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, 58 insertions, 58 deletions

diff --git a/src/clone.c b/src/clone.c
index 752df3b92..cf4cc3c7f 100644
--- a/src/clone.c
+++ b/src/clone.c
@@ -34,7 +34,7 @@ static int create_branch(
 {
 	git_commit *head_obj = NULL;
 	git_reference *branch_ref = NULL;
-	git_buf refname = GIT_BUF_INIT;
+	git_str refname = GIT_STR_INIT;
 	int error;
 
 	/* Find the target commit */
@@ -42,11 +42,11 @@ static int create_branch(
 		return error;
 
 	/* Create the new branch */
-	if ((error = git_buf_printf(&refname, GIT_REFS_HEADS_DIR "%s", name)) < 0)
+	if ((error = git_str_printf(&refname, GIT_REFS_HEADS_DIR "%s", name)) < 0)
 		return error;
 
-	error = git_reference_create(&branch_ref, repo, git_buf_cstr(&refname), target, 0, log_message);
-	git_buf_dispose(&refname);
+	error = git_reference_create(&branch_ref, repo, git_str_cstr(&refname), target, 0, log_message);
+	git_str_dispose(&refname);
 	git_commit_free(head_obj);
 
 	if (!error)
@@ -64,29 +64,29 @@ static int setup_tracking_config(
 	const char *merge_target)
 {
 	git_config *cfg;
-	git_buf remote_key = GIT_BUF_INIT, merge_key = GIT_BUF_INIT;
+	git_str remote_key = GIT_STR_INIT, merge_key = GIT_STR_INIT;
 	int error = -1;
 
 	if (git_repository_config__weakptr(&cfg, repo) < 0)
 		return -1;
 
-	if (git_buf_printf(&remote_key, "branch.%s.remote", branch_name) < 0)
+	if (git_str_printf(&remote_key, "branch.%s.remote", branch_name) < 0)
 		goto cleanup;
 
-	if (git_buf_printf(&merge_key, "branch.%s.merge", branch_name) < 0)
+	if (git_str_printf(&merge_key, "branch.%s.merge", branch_name) < 0)
 		goto cleanup;
 
-	if (git_config_set_string(cfg, git_buf_cstr(&remote_key), remote_name) < 0)
+	if (git_config_set_string(cfg, git_str_cstr(&remote_key), remote_name) < 0)
 		goto cleanup;
 
-	if (git_config_set_string(cfg, git_buf_cstr(&merge_key), merge_target) < 0)
+	if (git_config_set_string(cfg, git_str_cstr(&merge_key), merge_target) < 0)
 		goto cleanup;
 
 	error = 0;
 
 cleanup:
-	git_buf_dispose(&remote_key);
-	git_buf_dispose(&merge_key);
+	git_str_dispose(&remote_key);
+	git_str_dispose(&merge_key);
 	return error;
 }
 
@@ -139,7 +139,7 @@ static int update_head_to_new_branch(
 
 static int update_head_to_default(git_repository *repo)
 {
-	git_buf initialbranch = GIT_BUF_INIT;
+	git_str initialbranch = GIT_STR_INIT;
 	const char *branch_name;
 	int error = 0;
 
@@ -158,24 +158,24 @@ static int update_head_to_default(git_repository *repo)
 		initialbranch.ptr);
 
 done:
-	git_buf_dispose(&initialbranch);
+	git_str_dispose(&initialbranch);
 	return error;
 }
 
 static int update_remote_head(
 	git_repository *repo,
 	git_remote *remote,
-	git_buf *target,
+	git_str *target,
 	const char *reflog_message)
 {
 	git_refspec *refspec;
 	git_reference *remote_head = NULL;
-	git_buf remote_head_name = GIT_BUF_INIT;
-	git_buf remote_branch_name = GIT_BUF_INIT;
+	git_str remote_head_name = GIT_STR_INIT;
+	git_str remote_branch_name = GIT_STR_INIT;
 	int error;
 
 	/* Determine the remote tracking ref name from the local branch */
-	refspec = git_remote__matching_refspec(remote, git_buf_cstr(target));
+	refspec = git_remote__matching_refspec(remote, git_str_cstr(target));
 
 	if (refspec == NULL) {
 		git_error_set(GIT_ERROR_NET, "the remote's default branch does not fit the refspec configuration");
@@ -183,13 +183,13 @@ static int update_remote_head(
 		goto cleanup;
 	}
 
-	if ((error = git_refspec_transform(
+	if ((error = git_refspec__transform(
 		&remote_branch_name,
 		refspec,
-		git_buf_cstr(target))) < 0)
+		git_str_cstr(target))) < 0)
 		goto cleanup;
 
-	if ((error = git_buf_printf(&remote_head_name,
+	if ((error = git_str_printf(&remote_head_name,
 		"%s%s/%s",
 		GIT_REFS_REMOTES_DIR,
 		git_remote_name(remote),
@@ -199,15 +199,15 @@ static int update_remote_head(
 	error = git_reference_symbolic_create(
 		&remote_head,
 		repo,
-		git_buf_cstr(&remote_head_name),
-		git_buf_cstr(&remote_branch_name),
+		git_str_cstr(&remote_head_name),
+		git_str_cstr(&remote_branch_name),
 		true,
 		reflog_message);
 
 cleanup:
 	git_reference_free(remote_head);
-	git_buf_dispose(&remote_branch_name);
-	git_buf_dispose(&remote_head_name);
+	git_str_dispose(&remote_branch_name);
+	git_str_dispose(&remote_head_name);
 	return error;
 }
 
@@ -220,7 +220,7 @@ static int update_head_to_remote(
 	size_t refs_len;
 	const git_remote_head *remote_head, **refs;
 	const git_oid *remote_head_id;
-	git_buf branch = GIT_BUF_INIT;
+	git_str branch = GIT_STR_INIT;
 
 	if ((error = git_remote_ls(&refs, &refs_len, remote)) < 0)
 		return error;
@@ -235,7 +235,7 @@ static int update_head_to_remote(
 
 	remote_head_id = &remote_head->oid;
 
-	error = git_remote_default_branch(&branch, remote);
+	error = git_remote__default_branch(&branch, remote);
 	if (error == GIT_ENOTFOUND) {
 		error = git_repository_set_head_detached(
 			repo, remote_head_id);
@@ -248,11 +248,11 @@ static int update_head_to_remote(
 	error = update_head_to_new_branch(
 		repo,
 		remote_head_id,
-		git_buf_cstr(&branch),
+		git_str_cstr(&branch),
 		reflog_message);
 
 cleanup:
-	git_buf_dispose(&branch);
+	git_str_dispose(&branch);
 
 	return error;
 }
@@ -264,36 +264,36 @@ static int update_head_to_branch(
 		const char *reflog_message)
 {
 	int retcode;
-	git_buf remote_branch_name = GIT_BUF_INIT;
+	git_str remote_branch_name = GIT_STR_INIT;
 	git_reference *remote_ref = NULL;
-	git_buf default_branch = GIT_BUF_INIT;
+	git_str default_branch = GIT_STR_INIT;
 
 	GIT_ASSERT_ARG(remote);
 	GIT_ASSERT_ARG(branch);
 
-	if ((retcode = git_buf_printf(&remote_branch_name, GIT_REFS_REMOTES_DIR "%s/%s",
+	if ((retcode = git_str_printf(&remote_branch_name, GIT_REFS_REMOTES_DIR "%s/%s",
 		git_remote_name(remote), branch)) < 0 )
 		goto cleanup;
 
-	if ((retcode = git_reference_lookup(&remote_ref, repo, git_buf_cstr(&remote_branch_name))) < 0)
+	if ((retcode = git_reference_lookup(&remote_ref, repo, git_str_cstr(&remote_branch_name))) < 0)
 		goto cleanup;
 
 	if ((retcode = update_head_to_new_branch(repo, git_reference_target(remote_ref), branch,
 			reflog_message)) < 0)
 		goto cleanup;
 
-	if ((retcode = git_remote_default_branch(&default_branch, remote)) < 0)
+	if ((retcode = git_remote__default_branch(&default_branch, remote)) < 0)
 		goto cleanup;
 
-	if (!git_remote__matching_refspec(remote, git_buf_cstr(&default_branch)))
+	if (!git_remote__matching_refspec(remote, git_str_cstr(&default_branch)))
 		goto cleanup;
 
 	retcode = update_remote_head(repo, remote, &default_branch, reflog_message);
 
 cleanup:
 	git_reference_free(remote_ref);
-	git_buf_dispose(&remote_branch_name);
-	git_buf_dispose(&default_branch);
+	git_str_dispose(&remote_branch_name);
+	git_str_dispose(&default_branch);
 	return retcode;
 }
 
@@ -392,7 +392,7 @@ static int checkout_branch(git_repository *repo, git_remote *remote, const git_c
 static int clone_into(git_repository *repo, git_remote *_remote, const git_fetch_options *opts, const git_checkout_options *co_opts, const char *branch)
 {
 	int error;
-	git_buf reflog_message = GIT_BUF_INIT;
+	git_str reflog_message = GIT_STR_INIT;
 	git_fetch_options fetch_opts;
 	git_remote *remote;
 
@@ -410,23 +410,23 @@ static int clone_into(git_repository *repo, git_remote *_remote, const git_fetch
 	memcpy(&fetch_opts, opts, sizeof(git_fetch_options));
 	fetch_opts.update_fetchhead = 0;
 	fetch_opts.download_tags = GIT_REMOTE_DOWNLOAD_TAGS_ALL;
-	git_buf_printf(&reflog_message, "clone: from %s", git_remote_url(remote));
+	git_str_printf(&reflog_message, "clone: from %s", git_remote_url(remote));
 
-	if ((error = git_remote_fetch(remote, NULL, &fetch_opts, git_buf_cstr(&reflog_message))) != 0)
+	if ((error = git_remote_fetch(remote, NULL, &fetch_opts, git_str_cstr(&reflog_message))) != 0)
 		goto cleanup;
 
-	error = checkout_branch(repo, remote, co_opts, branch, git_buf_cstr(&reflog_message));
+	error = checkout_branch(repo, remote, co_opts, branch, git_str_cstr(&reflog_message));
 
 cleanup:
 	git_remote_free(remote);
-	git_buf_dispose(&reflog_message);
+	git_str_dispose(&reflog_message);
 
 	return error;
 }
 
 int git_clone__should_clone_local(const char *url_or_path, git_clone_local_t local)
 {
-	git_buf fromurl = GIT_BUF_INIT;
+	git_str fromurl = GIT_STR_INIT;
 	const char *path = url_or_path;
 	bool is_url, is_local;
 
@@ -446,7 +446,7 @@ int git_clone__should_clone_local(const char *url_or_path, git_clone_local_t loc
 		git_path_isdir(path);
 
 done:
-	git_buf_dispose(&fromurl);
+	git_str_dispose(&fromurl);
 	return is_local;
 }
 
@@ -586,8 +586,8 @@ static int clone_local_into(git_repository *repo, git_remote *remote, const git_
 {
 	int error, flags;
 	git_repository *src;
-	git_buf src_odb = GIT_BUF_INIT, dst_odb = GIT_BUF_INIT, src_path = GIT_BUF_INIT;
-	git_buf reflog_message = GIT_BUF_INIT;
+	git_str src_odb = GIT_STR_INIT, dst_odb = GIT_STR_INIT, src_path = GIT_STR_INIT;
+	git_str reflog_message = GIT_STR_INIT;
 
 	GIT_ASSERT_ARG(repo);
 	GIT_ASSERT_ARG(remote);
@@ -606,13 +606,13 @@ static int clone_local_into(git_repository *repo, git_remote *remote, const git_
 		return error;
 
 	/* Copy .git/objects/ from the source to the target */
-	if ((error = git_repository_open(&src, git_buf_cstr(&src_path))) < 0) {
-		git_buf_dispose(&src_path);
+	if ((error = git_repository_open(&src, git_str_cstr(&src_path))) < 0) {
+		git_str_dispose(&src_path);
 		return error;
 	}
 
-	if (git_repository_item_path(&src_odb, src, GIT_REPOSITORY_ITEM_OBJECTS) < 0
-		|| git_repository_item_path(&dst_odb, repo, GIT_REPOSITORY_ITEM_OBJECTS) < 0) {
+	if (git_repository__item_path(&src_odb, src, GIT_REPOSITORY_ITEM_OBJECTS) < 0 ||
+	    git_repository__item_path(&dst_odb, repo, GIT_REPOSITORY_ITEM_OBJECTS) < 0) {
 		error = -1;
 		goto cleanup;
 	}
@@ -621,7 +621,7 @@ static int clone_local_into(git_repository *repo, git_remote *remote, const git_
 	if (can_link(git_repository_path(src), git_repository_path(repo), link))
 		flags |= GIT_CPDIR_LINK_FILES;
 
-	error = git_futils_cp_r(git_buf_cstr(&src_odb), git_buf_cstr(&dst_odb),
+	error = git_futils_cp_r(git_str_cstr(&src_odb), git_str_cstr(&dst_odb),
 				flags, GIT_OBJECT_DIR_MODE);
 
 	/*
@@ -631,25 +631,25 @@ static int clone_local_into(git_repository *repo, git_remote *remote, const git_
 	 */
 	if (error < 0 && link) {
 		flags &= ~GIT_CPDIR_LINK_FILES;
-		error = git_futils_cp_r(git_buf_cstr(&src_odb), git_buf_cstr(&dst_odb),
+		error = git_futils_cp_r(git_str_cstr(&src_odb), git_str_cstr(&dst_odb),
 					flags, GIT_OBJECT_DIR_MODE);
 	}
 
 	if (error < 0)
 		goto cleanup;
 
-	git_buf_printf(&reflog_message, "clone: from %s", git_remote_url(remote));
+	git_str_printf(&reflog_message, "clone: from %s", git_remote_url(remote));
 
-	if ((error = git_remote_fetch(remote, NULL, fetch_opts, git_buf_cstr(&reflog_message))) != 0)
+	if ((error = git_remote_fetch(remote, NULL, fetch_opts, git_str_cstr(&reflog_message))) != 0)
 		goto cleanup;
 
-	error = checkout_branch(repo, remote, co_opts, branch, git_buf_cstr(&reflog_message));
+	error = checkout_branch(repo, remote, co_opts, branch, git_str_cstr(&reflog_message));
 
 cleanup:
-	git_buf_dispose(&reflog_message);
-	git_buf_dispose(&src_path);
-	git_buf_dispose(&src_odb);
-	git_buf_dispose(&dst_odb);
+	git_str_dispose(&reflog_message);
+	git_str_dispose(&src_path);
+	git_str_dispose(&src_odb);
+	git_str_dispose(&dst_odb);
 	git_repository_free(src);
 	return error;
 }