Add (partial) support for Windows long paths
* Update android::base::utf8::open/unlink to support Windows long
paths
* Add android::base::utf8::fopen, also with support for Windows long
paths
* Upcoming CLs will add additional APIs to support additional use cases
Test: Added tests to utf8_test
Bug: 38268753
Change-Id: If72af327f3487766f5370a2f43ee9cabd4a8a810
diff --git a/utf8.cpp b/utf8.cpp
index 3cca700..5984fb0 100644
--- a/utf8.cpp
+++ b/utf8.cpp
@@ -19,7 +19,9 @@
#include "android-base/utf8.h"
#include <fcntl.h>
+#include <stdio.h>
+#include <algorithm>
#include <string>
#include "android-base/logging.h"
@@ -153,12 +155,58 @@
return UTF8ToWide(utf8.c_str(), utf8.length(), utf16);
}
+static bool isDriveLetter(wchar_t c) {
+ return (c >= L'a' && c <= L'z') || (c >= L'A' && c <= L'Z');
+}
+
+bool UTF8PathToWindowsLongPath(const char* utf8, std::wstring* utf16) {
+ if (!UTF8ToWide(utf8, utf16)) {
+ return false;
+ }
+ // Note: Although most Win32 File I/O API are limited to MAX_PATH (260
+ // characters), the CreateDirectory API is limited to 248 characters.
+ if (utf16->length() >= 248) {
+ // If path is of the form "x:\" or "x:/"
+ if (isDriveLetter((*utf16)[0]) && (*utf16)[1] == L':' &&
+ ((*utf16)[2] == L'\\' || (*utf16)[2] == L'/')) {
+ // Append long path prefix, and make sure there are no unix-style
+ // separators to ensure a fully compliant Win32 long path string.
+ utf16->insert(0, LR"(\\?\)");
+ std::replace(utf16->begin(), utf16->end(), L'/', L'\\');
+ }
+ }
+ return true;
+}
+
// Versions of standard library APIs that support UTF-8 strings.
namespace utf8 {
+FILE* fopen(const char* name, const char* mode) {
+ std::wstring name_utf16;
+ if (!UTF8PathToWindowsLongPath(name, &name_utf16)) {
+ return nullptr;
+ }
+
+ std::wstring mode_utf16;
+ if (!UTF8ToWide(mode, &mode_utf16)) {
+ return nullptr;
+ }
+
+ return _wfopen(name_utf16.c_str(), mode_utf16.c_str());
+}
+
+int mkdir(const char* name, mode_t mode) {
+ std::wstring name_utf16;
+ if (!UTF8PathToWindowsLongPath(name, &name_utf16)) {
+ return -1;
+ }
+
+ return _wmkdir(name_utf16.c_str());
+}
+
int open(const char* name, int flags, ...) {
std::wstring name_utf16;
- if (!UTF8ToWide(name, &name_utf16)) {
+ if (!UTF8PathToWindowsLongPath(name, &name_utf16)) {
return -1;
}
@@ -175,7 +223,7 @@
int unlink(const char* name) {
std::wstring name_utf16;
- if (!UTF8ToWide(name, &name_utf16)) {
+ if (!UTF8PathToWindowsLongPath(name, &name_utf16)) {
return -1;
}