upload android base code part6

android/system/core/base/utf8.cpp

@@ -0,0 +1,235 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <windows.h>
+
+#include "android-base/utf8.h"
+
+#include <fcntl.h>
+#include <stdio.h>
+
+#include <algorithm>
+#include <string>
+
+#include "android-base/logging.h"
+
+namespace android {
+namespace base {
+
+// Helper to set errno based on GetLastError() after WideCharToMultiByte()/MultiByteToWideChar().
+static void SetErrnoFromLastError() {
+  switch (GetLastError()) {
+    case ERROR_NO_UNICODE_TRANSLATION:
+      errno = EILSEQ;
+      break;
+    default:
+      errno = EINVAL;
+      break;
+  }
+}
+
+bool WideToUTF8(const wchar_t* utf16, const size_t size, std::string* utf8) {
+  utf8->clear();
+
+  if (size == 0) {
+    return true;
+  }
+
+  // TODO: Consider using std::wstring_convert once libcxx is supported on
+  // Windows.
+
+  // Only Vista or later has this flag that causes WideCharToMultiByte() to
+  // return an error on invalid characters.
+  const DWORD flags =
+#if (WINVER >= 0x0600)
+    WC_ERR_INVALID_CHARS;
+#else
+    0;
+#endif
+
+  const int chars_required = WideCharToMultiByte(CP_UTF8, flags, utf16, size,
+                                                 NULL, 0, NULL, NULL);
+  if (chars_required <= 0) {
+    SetErrnoFromLastError();
+    return false;
+  }
+
+  // This could potentially throw a std::bad_alloc exception.
+  utf8->resize(chars_required);
+
+  const int result = WideCharToMultiByte(CP_UTF8, flags, utf16, size,
+                                         &(*utf8)[0], chars_required, NULL,
+                                         NULL);
+  if (result != chars_required) {
+    SetErrnoFromLastError();
+    CHECK_LE(result, chars_required) << "WideCharToMultiByte wrote " << result
+        << " chars to buffer of " << chars_required << " chars";
+    utf8->clear();
+    return false;
+  }
+
+  return true;
+}
+
+bool WideToUTF8(const wchar_t* utf16, std::string* utf8) {
+  // Compute string length of NULL-terminated string with wcslen().
+  return WideToUTF8(utf16, wcslen(utf16), utf8);
+}
+
+bool WideToUTF8(const std::wstring& utf16, std::string* utf8) {
+  // Use the stored length of the string which allows embedded NULL characters
+  // to be converted.
+  return WideToUTF8(utf16.c_str(), utf16.length(), utf8);
+}
+
+// Internal helper function that takes MultiByteToWideChar() flags.
+static bool UTF8ToWideWithFlags(const char* utf8, const size_t size, std::wstring* utf16,
+                                const DWORD flags) {
+  utf16->clear();
+
+  if (size == 0) {
+    return true;
+  }
+
+  // TODO: Consider using std::wstring_convert once libcxx is supported on
+  // Windows.
+  const int chars_required = MultiByteToWideChar(CP_UTF8, flags, utf8, size,
+                                                 NULL, 0);
+  if (chars_required <= 0) {
+    SetErrnoFromLastError();
+    return false;
+  }
+
+  // This could potentially throw a std::bad_alloc exception.
+  utf16->resize(chars_required);
+
+  const int result = MultiByteToWideChar(CP_UTF8, flags, utf8, size,
+                                         &(*utf16)[0], chars_required);
+  if (result != chars_required) {
+    SetErrnoFromLastError();
+    CHECK_LE(result, chars_required) << "MultiByteToWideChar wrote " << result
+        << " chars to buffer of " << chars_required << " chars";
+    utf16->clear();
+    return false;
+  }
+
+  return true;
+}
+
+bool UTF8ToWide(const char* utf8, const size_t size, std::wstring* utf16) {
+  // If strictly interpreting as UTF-8 succeeds, return success.
+  if (UTF8ToWideWithFlags(utf8, size, utf16, MB_ERR_INVALID_CHARS)) {
+    return true;
+  }
+
+  const int saved_errno = errno;
+
+  // Fallback to non-strict interpretation, allowing invalid characters and
+  // converting as best as possible, and return false to signify a problem.
+  (void)UTF8ToWideWithFlags(utf8, size, utf16, 0);
+  errno = saved_errno;
+  return false;
+}
+
+bool UTF8ToWide(const char* utf8, std::wstring* utf16) {
+  // Compute string length of NULL-terminated string with strlen().
+  return UTF8ToWide(utf8, strlen(utf8), utf16);
+}
+
+bool UTF8ToWide(const std::string& utf8, std::wstring* utf16) {
+  // Use the stored length of the string which allows embedded NULL characters
+  // to be converted.
+  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 (!UTF8PathToWindowsLongPath(name, &name_utf16)) {
+    return -1;
+  }
+
+  int mode = 0;
+  if ((flags & O_CREAT) != 0) {
+    va_list args;
+    va_start(args, flags);
+    mode = va_arg(args, int);
+    va_end(args);
+  }
+
+  return _wopen(name_utf16.c_str(), flags, mode);
+}
+
+int unlink(const char* name) {
+  std::wstring name_utf16;
+  if (!UTF8PathToWindowsLongPath(name, &name_utf16)) {
+    return -1;
+  }
+
+  return _wunlink(name_utf16.c_str());
+}
+
+}  // namespace utf8
+}  // namespace base
+}  // namespace android