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, 48 insertions, 48 deletions

diff --git a/src/sysdir.c b/src/sysdir.c
index dcbd48bc3..457d7f8a8 100644
--- a/src/sysdir.c
+++ b/src/sysdir.c
@@ -8,7 +8,7 @@
 #include "sysdir.h"
 
 #include "runtime.h"
-#include "buffer.h"
+#include "str.h"
 #include "path.h"
 #include <ctype.h>
 #if GIT_WIN32
@@ -18,27 +18,27 @@
 #include <pwd.h>
 #endif
 
-static int git_sysdir_guess_programdata_dirs(git_buf *out)
+static int git_sysdir_guess_programdata_dirs(git_str *out)
 {
 #ifdef GIT_WIN32
 	return git_win32__find_programdata_dirs(out);
 #else
-	git_buf_clear(out);
+	git_str_clear(out);
 	return 0;
 #endif
 }
 
-static int git_sysdir_guess_system_dirs(git_buf *out)
+static int git_sysdir_guess_system_dirs(git_str *out)
 {
 #ifdef GIT_WIN32
 	return git_win32__find_system_dirs(out, L"etc\\");
 #else
-	return git_buf_sets(out, "/etc");
+	return git_str_sets(out, "/etc");
 #endif
 }
 
 #ifndef GIT_WIN32
-static int get_passwd_home(git_buf *out, uid_t uid)
+static int get_passwd_home(git_str *out, uid_t uid)
 {
 	struct passwd pwd, *pwdptr;
 	char *buf = NULL;
@@ -66,7 +66,7 @@ static int get_passwd_home(git_buf *out, uid_t uid)
 		goto out;
 	}
 
-	if ((error = git_buf_puts(out, pwdptr->pw_dir)) < 0)
+	if ((error = git_str_puts(out, pwdptr->pw_dir)) < 0)
 		goto out;
 
 out:
@@ -75,7 +75,7 @@ out:
 }
 #endif
 
-static int git_sysdir_guess_global_dirs(git_buf *out)
+static int git_sysdir_guess_global_dirs(git_str *out)
 {
 #ifdef GIT_WIN32
 	return git_win32__find_global_dirs(out);
@@ -114,12 +114,12 @@ static int git_sysdir_guess_global_dirs(git_buf *out)
 #endif
 }
 
-static int git_sysdir_guess_xdg_dirs(git_buf *out)
+static int git_sysdir_guess_xdg_dirs(git_str *out)
 {
 #ifdef GIT_WIN32
 	return git_win32__find_xdg_dirs(out);
 #else
-	git_buf env = GIT_BUF_INIT;
+	git_str env = GIT_STR_INIT;
 	int error;
 	uid_t uid, euid;
 
@@ -132,13 +132,13 @@ static int git_sysdir_guess_xdg_dirs(git_buf *out)
 	 */
 	if (uid == euid) {
 		if ((error = git__getenv(&env, "XDG_CONFIG_HOME")) == 0)
-			error = git_buf_joinpath(out, env.ptr, "git");
+			error = git_str_joinpath(out, env.ptr, "git");
 
 		if (error == GIT_ENOTFOUND && (error = git__getenv(&env, "HOME")) == 0)
-			error = git_buf_joinpath(out, env.ptr, ".config/git");
+			error = git_str_joinpath(out, env.ptr, ".config/git");
 	} else {
 		if ((error = get_passwd_home(&env, euid)) == 0)
-			error = git_buf_joinpath(out, env.ptr, ".config/git");
+			error = git_str_joinpath(out, env.ptr, ".config/git");
 	}
 
 	if (error == GIT_ENOTFOUND) {
@@ -146,31 +146,31 @@ static int git_sysdir_guess_xdg_dirs(git_buf *out)
 		error = 0;
 	}
 
-	git_buf_dispose(&env);
+	git_str_dispose(&env);
 	return error;
 #endif
 }
 
-static int git_sysdir_guess_template_dirs(git_buf *out)
+static int git_sysdir_guess_template_dirs(git_str *out)
 {
 #ifdef GIT_WIN32
 	return git_win32__find_system_dirs(out, L"share\\git-core\\templates");
 #else
-	return git_buf_sets(out, "/usr/share/git-core/templates");
+	return git_str_sets(out, "/usr/share/git-core/templates");
 #endif
 }
 
 struct git_sysdir__dir {
-	git_buf buf;
-	int (*guess)(git_buf *out);
+	git_str buf;
+	int (*guess)(git_str *out);
 };
 
 static struct git_sysdir__dir git_sysdir__dirs[] = {
-	{ GIT_BUF_INIT, git_sysdir_guess_system_dirs },
-	{ GIT_BUF_INIT, git_sysdir_guess_global_dirs },
-	{ GIT_BUF_INIT, git_sysdir_guess_xdg_dirs },
-	{ GIT_BUF_INIT, git_sysdir_guess_programdata_dirs },
-	{ GIT_BUF_INIT, git_sysdir_guess_template_dirs },
+	{ GIT_STR_INIT, git_sysdir_guess_system_dirs },
+	{ GIT_STR_INIT, git_sysdir_guess_global_dirs },
+	{ GIT_STR_INIT, git_sysdir_guess_xdg_dirs },
+	{ GIT_STR_INIT, git_sysdir_guess_programdata_dirs },
+	{ GIT_STR_INIT, git_sysdir_guess_template_dirs },
 };
 
 static void git_sysdir_global_shutdown(void)
@@ -178,7 +178,7 @@ static void git_sysdir_global_shutdown(void)
 	size_t i;
 
 	for (i = 0; i < ARRAY_SIZE(git_sysdir__dirs); ++i)
-		git_buf_dispose(&git_sysdir__dirs[i].buf);
+		git_str_dispose(&git_sysdir__dirs[i].buf);
 }
 
 int git_sysdir_global_init(void)
@@ -202,7 +202,7 @@ static int git_sysdir_check_selector(git_sysdir_t which)
 }
 
 
-int git_sysdir_get(const git_buf **out, git_sysdir_t which)
+int git_sysdir_get(const git_str **out, git_sysdir_t which)
 {
 	GIT_ASSERT_ARG(out);
 
@@ -219,7 +219,7 @@ int git_sysdir_get(const git_buf **out, git_sysdir_t which)
 int git_sysdir_set(git_sysdir_t which, const char *search_path)
 {
 	const char *expand_path = NULL;
-	git_buf merge = GIT_BUF_INIT;
+	git_str merge = GIT_STR_INIT;
 
 	GIT_ERROR_CHECK_ERROR(git_sysdir_check_selector(which));
 
@@ -233,48 +233,48 @@ int git_sysdir_set(git_sysdir_t which, const char *search_path)
 	/* if $PATH is not referenced, then just set the path */
 	if (!expand_path) {
 		if (search_path)
-			git_buf_sets(&git_sysdir__dirs[which].buf, search_path);
+			git_str_sets(&git_sysdir__dirs[which].buf, search_path);
 
 		goto done;
 	}
 
 	/* otherwise set to join(before $PATH, old value, after $PATH) */
 	if (expand_path > search_path)
-		git_buf_set(&merge, search_path, expand_path - search_path);
+		git_str_set(&merge, search_path, expand_path - search_path);
 
-	if (git_buf_len(&git_sysdir__dirs[which].buf))
-		git_buf_join(&merge, GIT_PATH_LIST_SEPARATOR,
+	if (git_str_len(&git_sysdir__dirs[which].buf))
+		git_str_join(&merge, GIT_PATH_LIST_SEPARATOR,
 			merge.ptr, git_sysdir__dirs[which].buf.ptr);
 
 	expand_path += strlen(PATH_MAGIC);
 	if (*expand_path)
-		git_buf_join(&merge, GIT_PATH_LIST_SEPARATOR, merge.ptr, expand_path);
+		git_str_join(&merge, GIT_PATH_LIST_SEPARATOR, merge.ptr, expand_path);
 
-	git_buf_swap(&git_sysdir__dirs[which].buf, &merge);
-	git_buf_dispose(&merge);
+	git_str_swap(&git_sysdir__dirs[which].buf, &merge);
+	git_str_dispose(&merge);
 
 done:
-	if (git_buf_oom(&git_sysdir__dirs[which].buf))
+	if (git_str_oom(&git_sysdir__dirs[which].buf))
 		return -1;
 
 	return 0;
 }
 
 static int git_sysdir_find_in_dirlist(
-	git_buf *path,
+	git_str *path,
 	const char *name,
 	git_sysdir_t which,
 	const char *label)
 {
 	size_t len;
 	const char *scan, *next = NULL;
-	const git_buf *syspath;
+	const git_str *syspath;
 
 	GIT_ERROR_CHECK_ERROR(git_sysdir_get(&syspath, which));
-	if (!syspath || !git_buf_len(syspath))
+	if (!syspath || !git_str_len(syspath))
 		goto done;
 
-	for (scan = git_buf_cstr(syspath); scan; scan = next) {
+	for (scan = git_str_cstr(syspath); scan; scan = next) {
 		/* find unescaped separator or end of string */
 		for (next = scan; *next; ++next) {
 			if (*next == GIT_PATH_LIST_SEPARATOR &&
@@ -287,9 +287,9 @@ static int git_sysdir_find_in_dirlist(
 		if (!len)
 			continue;
 
-		GIT_ERROR_CHECK_ERROR(git_buf_set(path, scan, len));
+		GIT_ERROR_CHECK_ERROR(git_str_set(path, scan, len));
 		if (name)
-			GIT_ERROR_CHECK_ERROR(git_buf_joinpath(path, path->ptr, name));
+			GIT_ERROR_CHECK_ERROR(git_str_joinpath(path, path->ptr, name));
 
 		if (git_path_exists(path->ptr))
 			return 0;
@@ -300,47 +300,47 @@ done:
 		git_error_set(GIT_ERROR_OS, "the %s file '%s' doesn't exist", label, name);
 	else
 		git_error_set(GIT_ERROR_OS, "the %s directory doesn't exist", label);
-	git_buf_dispose(path);
+	git_str_dispose(path);
 	return GIT_ENOTFOUND;
 }
 
-int git_sysdir_find_system_file(git_buf *path, const char *filename)
+int git_sysdir_find_system_file(git_str *path, const char *filename)
 {
 	return git_sysdir_find_in_dirlist(
 		path, filename, GIT_SYSDIR_SYSTEM, "system");
 }
 
-int git_sysdir_find_global_file(git_buf *path, const char *filename)
+int git_sysdir_find_global_file(git_str *path, const char *filename)
 {
 	return git_sysdir_find_in_dirlist(
 		path, filename, GIT_SYSDIR_GLOBAL, "global");
 }
 
-int git_sysdir_find_xdg_file(git_buf *path, const char *filename)
+int git_sysdir_find_xdg_file(git_str *path, const char *filename)
 {
 	return git_sysdir_find_in_dirlist(
 		path, filename, GIT_SYSDIR_XDG, "global/xdg");
 }
 
-int git_sysdir_find_programdata_file(git_buf *path, const char *filename)
+int git_sysdir_find_programdata_file(git_str *path, const char *filename)
 {
 	return git_sysdir_find_in_dirlist(
 		path, filename, GIT_SYSDIR_PROGRAMDATA, "ProgramData");
 }
 
-int git_sysdir_find_template_dir(git_buf *path)
+int git_sysdir_find_template_dir(git_str *path)
 {
 	return git_sysdir_find_in_dirlist(
 		path, NULL, GIT_SYSDIR_TEMPLATE, "template");
 }
 
-int git_sysdir_expand_global_file(git_buf *path, const char *filename)
+int git_sysdir_expand_global_file(git_str *path, const char *filename)
 {
 	int error;
 
 	if ((error = git_sysdir_find_global_file(path, NULL)) == 0) {
 		if (filename)
-			error = git_buf_joinpath(path, path->ptr, filename);
+			error = git_str_joinpath(path, path->ptr, filename);
 	}
 
 	return error;