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, 22 insertions, 22 deletions

diff --git a/src/win32/findfile.c b/src/win32/findfile.c
index 40d2d518a..caa79398a 100644
--- a/src/win32/findfile.c
+++ b/src/win32/findfile.c
@@ -34,7 +34,7 @@ static int git_win32__expand_path(_findfile_path *dest, const wchar_t *src)
 	return 0;
 }
 
-static int win32_path_to_8(git_buf *dest, const wchar_t *src)
+static int win32_path_to_8(git_str *dest, const wchar_t *src)
 {
 	git_win32_utf8_path utf8_path;
 
@@ -46,7 +46,7 @@ static int win32_path_to_8(git_buf *dest, const wchar_t *src)
 	/* Convert backslashes to forward slashes */
 	git_path_mkposix(utf8_path);
 
-	return git_buf_sets(dest, utf8_path);
+	return git_str_sets(dest, utf8_path);
 }
 
 static wchar_t *win32_walkpath(wchar_t *path, wchar_t *buf, size_t buflen)
@@ -70,7 +70,7 @@ static wchar_t *win32_walkpath(wchar_t *path, wchar_t *buf, size_t buflen)
 	return (path != base) ? path : NULL;
 }
 
-static int win32_find_git_in_path(git_buf *buf, const wchar_t *gitexe, const wchar_t *subdir)
+static int win32_find_git_in_path(git_str *buf, const wchar_t *gitexe, const wchar_t *subdir)
 {
 	wchar_t *env = _wgetenv(L"PATH"), lastch;
 	_findfile_path root;
@@ -106,7 +106,7 @@ static int win32_find_git_in_path(git_buf *buf, const wchar_t *gitexe, const wch
 }
 
 static int win32_find_git_in_registry(
-	git_buf *buf, const HKEY hive, const wchar_t *key, const wchar_t *subdir)
+	git_str *buf, const HKEY hive, const wchar_t *key, const wchar_t *subdir)
 {
 	HKEY hKey;
 	int error = GIT_ENOTFOUND;
@@ -141,12 +141,12 @@ static int win32_find_git_in_registry(
 }
 
 static int win32_find_existing_dirs(
-	git_buf *out, const wchar_t *tmpl[])
+	git_str *out, const wchar_t *tmpl[])
 {
 	_findfile_path path16;
-	git_buf buf = GIT_BUF_INIT;
+	git_str buf = GIT_STR_INIT;
 
-	git_buf_clear(out);
+	git_str_clear(out);
 
 	for (; *tmpl != NULL; tmpl++) {
 		if (!git_win32__expand_path(&path16, *tmpl) &&
@@ -156,43 +156,43 @@ static int win32_find_existing_dirs(
 			win32_path_to_8(&buf, path16.path);
 
 			if (buf.size)
-				git_buf_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
+				git_str_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
 		}
 	}
 
-	git_buf_dispose(&buf);
+	git_str_dispose(&buf);
 
-	return (git_buf_oom(out) ? -1 : 0);
+	return (git_str_oom(out) ? -1 : 0);
 }
 
-int git_win32__find_system_dirs(git_buf *out, const wchar_t *subdir)
+int git_win32__find_system_dirs(git_str *out, const wchar_t *subdir)
 {
-	git_buf buf = GIT_BUF_INIT;
+	git_str buf = GIT_STR_INIT;
 
 	/* directories where git.exe & git.cmd are found */
 	if (!win32_find_git_in_path(&buf, L"git.exe", subdir) && buf.size)
-		git_buf_set(out, buf.ptr, buf.size);
+		git_str_set(out, buf.ptr, buf.size);
 	else
-		git_buf_clear(out);
+		git_str_clear(out);
 
 	if (!win32_find_git_in_path(&buf, L"git.cmd", subdir) && buf.size)
-		git_buf_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
+		git_str_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
 
 	/* directories where git is installed according to registry */
 	if (!win32_find_git_in_registry(
 			&buf, HKEY_CURRENT_USER, REG_MSYSGIT_INSTALL_LOCAL, subdir) && buf.size)
-		git_buf_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
+		git_str_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
 
 	if (!win32_find_git_in_registry(
 			&buf, HKEY_LOCAL_MACHINE, REG_MSYSGIT_INSTALL, subdir) && buf.size)
-		git_buf_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
+		git_str_join(out, GIT_PATH_LIST_SEPARATOR, out->ptr, buf.ptr);
 
-	git_buf_dispose(&buf);
+	git_str_dispose(&buf);
 
-	return (git_buf_oom(out) ? -1 : 0);
+	return (git_str_oom(out) ? -1 : 0);
 }
 
-int git_win32__find_global_dirs(git_buf *out)
+int git_win32__find_global_dirs(git_str *out)
 {
 	static const wchar_t *global_tmpls[4] = {
 		L"%HOME%\\",
@@ -204,7 +204,7 @@ int git_win32__find_global_dirs(git_buf *out)
 	return win32_find_existing_dirs(out, global_tmpls);
 }
 
-int git_win32__find_xdg_dirs(git_buf *out)
+int git_win32__find_xdg_dirs(git_str *out)
 {
 	static const wchar_t *global_tmpls[7] = {
 		L"%XDG_CONFIG_HOME%\\git",
@@ -219,7 +219,7 @@ int git_win32__find_xdg_dirs(git_buf *out)
 	return win32_find_existing_dirs(out, global_tmpls);
 }
 
-int git_win32__find_programdata_dirs(git_buf *out)
+int git_win32__find_programdata_dirs(git_str *out)
 {
 	static const wchar_t *programdata_tmpls[2] = {
 		L"%PROGRAMDATA%\\Git",