1 files changed, 272 insertions, 0 deletions
diff --git a/src/libgit2/grafts.c b/src/libgit2/grafts.c
new file mode 100644
index 000000000..1d9373a56
--- /dev/null
+++ b/src/libgit2/grafts.c
@@ -0,0 +1,272 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "grafts.h"
+
+#include "futils.h"
+#include "oid.h"
+#include "oidarray.h"
+#include "parse.h"
+
+struct git_grafts {
+	/* Map of `git_commit_graft`s */
+	git_oidmap *commits;
+
+	/* Type of object IDs */
+	git_oid_t oid_type;
+
+	/* File backing the graft. NULL if it's an in-memory graft */
+	char *path;
+	unsigned char path_checksum[GIT_HASH_SHA256_SIZE];
+};
+
+int git_grafts_new(git_grafts **out, git_oid_t oid_type)
+{
+	git_grafts *grafts;
+
+	GIT_ASSERT_ARG(out && oid_type);
+
+	grafts = git__calloc(1, sizeof(*grafts));
+	GIT_ERROR_CHECK_ALLOC(grafts);
+
+	if ((git_oidmap_new(&grafts->commits)) < 0) {
+		git__free(grafts);
+		return -1;
+	}
+
+	grafts->oid_type = oid_type;
+
+	*out = grafts;
+	return 0;
+}
+
+int git_grafts_open(
+	git_grafts **out,
+	const char *path,
+	git_oid_t oid_type)
+{
+	git_grafts *grafts = NULL;
+	int error;
+
+	GIT_ASSERT_ARG(out && path && oid_type);
+
+	if ((error = git_grafts_new(&grafts, oid_type)) < 0)
+		goto error;
+
+	grafts->path = git__strdup(path);
+	GIT_ERROR_CHECK_ALLOC(grafts->path);
+
+	if ((error = git_grafts_refresh(grafts)) < 0)
+		goto error;
+
+	*out = grafts;
+
+error:
+	if (error < 0)
+		git_grafts_free(grafts);
+
+	return error;
+}
+
+int git_grafts_open_or_refresh(
+	git_grafts **out,
+	const char *path,
+	git_oid_t oid_type)
+{
+	GIT_ASSERT_ARG(out && path && oid_type);
+
+	return *out ? git_grafts_refresh(*out) : git_grafts_open(out, path, oid_type);
+}
+
+void git_grafts_free(git_grafts *grafts)
+{
+	if (!grafts)
+		return;
+	git__free(grafts->path);
+	git_grafts_clear(grafts);
+	git_oidmap_free(grafts->commits);
+	git__free(grafts);
+}
+
+void git_grafts_clear(git_grafts *grafts)
+{
+	git_commit_graft *graft;
+
+	if (!grafts)
+		return;
+
+	git_oidmap_foreach_value(grafts->commits, graft, {
+		git__free(graft->parents.ptr);
+		git__free(graft);
+	});
+
+	git_oidmap_clear(grafts->commits);
+}
+
+int git_grafts_refresh(git_grafts *grafts)
+{
+	git_str contents = GIT_STR_INIT;
+	int error, updated = 0;
+
+	GIT_ASSERT_ARG(grafts);
+
+	if (!grafts->path)
+		return 0;
+
+	if ((error = git_futils_readbuffer_updated(&contents, grafts->path,
+				grafts->path_checksum, &updated)) < 0) {
+
+		if (error == GIT_ENOTFOUND) {
+			git_grafts_clear(grafts);
+			error = 0;
+		}
+
+		goto cleanup;
+	}
+
+	if (!updated) {
+		goto cleanup;
+	}
+
+	if ((error = git_grafts_parse(grafts, contents.ptr, contents.size)) < 0)
+		goto cleanup;
+
+cleanup:
+	git_str_dispose(&contents);
+	return error;
+}
+
+int git_grafts_parse(git_grafts *grafts, const char *buf, size_t len)
+{
+	git_array_oid_t parents = GIT_ARRAY_INIT;
+	git_parse_ctx parser;
+	int error;
+
+	git_grafts_clear(grafts);
+
+	if ((error = git_parse_ctx_init(&parser, buf, len)) < 0)
+		goto error;
+
+	for (; parser.remain_len; git_parse_advance_line(&parser)) {
+		git_oid graft_oid;
+
+		if ((error = git_parse_advance_oid(&graft_oid, &parser, grafts->oid_type)) < 0) {
+			git_error_set(GIT_ERROR_GRAFTS, "invalid graft OID at line %" PRIuZ, parser.line_num);
+			goto error;
+		}
+
+		while (parser.line_len && git_parse_advance_expected(&parser, "\n", 1) != 0) {
+			git_oid *id = git_array_alloc(parents);
+			GIT_ERROR_CHECK_ALLOC(id);
+
+			if ((error = git_parse_advance_expected(&parser, " ", 1)) < 0 ||
+			    (error = git_parse_advance_oid(id, &parser, grafts->oid_type)) < 0) {
+				git_error_set(GIT_ERROR_GRAFTS, "invalid parent OID at line %" PRIuZ, parser.line_num);
+				goto error;
+			}
+		}
+
+		if ((error = git_grafts_add(grafts, &graft_oid, parents)) < 0)
+			goto error;
+
+		git_array_clear(parents);
+	}
+
+error:
+	git_array_clear(parents);
+	return error;
+}
+
+int git_grafts_add(git_grafts *grafts, const git_oid *oid, git_array_oid_t parents)
+{
+	git_commit_graft *graft;
+	git_oid *parent_oid;
+	int error;
+	size_t i;
+
+	GIT_ASSERT_ARG(grafts && oid);
+
+	graft = git__calloc(1, sizeof(*graft));
+	GIT_ERROR_CHECK_ALLOC(graft);
+
+	git_array_init_to_size(graft->parents, git_array_size(parents));
+	git_array_foreach(parents, i, parent_oid) {
+		git_oid *id = git_array_alloc(graft->parents);
+		GIT_ERROR_CHECK_ALLOC(id);
+
+		git_oid_cpy(id, parent_oid);
+	}
+	git_oid_cpy(&graft->oid, oid);
+
+	if ((error = git_grafts_remove(grafts, &graft->oid)) < 0 && error != GIT_ENOTFOUND)
+		goto cleanup;
+
+	if ((error = git_oidmap_set(grafts->commits, &graft->oid, graft)) < 0)
+		goto cleanup;
+
+	return 0;
+
+cleanup:
+	git_array_clear(graft->parents);
+	git__free(graft);
+	return error;
+}
+
+int git_grafts_remove(git_grafts *grafts, const git_oid *oid)
+{
+	git_commit_graft *graft;
+	int error;
+
+	GIT_ASSERT_ARG(grafts && oid);
+
+	if ((graft = git_oidmap_get(grafts->commits, oid)) == NULL)
+		return GIT_ENOTFOUND;
+
+	if ((error = git_oidmap_delete(grafts->commits, oid)) < 0)
+		return error;
+
+	git__free(graft->parents.ptr);
+	git__free(graft);
+
+	return 0;
+}
+
+int git_grafts_get(git_commit_graft **out, git_grafts *grafts, const git_oid *oid)
+{
+	GIT_ASSERT_ARG(out && grafts && oid);
+	if ((*out = git_oidmap_get(grafts->commits, oid)) == NULL)
+		return GIT_ENOTFOUND;
+	return 0;
+}
+
+int git_grafts_oids(git_oid **out, size_t *out_len, git_grafts *grafts)
+{
+	git_array_oid_t array = GIT_ARRAY_INIT;
+	const git_oid *oid;
+	size_t existing, i = 0;
+
+	GIT_ASSERT_ARG(out && grafts);
+
+	if ((existing = git_oidmap_size(grafts->commits)) > 0)
+		git_array_init_to_size(array, existing);
+
+	while (git_oidmap_iterate(NULL, grafts->commits, &i, &oid) == 0) {
+		git_oid *cpy = git_array_alloc(array);
+		GIT_ERROR_CHECK_ALLOC(cpy);
+		git_oid_cpy(cpy, oid);
+	}
+
+	*out = array.ptr;
+	*out_len = array.size;
+
+	return 0;
+}
+
+size_t git_grafts_size(git_grafts *grafts)
+{
+	return git_oidmap_size(grafts->commits);
+}