From 2e0afafebd8c5a1a8cdddb0714073461229ecfef Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Thu, 22 Feb 2007 01:59:14 +0100 Subject: Add git-bundle: move objects and references by archive Some workflows require use of repositories on machines that cannot be connected, preventing use of git-fetch / git-push to transport objects and references between the repositories. git-bundle provides an alternate transport mechanism, effectively allowing git-fetch and git-pull to operate using sneakernet transport. `git-bundle create` allows the user to create a bundle containing one or more branches or tags, but with specified basis assumed to exist on the target repository. At the receiving end, git-bundle acts like git-fetch-pack, allowing the user to invoke git-fetch or git-pull using the bundle file as the URL. git-fetch and git-ls-remote determine they have a bundle URL by checking that the URL points to a file, but are otherwise unchanged in operation with bundles. The original patch was done by Mark Levedahl . It was updated to make git-bundle a builtin, and get rid of the tar format: now, the first line is supposed to say "# v2 git bundle", the next lines either contain a prerequisite ("-" followed by the hash of the needed commit), or a ref (the hash of a commit, followed by the name of the ref), and finally the pack. As a result, the bundle argument can be "-" now. Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- builtin-bundle.c | 389 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 389 insertions(+) create mode 100644 builtin-bundle.c (limited to 'builtin-bundle.c') diff --git a/builtin-bundle.c b/builtin-bundle.c new file mode 100644 index 000000000..4bd596ab2 --- /dev/null +++ b/builtin-bundle.c @@ -0,0 +1,389 @@ +#include "cache.h" +#include "object.h" +#include "commit.h" +#include "diff.h" +#include "revision.h" +#include "list-objects.h" +#include "exec_cmd.h" + +/* + * Basic handler for bundle files to connect repositories via sneakernet. + * Invocation must include action. + * This function can create a bundle or provide information on an existing + * bundle supporting git-fetch, git-pull, and git-ls-remote + */ + +static const char *bundle_usage="git-bundle (--create | --verify | --list-heads [refname]... | --unbundle [refname]... )"; + +static const char bundle_signature[] = "# v2 git bundle\n"; + +struct ref_list { + unsigned int nr, alloc; + struct { + unsigned char sha1[20]; + char *name; + } *list; +}; + +static void add_to_ref_list(const unsigned char *sha1, const char *name, + struct ref_list *list) +{ + if (list->nr + 1 >= list->alloc) { + list->alloc = alloc_nr(list->nr + 1); + list->list = xrealloc(list->list, + list->alloc * sizeof(list->list[0])); + } + memcpy(list->list[list->nr].sha1, sha1, 20); + list->list[list->nr].name = xstrdup(name); + list->nr++; +} + +struct bundle_header { + struct ref_list prerequisites, references; +}; + +/* this function returns the length of the string */ +static int read_string(int fd, char *buffer, int size) +{ + int i; + for (i = 0; i < size - 1; i++) { + int count = read(fd, buffer + i, 1); + if (count < 0) + return error("Read error: %s", strerror(errno)); + if (count == 0) { + i--; + break; + } + if (buffer[i] == '\n') + break; + } + buffer[i + 1] = '\0'; + return i + 1; +} + +/* returns an fd */ +static int read_header(const char *path, struct bundle_header *header) { + char buffer[1024]; + int fd = open(path, O_RDONLY); + + if (fd < 0) + return error("could not open '%s'", path); + if (read_string(fd, buffer, sizeof(buffer)) < 0 || + strcmp(buffer, bundle_signature)) { + close(fd); + return error("'%s' does not look like a v2 bundle file", path); + } + while (read_string(fd, buffer, sizeof(buffer)) > 0 + && buffer[0] != '\n') { + int offset = buffer[0] == '-' ? 1 : 0; + int len = strlen(buffer); + unsigned char sha1[20]; + struct ref_list *list = offset ? &header->prerequisites + : &header->references; + if (get_sha1_hex(buffer + offset, sha1)) { + close(fd); + return error("invalid SHA1: %s", buffer); + } + if (buffer[len - 1] == '\n') + buffer[len - 1] = '\0'; + add_to_ref_list(sha1, buffer + 41 + offset, list); + } + return fd; +} + +/* if in && *in >= 0, take that as input file descriptor instead */ +static int fork_with_pipe(const char **argv, int *in, int *out) +{ + int needs_in, needs_out; + int fdin[2], fdout[2], pid; + + needs_in = in && *in < 0; + if (needs_in) { + if (pipe(fdin) < 0) + return error("could not setup pipe"); + *in = fdin[1]; + } + + needs_out = out && *out < 0; + if (needs_out) { + if (pipe(fdout) < 0) + return error("could not setup pipe"); + *out = fdout[0]; + } + + if ((pid = fork()) < 0) { + if (needs_in) { + close(fdin[0]); + close(fdin[1]); + } + if (needs_out) { + close(fdout[0]); + close(fdout[1]); + } + return error("could not fork"); + } + if (!pid) { + if (needs_in) { + dup2(fdin[0], 0); + close(fdin[0]); + close(fdin[1]); + } else if (in) + dup2(*in, 0); + if (needs_out) { + dup2(fdout[1], 1); + close(fdout[0]); + close(fdout[1]); + } else if (out) + dup2(*out, 1); + exit(execv_git_cmd(argv)); + } + if (needs_in) + close(fdin[0]); + if (needs_out) + close(fdout[1]); + return pid; +} + +static int verify_bundle(struct bundle_header *header) +{ + /* + * Do fast check, then if any prereqs are missing then go line by line + * to be verbose about the errors + */ + struct ref_list *p = &header->prerequisites; + const char *argv[5] = {"rev-list", "--stdin", "--not", "--all", NULL}; + int pid, in, out, i, ret = 0; + char buffer[1024]; + + in = out = -1; + pid = fork_with_pipe(argv, &in, &out); + if (pid < 0) + return error("Could not fork rev-list"); + if (!fork()) { + for (i = 0; i < p->nr; i++) { + write(in, sha1_to_hex(p->list[i].sha1), 40); + write(in, "\n", 1); + } + close(in); + exit(0); + } + close(in); + while (read_string(out, buffer, sizeof(buffer)) > 0) { + if (ret++ == 0) + error ("The bundle requires the following commits you lack:"); + fprintf(stderr, "%s", buffer); + } + close(out); + while (waitpid(pid, &i, 0) < 0) + if (errno != EINTR) + return -1; + if (!ret && (!WIFEXITED(i) || WEXITSTATUS(i))) + return error("At least one prerequisite is lacking."); + + return ret; +} + +static int list_heads(struct bundle_header *header, int argc, const char **argv) +{ + int i; + struct ref_list *r = &header->references; + + for (i = 0; i < r->nr; i++) { + if (argc > 1) { + int j; + for (j = 1; j < argc; j++) + if (!strcmp(r->list[i].name, argv[j])) + break; + if (j == argc) + continue; + } + printf("%s %s\n", sha1_to_hex(r->list[i].sha1), + r->list[i].name); + } + return 0; +} + +static void show_commit(struct commit *commit) +{ + write(1, sha1_to_hex(commit->object.sha1), 40); + write(1, "\n", 1); + if (commit->parents) { + free_commit_list(commit->parents); + commit->parents = NULL; + } +} + +static void show_object(struct object_array_entry *p) +{ + /* An object with name "foo\n0000000..." can be used to + * * confuse downstream git-pack-objects very badly. + * */ + const char *ep = strchr(p->name, '\n'); + int len = ep ? ep - p->name : strlen(p->name); + write(1, sha1_to_hex(p->item->sha1), 40); + write(1, " ", 1); + if (len) + write(1, p->name, len); + write(1, "\n", 1); +} + +static int create_bundle(struct bundle_header *header, const char *path, + int argc, const char **argv) +{ + int bundle_fd = -1; + const char **argv_boundary = xmalloc((argc + 3) * sizeof(const char *)); + const char **argv_pack = xmalloc(4 * sizeof(const char *)); + int pid, in, out, i, status; + char buffer[1024]; + struct rev_info revs; + + bundle_fd = (!strcmp(path, "-") ? 1 : + open(path, O_CREAT | O_WRONLY, 0666)); + if (bundle_fd < 0) + return error("Could not write to '%s'", path); + + /* write signature */ + write(bundle_fd, bundle_signature, strlen(bundle_signature)); + + /* write prerequisites */ + memcpy(argv_boundary + 2, argv + 1, argc * sizeof(const char *)); + argv_boundary[0] = "rev-list"; + argv_boundary[1] = "--boundary"; + argv_boundary[argc + 1] = NULL; + out = -1; + pid = fork_with_pipe(argv_boundary, NULL, &out); + if (pid < 0) + return -1; + while ((i = read_string(out, buffer, sizeof(buffer))) > 0) + if (buffer[0] == '-') + write(bundle_fd, buffer, i); + while ((i = waitpid(pid, &status, 0)) < 0) + if (errno != EINTR) + return error("rev-list died"); + if (!WIFEXITED(status) || WEXITSTATUS(status)) + return error("rev-list died %d", WEXITSTATUS(status)); + + /* write references */ + save_commit_buffer = 0; + init_revisions(&revs, NULL); + revs.tag_objects = 1; + revs.tree_objects = 1; + revs.blob_objects = 1; + argc = setup_revisions(argc, argv, &revs, NULL); + if (argc > 1) + return error("unrecognized argument: %s'", argv[1]); + for (i = 0; i < revs.pending.nr; i++) { + struct object_array_entry *e = revs.pending.objects + i; + if (!(e->item->flags & UNINTERESTING)) { + unsigned char sha1[20]; + char *ref; + if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1) + continue; + write(bundle_fd, sha1_to_hex(e->item->sha1), 40); + write(bundle_fd, " ", 1); + write(bundle_fd, ref, strlen(ref)); + write(bundle_fd, "\n", 1); + free(ref); + } + } + + /* end header */ + write(bundle_fd, "\n", 1); + + /* write pack */ + argv_pack[0] = "pack-objects"; + argv_pack[1] = "--all-progress"; + argv_pack[2] = "--stdout"; + argv_pack[3] = NULL; + in = -1; + out = bundle_fd; + pid = fork_with_pipe(argv_pack, &in, &out); + if (pid < 0) + return error("Could not spawn pack-objects"); + close(1); + close(bundle_fd); + dup2(in, 1); + close(in); + prepare_revision_walk(&revs); + traverse_commit_list(&revs, show_commit, show_object); + close(1); + while (waitpid(pid, &status, 0) < 0) + if (errno != EINTR) + return -1; + if (!WIFEXITED(status) || WEXITSTATUS(status)) + return error ("pack-objects died"); + return 0; +} + +static int unbundle(struct bundle_header *header, int bundle_fd, + int argc, const char **argv) +{ + const char *argv_index_pack[] = {"index-pack", "--stdin", NULL}; + int pid, status, dev_null; + + if (verify_bundle(header)) + return -1; + dev_null = open("/dev/null", O_WRONLY); + pid = fork_with_pipe(argv_index_pack, &bundle_fd, &dev_null); + if (pid < 0) + return error("Could not spawn index-pack"); + close(bundle_fd); + while (waitpid(pid, &status, 0) < 0) + if (errno != EINTR) + return error("index-pack died"); + if (!WIFEXITED(status) || WEXITSTATUS(status)) + return error("index-pack exited with status %d", + WEXITSTATUS(status)); + return list_heads(header, argc, argv); +} + +int cmd_bundle(int argc, const char **argv, const char *prefix) +{ + struct bundle_header header; + int nongit = 0; + const char *cmd, *bundle_file; + int bundle_fd = -1; + char buffer[PATH_MAX]; + + if (argc < 3) + usage(bundle_usage); + + cmd = argv[1]; + bundle_file = argv[2]; + argc -= 2; + argv += 2; + + prefix = setup_git_directory_gently(&nongit); + if (prefix && bundle_file[0] != '/') { + snprintf(buffer, sizeof(buffer), "%s/%s", prefix, bundle_file); + bundle_file = buffer; + } + + memset(&header, 0, sizeof(header)); + if (strcmp(cmd, "create") && + !(bundle_fd = read_header(bundle_file, &header))) + return 1; + + if (!strcmp(cmd, "verify")) { + close(bundle_fd); + if (verify_bundle(&header)) + return 1; + fprintf(stderr, "%s is okay\n", bundle_file); + return 0; + } + if (!strcmp(cmd, "list-heads")) { + close(bundle_fd); + return !!list_heads(&header, argc, argv); + } + if (!strcmp(cmd, "create")) { + if (nongit) + die("Need a repository to create a bundle."); + return !!create_bundle(&header, bundle_file, argc, argv); + } else if (!strcmp(cmd, "unbundle")) { + if (nongit) + die("Need a repository to unbundle."); + return !!unbundle(&header, bundle_fd, argc, argv); + } else + usage(bundle_usage); +} + -- cgit v1.2.1