branch: add git_branch_foreach()

include/git2/branch.h

@@ -96,6 +96,31 @@ GIT_EXTERN(int) git_branch_list(
 		unsigned int list_flags);
 
 /**
+ * Loop over all the branches and issue a callback for each one.
+ *
+ * @param repo Repository where to find the branches.
+ *
+ * @param list_flags Filtering flags for the branch
+ * listing. Valid values are GIT_BRANCH_LOCAL, GIT_BRANCH_REMOTE
+ * or a combination of the two.
+ *
+ * @param branch_cb Callback to invoke per found branch.
+ *
+ * @param payload Extra parameter to callback function.
+ *
+ * @return 0 or an error code.
+ */
+GIT_EXTERN(int) git_branch_foreach(
+		git_repository *repo,
+		unsigned int list_flags,
+		int (*branch_cb)(
+			const char *branch_name,
+			git_branch_t branch_type,
+			void *payload),
+		void *payload
+);
+
+/**
  * Move/rename an existing branch reference.
  *
  * @param repo Repository where lives the branch.

src/branch.c

@@ -183,6 +183,49 @@ int git_branch_list(git_strarray *branch_names, git_repository *repo, unsigned i
 	return 0;
 }
 
+typedef struct {
+	int (*branch_cb)(
+			const char *branch_name,
+			git_branch_t branch_type,
+			void *payload);
+	void *callback_payload;
+	unsigned int branch_type;
+} branch_foreach_filter;
+
+static int branch_foreach_cb(const char *branch_name, void *payload)
+{
+	branch_foreach_filter *filter = (branch_foreach_filter *)payload;
+
+	if (filter->branch_type & GIT_BRANCH_LOCAL &&
+		git__prefixcmp(branch_name, GIT_REFS_HEADS_DIR) == 0)
+		return filter->branch_cb(branch_name + strlen(GIT_REFS_HEADS_DIR), GIT_BRANCH_LOCAL, filter->callback_payload);
+
+	if (filter->branch_type & GIT_BRANCH_REMOTE &&
+		git__prefixcmp(branch_name, GIT_REFS_REMOTES_DIR) == 0)
+		return filter->branch_cb(branch_name + strlen(GIT_REFS_REMOTES_DIR), GIT_BRANCH_REMOTE, filter->callback_payload);
+
+	return 0;
+}
+
+int git_branch_foreach(
+		git_repository *repo,
+		unsigned int list_flags,
+		int (*branch_cb)(
+			const char *branch_name,
+			git_branch_t branch_type,
+			void *payload),
+		void *payload
+)
+{
+	branch_foreach_filter filter;
+
+	filter.branch_cb = branch_cb;
+	filter.branch_type = list_flags;
+	filter.callback_payload = payload;
+
+	return git_reference_foreach(repo, GIT_REF_LISTALL, &branch_foreach_cb, (void *)&filter);
+}
+
 int git_branch_move(git_repository *repo, const char *old_branch_name, const char *new_branch_name, int force)
 {
 	git_reference *reference = NULL;

tests-clar/refs/branches/foreach.c

+#include "clar_libgit2.h"
+#include "refs.h"
+#include "branch.h"
+
+static git_repository *repo;
+static git_reference *fake_remote;
+
+void test_refs_branches_foreach__initialize(void)
+{
+	git_oid id;
+
+	cl_fixture_sandbox("testrepo.git");
+	cl_git_pass(git_repository_open(&repo, "testrepo.git"));
+
+	cl_git_pass(git_oid_fromstr(&id, "be3563ae3f795b2b4353bcce3a527ad0a4f7f644"));
+	cl_git_pass(git_reference_create_oid(&fake_remote, repo, "refs/remotes/nulltoken/master", &id, 0));
+}
+
+void test_refs_branches_foreach__cleanup(void)
+{
+	git_reference_free(fake_remote);
+	git_repository_free(repo);
+
+	cl_fixture_cleanup("testrepo.git");
+}
+
+static int count_branch_list_cb(const char *branch_name, git_branch_t branch_type, void *payload)
+{
+	int *count = (int *)payload;
+
+	(*count)++;
+
+	return 0;
+}
+
+static void assert_retrieval(unsigned int flags, unsigned int expected_count)
+{
+	int count = 0;
+
+	cl_git_pass(git_branch_foreach(repo, flags, count_branch_list_cb, &count));
+
+	cl_assert_equal_i(expected_count, count);
+}
+
+void test_refs_branches_foreach__retrieve_all_branches(void)
+{
+	assert_retrieval(GIT_BRANCH_LOCAL | GIT_BRANCH_REMOTE, 9);
+}
+
+void test_refs_branches_foreach__retrieve_remote_branches(void)
+{
+	assert_retrieval(GIT_BRANCH_REMOTE, 2);
+}
+
+void test_refs_branches_foreach__retrieve_local_branches(void)
+{
+	assert_retrieval(GIT_BRANCH_LOCAL, 7);
+}
+
+struct expectations {
+	const char *branch_name;
+	int encounters;
+};
+
+static void assert_branch_has_been_found(struct expectations *findings, const char* expected_branch_name)
+{
+	int pos = 0;
+
+	while (findings[pos].branch_name)
+	{
+		if (strcmp(expected_branch_name, findings[pos].branch_name) == 0) {
+			cl_assert_equal_i(1, findings[pos].encounters);
+			return;
+		}
+
+		pos++;
+	}
+
+	cl_fail("expected branch not found in list.");
+}
+
+static int contains_branch_list_cb(const char *branch_name, git_branch_t branch_type, void *payload)
+{
+	int pos = 0;
+
+	struct expectations *exp = (struct expectations *)payload;
+
+	while (exp[pos].branch_name)
+	{
+		if (strcmp(branch_name, exp[pos].branch_name) == 0)
+			exp[pos].encounters++;
+		
+		pos++;
+	}
+
+	return 0;
+}
+
+/*
+ * $ git branch -r
+ *  nulltoken/HEAD -> nulltoken/master
+ *  nulltoken/master
+ */
+void test_refs_branches_foreach__retrieve_remote_symbolic_HEAD_when_present(void)
+{
+	struct expectations exp[] = {
+		{ "nulltoken/HEAD", 0 },
+		{ "nulltoken/master", 0 },
+		{ NULL, 0 }
+	};
+
+	git_reference_free(fake_remote);
+	cl_git_pass(git_reference_create_symbolic(&fake_remote, repo, "refs/remotes/nulltoken/HEAD", "refs/remotes/nulltoken/master", 0));
+
+	assert_retrieval(GIT_BRANCH_REMOTE, 3);
+
+	cl_git_pass(git_branch_foreach(repo, GIT_BRANCH_REMOTE, contains_branch_list_cb, &exp));
+
+	assert_branch_has_been_found(exp, "nulltoken/HEAD");
+	assert_branch_has_been_found(exp, "nulltoken/HEAD");
+}