git/builtin-bundle.c

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C
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#include "cache.h"
#include "object.h"
#include "commit.h"
#include "diff.h"
#include "revision.h"
#include "list-objects.h"
#include "run-command.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 ref_list_entry {
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;
struct ref_list 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 = xread(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 is_prereq = buffer[0] == '-';
int offset = is_prereq ? 1 : 0;
int len = strlen(buffer);
unsigned char sha1[20];
struct ref_list *list = is_prereq ? &header->prerequisites
: &header->references;
char delim;
if (buffer[len - 1] == '\n')
buffer[len - 1] = '\0';
if (get_sha1_hex(buffer + offset, sha1)) {
warning("unrecognized header: %s", buffer);
continue;
}
delim = buffer[40 + offset];
if (!isspace(delim) && (delim != '\0' || !is_prereq))
die ("invalid header: %s", buffer);
add_to_ref_list(sha1, isspace(delim) ?
buffer + 41 + offset : "", list);
}
return fd;
}
static int list_refs(struct ref_list *r, int argc, const char **argv)
{
int i;
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;
}
#define PREREQ_MARK (1u<<16)
static int verify_bundle(struct bundle_header *header, int verbose)
{
/*
* 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;
struct rev_info revs;
const char *argv[] = {NULL, "--all"};
struct object_array refs;
struct commit *commit;
int i, ret = 0, req_nr;
const char *message = "Repository lacks these prerequisite commits:";
init_revisions(&revs, NULL);
for (i = 0; i < p->nr; i++) {
struct ref_list_entry *e = p->list + i;
struct object *o = parse_object(e->sha1);
if (o) {
o->flags |= PREREQ_MARK;
add_pending_object(&revs, o, e->name);
continue;
}
if (++ret == 1)
error(message);
error("%s %s", sha1_to_hex(e->sha1), e->name);
}
if (revs.pending.nr != p->nr)
return ret;
req_nr = revs.pending.nr;
setup_revisions(2, argv, &revs, NULL);
memset(&refs, 0, sizeof(struct object_array));
for (i = 0; i < revs.pending.nr; i++) {
struct object_array_entry *e = revs.pending.objects + i;
add_object_array(e->item, e->name, &refs);
}
prepare_revision_walk(&revs);
i = req_nr;
while (i && (commit = get_revision(&revs)))
if (commit->object.flags & PREREQ_MARK)
i--;
for (i = 0; i < req_nr; i++)
if (!(refs.objects[i].item->flags & SHOWN)) {
if (++ret == 1)
error(message);
error("%s %s", sha1_to_hex(refs.objects[i].item->sha1),
refs.objects[i].name);
}
for (i = 0; i < refs.nr; i++)
clear_commit_marks((struct commit *)refs.objects[i].item, -1);
if (verbose) {
struct ref_list *r;
r = &header->references;
printf("The bundle contains %d ref%s\n",
r->nr, (1 < r->nr) ? "s" : "");
list_refs(r, 0, NULL);
r = &header->prerequisites;
printf("The bundle requires these %d ref%s\n",
r->nr, (1 < r->nr) ? "s" : "");
list_refs(r, 0, NULL);
}
return ret;
}
static int list_heads(struct bundle_header *header, int argc, const char **argv)
{
return list_refs(&header->references, argc, argv);
}
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 + 4) * sizeof(const char *));
const char **argv_pack = xmalloc(5 * sizeof(const char *));
int i, ref_count = 0;
char buffer[1024];
struct rev_info revs;
struct child_process rls;
bundle_fd = (!strcmp(path, "-") ? 1 :
open(path, O_CREAT | O_EXCL | O_WRONLY, 0666));
if (bundle_fd < 0)
return error("Could not create '%s': %s", path, strerror(errno));
/* write signature */
write_or_die(bundle_fd, bundle_signature, strlen(bundle_signature));
/* init revs to list objects for pack-objects later */
save_commit_buffer = 0;
init_revisions(&revs, NULL);
/* write prerequisites */
memcpy(argv_boundary + 3, argv + 1, argc * sizeof(const char *));
argv_boundary[0] = "rev-list";
argv_boundary[1] = "--boundary";
argv_boundary[2] = "--pretty=oneline";
argv_boundary[argc + 2] = NULL;
memset(&rls, 0, sizeof(rls));
rls.argv = argv_boundary;
rls.out = -1;
rls.git_cmd = 1;
if (start_command(&rls))
return -1;
while ((i = read_string(rls.out, buffer, sizeof(buffer))) > 0) {
unsigned char sha1[20];
if (buffer[0] == '-') {
write_or_die(bundle_fd, buffer, i);
if (!get_sha1_hex(buffer + 1, sha1)) {
struct object *object = parse_object(sha1);
object->flags |= UNINTERESTING;
add_pending_object(&revs, object, buffer);
}
} else if (!get_sha1_hex(buffer, sha1)) {
struct object *object = parse_object(sha1);
object->flags |= SHOWN;
}
}
if (finish_command(&rls))
return error("rev-list died");
/* write references */
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;
unsigned char sha1[20];
char *ref;
if (e->item->flags & UNINTERESTING)
continue;
if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
continue;
/*
* Make sure the refs we wrote out is correct; --max-count and
* other limiting options could have prevented all the tips
* from getting output.
*/
if (!(e->item->flags & SHOWN)) {
warning("ref '%s' is excluded by the rev-list options",
e->name);
continue;
}
ref_count++;
write_or_die(bundle_fd, sha1_to_hex(e->item->sha1), 40);
write_or_die(bundle_fd, " ", 1);
write_or_die(bundle_fd, ref, strlen(ref));
write_or_die(bundle_fd, "\n", 1);
free(ref);
}
if (!ref_count)
die ("Refusing to create empty bundle.");
/* end header */
write_or_die(bundle_fd, "\n", 1);
/* write pack */
argv_pack[0] = "pack-objects";
argv_pack[1] = "--all-progress";
argv_pack[2] = "--stdout";
argv_pack[3] = "--thin";
argv_pack[4] = NULL;
memset(&rls, 0, sizeof(rls));
rls.argv = argv_pack;
rls.in = -1;
rls.out = bundle_fd;
rls.git_cmd = 1;
if (start_command(&rls))
return error("Could not spawn pack-objects");
for (i = 0; i < revs.pending.nr; i++) {
struct object *object = revs.pending.objects[i].item;
if (object->flags & UNINTERESTING)
write(rls.in, "^", 1);
write(rls.in, sha1_to_hex(object->sha1), 40);
write(rls.in, "\n", 1);
}
if (finish_command(&rls))
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",
"--fix-thin", "--stdin", NULL};
struct child_process ip;
if (verify_bundle(header, 0))
return -1;
memset(&ip, 0, sizeof(ip));
ip.argv = argv_index_pack;
ip.in = bundle_fd;
ip.no_stdout = 1;
ip.git_cmd = 1;
if (run_command(&ip))
return error("index-pack died");
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)) < 0)
return 1;
if (!strcmp(cmd, "verify")) {
close(bundle_fd);
if (verify_bundle(&header, 1))
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);
}