid = fork(); + if (pid < 0) + die("git-clone-pack: unable to fork off git-unpack-objects"); + if (!pid) { + close(fd[1]); + dup2(fd[0], 0); + close(fd[0]); + execlp("git-unpack-objects", "git-unpack-objects", NULL); + die("git-unpack-objects exec failed"); + } + close(fd[0]); + close(fd[1]); + while (waitpid(pid, &status, 0) < 0) { + if (errno != EINTR) + die("waiting for git-unpack-objects: %s", strerror(errno)); + } + if (WIFEXITED(status)) { + int code = WEXITSTATUS(status); + if (code) + die("git-unpack-objects died with error code %d", code); + write_refs(refs); + return 0; + } + if (WIFSIGNALED(status)) { + int sig = WTERMSIG(status); + die("git-unpack-objects died of signal %d", sig); + } + die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status); +} + +int main(int argc, char **argv) +{ + int i, ret, nr_heads; + char *dest = NULL, **heads; + int fd[2]; + pid_t pid; + + nr_heads = 0; + heads = NULL; + for (i = 1; i < argc; i++) { + char *arg = argv[i]; + + if (*arg == '-') { + /* Arguments go here */ + usage(clone_pack_usage); + } + dest = arg; + heads = argv + i + 1; + nr_heads = argc - i - 1; + break; + } + if (!dest) + usage(clone_pack_usage); + pid = git_connect(fd, dest, exec); + if (pid < 0) + return 1; + ret = clone_pack(fd, nr_heads, heads); + close(fd[0]); + close(fd[1]); + finish_connect(pid); + return ret; +} -- 2.11.0