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, 18 insertions, 18 deletions

diff --git a/src/errors.c b/src/errors.c
index ce883b2da..3614b9ce5 100644
--- a/src/errors.c
+++ b/src/errors.c
@@ -9,7 +9,7 @@
 
 #include "threadstate.h"
 #include "posix.h"
-#include "buffer.h"
+#include "str.h"
 #include "libgit2.h"
 
 /********************************************
@@ -29,7 +29,7 @@ static git_error g_git_uninitialized_error = {
 static void set_error_from_buffer(int error_class)
 {
 	git_error *error = &GIT_THREADSTATE->error_t;
-	git_buf *buf = &GIT_THREADSTATE->error_buf;
+	git_str *buf = &GIT_THREADSTATE->error_buf;
 
 	error->message = buf->ptr;
 	error->klass = error_class;
@@ -39,11 +39,11 @@ static void set_error_from_buffer(int error_class)
 
 static void set_error(int error_class, char *string)
 {
-	git_buf *buf = &GIT_THREADSTATE->error_buf;
+	git_str *buf = &GIT_THREADSTATE->error_buf;
 
-	git_buf_clear(buf);
+	git_str_clear(buf);
 	if (string) {
-		git_buf_puts(buf, string);
+		git_str_puts(buf, string);
 		git__free(string);
 	}
 
@@ -70,20 +70,20 @@ void git_error_vset(int error_class, const char *fmt, va_list ap)
 	DWORD win32_error_code = (error_class == GIT_ERROR_OS) ? GetLastError() : 0;
 #endif
 	int error_code = (error_class == GIT_ERROR_OS) ? errno : 0;
-	git_buf *buf = &GIT_THREADSTATE->error_buf;
+	git_str *buf = &GIT_THREADSTATE->error_buf;
 
-	git_buf_clear(buf);
+	git_str_clear(buf);
 	if (fmt) {
-		git_buf_vprintf(buf, fmt, ap);
+		git_str_vprintf(buf, fmt, ap);
 		if (error_class == GIT_ERROR_OS)
-			git_buf_PUTS(buf, ": ");
+			git_str_PUTS(buf, ": ");
 	}
 
 	if (error_class == GIT_ERROR_OS) {
 #ifdef GIT_WIN32
 		char * win32_error = git_win32_get_error_message(win32_error_code);
 		if (win32_error) {
-			git_buf_puts(buf, win32_error);
+			git_str_puts(buf, win32_error);
 			git__free(win32_error);
 
 			SetLastError(0);
@@ -91,26 +91,26 @@ void git_error_vset(int error_class, const char *fmt, va_list ap)
 		else
 #endif
 		if (error_code)
-			git_buf_puts(buf, strerror(error_code));
+			git_str_puts(buf, strerror(error_code));
 
 		if (error_code)
 			errno = 0;
 	}
 
-	if (!git_buf_oom(buf))
+	if (!git_str_oom(buf))
 		set_error_from_buffer(error_class);
 }
 
 int git_error_set_str(int error_class, const char *string)
 {
-	git_buf *buf = &GIT_THREADSTATE->error_buf;
+	git_str *buf = &GIT_THREADSTATE->error_buf;
 
 	GIT_ASSERT_ARG(string);
 
-	git_buf_clear(buf);
-	git_buf_puts(buf, string);
+	git_str_clear(buf);
+	git_str_puts(buf, string);
 
-	if (git_buf_oom(buf))
+	if (git_str_oom(buf))
 		return -1;
 
 	set_error_from_buffer(error_class);
@@ -142,7 +142,7 @@ const git_error *git_error_last(void)
 int git_error_state_capture(git_error_state *state, int error_code)
 {
 	git_error *error = GIT_THREADSTATE->last_error;
-	git_buf *error_buf = &GIT_THREADSTATE->error_buf;
+	git_str *error_buf = &GIT_THREADSTATE->error_buf;
 
 	memset(state, 0, sizeof(git_error_state));
 
@@ -158,7 +158,7 @@ int git_error_state_capture(git_error_state *state, int error_code)
 		if (state->oom)
 			state->error_msg.message = g_git_oom_error.message;
 		else
-			state->error_msg.message = git_buf_detach(error_buf);
+			state->error_msg.message = git_str_detach(error_buf);
 	}
 
 	git_error_clear();