Migrate ODB files to new error handling

This migrates odb.c, odb_loose.c, odb_pack.c and pack.c to
the new style of error handling.  Also got the unix and win32
versions of map.c.  There are some minor changes to other
files but no others were completely converted.

This also contains an update to filebuf so that a zeroed out
filebuf will not think that the fd (== 0) is actually open
(and inadvertently call close() on fd 0 if cleaned up).

Lastly, this was built and tested on win32 and contains a
bunch of fixes for the win32 build which was pretty broken.

1 files changed, 70 insertions, 88 deletions

diff --git a/src/odb_pack.c b/src/odb_pack.c
index 159c88685..7add3718a 100644
--- a/src/odb_pack.c
+++ b/src/odb_pack.c
@@ -137,19 +137,19 @@ static int packfile_load__cb(void *_data, git_buf *path);
 static int packfile_refresh_all(struct pack_backend *backend);
 
 static int pack_entry_find(struct git_pack_entry *e,
-		struct pack_backend *backend, const git_oid *oid);
+	struct pack_backend *backend, const git_oid *oid);
 
 /* Can find the offset of an object given
  * a prefix of an identifier.
- * Throws GIT_EAMBIGUOUSOIDPREFIX if short oid
- * is ambiguous.
+ * Sets GIT_EAMBIGUOUS if short oid is ambiguous.
  * This method assumes that len is between
  * GIT_OID_MINPREFIXLEN and GIT_OID_HEXSZ.
  */
-static int pack_entry_find_prefix(struct git_pack_entry *e,
-					struct pack_backend *backend,
-					const git_oid *short_oid,
-					unsigned int len);
+static int pack_entry_find_prefix(
+	struct git_pack_entry *e,
+	struct pack_backend *backend,
+	const git_oid *short_oid,
+	unsigned int len);
 
 
 
@@ -215,27 +215,22 @@ static int packfile_load__cb(void *_data, git_buf *path)
 	size_t i;
 
 	if (git__suffixcmp(path->ptr, ".idx") != 0)
-		return GIT_SUCCESS; /* not an index */
+		return 0; /* not an index */
 
 	for (i = 0; i < backend->packs.length; ++i) {
 		struct git_pack_file *p = git_vector_get(&backend->packs, i);
 		if (memcmp(p->pack_name, path->ptr, path->size - strlen(".idx")) == 0)
-			return GIT_SUCCESS;
+			return 0;
 	}
 
 	error = git_packfile_check(&pack, path->ptr);
-	if (error == GIT_ENOTFOUND) {
+	if (error == GIT_ENOTFOUND)
 		/* ignore missing .pack file as git does */
 		return GIT_SUCCESS;
-	} else if (error < GIT_SUCCESS)
-		return git__rethrow(error, "Failed to load packfile");
-
-	if (git_vector_insert(&backend->packs, pack) < GIT_SUCCESS) {
-		git__free(pack);
-		return GIT_ENOMEM;
-	}
+	else if (error < 0)
+		return error;
 
-	return GIT_SUCCESS;
+	return git_vector_insert(&backend->packs, pack);
 }
 
 static int packfile_refresh_all(struct pack_backend *backend)
@@ -244,10 +239,10 @@ static int packfile_refresh_all(struct pack_backend *backend)
 	struct stat st;
 
 	if (backend->pack_folder == NULL)
-		return GIT_SUCCESS;
+		return 0;
 
 	if (p_stat(backend->pack_folder, &st) < 0 || !S_ISDIR(st.st_mode))
-		return git__throw(GIT_ENOTFOUND, "Failed to refresh packfiles. Backend not found");
+		return git_odb__error_notfound("failed to refresh packfiles");
 
 	if (st.st_mtime != backend->pack_folder_mtime) {
 		git_buf path = GIT_BUF_INIT;
@@ -257,14 +252,15 @@ static int packfile_refresh_all(struct pack_backend *backend)
 		error = git_path_direach(&path, packfile_load__cb, (void *)backend);
 
 		git_buf_free(&path);
-		if (error < GIT_SUCCESS)
-			return git__rethrow(error, "Failed to refresh packfiles");
+
+		if (error < 0)
+			return error;
 
 		git_vector_sort(&backend->packs);
 		backend->pack_folder_mtime = st.st_mtime;
 	}
 
-	return GIT_SUCCESS;
+	return 0;
 }
 
 static int pack_entry_find(struct git_pack_entry *e, struct pack_backend *backend, const git_oid *oid)
@@ -272,12 +268,12 @@ static int pack_entry_find(struct git_pack_entry *e, struct pack_backend *backen
 	int error;
 	size_t i;
 
-	if ((error = packfile_refresh_all(backend)) < GIT_SUCCESS)
-		return git__rethrow(error, "Failed to find pack entry");
+	if ((error = packfile_refresh_all(backend)) < 0)
+		return error;
 
 	if (backend->last_found &&
-		git_pack_entry_find(e, backend->last_found, oid, GIT_OID_HEXSZ) == GIT_SUCCESS)
-		return GIT_SUCCESS;
+		git_pack_entry_find(e, backend->last_found, oid, GIT_OID_HEXSZ) == 0)
+		return 0;
 
 	for (i = 0; i < backend->packs.length; ++i) {
 		struct git_pack_file *p;
@@ -286,13 +282,13 @@ static int pack_entry_find(struct git_pack_entry *e, struct pack_backend *backen
 		if (p == backend->last_found)
 			continue;
 
-		if (git_pack_entry_find(e, p, oid, GIT_OID_HEXSZ) == GIT_SUCCESS) {
+		if (git_pack_entry_find(e, p, oid, GIT_OID_HEXSZ) == 0) {
 			backend->last_found = p;
-			return GIT_SUCCESS;
+			return 0;
 		}
 	}
 
-	return git__throw(GIT_ENOTFOUND, "Failed to find pack entry");
+	return git_odb__error_notfound("failed to find pack entry");
 }
 
 static int pack_entry_find_prefix(
@@ -305,16 +301,15 @@ static int pack_entry_find_prefix(
 	size_t i;
 	unsigned found = 0;
 
-	if ((error = packfile_refresh_all(backend)) < GIT_SUCCESS)
-		return git__rethrow(error, "Failed to find pack entry");
+	if ((error = packfile_refresh_all(backend)) < 0)
+		return error;
 
 	if (backend->last_found) {
 		error = git_pack_entry_find(e, backend->last_found, short_oid, len);
-		if (error == GIT_EAMBIGUOUSOIDPREFIX) {
-			return git__rethrow(error, "Failed to find pack entry. Ambiguous sha1 prefix");
-		} else if (error == GIT_SUCCESS) {
+		if (error == GIT_EAMBIGUOUS)
+			return error;
+		if (!error)
 			found = 1;
-		}
 	}
 
 	for (i = 0; i < backend->packs.length; ++i) {
@@ -325,24 +320,21 @@ static int pack_entry_find_prefix(
 			continue;
 
 		error = git_pack_entry_find(e, p, short_oid, len);
-		if (error == GIT_EAMBIGUOUSOIDPREFIX) {
-			return git__rethrow(error, "Failed to find pack entry. Ambiguous sha1 prefix");
-		} else if (error == GIT_SUCCESS) {
-			found++;
-			if (found > 1)
+		if (error == GIT_EAMBIGUOUS)
+			return error;
+		if (!error) {
+			if (++found > 1)
 				break;
 			backend->last_found = p;
 		}
 	}
 
-	if (!found) {
-		return git__rethrow(GIT_ENOTFOUND, "Failed to find pack entry");
-	} else if (found > 1) {
-		return git__rethrow(GIT_EAMBIGUOUSOIDPREFIX, "Failed to find pack entry. Ambiguous sha1 prefix");
-	} else {
-		return GIT_SUCCESS;
-	}
-
+	if (!found)
+		return git_odb__error_notfound("failed to find pack entry");
+	else if (found > 1)
+		return git_odb__error_ambiguous("found multiple pack entries");
+	else
+		return 0;
 }
 
 
@@ -374,17 +366,15 @@ static int pack_backend__read(void **buffer_p, size_t *len_p, git_otype *type_p,
 	git_rawobj raw;
 	int error;
 
-	if ((error = pack_entry_find(&e, (struct pack_backend *)backend, oid)) < GIT_SUCCESS)
-		return git__rethrow(error, "Failed to read pack backend");
-
-	if ((error = git_packfile_unpack(&raw, e.p, &e.offset)) < GIT_SUCCESS)
-		return git__rethrow(error, "Failed to read pack backend");
+	if ((error = pack_entry_find(&e, (struct pack_backend *)backend, oid)) < 0 ||
+		(error = git_packfile_unpack(&raw, e.p, &e.offset)) < 0)
+		return error;
 
 	*buffer_p = raw.data;
 	*len_p = raw.len;
 	*type_p = raw.type;
 
-	return GIT_SUCCESS;
+	return 0;
 }
 
 static int pack_backend__read_prefix(
@@ -396,40 +386,38 @@ static int pack_backend__read_prefix(
 	const git_oid *short_oid,
 	unsigned int len)
 {
+	int error = 0;
+
 	if (len < GIT_OID_MINPREFIXLEN)
-		return git__throw(GIT_EAMBIGUOUSOIDPREFIX, "Failed to read pack backend. Prefix length is lower than %d.", GIT_OID_MINPREFIXLEN);
+		error = git_odb__error_ambiguous("prefix length too short");
 
-	if (len >= GIT_OID_HEXSZ) {
+	else if (len >= GIT_OID_HEXSZ) {
 		/* We can fall back to regular read method */
-		int error = pack_backend__read(buffer_p, len_p, type_p, backend, short_oid);
-		if (error == GIT_SUCCESS)
+		error = pack_backend__read(buffer_p, len_p, type_p, backend, short_oid);
+		if (!error)
 			git_oid_cpy(out_oid, short_oid);
-
-		return error;
 	} else {
 		struct git_pack_entry e;
 		git_rawobj raw;
-		int error;
-
-		if ((error = pack_entry_find_prefix(&e, (struct pack_backend *)backend, short_oid, len)) < GIT_SUCCESS)
-			return git__rethrow(error, "Failed to read pack backend");
 
-		if ((error = git_packfile_unpack(&raw, e.p, &e.offset)) < GIT_SUCCESS)
-			return git__rethrow(error, "Failed to read pack backend");
-
-		*buffer_p = raw.data;
-		*len_p = raw.len;
-		*type_p = raw.type;
-		git_oid_cpy(out_oid, &e.sha1);
+		if ((error = pack_entry_find_prefix(
+				&e, (struct pack_backend *)backend, short_oid, len)) == 0 &&
+			(error = git_packfile_unpack(&raw, e.p, &e.offset)) == 0)
+		{
+			*buffer_p = raw.data;
+			*len_p = raw.len;
+			*type_p = raw.type;
+			git_oid_cpy(out_oid, &e.sha1);
+		}
 	}
 
-	return GIT_SUCCESS;
+	return error;
 }
 
 static int pack_backend__exists(git_odb_backend *backend, const git_oid *oid)
 {
 	struct git_pack_entry e;
-	return pack_entry_find(&e, (struct pack_backend *)backend, oid) == GIT_SUCCESS;
+	return pack_entry_find(&e, (struct pack_backend *)backend, oid) == 0;
 }
 
 static void pack_backend__free(git_odb_backend *_backend)
@@ -455,19 +443,16 @@ int git_odb_backend_pack(git_odb_backend **backend_out, const char *objects_dir)
 {
 	struct pack_backend *backend = NULL;
 	git_buf path = GIT_BUF_INIT;
-	int error = GIT_SUCCESS;
 
 	backend = git__calloc(1, sizeof(struct pack_backend));
-	if (backend == NULL)
-		return GIT_ENOMEM;
-
-	error = git_vector_init(&backend->packs, 8, packfile_sort__cb);
-	if (error < GIT_SUCCESS)
-		goto cleanup;
+	GITERR_CHECK_ALLOC(backend);
 
-	error = git_buf_joinpath(&path, objects_dir, "pack");
-	if (error < GIT_SUCCESS)
-		goto cleanup;
+	if (git_vector_init(&backend->packs, 8, packfile_sort__cb) < 0 ||
+		git_buf_joinpath(&path, objects_dir, "pack") < 0)
+	{
+		git__free(backend);
+		return -1;
+	}
 
 	if (git_path_isdir(git_buf_cstr(&path)) == true) {
 		backend->pack_folder = git_buf_detach(&path);
@@ -482,10 +467,7 @@ int git_odb_backend_pack(git_odb_backend **backend_out, const char *objects_dir)
 
 	*backend_out = (git_odb_backend *)backend;
 
-cleanup:
-	if (error < GIT_SUCCESS)
-		git__free(backend);
 	git_buf_free(&path);
 
-	return error;
+	return 0;
 }