X-Git-Url: https://git.octo.it/?p=git.git;a=blobdiff_plain;f=update-ref.c;h=a1e6bb90fe598dfd030c98f37a5d48c3a30590eb;hp=6919cead4beb2a8aae42c9fbac01e1093477b26d;hb=HEAD;hpb=9b143c6e155a8eead165b2a813b533e0f3e0018a diff --git a/update-ref.c b/update-ref.c index 6919cead..a1e6bb90 100644 --- a/update-ref.c +++ b/update-ref.c @@ -1,142 +1,56 @@ #include "cache.h" #include "refs.h" -#include -static const char git_update_ref_usage[] = "git-update-ref []"; +static const char git_update_ref_usage[] = +"git-update-ref [] [-m ]"; -#define MAXDEPTH 5 - -static const char *resolve_ref(const char *path, unsigned char *sha1) +int main(int argc, char **argv) { - int depth = MAXDEPTH, len; - char buffer[256]; - - for (;;) { - struct stat st; - char *buf; - int fd; - - if (--depth < 0) - return NULL; + const char *refname=NULL, *value=NULL, *oldval=NULL, *msg=NULL; + struct ref_lock *lock; + unsigned char sha1[20], oldsha1[20]; + int i; - /* Special case: non-existing file */ - if (lstat(path, &st) < 0) { - if (errno != ENOENT) - return NULL; - memset(sha1, 0, 20); - return path; + setup_git_directory(); + git_config(git_default_config); + + for (i = 1; i < argc; i++) { + if (!strcmp("-m", argv[i])) { + if (i+1 >= argc) + usage(git_update_ref_usage); + msg = argv[++i]; + if (!*msg) + die("Refusing to perform update with empty message."); + if (strchr(msg, '\n')) + die("Refusing to perform update with \\n in message."); + continue; } - - /* Follow "normalized" - ie "refs/.." symlinks by hand */ - if (S_ISLNK(st.st_mode)) { - len = readlink(path, buffer, sizeof(buffer)-1); - if (len >= 5 && !memcmp("refs/", buffer, 5)) { - path = git_path("%.*s", len, buffer); - continue; - } + if (!refname) { + refname = argv[i]; + continue; + } + if (!value) { + value = argv[i]; + continue; + } + if (!oldval) { + oldval = argv[i]; + continue; } - - /* - * Anything else, just open it and try to use it as - * a ref - */ - fd = open(path, O_RDONLY); - if (fd < 0) - return NULL; - len = read(fd, buffer, sizeof(buffer)-1); - close(fd); - - /* - * Is it a symbolic ref? - */ - if (len < 4 || memcmp("ref:", buffer, 4)) - break; - buf = buffer + 4; - len -= 4; - while (len && isspace(*buf)) - buf++, len--; - while (len && isspace(buf[len-1])) - buf[--len] = 0; - path = git_path("%.*s", len, buf); } - if (len < 40 || get_sha1_hex(buffer, sha1)) - return NULL; - return path; -} - -static int re_verify(const char *path, unsigned char *oldsha1, unsigned char *currsha1) -{ - char buf[40]; - int fd = open(path, O_RDONLY), nr; - if (fd < 0) - return -1; - nr = read(fd, buf, 40); - close(fd); - if (nr != 40 || get_sha1_hex(buf, currsha1) < 0) - return -1; - return memcmp(oldsha1, currsha1, 20) ? -1 : 0; -} - -int main(int argc, char **argv) -{ - char *hex; - const char *refname, *value, *oldval, *path, *lockpath; - unsigned char sha1[20], oldsha1[20], currsha1[20]; - int fd, written; - - setup_git_directory(); - if (argc < 3 || argc > 4) + if (!refname || !value) usage(git_update_ref_usage); - refname = argv[1]; - value = argv[2]; - oldval = argv[3]; - if (get_sha1(value, sha1) < 0) + if (get_sha1(value, sha1)) die("%s: not a valid SHA1", value); memset(oldsha1, 0, 20); - if (oldval && get_sha1(oldval, oldsha1) < 0) + if (oldval && get_sha1(oldval, oldsha1)) die("%s: not a valid old SHA1", oldval); - path = resolve_ref(git_path("%s", refname), currsha1); - if (!path) - die("No such ref: %s", refname); - - if (oldval) { - if (memcmp(currsha1, oldsha1, 20)) - die("Ref %s changed to %s", refname, sha1_to_hex(currsha1)); - /* Nothing to do? */ - if (!memcmp(oldsha1, sha1, 20)) - exit(0); - } - path = strdup(path); - lockpath = mkpath("%s.lock", path); - - fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666); - if (fd < 0) - die("Unable to create %s", lockpath); - hex = sha1_to_hex(sha1); - hex[40] = '\n'; - written = write(fd, hex, 41); - close(fd); - if (written != 41) { - unlink(lockpath); - die("Unable to write to %s", lockpath); - } - - /* - * Re-read the ref after getting the lock to verify - */ - if (oldval && re_verify(path, oldsha1, currsha1) < 0) { - unlink(lockpath); - die("Ref lock failed"); - } - - /* - * Finally, replace the old ref with the new one - */ - if (rename(lockpath, path) < 0) { - unlink(lockpath); - die("Unable to create %s", path); - } + lock = lock_any_ref_for_update(refname, oldval ? oldsha1 : NULL, 0); + if (!lock) + return 1; + if (write_ref_sha1(lock, sha1, msg) < 0) + return 1; return 0; }