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, 34 insertions, 34 deletions

diff --git a/src/index.c b/src/index.c
index 2e24fff69..b8aa310d3 100644
--- a/src/index.c
+++ b/src/index.c
@@ -641,7 +641,7 @@ static int compare_checksum(git_index *index)
 int git_index_read(git_index *index, int force)
 {
 	int error = 0, updated;
-	git_buf buffer = GIT_BUF_INIT;
+	git_str buffer = GIT_STR_INIT;
 	git_futils_filestamp stamp = index->stamp;
 
 	if (!index->index_file_path)
@@ -687,7 +687,7 @@ int git_index_read(git_index *index, int force)
 		index->dirty = 0;
 	}
 
-	git_buf_dispose(&buffer);
+	git_str_dispose(&buffer);
 	return error;
 }
 
@@ -969,7 +969,7 @@ static int index_entry_init(
 {
 	int error = 0;
 	git_index_entry *entry = NULL;
-	git_buf path = GIT_BUF_INIT;
+	git_str path = GIT_STR_INIT;
 	struct stat st;
 	git_oid oid;
 	git_repository *repo;
@@ -992,7 +992,7 @@ static int index_entry_init(
 		return -1;
 
 	error = git_path_lstat(path.ptr, &st);
-	git_buf_dispose(&path);
+	git_str_dispose(&path);
 
 	if (error < 0)
 		return error;
@@ -1525,7 +1525,7 @@ int git_index_add_from_buffer(
 static int add_repo_as_submodule(git_index_entry **out, git_index *index, const char *path)
 {
 	git_repository *sub;
-	git_buf abspath = GIT_BUF_INIT;
+	git_str abspath = GIT_STR_INIT;
 	git_repository *repo = INDEX_OWNER(index);
 	git_reference *head;
 	git_index_entry *entry;
@@ -1556,7 +1556,7 @@ static int add_repo_as_submodule(git_index_entry **out, git_index *index, const
 
 	git_reference_free(head);
 	git_repository_free(sub);
-	git_buf_dispose(&abspath);
+	git_str_dispose(&abspath);
 
 	*out = entry;
 	return 0;
@@ -1722,12 +1722,12 @@ int git_index_remove(git_index *index, const char *path, int stage)
 
 int git_index_remove_directory(git_index *index, const char *dir, int stage)
 {
-	git_buf pfx = GIT_BUF_INIT;
+	git_str pfx = GIT_STR_INIT;
 	int error = 0;
 	size_t pos;
 	git_index_entry *entry;
 
-	if (!(error = git_buf_sets(&pfx, dir)) &&
+	if (!(error = git_str_sets(&pfx, dir)) &&
 		!(error = git_path_to_dir(&pfx)))
 		index_find(&pos, index, pfx.ptr, pfx.size, GIT_INDEX_STAGE_ANY);
 
@@ -1746,7 +1746,7 @@ int git_index_remove_directory(git_index *index, const char *dir, int stage)
 		/* removed entry at 'pos' so we don't need to increment */
 	}
 
-	git_buf_dispose(&pfx);
+	git_str_dispose(&pfx);
 
 	return error;
 }
@@ -2892,7 +2892,7 @@ done:
 	return error;
 }
 
-static int write_extension(git_filebuf *file, struct index_extension *header, git_buf *data)
+static int write_extension(git_filebuf *file, struct index_extension *header, git_str *data)
 {
 	struct index_extension ondisk;
 
@@ -2904,30 +2904,30 @@ static int write_extension(git_filebuf *file, struct index_extension *header, gi
 	return git_filebuf_write(file, data->ptr, data->size);
 }
 
-static int create_name_extension_data(git_buf *name_buf, git_index_name_entry *conflict_name)
+static int create_name_extension_data(git_str *name_buf, git_index_name_entry *conflict_name)
 {
 	int error = 0;
 
 	if (conflict_name->ancestor == NULL)
-		error = git_buf_put(name_buf, "\0", 1);
+		error = git_str_put(name_buf, "\0", 1);
 	else
-		error = git_buf_put(name_buf, conflict_name->ancestor, strlen(conflict_name->ancestor) + 1);
+		error = git_str_put(name_buf, conflict_name->ancestor, strlen(conflict_name->ancestor) + 1);
 
 	if (error != 0)
 		goto on_error;
 
 	if (conflict_name->ours == NULL)
-		error = git_buf_put(name_buf, "\0", 1);
+		error = git_str_put(name_buf, "\0", 1);
 	else
-		error = git_buf_put(name_buf, conflict_name->ours, strlen(conflict_name->ours) + 1);
+		error = git_str_put(name_buf, conflict_name->ours, strlen(conflict_name->ours) + 1);
 
 	if (error != 0)
 		goto on_error;
 
 	if (conflict_name->theirs == NULL)
-		error = git_buf_put(name_buf, "\0", 1);
+		error = git_str_put(name_buf, "\0", 1);
 	else
-		error = git_buf_put(name_buf, conflict_name->theirs, strlen(conflict_name->theirs) + 1);
+		error = git_str_put(name_buf, conflict_name->theirs, strlen(conflict_name->theirs) + 1);
 
 on_error:
 	return error;
@@ -2935,7 +2935,7 @@ on_error:
 
 static int write_name_extension(git_index *index, git_filebuf *file)
 {
-	git_buf name_buf = GIT_BUF_INIT;
+	git_str name_buf = GIT_STR_INIT;
 	git_vector *out = &index->names;
 	git_index_name_entry *conflict_name;
 	struct index_extension extension;
@@ -2953,28 +2953,28 @@ static int write_name_extension(git_index *index, git_filebuf *file)
 
 	error = write_extension(file, &extension, &name_buf);
 
-	git_buf_dispose(&name_buf);
+	git_str_dispose(&name_buf);
 
 done:
 	return error;
 }
 
-static int create_reuc_extension_data(git_buf *reuc_buf, git_index_reuc_entry *reuc)
+static int create_reuc_extension_data(git_str *reuc_buf, git_index_reuc_entry *reuc)
 {
 	int i;
 	int error = 0;
 
-	if ((error = git_buf_put(reuc_buf, reuc->path, strlen(reuc->path) + 1)) < 0)
+	if ((error = git_str_put(reuc_buf, reuc->path, strlen(reuc->path) + 1)) < 0)
 		return error;
 
 	for (i = 0; i < 3; i++) {
-		if ((error = git_buf_printf(reuc_buf, "%o", reuc->mode[i])) < 0 ||
-			(error = git_buf_put(reuc_buf, "\0", 1)) < 0)
+		if ((error = git_str_printf(reuc_buf, "%o", reuc->mode[i])) < 0 ||
+			(error = git_str_put(reuc_buf, "\0", 1)) < 0)
 			return error;
 	}
 
 	for (i = 0; i < 3; i++) {
-		if (reuc->mode[i] && (error = git_buf_put(reuc_buf, (char *)&reuc->oid[i].id, GIT_OID_RAWSZ)) < 0)
+		if (reuc->mode[i] && (error = git_str_put(reuc_buf, (char *)&reuc->oid[i].id, GIT_OID_RAWSZ)) < 0)
 			return error;
 	}
 
@@ -2983,7 +2983,7 @@ static int create_reuc_extension_data(git_buf *reuc_buf, git_index_reuc_entry *r
 
 static int write_reuc_extension(git_index *index, git_filebuf *file)
 {
-	git_buf reuc_buf = GIT_BUF_INIT;
+	git_str reuc_buf = GIT_STR_INIT;
 	git_vector *out = &index->reuc;
 	git_index_reuc_entry *reuc;
 	struct index_extension extension;
@@ -3001,7 +3001,7 @@ static int write_reuc_extension(git_index *index, git_filebuf *file)
 
 	error = write_extension(file, &extension, &reuc_buf);
 
-	git_buf_dispose(&reuc_buf);
+	git_str_dispose(&reuc_buf);
 
 done:
 	return error;
@@ -3010,7 +3010,7 @@ done:
 static int write_tree_extension(git_index *index, git_filebuf *file)
 {
 	struct index_extension extension;
-	git_buf buf = GIT_BUF_INIT;
+	git_str buf = GIT_STR_INIT;
 	int error;
 
 	if (index->tree == NULL)
@@ -3025,7 +3025,7 @@ static int write_tree_extension(git_index *index, git_filebuf *file)
 
 	error = write_extension(file, &extension, &buf);
 
-	git_buf_dispose(&buf);
+	git_str_dispose(&buf);
 
 	return error;
 }
@@ -3115,13 +3115,13 @@ static int read_tree_cb(
 {
 	read_tree_data *data = payload;
 	git_index_entry *entry = NULL, *old_entry;
-	git_buf path = GIT_BUF_INIT;
+	git_str path = GIT_STR_INIT;
 	size_t pos;
 
 	if (git_tree_entry__is_tree(tentry))
 		return 0;
 
-	if (git_buf_joinpath(&path, root, tentry->filename) < 0)
+	if (git_str_joinpath(&path, root, tentry->filename) < 0)
 		return -1;
 
 	if (index_entry_create(&entry, INDEX_OWNER(data->index), path.ptr, NULL, false) < 0)
@@ -3143,7 +3143,7 @@ static int read_tree_cb(
 	}
 
 	index_entry_adjust_namemask(entry, path.size);
-	git_buf_dispose(&path);
+	git_str_dispose(&path);
 
 	if (git_vector_insert(data->new_entries, entry) < 0) {
 		index_entry_free(entry);
@@ -3540,7 +3540,7 @@ static int index_apply_to_all(
 	size_t i;
 	git_pathspec ps;
 	const char *match;
-	git_buf path = GIT_BUF_INIT;
+	git_str path = GIT_STR_INIT;
 
 	GIT_ASSERT_ARG(index);
 
@@ -3569,7 +3569,7 @@ static int index_apply_to_all(
 		}
 
 		/* index manipulation may alter entry, so don't depend on it */
-		if ((error = git_buf_sets(&path, entry->path)) < 0)
+		if ((error = git_str_sets(&path, entry->path)) < 0)
 			break;
 
 		switch (action) {
@@ -3598,7 +3598,7 @@ static int index_apply_to_all(
 		}
 	}
 
-	git_buf_dispose(&path);
+	git_str_dispose(&path);
 	git_pathspec__clear(&ps);
 
 	return error;