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, 59 insertions, 60 deletions

diff --git a/tests/core/link.c b/tests/core/link.c
index 0493edf1d..6ab79b2a8 100644
--- a/tests/core/link.c
+++ b/tests/core/link.c
@@ -1,6 +1,5 @@
 #include "clar_libgit2.h"
 #include "posix.h"
-#include "buffer.h"
 #include "path.h"
 
 #ifdef GIT_WIN32
@@ -82,7 +81,7 @@ static void do_junction(const char *old, const char *new)
 {
 	GIT_REPARSE_DATA_BUFFER *reparse_buf;
 	HANDLE handle;
-	git_buf unparsed_buf = GIT_BUF_INIT;
+	git_str unparsed_buf = GIT_STR_INIT;
 	wchar_t *subst_utf16, *print_utf16;
 	DWORD ioctl_ret;
 	int subst_utf16_len, subst_byte_len, print_utf16_len, print_byte_len, ret;
@@ -93,14 +92,14 @@ static void do_junction(const char *old, const char *new)
 	 * backslashes instead of forward, and end in a trailing backslash.
 	 * eg: \??\C:\Foo\
 	 */
-	git_buf_puts(&unparsed_buf, "\\??\\");
+	git_str_puts(&unparsed_buf, "\\??\\");
 
 	for (i = 0; i < strlen(old); i++)
-		git_buf_putc(&unparsed_buf, old[i] == '/' ? '\\' : old[i]);
+		git_str_putc(&unparsed_buf, old[i] == '/' ? '\\' : old[i]);
 
-	git_buf_putc(&unparsed_buf, '\\');
+	git_str_putc(&unparsed_buf, '\\');
 
-	subst_utf16_len = git__utf8_to_16(NULL, 0, git_buf_cstr(&unparsed_buf));
+	subst_utf16_len = git__utf8_to_16(NULL, 0, git_str_cstr(&unparsed_buf));
 	subst_byte_len = subst_utf16_len * sizeof(WCHAR);
 
 	print_utf16_len = subst_utf16_len - 4;
@@ -127,11 +126,11 @@ static void do_junction(const char *old, const char *new)
 	print_utf16 = subst_utf16 + subst_utf16_len + 1;
 
 	ret = git__utf8_to_16(subst_utf16, subst_utf16_len + 1,
-		git_buf_cstr(&unparsed_buf));
+		git_str_cstr(&unparsed_buf));
 	cl_assert_equal_i(subst_utf16_len, ret);
 
 	ret = git__utf8_to_16(print_utf16,
-		print_utf16_len + 1, git_buf_cstr(&unparsed_buf) + 4);
+		print_utf16_len + 1, git_str_cstr(&unparsed_buf) + 4);
 	cl_assert_equal_i(print_utf16_len, ret);
 
 	reparse_buf->ReparseTag = IO_REPARSE_TAG_MOUNT_POINT;
@@ -147,7 +146,7 @@ static void do_junction(const char *old, const char *new)
 	CloseHandle(handle);
 	LocalFree(reparse_buf);
 
-	git_buf_dispose(&unparsed_buf);
+	git_str_dispose(&unparsed_buf);
 }
 
 static void do_custom_reparse(const char *path)
@@ -300,7 +299,7 @@ void test_core_link__stat_dangling_symlink_directory(void)
 
 void test_core_link__lstat_symlink(void)
 {
-	git_buf target_path = GIT_BUF_INIT;
+	git_str target_path = GIT_STR_INIT;
 	struct stat st;
 
 	if (!should_run())
@@ -309,10 +308,10 @@ void test_core_link__lstat_symlink(void)
 	/* Windows always writes the canonical path as the link target, so
 	 * write the full path on all platforms.
 	 */
-	git_buf_join(&target_path, '/', clar_sandbox_path(), "lstat_target");
+	git_str_join(&target_path, '/', clar_sandbox_path(), "lstat_target");
 
 	cl_git_rewritefile("lstat_target", "This is the target of a symbolic link.\n");
-	do_symlink(git_buf_cstr(&target_path), "lstat_symlink", 0);
+	do_symlink(git_str_cstr(&target_path), "lstat_symlink", 0);
 
 	cl_must_pass(p_lstat("lstat_target", &st));
 	cl_assert(S_ISREG(st.st_mode));
@@ -320,32 +319,32 @@ void test_core_link__lstat_symlink(void)
 
 	cl_must_pass(p_lstat("lstat_symlink", &st));
 	cl_assert(S_ISLNK(st.st_mode));
-	cl_assert_equal_i(git_buf_len(&target_path), st.st_size);
+	cl_assert_equal_i(git_str_len(&target_path), st.st_size);
 
-	git_buf_dispose(&target_path);
+	git_str_dispose(&target_path);
 }
 
 void test_core_link__lstat_symlink_directory(void)
 {
-	git_buf target_path = GIT_BUF_INIT;
+	git_str target_path = GIT_STR_INIT;
 	struct stat st;
 
 	if (!should_run())
 		clar__skip();
 
-	git_buf_join(&target_path, '/', clar_sandbox_path(), "lstat_dirtarget");
+	git_str_join(&target_path, '/', clar_sandbox_path(), "lstat_dirtarget");
 
 	p_mkdir("lstat_dirtarget", 0777);
-	do_symlink(git_buf_cstr(&target_path), "lstat_dirlink", 1);
+	do_symlink(git_str_cstr(&target_path), "lstat_dirlink", 1);
 
 	cl_must_pass(p_lstat("lstat_dirtarget", &st));
 	cl_assert(S_ISDIR(st.st_mode));
 
 	cl_must_pass(p_lstat("lstat_dirlink", &st));
 	cl_assert(S_ISLNK(st.st_mode));
-	cl_assert_equal_i(git_buf_len(&target_path), st.st_size);
+	cl_assert_equal_i(git_str_len(&target_path), st.st_size);
 
-	git_buf_dispose(&target_path);
+	git_str_dispose(&target_path);
 }
 
 void test_core_link__lstat_dangling_symlink(void)
@@ -383,13 +382,13 @@ void test_core_link__lstat_dangling_symlink_directory(void)
 void test_core_link__stat_junction(void)
 {
 #ifdef GIT_WIN32
-	git_buf target_path = GIT_BUF_INIT;
+	git_str target_path = GIT_STR_INIT;
 	struct stat st;
 
-	git_buf_join(&target_path, '/', clar_sandbox_path(), "stat_junctarget");
+	git_str_join(&target_path, '/', clar_sandbox_path(), "stat_junctarget");
 
 	p_mkdir("stat_junctarget", 0777);
-	do_junction(git_buf_cstr(&target_path), "stat_junction");
+	do_junction(git_str_cstr(&target_path), "stat_junction");
 
 	cl_must_pass(p_stat("stat_junctarget", &st));
 	cl_assert(S_ISDIR(st.st_mode));
@@ -397,40 +396,40 @@ void test_core_link__stat_junction(void)
 	cl_must_pass(p_stat("stat_junction", &st));
 	cl_assert(S_ISDIR(st.st_mode));
 
-	git_buf_dispose(&target_path);
+	git_str_dispose(&target_path);
 #endif
 }
 
 void test_core_link__stat_dangling_junction(void)
 {
 #ifdef GIT_WIN32
-	git_buf target_path = GIT_BUF_INIT;
+	git_str target_path = GIT_STR_INIT;
 	struct stat st;
 
-	git_buf_join(&target_path, '/', clar_sandbox_path(), "stat_nonexistent_junctarget");
+	git_str_join(&target_path, '/', clar_sandbox_path(), "stat_nonexistent_junctarget");
 
 	p_mkdir("stat_nonexistent_junctarget", 0777);
-	do_junction(git_buf_cstr(&target_path), "stat_dangling_junction");
+	do_junction(git_str_cstr(&target_path), "stat_dangling_junction");
 
 	RemoveDirectory("stat_nonexistent_junctarget");
 
 	cl_must_fail(p_stat("stat_nonexistent_junctarget", &st));
 	cl_must_fail(p_stat("stat_dangling_junction", &st));
 
-	git_buf_dispose(&target_path);
+	git_str_dispose(&target_path);
 #endif
 }
 
 void test_core_link__lstat_junction(void)
 {
 #ifdef GIT_WIN32
-	git_buf target_path = GIT_BUF_INIT;
+	git_str target_path = GIT_STR_INIT;
 	struct stat st;
 
-	git_buf_join(&target_path, '/', clar_sandbox_path(), "lstat_junctarget");
+	git_str_join(&target_path, '/', clar_sandbox_path(), "lstat_junctarget");
 
 	p_mkdir("lstat_junctarget", 0777);
-	do_junction(git_buf_cstr(&target_path), "lstat_junction");
+	do_junction(git_str_cstr(&target_path), "lstat_junction");
 
 	cl_must_pass(p_lstat("lstat_junctarget", &st));
 	cl_assert(S_ISDIR(st.st_mode));
@@ -438,20 +437,20 @@ void test_core_link__lstat_junction(void)
 	cl_must_pass(p_lstat("lstat_junction", &st));
 	cl_assert(S_ISLNK(st.st_mode));
 
-	git_buf_dispose(&target_path);
+	git_str_dispose(&target_path);
 #endif
 }
 
 void test_core_link__lstat_dangling_junction(void)
 {
 #ifdef GIT_WIN32
-	git_buf target_path = GIT_BUF_INIT;
+	git_str target_path = GIT_STR_INIT;
 	struct stat st;
 
-	git_buf_join(&target_path, '/', clar_sandbox_path(), "lstat_nonexistent_junctarget");
+	git_str_join(&target_path, '/', clar_sandbox_path(), "lstat_nonexistent_junctarget");
 
 	p_mkdir("lstat_nonexistent_junctarget", 0777);
-	do_junction(git_buf_cstr(&target_path), "lstat_dangling_junction");
+	do_junction(git_str_cstr(&target_path), "lstat_dangling_junction");
 
 	RemoveDirectory("lstat_nonexistent_junctarget");
 
@@ -459,9 +458,9 @@ void test_core_link__lstat_dangling_junction(void)
 
 	cl_must_pass(p_lstat("lstat_dangling_junction", &st));
 	cl_assert(S_ISLNK(st.st_mode));
-	cl_assert_equal_i(git_buf_len(&target_path), st.st_size);
+	cl_assert_equal_i(git_str_len(&target_path), st.st_size);
 
-	git_buf_dispose(&target_path);
+	git_str_dispose(&target_path);
 #endif
 }
 
@@ -554,79 +553,79 @@ void test_core_link__readlink_normal_file(void)
 
 void test_core_link__readlink_symlink(void)
 {
-	git_buf target_path = GIT_BUF_INIT;
+	git_str target_path = GIT_STR_INIT;
 	int len;
 	char buf[2048];
 
 	if (!should_run())
 		clar__skip();
 
-	git_buf_join(&target_path, '/', clar_sandbox_path(), "readlink_target");
+	git_str_join(&target_path, '/', clar_sandbox_path(), "readlink_target");
 
 	cl_git_rewritefile("readlink_target", "This is the target of a symlink\n");
-	do_symlink(git_buf_cstr(&target_path), "readlink_link", 0);
+	do_symlink(git_str_cstr(&target_path), "readlink_link", 0);
 
 	len = p_readlink("readlink_link", buf, 2048);
 	cl_must_pass(len);
 
 	buf[len] = 0;
 
-	cl_assert_equal_s(git_buf_cstr(&target_path), buf);
+	cl_assert_equal_s(git_str_cstr(&target_path), buf);
 
-	git_buf_dispose(&target_path);
+	git_str_dispose(&target_path);
 }
 
 void test_core_link__readlink_dangling(void)
 {
-	git_buf target_path = GIT_BUF_INIT;
+	git_str target_path = GIT_STR_INIT;
 	int len;
 	char buf[2048];
 
 	if (!should_run())
 		clar__skip();
 
-	git_buf_join(&target_path, '/', clar_sandbox_path(), "readlink_nonexistent");
+	git_str_join(&target_path, '/', clar_sandbox_path(), "readlink_nonexistent");
 
-	do_symlink(git_buf_cstr(&target_path), "readlink_dangling", 0);
+	do_symlink(git_str_cstr(&target_path), "readlink_dangling", 0);
 
 	len = p_readlink("readlink_dangling", buf, 2048);
 	cl_must_pass(len);
 
 	buf[len] = 0;
 
-	cl_assert_equal_s(git_buf_cstr(&target_path), buf);
+	cl_assert_equal_s(git_str_cstr(&target_path), buf);
 
-	git_buf_dispose(&target_path);
+	git_str_dispose(&target_path);
 }
 
 void test_core_link__readlink_multiple(void)
 {
-	git_buf target_path = GIT_BUF_INIT,
-		path3 = GIT_BUF_INIT, path2 = GIT_BUF_INIT, path1 = GIT_BUF_INIT;
+	git_str target_path = GIT_STR_INIT,
+		path3 = GIT_STR_INIT, path2 = GIT_STR_INIT, path1 = GIT_STR_INIT;
 	int len;
 	char buf[2048];
 
 	if (!should_run())
 		clar__skip();
 
-	git_buf_join(&target_path, '/', clar_sandbox_path(), "readlink_final");
-	git_buf_join(&path3, '/', clar_sandbox_path(), "readlink_3");
-	git_buf_join(&path2, '/', clar_sandbox_path(), "readlink_2");
-	git_buf_join(&path1, '/', clar_sandbox_path(), "readlink_1");
+	git_str_join(&target_path, '/', clar_sandbox_path(), "readlink_final");
+	git_str_join(&path3, '/', clar_sandbox_path(), "readlink_3");
+	git_str_join(&path2, '/', clar_sandbox_path(), "readlink_2");
+	git_str_join(&path1, '/', clar_sandbox_path(), "readlink_1");
 
-	do_symlink(git_buf_cstr(&target_path), git_buf_cstr(&path3), 0);
-	do_symlink(git_buf_cstr(&path3), git_buf_cstr(&path2), 0);
-	do_symlink(git_buf_cstr(&path2), git_buf_cstr(&path1), 0);
+	do_symlink(git_str_cstr(&target_path), git_str_cstr(&path3), 0);
+	do_symlink(git_str_cstr(&path3), git_str_cstr(&path2), 0);
+	do_symlink(git_str_cstr(&path2), git_str_cstr(&path1), 0);
 
 	len = p_readlink("readlink_1", buf, 2048);
 	cl_must_pass(len);
 
 	buf[len] = 0;
 
-	cl_assert_equal_s(git_buf_cstr(&path2), buf);
+	cl_assert_equal_s(git_str_cstr(&path2), buf);
 
-	git_buf_dispose(&path1);
-	git_buf_dispose(&path2);
-	git_buf_dispose(&path3);
-	git_buf_dispose(&target_path);
+	git_str_dispose(&path1);
+	git_str_dispose(&path2);
+	git_str_dispose(&path3);
+	git_str_dispose(&target_path);
 }