X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=refs.c;h=96ea8b6907b1e4be9c7b8575ff7e4a36f5a7a5f8;hb=c3e43938839752b48ff3a36862ae59f1cd1e630d;hp=157de432ced603cd27f6c181195fa8f72a023c8f;hpb=5cc3cef997503e7543d927dbe23daca891131168;p=git.git

diff --git a/refs.c b/refs.c
index 157de432c..96ea8b690 100644
--- a/refs.c
+++ b/refs.c
@@ -1,12 +1,18 @@
 #include "refs.h"
 #include "cache.h"
+#include "object.h"
+#include "tag.h"
 
 #include <errno.h>
 
+/* ISSYMREF=01 and ISPACKED=02 are public interfaces */
+#define REF_KNOWS_PEELED 04
+
 struct ref_list {
 	struct ref_list *next;
 	unsigned char flag; /* ISSYMREF? ISPACKED? */
 	unsigned char sha1[20];
+	unsigned char peeled[20];
 	char name[FLEX_ARRAY];
 };
 
@@ -34,11 +40,13 @@ static const char *parse_ref_line(char *line, unsigned char *sha1)
 	if (line[len] != '\n')
 		return NULL;
 	line[len] = 0;
+
 	return line;
 }
 
 static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
-				int flag, struct ref_list *list)
+				int flag, struct ref_list *list,
+				struct ref_list **new_entry)
 {
 	int len;
 	struct ref_list **p = &list, *entry;
@@ -50,8 +58,11 @@ static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
 			break;
 
 		/* Same as existing entry? */
-		if (!cmp)
+		if (!cmp) {
+			if (new_entry)
+				*new_entry = entry;
 			return list;
+		}
 		p = &entry->next;
 	}
 
@@ -59,10 +70,13 @@ static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
 	len = strlen(name) + 1;
 	entry = xmalloc(sizeof(struct ref_list) + len);
 	hashcpy(entry->sha1, sha1);
+	hashclr(entry->peeled);
 	memcpy(entry->name, name, len);
 	entry->flag = flag;
 	entry->next = *p;
 	*p = entry;
+	if (new_entry)
+		*new_entry = entry;
 	return list;
 }
 
@@ -98,25 +112,50 @@ static void invalidate_cached_refs(void)
 	ca->did_loose = ca->did_packed = 0;
 }
 
+static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
+{
+	struct ref_list *list = NULL;
+	struct ref_list *last = NULL;
+	char refline[PATH_MAX];
+	int flag = REF_ISPACKED;
+
+	while (fgets(refline, sizeof(refline), f)) {
+		unsigned char sha1[20];
+		const char *name;
+		static const char header[] = "# pack-refs with:";
+
+		if (!strncmp(refline, header, sizeof(header)-1)) {
+			const char *traits = refline + sizeof(header) - 1;
+			if (strstr(traits, " peeled "))
+				flag |= REF_KNOWS_PEELED;
+			/* perhaps other traits later as well */
+			continue;
+		}
+
+		name = parse_ref_line(refline, sha1);
+		if (name) {
+			list = add_ref(name, sha1, flag, list, &last);
+			continue;
+		}
+		if (last &&
+		    refline[0] == '^' &&
+		    strlen(refline) == 42 &&
+		    refline[41] == '\n' &&
+		    !get_sha1_hex(refline + 1, sha1))
+			hashcpy(last->peeled, sha1);
+	}
+	cached_refs->packed = list;
+}
+
 static struct ref_list *get_packed_refs(void)
 {
 	if (!cached_refs.did_packed) {
-		struct ref_list *refs = NULL;
 		FILE *f = fopen(git_path("packed-refs"), "r");
+		cached_refs.packed = NULL;
 		if (f) {
-			struct ref_list *list = NULL;
-			char refline[PATH_MAX];
-			while (fgets(refline, sizeof(refline), f)) {
-				unsigned char sha1[20];
-				const char *name = parse_ref_line(refline, sha1);
-				if (!name)
-					continue;
-				list = add_ref(name, sha1, REF_ISPACKED, list);
-			}
+			read_packed_refs(f, &cached_refs);
 			fclose(f);
-			refs = list;
 		}
-		cached_refs.packed = refs;
 		cached_refs.did_packed = 1;
 	}
 	return cached_refs.packed;
@@ -159,7 +198,7 @@ static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
 				error("%s points nowhere!", ref);
 				continue;
 			}
-			list = add_ref(ref, sha1, flag, list);
+			list = add_ref(ref, sha1, flag, list, NULL);
 		}
 		free(ref);
 		closedir(dir);
@@ -234,6 +273,12 @@ const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *
 			}
 		}
 
+		/* Is it a directory? */
+		if (S_ISDIR(st.st_mode)) {
+			errno = EISDIR;
+			return NULL;
+		}
+
 		/*
 		 * Anything else, just open it and try to use it as
 		 * a ref
@@ -316,6 +361,57 @@ int read_ref(const char *ref, unsigned char *sha1)
 	return -1;
 }
 
+static int do_one_ref(const char *base, each_ref_fn fn, int trim,
+		      void *cb_data, struct ref_list *entry)
+{
+	if (strncmp(base, entry->name, trim))
+		return 0;
+	if (is_null_sha1(entry->sha1))
+		return 0;
+	if (!has_sha1_file(entry->sha1)) {
+		error("%s does not point to a valid object!", entry->name);
+		return 0;
+	}
+	return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
+}
+
+int peel_ref(const char *ref, unsigned char *sha1)
+{
+	int flag;
+	unsigned char base[20];
+	struct object *o;
+
+	if (!resolve_ref(ref, base, 1, &flag))
+		return -1;
+
+	if ((flag & REF_ISPACKED)) {
+		struct ref_list *list = get_packed_refs();
+
+		while (list) {
+			if (!strcmp(list->name, ref)) {
+				if (list->flag & REF_KNOWS_PEELED) {
+					hashcpy(sha1, list->peeled);
+					return 0;
+				}
+				/* older pack-refs did not leave peeled ones */
+				break;
+			}
+			list = list->next;
+		}
+	}
+
+	/* fallback - callers should not call this for unpacked refs */
+	o = parse_object(base);
+	if (o->type == OBJ_TAG) {
+		o = deref_tag(o, ref, 0);
+		if (o) {
+			hashcpy(sha1, o->sha1);
+			return 0;
+		}
+	}
+	return -1;
+}
+
 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
 			   void *cb_data)
 {
@@ -337,29 +433,15 @@ static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
 			entry = packed;
 			packed = packed->next;
 		}
-		if (strncmp(base, entry->name, trim))
-			continue;
-		if (is_null_sha1(entry->sha1))
-			continue;
-		if (!has_sha1_file(entry->sha1)) {
-			error("%s does not point to a valid object!", entry->name);
-			continue;
-		}
-		retval = fn(entry->name + trim, entry->sha1,
-			    entry->flag, cb_data);
+		retval = do_one_ref(base, fn, trim, cb_data, entry);
 		if (retval)
 			return retval;
 	}
 
-	packed = packed ? packed : loose;
-	while (packed) {
-		if (!strncmp(base, packed->name, trim)) {
-			retval = fn(packed->name + trim, packed->sha1,
-				    packed->flag, cb_data);
-			if (retval)
-				return retval;
-		}
-		packed = packed->next;
+	for (packed = packed ? packed : loose; packed; packed = packed->next) {
+		retval = do_one_ref(base, fn, trim, cb_data, packed);
+		if (retval)
+			return retval;
 	}
 	return 0;
 }
@@ -406,33 +488,6 @@ int get_ref_sha1(const char *ref, unsigned char *sha1)
 	return read_ref(mkpath("refs/%s", ref), sha1);
 }
 
-int delete_ref(const char *refname, unsigned char *sha1)
-{
-	struct ref_lock *lock;
-	int err, i, ret = 0;
-
-	lock = lock_any_ref_for_update(refname, sha1);
-	if (!lock)
-		return 1;
-	i = strlen(lock->lk->filename) - 5; /* .lock */
-	lock->lk->filename[i] = 0;
-	err = unlink(lock->lk->filename);
-	if (err) {
-		ret = 1;
-		error("unlink(%s) failed: %s",
-		      lock->lk->filename, strerror(errno));
-	}
-	lock->lk->filename[i] = '.';
-
-	err = unlink(lock->log_file);
-	if (err && errno != ENOENT)
-		fprintf(stderr, "warning: unlink(%s) failed: %s",
-			lock->log_file, strerror(errno));
-
-	invalidate_cached_refs();
-	return ret;
-}
-
 /*
  * Make sure "ref" is something reasonable to have under ".git/refs/";
  * We do not like it if:
@@ -525,7 +580,7 @@ static int remove_empty_dir_recursive(char *path, int len)
 		    strcpy(path + len, e->d_name) &&
 		    !lstat(path, &st) &&
 		    S_ISDIR(st.st_mode) &&
-		    remove_empty_dir_recursive(path, len + namlen))
+		    !remove_empty_dir_recursive(path, len + namlen))
 			continue; /* happy */
 
 		/* path too long, stat fails, or non-directory still exists */
@@ -555,7 +610,7 @@ static int remove_empty_directories(char *file)
 	return remove_empty_dir_recursive(path, len);
 }
 
-static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1)
+static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int *flag)
 {
 	char *ref_file;
 	const char *orig_ref = ref;
@@ -567,7 +622,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char
 	lock = xcalloc(1, sizeof(struct ref_lock));
 	lock->lock_fd = -1;
 
-	ref = resolve_ref(ref, lock->old_sha1, mustexist, NULL);
+	ref = resolve_ref(ref, lock->old_sha1, mustexist, flag);
 	if (!ref && errno == EISDIR) {
 		/* we are trying to lock foo but we used to
 		 * have foo/bar which now does not exist;
@@ -580,7 +635,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char
 			error("there are still refs under '%s'", orig_ref);
 			goto error_return;
 		}
-		ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, NULL);
+		ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, flag);
 	}
 	if (!ref) {
 		last_errno = errno;
@@ -588,6 +643,30 @@ static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char
 			orig_ref, strerror(errno));
 		goto error_return;
 	}
+	if (is_null_sha1(lock->old_sha1)) {
+		/* The ref did not exist and we are creating it.
+		 * Make sure there is no existing ref that is packed
+		 * whose name begins with our refname, nor a ref whose
+		 * name is a proper prefix of our refname.
+		 */
+		int namlen = strlen(ref); /* e.g. 'foo/bar' */
+		struct ref_list *list = get_packed_refs();
+		while (list) {
+			/* list->name could be 'foo' or 'foo/bar/baz' */
+			int len = strlen(list->name);
+			int cmplen = (namlen < len) ? namlen : len;
+			const char *lead = (namlen < len) ? list->name : ref;
+
+			if (!strncmp(ref, list->name, cmplen) &&
+			    lead[cmplen] == '/') {
+				error("'%s' exists; cannot create '%s'",
+				      list->name, ref);
+				goto error_return;
+			}
+			list = list->next;
+		}
+	}
+
 	lock->lk = xcalloc(1, sizeof(struct lock_file));
 
 	lock->ref_name = xstrdup(ref);
@@ -616,12 +695,85 @@ struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
 	if (check_ref_format(ref))
 		return NULL;
 	strcpy(refpath, mkpath("refs/%s", ref));
-	return lock_ref_sha1_basic(refpath, old_sha1);
+	return lock_ref_sha1_basic(refpath, old_sha1, NULL);
 }
 
 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1)
 {
-	return lock_ref_sha1_basic(ref, old_sha1);
+	return lock_ref_sha1_basic(ref, old_sha1, NULL);
+}
+
+static struct lock_file packlock;
+
+static int repack_without_ref(const char *refname)
+{
+	struct ref_list *list, *packed_ref_list;
+	int fd;
+	int found = 0;
+
+	packed_ref_list = get_packed_refs();
+	for (list = packed_ref_list; list; list = list->next) {
+		if (!strcmp(refname, list->name)) {
+			found = 1;
+			break;
+		}
+	}
+	if (!found)
+		return 0;
+	memset(&packlock, 0, sizeof(packlock));
+	fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
+	if (fd < 0)
+		return error("cannot delete '%s' from packed refs", refname);
+
+	for (list = packed_ref_list; list; list = list->next) {
+		char line[PATH_MAX + 100];
+		int len;
+
+		if (!strcmp(refname, list->name))
+			continue;
+		len = snprintf(line, sizeof(line), "%s %s\n",
+			       sha1_to_hex(list->sha1), list->name);
+		/* this should not happen but just being defensive */
+		if (len > sizeof(line))
+			die("too long a refname '%s'", list->name);
+		write_or_die(fd, line, len);
+	}
+	return commit_lock_file(&packlock);
+}
+
+int delete_ref(const char *refname, unsigned char *sha1)
+{
+	struct ref_lock *lock;
+	int err, i, ret = 0, flag = 0;
+
+	lock = lock_ref_sha1_basic(refname, sha1, &flag);
+	if (!lock)
+		return 1;
+	if (!(flag & REF_ISPACKED)) {
+		/* loose */
+		i = strlen(lock->lk->filename) - 5; /* .lock */
+		lock->lk->filename[i] = 0;
+		err = unlink(lock->lk->filename);
+		if (err) {
+			ret = 1;
+			error("unlink(%s) failed: %s",
+			      lock->lk->filename, strerror(errno));
+		}
+		lock->lk->filename[i] = '.';
+	}
+	/* removing the loose one could have resurrected an earlier
+	 * packed one.  Also, if it was not loose we need to repack
+	 * without it.
+	 */
+	ret |= repack_without_ref(refname);
+
+	err = unlink(lock->log_file);
+	if (err && errno != ENOENT)
+		fprintf(stderr, "warning: unlink(%s) failed: %s",
+			lock->log_file, strerror(errno));
+	invalidate_cached_refs();
+	unlock_ref(lock);
+	return ret;
 }
 
 void unlock_ref(struct ref_lock *lock)
@@ -645,7 +797,8 @@ static int log_ref_write(struct ref_lock *lock,
 	char *logrec;
 	const char *committer;
 
-	if (log_all_ref_updates) {
+	if (log_all_ref_updates &&
+	    !strncmp(lock->ref_name, "refs/heads/", 11)) {
 		if (safe_create_leading_directories(lock->log_file) < 0)
 			return error("unable to create directory for %s",
 				lock->log_file);
@@ -654,10 +807,20 @@ static int log_ref_write(struct ref_lock *lock,
 
 	logfd = open(lock->log_file, oflags, 0666);
 	if (logfd < 0) {
-		if (!log_all_ref_updates && errno == ENOENT)
+		if (!(oflags & O_CREAT) && errno == ENOENT)
 			return 0;
-		return error("Unable to append to %s: %s",
-			lock->log_file, strerror(errno));
+
+		if ((oflags & O_CREAT) && errno == EISDIR) {
+			if (remove_empty_directories(lock->log_file)) {
+				return error("There are still logs under '%s'",
+					     lock->log_file);
+			}
+			logfd = open(lock->log_file, oflags, 0666);
+		}
+
+		if (logfd < 0)
+			return error("Unable to append to %s: %s",
+				     lock->log_file, strerror(errno));
 	}
 
 	committer = git_committer_info(1);
@@ -719,7 +882,7 @@ int write_ref_sha1(struct ref_lock *lock,
 	return 0;
 }
 
-int read_ref_at(const char *ref, unsigned long at_time, unsigned char *sha1)
+int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned char *sha1)
 {
 	const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
 	char *tz_c;
@@ -752,7 +915,7 @@ int read_ref_at(const char *ref, unsigned long at_time, unsigned char *sha1)
 		if (!lastgt)
 			die("Log %s is corrupt.", logfile);
 		date = strtoul(lastgt + 1, &tz_c, 10);
-		if (date <= at_time) {
+		if (date <= at_time || cnt == 0) {
 			if (lastrec) {
 				if (get_sha1_hex(lastrec, logged_sha1))
 					die("Log %s is corrupt.", logfile);
@@ -783,6 +946,8 @@ int read_ref_at(const char *ref, unsigned long at_time, unsigned char *sha1)
 			return 0;
 		}
 		lastrec = rec;
+		if (cnt > 0)
+			cnt--;
 	}
 
 	rec = logdata;