str: introduce `git_str` for internal, `git_buf` is externalethomson/gitstr

libgit2 has two distinct requirements that were previously solved by
`git_buf`.  We require:

1. A general purpose string class that provides a number of utility APIs
   for manipulating data (eg, concatenating, truncating, etc).
2. A structure that we can use to return strings to callers that they
   can take ownership of.

By using a single class (`git_buf`) for both of these purposes, we have
confused the API to the point that refactorings are difficult and
reasoning about correctness is also difficult.

Move the utility class `git_buf` to be called `git_str`: this represents
its general purpose, as an internal string buffer class.  The name also
is an homage to Junio Hamano ("gitstr").

The public API remains `git_buf`, and has a much smaller footprint.  It
is generally only used as an "out" param with strict requirements that
follow the documentation.  (Exceptions exist for some legacy APIs to
avoid breaking callers unnecessarily.)

Utility functions exist to convert a user-specified `git_buf` to a
`git_str` so that we can call internal functions, then converting it
back again.

1 files changed, 41 insertions, 41 deletions

diff --git a/src/iterator.c b/src/iterator.c
index ce9f305ef..5549c636a 100644
--- a/src/iterator.c
+++ b/src/iterator.c
@@ -424,7 +424,7 @@ typedef struct {
 	git_tree *tree;
 
 	/* path to this particular frame (folder) */
-	git_buf path;
+	git_str path;
 
 	/* a sorted list of the entries for this frame (folder), these are
 	 * actually pointers to the iterator's entry pool.
@@ -441,7 +441,7 @@ typedef struct {
 	 * parent path.
 	 */
 	git_vector similar_trees;
-	git_array_t(git_buf) similar_paths;
+	git_array_t(git_str) similar_paths;
 } tree_iterator_frame;
 
 typedef struct {
@@ -450,7 +450,7 @@ typedef struct {
 	git_array_t(tree_iterator_frame) frames;
 
 	git_index_entry entry;
-	git_buf entry_path;
+	git_str entry_path;
 
 	/* a pool of entries to reduce the number of allocations */
 	git_pool entry_pool;
@@ -508,20 +508,20 @@ static int tree_iterator_entry_sort_icase(const void *ptr_a, const void *ptr_b)
 }
 
 static int tree_iterator_compute_path(
-	git_buf *out,
+	git_str *out,
 	tree_iterator_entry *entry)
 {
-	git_buf_clear(out);
+	git_str_clear(out);
 
 	if (entry->parent_path)
-		git_buf_joinpath(out, entry->parent_path, entry->tree_entry->filename);
+		git_str_joinpath(out, entry->parent_path, entry->tree_entry->filename);
 	else
-		git_buf_puts(out, entry->tree_entry->filename);
+		git_str_puts(out, entry->tree_entry->filename);
 
 	if (git_tree_entry__is_tree(entry->tree_entry))
-		git_buf_putc(out, '/');
+		git_str_putc(out, '/');
 
-	if (git_buf_oom(out))
+	if (git_str_oom(out))
 		return -1;
 
 	return 0;
@@ -601,7 +601,7 @@ GIT_INLINE(int) tree_iterator_frame_push_neighbors(
 	tree_iterator_entry *entry, *new_entry;
 	git_tree *tree = NULL;
 	git_tree_entry *tree_entry;
-	git_buf *path;
+	git_str *path;
 	size_t new_size, i;
 	int error = 0;
 
@@ -621,7 +621,7 @@ GIT_INLINE(int) tree_iterator_frame_push_neighbors(
 		path = git_array_alloc(parent_frame->similar_paths);
 		GIT_ERROR_CHECK_ALLOC(path);
 
-		memset(path, 0, sizeof(git_buf));
+		memset(path, 0, sizeof(git_str));
 
 		if ((error = tree_iterator_compute_path(path, entry)) < 0)
 			break;
@@ -681,7 +681,7 @@ done:
 static int tree_iterator_frame_pop(tree_iterator *iter)
 {
 	tree_iterator_frame *frame;
-	git_buf *buf = NULL;
+	git_str *buf = NULL;
 	git_tree *tree;
 	size_t i;
 
@@ -694,7 +694,7 @@ static int tree_iterator_frame_pop(tree_iterator *iter)
 
 	do {
 		buf = git_array_pop(frame->similar_paths);
-		git_buf_dispose(buf);
+		git_str_dispose(buf);
 	} while (buf != NULL);
 
 	git_array_clear(frame->similar_paths);
@@ -704,7 +704,7 @@ static int tree_iterator_frame_pop(tree_iterator *iter)
 
 	git_vector_free(&frame->similar_trees);
 
-	git_buf_dispose(&frame->path);
+	git_str_dispose(&frame->path);
 
 	return 0;
 }
@@ -892,7 +892,7 @@ static void tree_iterator_clear(tree_iterator *iter)
 	git_array_clear(iter->frames);
 
 	git_pool_clear(&iter->entry_pool);
-	git_buf_clear(&iter->entry_path);
+	git_str_clear(&iter->entry_path);
 
 	iterator_clear(&iter->base);
 }
@@ -925,7 +925,7 @@ static void tree_iterator_free(git_iterator *i)
 	tree_iterator_clear(iter);
 
 	git_tree_free(iter->root);
-	git_buf_dispose(&iter->entry_path);
+	git_str_dispose(&iter->entry_path);
 }
 
 int git_iterator_for_tree(
@@ -1040,11 +1040,11 @@ typedef struct {
 
 	/* info about the current entry */
 	git_index_entry entry;
-	git_buf current_path;
+	git_str current_path;
 	int current_is_ignored;
 
 	/* temporary buffer for advance_over */
-	git_buf tmp_buf;
+	git_str tmp_buf;
 } filesystem_iterator;
 
 
@@ -1266,7 +1266,7 @@ static int filesystem_iterator_entry_hash(
 	filesystem_iterator *iter,
 	filesystem_iterator_entry *entry)
 {
-	git_buf fullpath = GIT_BUF_INIT;
+	git_str fullpath = GIT_STR_INIT;
 	int error;
 
 	if (S_ISDIR(entry->st.st_mode)) {
@@ -1278,11 +1278,11 @@ static int filesystem_iterator_entry_hash(
 		return git_repository_hashfile(&entry->id,
 			iter->base.repo, entry->path, GIT_OBJECT_BLOB, NULL);
 
-	if (!(error = git_buf_joinpath(&fullpath, iter->root, entry->path)) &&
+	if (!(error = git_str_joinpath(&fullpath, iter->root, entry->path)) &&
 	    !(error = git_path_validate_workdir_buf(iter->base.repo, &fullpath)))
 		error = git_odb_hashfile(&entry->id, fullpath.ptr, GIT_OBJECT_BLOB);
 
-	git_buf_dispose(&fullpath);
+	git_str_dispose(&fullpath);
 	return error;
 }
 
@@ -1337,7 +1337,7 @@ static int filesystem_iterator_frame_push(
 {
 	filesystem_iterator_frame *new_frame = NULL;
 	git_path_diriter diriter = GIT_PATH_DIRITER_INIT;
-	git_buf root = GIT_BUF_INIT;
+	git_str root = GIT_STR_INIT;
 	const char *path;
 	filesystem_iterator_entry *entry;
 	struct stat statbuf;
@@ -1356,11 +1356,11 @@ static int filesystem_iterator_frame_push(
 	memset(new_frame, 0, sizeof(filesystem_iterator_frame));
 
 	if (frame_entry)
-		git_buf_joinpath(&root, iter->root, frame_entry->path);
+		git_str_joinpath(&root, iter->root, frame_entry->path);
 	else
-		git_buf_puts(&root, iter->root);
+		git_str_puts(&root, iter->root);
 
-	if (git_buf_oom(&root) ||
+	if (git_str_oom(&root) ||
 	    git_path_validate_workdir_buf(iter->base.repo, &root) < 0) {
 		error = -1;
 		goto done;
@@ -1471,7 +1471,7 @@ done:
 	if (error < 0)
 		git_array_pop(iter->frames);
 
-	git_buf_dispose(&root);
+	git_str_dispose(&root);
 	git_path_diriter_free(&diriter);
 	return error;
 }
@@ -1551,7 +1551,7 @@ static int filesystem_iterator_is_dir(
 	const filesystem_iterator_entry *entry)
 {
 	struct stat st;
-	git_buf fullpath = GIT_BUF_INIT;
+	git_str fullpath = GIT_STR_INIT;
 	int error = 0;
 
 	if (S_ISDIR(entry->st.st_mode)) {
@@ -1564,7 +1564,7 @@ static int filesystem_iterator_is_dir(
 		goto done;
 	}
 
-	if ((error = git_buf_joinpath(&fullpath, iter->root, entry->path)) < 0 ||
+	if ((error = git_str_joinpath(&fullpath, iter->root, entry->path)) < 0 ||
 	    (error = git_path_validate_workdir_buf(iter->base.repo, &fullpath)) < 0 ||
 	    (error = p_stat(fullpath.ptr, &st)) < 0)
 		goto done;
@@ -1572,7 +1572,7 @@ static int filesystem_iterator_is_dir(
 	*is_dir = S_ISDIR(st.st_mode);
 
 done:
-	git_buf_dispose(&fullpath);
+	git_str_dispose(&fullpath);
 	return error;
 }
 
@@ -1673,7 +1673,7 @@ static int filesystem_iterator_advance_into(
 	return filesystem_iterator_advance(out, i);
 }
 
-int git_iterator_current_workdir_path(git_buf **out, git_iterator *i)
+int git_iterator_current_workdir_path(git_str **out, git_iterator *i)
 {
 	filesystem_iterator *iter = GIT_CONTAINER_OF(i, filesystem_iterator, base);
 	const git_index_entry *entry;
@@ -1684,10 +1684,10 @@ int git_iterator_current_workdir_path(git_buf **out, git_iterator *i)
 		return 0;
 	}
 
-	git_buf_truncate(&iter->current_path, iter->root_len);
+	git_str_truncate(&iter->current_path, iter->root_len);
 
 	if (git_iterator_current(&entry, i) < 0 ||
-		git_buf_puts(&iter->current_path, entry->path) < 0)
+		git_str_puts(&iter->current_path, entry->path) < 0)
 		return -1;
 
 	*out = &iter->current_path;
@@ -1790,8 +1790,8 @@ static int filesystem_iterator_advance_over(
 		return filesystem_iterator_advance(out, i);
 	}
 
-	git_buf_clear(&iter->tmp_buf);
-	if ((error = git_buf_puts(&iter->tmp_buf, entry->path)) < 0)
+	git_str_clear(&iter->tmp_buf);
+	if ((error = git_str_puts(&iter->tmp_buf, entry->path)) < 0)
 		return error;
 
 	base = iter->tmp_buf.ptr;
@@ -1858,7 +1858,7 @@ static void filesystem_iterator_clear(filesystem_iterator *iter)
 	git_array_clear(iter->frames);
 	git_ignore__free(&iter->ignores);
 
-	git_buf_dispose(&iter->tmp_buf);
+	git_str_dispose(&iter->tmp_buf);
 
 	iterator_clear(&iter->base);
 }
@@ -1892,7 +1892,7 @@ static void filesystem_iterator_free(git_iterator *i)
 {
 	filesystem_iterator *iter = GIT_CONTAINER_OF(i, filesystem_iterator, base);
 	git__free(iter->root);
-	git_buf_dispose(&iter->current_path);
+	git_str_dispose(&iter->current_path);
 	git_tree_free(iter->tree);
 	if (iter->index)
 		git_index_snapshot_release(&iter->index_snapshot, iter->index);
@@ -1946,7 +1946,7 @@ static int iterator_for_filesystem(
 	iter->root[root_len] = '\0';
 	iter->root_len = root_len;
 
-	if ((error = git_buf_puts(&iter->current_path, iter->root)) < 0)
+	if ((error = git_str_puts(&iter->current_path, iter->root)) < 0)
 		goto on_error;
 
 	if ((error = iterator_init_common(&iter->base, repo, index, options)) < 0)
@@ -2024,7 +2024,7 @@ typedef struct {
 
 	/* the pseudotree entry */
 	git_index_entry tree_entry;
-	git_buf tree_buf;
+	git_str tree_buf;
 	bool skip_tree;
 
 	const git_index_entry *entry;
@@ -2064,8 +2064,8 @@ static bool index_iterator_create_pseudotree(
 	if ((dirsep = strchr(relative_path, '/')) == NULL)
 		return false;
 
-	git_buf_clear(&iter->tree_buf);
-	git_buf_put(&iter->tree_buf, path, (dirsep - path) + 1);
+	git_str_clear(&iter->tree_buf);
+	git_str_put(&iter->tree_buf, path, (dirsep - path) + 1);
 
 	iter->tree_entry.mode = GIT_FILEMODE_TREE;
 	iter->tree_entry.path = iter->tree_buf.ptr;
@@ -2230,7 +2230,7 @@ static void index_iterator_free(git_iterator *i)
 	index_iterator *iter = GIT_CONTAINER_OF(i, index_iterator, base);
 
 	git_index_snapshot_release(&iter->entries, iter->base.index);
-	git_buf_dispose(&iter->tree_buf);
+	git_str_dispose(&iter->tree_buf);
 }
 
 int git_iterator_for_index(