Merge branch 'db/remote'

* db/remote:
  Move refspec pattern matching to match_refs().
  Update local tracking refs when pushing
  Add handlers for fetch-side configuration of remotes.
  Move refspec parser from connect.c and cache.h to remote.{c,h}
  Move remote parsing into a library file out of builtin-push.

1 files changed, 553 insertions, 0 deletions

diff --git a/remote.c b/remote.c
new file mode 100644
index 000000000..d904616cd
--- /dev/null
+++ b/remote.c
@@ -0,0 +1,553 @@
+#include "cache.h"
+#include "remote.h"
+#include "refs.h"
+
+static struct remote **remotes;
+static int allocated_remotes;
+
+#define BUF_SIZE (2048)
+static char buffer[BUF_SIZE];
+
+static void add_push_refspec(struct remote *remote, const char *ref)
+{
+	int nr = remote->push_refspec_nr + 1;
+	remote->push_refspec =
+		xrealloc(remote->push_refspec, nr * sizeof(char *));
+	remote->push_refspec[nr-1] = ref;
+	remote->push_refspec_nr = nr;
+}
+
+static void add_fetch_refspec(struct remote *remote, const char *ref)
+{
+	int nr = remote->fetch_refspec_nr + 1;
+	remote->fetch_refspec =
+		xrealloc(remote->fetch_refspec, nr * sizeof(char *));
+	remote->fetch_refspec[nr-1] = ref;
+	remote->fetch_refspec_nr = nr;
+}
+
+static void add_uri(struct remote *remote, const char *uri)
+{
+	int nr = remote->uri_nr + 1;
+	remote->uri =
+		xrealloc(remote->uri, nr * sizeof(char *));
+	remote->uri[nr-1] = uri;
+	remote->uri_nr = nr;
+}
+
+static struct remote *make_remote(const char *name, int len)
+{
+	int i, empty = -1;
+
+	for (i = 0; i < allocated_remotes; i++) {
+		if (!remotes[i]) {
+			if (empty < 0)
+				empty = i;
+		} else {
+			if (len ? (!strncmp(name, remotes[i]->name, len) &&
+				   !remotes[i]->name[len]) :
+			    !strcmp(name, remotes[i]->name))
+				return remotes[i];
+		}
+	}
+
+	if (empty < 0) {
+		empty = allocated_remotes;
+		allocated_remotes += allocated_remotes ? allocated_remotes : 1;
+		remotes = xrealloc(remotes,
+				   sizeof(*remotes) * allocated_remotes);
+		memset(remotes + empty, 0,
+		       (allocated_remotes - empty) * sizeof(*remotes));
+	}
+	remotes[empty] = xcalloc(1, sizeof(struct remote));
+	if (len)
+		remotes[empty]->name = xstrndup(name, len);
+	else
+		remotes[empty]->name = xstrdup(name);
+	return remotes[empty];
+}
+
+static void read_remotes_file(struct remote *remote)
+{
+	FILE *f = fopen(git_path("remotes/%s", remote->name), "r");
+
+	if (!f)
+		return;
+	while (fgets(buffer, BUF_SIZE, f)) {
+		int value_list;
+		char *s, *p;
+
+		if (!prefixcmp(buffer, "URL:")) {
+			value_list = 0;
+			s = buffer + 4;
+		} else if (!prefixcmp(buffer, "Push:")) {
+			value_list = 1;
+			s = buffer + 5;
+		} else if (!prefixcmp(buffer, "Pull:")) {
+			value_list = 2;
+			s = buffer + 5;
+		} else
+			continue;
+
+		while (isspace(*s))
+			s++;
+		if (!*s)
+			continue;
+
+		p = s + strlen(s);
+		while (isspace(p[-1]))
+			*--p = 0;
+
+		switch (value_list) {
+		case 0:
+			add_uri(remote, xstrdup(s));
+			break;
+		case 1:
+			add_push_refspec(remote, xstrdup(s));
+			break;
+		case 2:
+			add_fetch_refspec(remote, xstrdup(s));
+			break;
+		}
+	}
+	fclose(f);
+}
+
+static void read_branches_file(struct remote *remote)
+{
+	const char *slash = strchr(remote->name, '/');
+	int n = slash ? slash - remote->name : 1000;
+	FILE *f = fopen(git_path("branches/%.*s", n, remote->name), "r");
+	char *s, *p;
+	int len;
+
+	if (!f)
+		return;
+	s = fgets(buffer, BUF_SIZE, f);
+	fclose(f);
+	if (!s)
+		return;
+	while (isspace(*s))
+		s++;
+	if (!*s)
+		return;
+	p = s + strlen(s);
+	while (isspace(p[-1]))
+		*--p = 0;
+	len = p - s;
+	if (slash)
+		len += strlen(slash);
+	p = xmalloc(len + 1);
+	strcpy(p, s);
+	if (slash)
+		strcat(p, slash);
+	add_uri(remote, p);
+}
+
+static char *default_remote_name = NULL;
+static const char *current_branch = NULL;
+static int current_branch_len = 0;
+
+static int handle_config(const char *key, const char *value)
+{
+	const char *name;
+	const char *subkey;
+	struct remote *remote;
+	if (!prefixcmp(key, "branch.") && current_branch &&
+	    !strncmp(key + 7, current_branch, current_branch_len) &&
+	    !strcmp(key + 7 + current_branch_len, ".remote")) {
+		free(default_remote_name);
+		default_remote_name = xstrdup(value);
+	}
+	if (prefixcmp(key,  "remote."))
+		return 0;
+	name = key + 7;
+	subkey = strrchr(name, '.');
+	if (!subkey)
+		return error("Config with no key for remote %s", name);
+	if (*subkey == '/') {
+		warning("Config remote shorthand cannot begin with '/': %s", name);
+		return 0;
+	}
+	remote = make_remote(name, subkey - name);
+	if (!value) {
+		/* if we ever have a boolean variable, e.g. "remote.*.disabled"
+		 * [remote "frotz"]
+		 *      disabled
+		 * is a valid way to set it to true; we get NULL in value so
+		 * we need to handle it here.
+		 *
+		 * if (!strcmp(subkey, ".disabled")) {
+		 *      val = git_config_bool(key, value);
+		 *      return 0;
+		 * } else
+		 *
+		 */
+		return 0; /* ignore unknown booleans */
+	}
+	if (!strcmp(subkey, ".url")) {
+		add_uri(remote, xstrdup(value));
+	} else if (!strcmp(subkey, ".push")) {
+		add_push_refspec(remote, xstrdup(value));
+	} else if (!strcmp(subkey, ".fetch")) {
+		add_fetch_refspec(remote, xstrdup(value));
+	} else if (!strcmp(subkey, ".receivepack")) {
+		if (!remote->receivepack)
+			remote->receivepack = xstrdup(value);
+		else
+			error("more than one receivepack given, using the first");
+	}
+	return 0;
+}
+
+static void read_config(void)
+{
+	unsigned char sha1[20];
+	const char *head_ref;
+	int flag;
+	if (default_remote_name) // did this already
+		return;
+	default_remote_name = xstrdup("origin");
+	current_branch = NULL;
+	head_ref = resolve_ref("HEAD", sha1, 0, &flag);
+	if (head_ref && (flag & REF_ISSYMREF) &&
+	    !prefixcmp(head_ref, "refs/heads/")) {
+		current_branch = head_ref + strlen("refs/heads/");
+		current_branch_len = strlen(current_branch);
+	}
+	git_config(handle_config);
+}
+
+static struct refspec *parse_ref_spec(int nr_refspec, const char **refspec)
+{
+	int i;
+	struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
+	for (i = 0; i < nr_refspec; i++) {
+		const char *sp, *ep, *gp;
+		sp = refspec[i];
+		if (*sp == '+') {
+			rs[i].force = 1;
+			sp++;
+		}
+		gp = strchr(sp, '*');
+		ep = strchr(sp, ':');
+		if (gp && ep && gp > ep)
+			gp = NULL;
+		if (ep) {
+			if (ep[1]) {
+				const char *glob = strchr(ep + 1, '*');
+				if (!glob)
+					gp = NULL;
+				if (gp)
+					rs[i].dst = xstrndup(ep + 1,
+							     glob - ep - 1);
+				else
+					rs[i].dst = xstrdup(ep + 1);
+			}
+		} else {
+			ep = sp + strlen(sp);
+		}
+		if (gp) {
+			rs[i].pattern = 1;
+			ep = gp;
+		}
+		rs[i].src = xstrndup(sp, ep - sp);
+	}
+	return rs;
+}
+
+struct remote *remote_get(const char *name)
+{
+	struct remote *ret;
+
+	read_config();
+	if (!name)
+		name = default_remote_name;
+	ret = make_remote(name, 0);
+	if (name[0] != '/') {
+		if (!ret->uri)
+			read_remotes_file(ret);
+		if (!ret->uri)
+			read_branches_file(ret);
+	}
+	if (!ret->uri)
+		add_uri(ret, name);
+	if (!ret->uri)
+		return NULL;
+	ret->fetch = parse_ref_spec(ret->fetch_refspec_nr, ret->fetch_refspec);
+	ret->push = parse_ref_spec(ret->push_refspec_nr, ret->push_refspec);
+	return ret;
+}
+
+int remote_has_uri(struct remote *remote, const char *uri)
+{
+	int i;
+	for (i = 0; i < remote->uri_nr; i++) {
+		if (!strcmp(remote->uri[i], uri))
+			return 1;
+	}
+	return 0;
+}
+
+int remote_find_tracking(struct remote *remote, struct refspec *refspec)
+{
+	int i;
+	for (i = 0; i < remote->fetch_refspec_nr; i++) {
+		struct refspec *fetch = &remote->fetch[i];
+		if (!fetch->dst)
+			continue;
+		if (fetch->pattern) {
+			if (!prefixcmp(refspec->src, fetch->src)) {
+				refspec->dst =
+					xmalloc(strlen(fetch->dst) +
+						strlen(refspec->src) -
+						strlen(fetch->src) + 1);
+				strcpy(refspec->dst, fetch->dst);
+				strcpy(refspec->dst + strlen(fetch->dst),
+				       refspec->src + strlen(fetch->src));
+				refspec->force = fetch->force;
+				return 0;
+			}
+		} else {
+			if (!strcmp(refspec->src, fetch->src)) {
+				refspec->dst = xstrdup(fetch->dst);
+				refspec->force = fetch->force;
+				return 0;
+			}
+		}
+	}
+	refspec->dst = NULL;
+	return -1;
+}
+
+static int count_refspec_match(const char *pattern,
+			       struct ref *refs,
+			       struct ref **matched_ref)
+{
+	int patlen = strlen(pattern);
+	struct ref *matched_weak = NULL;
+	struct ref *matched = NULL;
+	int weak_match = 0;
+	int match = 0;
+
+	for (weak_match = match = 0; refs; refs = refs->next) {
+		char *name = refs->name;
+		int namelen = strlen(name);
+		int weak_match;
+
+		if (namelen < patlen ||
+		    memcmp(name + namelen - patlen, pattern, patlen))
+			continue;
+		if (namelen != patlen && name[namelen - patlen - 1] != '/')
+			continue;
+
+		/* A match is "weak" if it is with refs outside
+		 * heads or tags, and did not specify the pattern
+		 * in full (e.g. "refs/remotes/origin/master") or at
+		 * least from the toplevel (e.g. "remotes/origin/master");
+		 * otherwise "git push $URL master" would result in
+		 * ambiguity between remotes/origin/master and heads/master
+		 * at the remote site.
+		 */
+		if (namelen != patlen &&
+		    patlen != namelen - 5 &&
+		    prefixcmp(name, "refs/heads/") &&
+		    prefixcmp(name, "refs/tags/")) {
+			/* We want to catch the case where only weak
+			 * matches are found and there are multiple
+			 * matches, and where more than one strong
+			 * matches are found, as ambiguous.  One
+			 * strong match with zero or more weak matches
+			 * are acceptable as a unique match.
+			 */
+			matched_weak = refs;
+			weak_match++;
+		}
+		else {
+			matched = refs;
+			match++;
+		}
+	}
+	if (!matched) {
+		*matched_ref = matched_weak;
+		return weak_match;
+	}
+	else {
+		*matched_ref = matched;
+		return match;
+	}
+}
+
+static void link_dst_tail(struct ref *ref, struct ref ***tail)
+{
+	**tail = ref;
+	*tail = &ref->next;
+	**tail = NULL;
+}
+
+static struct ref *try_explicit_object_name(const char *name)
+{
+	unsigned char sha1[20];
+	struct ref *ref;
+	int len;
+
+	if (!*name) {
+		ref = xcalloc(1, sizeof(*ref) + 20);
+		strcpy(ref->name, "(delete)");
+		hashclr(ref->new_sha1);
+		return ref;
+	}
+	if (get_sha1(name, sha1))
+		return NULL;
+	len = strlen(name) + 1;
+	ref = xcalloc(1, sizeof(*ref) + len);
+	memcpy(ref->name, name, len);
+	hashcpy(ref->new_sha1, sha1);
+	return ref;
+}
+
+static int match_explicit_refs(struct ref *src, struct ref *dst,
+			       struct ref ***dst_tail, struct refspec *rs,
+			       int rs_nr)
+{
+	int i, errs;
+	for (i = errs = 0; i < rs_nr; i++) {
+		struct ref *matched_src, *matched_dst;
+
+		const char *dst_value = rs[i].dst;
+
+		if (rs[i].pattern)
+			continue;
+
+		if (dst_value == NULL)
+			dst_value = rs[i].src;
+
+		matched_src = matched_dst = NULL;
+		switch (count_refspec_match(rs[i].src, src, &matched_src)) {
+		case 1:
+			break;
+		case 0:
+			/* The source could be in the get_sha1() format
+			 * not a reference name.  :refs/other is a
+			 * way to delete 'other' ref at the remote end.
+			 */
+			matched_src = try_explicit_object_name(rs[i].src);
+			if (matched_src)
+				break;
+			errs = 1;
+			error("src refspec %s does not match any.",
+			      rs[i].src);
+			break;
+		default:
+			errs = 1;
+			error("src refspec %s matches more than one.",
+			      rs[i].src);
+			break;
+		}
+		switch (count_refspec_match(dst_value, dst, &matched_dst)) {
+		case 1:
+			break;
+		case 0:
+			if (!memcmp(dst_value, "refs/", 5)) {
+				int len = strlen(dst_value) + 1;
+				matched_dst = xcalloc(1, sizeof(*dst) + len);
+				memcpy(matched_dst->name, dst_value, len);
+				link_dst_tail(matched_dst, dst_tail);
+			}
+			else if (!strcmp(rs[i].src, dst_value) &&
+				 matched_src) {
+				/* pushing "master:master" when
+				 * remote does not have master yet.
+				 */
+				int len = strlen(matched_src->name) + 1;
+				matched_dst = xcalloc(1, sizeof(*dst) + len);
+				memcpy(matched_dst->name, matched_src->name,
+				       len);
+				link_dst_tail(matched_dst, dst_tail);
+			}
+			else {
+				errs = 1;
+				error("dst refspec %s does not match any "
+				      "existing ref on the remote and does "
+				      "not start with refs/.", dst_value);
+			}
+			break;
+		default:
+			errs = 1;
+			error("dst refspec %s matches more than one.",
+			      dst_value);
+			break;
+		}
+		if (errs)
+			continue;
+		if (matched_dst->peer_ref) {
+			errs = 1;
+			error("dst ref %s receives from more than one src.",
+			      matched_dst->name);
+		}
+		else {
+			matched_dst->peer_ref = matched_src;
+			matched_dst->force = rs[i].force;
+		}
+	}
+	return -errs;
+}
+
+static struct ref *find_ref_by_name(struct ref *list, const char *name)
+{
+	for ( ; list; list = list->next)
+		if (!strcmp(list->name, name))
+			return list;
+	return NULL;
+}
+
+static int check_pattern_match(struct refspec *rs, int rs_nr, struct ref *src)
+{
+	int i;
+	if (!rs_nr)
+		return 1;
+	for (i = 0; i < rs_nr; i++) {
+		if (rs[i].pattern && !prefixcmp(src->name, rs[i].src))
+			return 1;
+	}
+	return 0;
+}
+
+int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
+	       int nr_refspec, char **refspec, int all)
+{
+	struct refspec *rs =
+		parse_ref_spec(nr_refspec, (const char **) refspec);
+
+	if (match_explicit_refs(src, dst, dst_tail, rs, nr_refspec))
+		return -1;
+
+	/* pick the remainder */
+	for ( ; src; src = src->next) {
+		struct ref *dst_peer;
+		if (src->peer_ref)
+			continue;
+		if (!check_pattern_match(rs, nr_refspec, src))
+			continue;
+
+		dst_peer = find_ref_by_name(dst, src->name);
+		if (dst_peer && dst_peer->peer_ref)
+			/* We're already sending something to this ref. */
+			continue;
+		if (!dst_peer && !nr_refspec && !all)
+			/* Remote doesn't have it, and we have no
+			 * explicit pattern, and we don't have
+			 * --all. */
+			continue;
+		if (!dst_peer) {
+			/* Create a new one and link it */
+			int len = strlen(src->name) + 1;
+			dst_peer = xcalloc(1, sizeof(*dst_peer) + len);
+			memcpy(dst_peer->name, src->name, len);
+			hashcpy(dst_peer->new_sha1, src->new_sha1);
+			link_dst_tail(dst_peer, dst_tail);
+		}
+		dst_peer->peer_ref = src;
+	}
+	return 0;
+}