Make base:ReplaceFile return an informative error.

base/platform_file_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/platform_file.h"
 
 #include <io.h>
 
 #include "base/files/file_path.h"
 #include "base/logging.h"
@@ skipping 72 matching lines @@
   if (created && (INVALID_HANDLE_VALUE != file)) {
     if (flags & (PLATFORM_FILE_OPEN_ALWAYS))
       *created = (ERROR_ALREADY_EXISTS != GetLastError());
     else if (flags & (PLATFORM_FILE_CREATE_ALWAYS | PLATFORM_FILE_CREATE))
       *created = true;
   }
 
   if (error) {
     if (file != kInvalidPlatformFileValue)
       *error = PLATFORM_FILE_OK;
-    else {
-      DWORD last_error = GetLastError();
-      switch (last_error) {
-        case ERROR_SHARING_VIOLATION:
-          *error = PLATFORM_FILE_ERROR_IN_USE;
-          break;
-        case ERROR_FILE_EXISTS:
-          *error = PLATFORM_FILE_ERROR_EXISTS;
-          break;
-        case ERROR_FILE_NOT_FOUND:
-        case ERROR_PATH_NOT_FOUND:
-          *error = PLATFORM_FILE_ERROR_NOT_FOUND;
-          break;
-        case ERROR_ACCESS_DENIED:
-          *error = PLATFORM_FILE_ERROR_ACCESS_DENIED;
-          break;
-        case ERROR_TOO_MANY_OPEN_FILES:
-          *error = PLATFORM_FILE_ERROR_TOO_MANY_OPENED;
-          break;
-        case ERROR_OUTOFMEMORY:
-        case ERROR_NOT_ENOUGH_MEMORY:
-          *error = PLATFORM_FILE_ERROR_NO_MEMORY;
-          break;
-        case ERROR_HANDLE_DISK_FULL:
-        case ERROR_DISK_FULL:
-        case ERROR_DISK_RESOURCES_EXHAUSTED:
-          *error = PLATFORM_FILE_ERROR_NO_SPACE;
-          break;
-        case ERROR_USER_MAPPED_FILE:
-          *error = PLATFORM_FILE_ERROR_INVALID_OPERATION;
-          break;
-        case ERROR_NOT_READY:
-        case ERROR_SECTOR_NOT_FOUND:
-        case ERROR_DEV_NOT_EXIST:
-        case ERROR_IO_DEVICE:
-        case ERROR_FILE_CORRUPT:
-        case ERROR_DISK_CORRUPT:
-          *error = PLATFORM_FILE_ERROR_IO;
-          break;
-        default:
-          UMA_HISTOGRAM_SPARSE_SLOWLY("PlatformFile.UnknownCreateFileErrors",
-                                      last_error);
-          *error = PLATFORM_FILE_ERROR_FAILED;
-      }
-    }
+    else
+      *error = LastErrorToPlatformFileError(GetLastError());
   }
 
   return file;
 }
 
 FILE* FdopenPlatformFile(PlatformFile file, const char* mode) {
   if (file == kInvalidPlatformFileValue)
     return NULL;
   int fd = _open_osfhandle(reinterpret_cast<intptr_t>(file), 0);
   if (fd < 0)
@@ skipping 144 matching lines @@
   info->size = size.QuadPart;
   info->is_directory =
       (file_info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
   info->is_symbolic_link = false; // Windows doesn't have symbolic links.
   info->last_modified = base::Time::FromFileTime(file_info.ftLastWriteTime);
   info->last_accessed = base::Time::FromFileTime(file_info.ftLastAccessTime);
   info->creation_time = base::Time::FromFileTime(file_info.ftCreationTime);
   return true;
 }
 
+PlatformFileError LastErrorToPlatformFileError(DWORD last_error) {
+  switch (last_error) {
+    case ERROR_SHARING_VIOLATION:
+      return PLATFORM_FILE_ERROR_IN_USE;
+    case ERROR_FILE_EXISTS:
+      return PLATFORM_FILE_ERROR_EXISTS;
+    case ERROR_FILE_NOT_FOUND:
+    case ERROR_PATH_NOT_FOUND:
+      return PLATFORM_FILE_ERROR_NOT_FOUND;
+    case ERROR_ACCESS_DENIED:
+      return PLATFORM_FILE_ERROR_ACCESS_DENIED;
+    case ERROR_TOO_MANY_OPEN_FILES:
+      return PLATFORM_FILE_ERROR_TOO_MANY_OPENED;
+    case ERROR_OUTOFMEMORY:
+    case ERROR_NOT_ENOUGH_MEMORY:
+      return PLATFORM_FILE_ERROR_NO_MEMORY;
+    case ERROR_HANDLE_DISK_FULL:
+    case ERROR_DISK_FULL:
+    case ERROR_DISK_RESOURCES_EXHAUSTED:
+      return PLATFORM_FILE_ERROR_NO_SPACE;
+    case ERROR_USER_MAPPED_FILE:
+      return PLATFORM_FILE_ERROR_INVALID_OPERATION;
+    case ERROR_NOT_READY:
+    case ERROR_SECTOR_NOT_FOUND:
+    case ERROR_DEV_NOT_EXIST:
+    case ERROR_IO_DEVICE:
+    case ERROR_FILE_CORRUPT:
+    case ERROR_DISK_CORRUPT:
+      return PLATFORM_FILE_ERROR_IO;
+    default:
+      UMA_HISTOGRAM_SPARSE_SLOWLY("PlatformFile.UnknownCreateFileErrors",
+                                  last_error);
+      return PLATFORM_FILE_ERROR_FAILED;
+  }
+}
+
 }  // namespace base