git_path_diriter: use FindFirstFile in win32

Using FindFirstFile and FindNextFile in win32 allows us to
use the directory information that is returned, instead of
us having to get the file attributes all over again, which
is a distinct cost savings on win32.

1 files changed, 186 insertions, 2 deletions

diff --git a/src/path.c b/src/path.c
index ee566985a..6c9852b79 100644
--- a/src/path.c
+++ b/src/path.c
@@ -1078,6 +1078,182 @@ int git_path_direach(
 	return error;
 }
 
+#if defined(GIT_WIN32) && !defined(__MINGW32__)
+
+/* Using _FIND_FIRST_EX_LARGE_FETCH may increase performance in Windows 7
+ * and better.  Prior versions will ignore this.
+ */
+#ifndef FIND_FIRST_EX_LARGE_FETCH
+# define FIND_FIRST_EX_LARGE_FETCH 2
+#endif
+
+int git_path_diriter_init(
+	git_path_diriter *diriter,
+	const char *path,
+	unsigned int flags)
+{
+	git_win32_path path_filter;
+	git_buf hack = {0};
+
+	assert(diriter && path);
+
+	memset(diriter, 0, sizeof(git_path_diriter));
+	diriter->handle = INVALID_HANDLE_VALUE;
+
+	if (git_buf_puts(&diriter->path_utf8, path) < 0)
+		return -1;
+
+	git_path_trim_slashes(&diriter->path_utf8);
+
+	if (diriter->path_utf8.size == 0) {
+		giterr_set(GITERR_FILESYSTEM, "Could not open directory '%s'", path);
+		return -1;
+	}
+
+	if ((diriter->parent_len = git_win32_path_from_utf8(diriter->path, diriter->path_utf8.ptr)) < 0 ||
+			!git_win32__findfirstfile_filter(path_filter, diriter->path_utf8.ptr)) {
+		giterr_set(GITERR_OS, "Could not parse the directory path '%s'", path);
+		return -1;
+	}
+
+	diriter->handle = FindFirstFileExW(
+		path_filter,
+		FindExInfoBasic,
+		&diriter->current,
+		FindExSearchNameMatch,
+		NULL,
+		FIND_FIRST_EX_LARGE_FETCH);
+
+	if (diriter->handle == INVALID_HANDLE_VALUE) {
+		giterr_set(GITERR_OS, "Could not open directory '%s'", path);
+		return -1;
+	}
+
+	diriter->parent_utf8_len = diriter->path_utf8.size;
+	diriter->flags = flags;
+	return 0;
+}
+
+static int diriter_update_utf16(git_path_diriter *diriter)
+{
+	size_t filename_len, path_len;
+
+	filename_len = wcslen(diriter->current.cFileName);
+
+	if (GIT_ADD_SIZET_OVERFLOW(&path_len, diriter->parent_len, filename_len) ||
+		GIT_ADD_SIZET_OVERFLOW(&path_len, path_len, 2))
+		return -1;
+
+	if (path_len > GIT_WIN_PATH_UTF16) {
+		giterr_set(GITERR_FILESYSTEM,
+			"invalid path '%.*ls\\%ls' (path too long)",
+			diriter->parent_len, diriter->path, diriter->current.cFileName);
+		return -1;
+	}
+
+	diriter->path[diriter->parent_len] = L'\\';
+	memcpy(&diriter->path[diriter->parent_len+1],
+		diriter->current.cFileName, filename_len * sizeof(wchar_t));
+	diriter->path[path_len-1] = L'\0';
+
+	return 0;
+}
+
+static int diriter_update_utf8(git_path_diriter *diriter)
+{
+	git_win32_utf8_path filename_utf8;
+	wchar_t *filename_utf16;
+	int filename_utf8_len;
+
+	/* Don't copy the full UTF-16 path into the UTF-8 path, only do the
+	 * UTF16 -> UTF8 conversion of the filename portion. This prevents us
+	 * from trying to encode the parent path differently, which would be
+	 * bad since we do arithmetic based on the already computed parent len.
+	 */
+
+	filename_utf16 = &diriter->path[diriter->parent_len + 1];
+
+	if ((filename_utf8_len = git_win32_path_to_utf8(filename_utf8, filename_utf16)) < 0)
+		return filename_utf8_len;
+
+	git_buf_truncate(&diriter->path_utf8, diriter->parent_utf8_len);
+	git_buf_putc(&diriter->path_utf8, '/');
+	git_buf_put(&diriter->path_utf8, filename_utf8, (size_t)filename_utf8_len);
+
+	if (git_buf_oom(&diriter->path_utf8))
+		return -1;
+
+	return 0;
+}
+
+int git_path_diriter_next(git_path_diriter *diriter)
+{
+	bool skip_dot = !(diriter->flags & GIT_PATH_DIR_INCLUDE_DOT_AND_DOTDOT);
+
+	do {
+		/* Our first time through, we already have the data from
+		 * FindFirstFileW.  Use it, otherwise get the next file.
+		 */
+		if (!diriter->needs_next)
+			diriter->needs_next = 1;
+		else if (!FindNextFileW(diriter->handle, &diriter->current))
+			return GIT_ITEROVER;
+	} while (skip_dot && git_path_is_dot_or_dotdotW(diriter->current.cFileName));
+
+	if (diriter_update_utf16(diriter) < 0 || diriter_update_utf8(diriter) < 0)
+		return -1;
+
+	return 0;
+}
+
+int git_path_diriter_filename(
+	const char **out,
+	size_t *out_len,
+	git_path_diriter *diriter)
+{
+	assert(out && out_len && diriter);
+
+	assert(diriter->path_utf8.size > diriter->parent_utf8_len);
+
+	*out = &diriter->path_utf8.ptr[diriter->parent_utf8_len+1];
+	*out_len = diriter->path_utf8.size - diriter->parent_utf8_len - 1;
+	return 0;
+}
+
+int git_path_diriter_fullpath(
+	const char **out,
+	size_t *out_len,
+	git_path_diriter *diriter)
+{
+	assert(out && out_len && diriter);
+
+	*out = diriter->path_utf8.ptr;
+	*out_len = diriter->path_utf8.size;
+	return 0;
+}
+
+int git_path_diriter_stat(struct stat *out, git_path_diriter *diriter)
+{
+	assert(out && diriter);
+
+	return git_win32__file_attribute_to_stat(out,
+		(WIN32_FILE_ATTRIBUTE_DATA *)&diriter->current,
+		diriter->path);
+}
+
+void git_path_diriter_free(git_path_diriter *diriter)
+{
+	if (diriter == NULL)
+		return;
+
+	if (diriter->handle != INVALID_HANDLE_VALUE) {
+		FindClose(diriter->handle);
+		diriter->handle = INVALID_HANDLE_VALUE;
+	}
+}
+
+#else
+
 int git_path_diriter_init(
 	git_path_diriter *diriter,
 	const char *path,
@@ -1090,9 +1266,13 @@ int git_path_diriter_init(
 	if (git_buf_puts(&diriter->path, path) < 0)
 		return -1;
 
-	git_path_mkposix(diriter->path.ptr);
 	git_path_trim_slashes(&diriter->path);
 
+	if (diriter->path.size == 0) {
+		giterr_set(GITERR_FILESYSTEM, "Could not open directory '%s'", path);
+		return -1;
+	}
+
 	if ((diriter->dir = opendir(diriter->path.ptr)) == NULL) {
 		git_buf_free(&diriter->path);
 
@@ -1159,6 +1339,8 @@ int git_path_diriter_filename(
 {
 	assert(out && out_len && diriter);
 
+	assert(diriter->path.size > diriter->parent_len);
+
 	*out = &diriter->path.ptr[diriter->parent_len+1];
 	*out_len = diriter->path.size - diriter->parent_len - 1;
 	return 0;
@@ -1200,13 +1382,15 @@ void git_path_diriter_free(git_path_diriter *diriter)
 	git_buf_free(&diriter->path);
 }
 
+#endif
+
 int git_path_dirload(
 	git_vector *contents,
 	const char *path,
 	size_t prefix_len,
 	unsigned int flags)
 {
-	git_path_diriter iter = {0};
+	git_path_diriter iter = GIT_PATH_DIRITER_INIT;
 	const char *name;
 	size_t name_len;
 	char *dup;