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authorJohannes Schindelin <Johannes.Schindelin@gmx.de>2007-02-22 00:59:14 (GMT)
committerJunio C Hamano <junkio@cox.net>2007-02-23 06:30:33 (GMT)
commit2e0afafebd8c5a1a8cdddb0714073461229ecfef (patch)
treeeba8a2fa0f5c7d5de4043141bd6ce33bb7b34034 /builtin-bundle.c
parent437b1b20df4b356c9342dac8d38849f24ef44f27 (diff)
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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 <mdl123@verizon.net>. 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 <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <junkio@cox.net>
Diffstat (limited to 'builtin-bundle.c')
-rw-r--r--builtin-bundle.c389
1 files changed, 389 insertions, 0 deletions
diff --git a/builtin-bundle.c b/builtin-bundle.c
new file mode 100644
index 0000000..4bd596a
--- /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 <bundle> <git-rev-list args> | --verify <bundle> | --list-heads <bundle> [refname]... | --unbundle <bundle> [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);
+}
+