AppendToFile implementation.

base/file_util_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/file_util.h"
 
 #include <windows.h>
 #include <propvarutil.h>
 #include <psapi.h>
 #include <shellapi.h>
@@ skipping 704 matching lines @@
     DLOG(WARNING) << "writing file " << filename.value()
                   << " failed, error code=" << GetLastError();
   } else {
     // Didn't write all the bytes.
     DLOG(WARNING) << "wrote" << written << " bytes to "
                   << filename.value() << " expected " << size;
   }
   return -1;
 }
 
+int AppendToFile(const FilePath& filename, const char* data, int size) {
+  base::ThreadRestrictions::AssertIOAllowed();
+  base::win::ScopedHandle file(CreateFile(filename.value().c_str(),
+                                          FILE_APPEND_DATA,
+                                          0,
+                                          NULL,
+                                          OPEN_EXISTING,
+                                          0,
+                                          NULL));
+  if (!file) {
+    DLOG(WARNING) << "CreateFile failed for path " << filename.value()
+                  << " error code=" << GetLastError();
+    return -1;
+  }
+
+  DWORD written;
+  BOOL result = ::WriteFile(file, data, size, &written, NULL);
+  if (result && static_cast<int>(written) == size)
+    return written;
+
+  if (!result) {
+    // WriteFile failed.
+    DLOG(WARNING) << "writing file " << filename.value()
+                  << " failed, error code=" << GetLastError();
+  } else {
+    // Didn't write all the bytes.
+    DLOG(WARNING) << "wrote" << written << " bytes to "
+                  << filename.value() << " expected " << size;
+  }
+  return -1;
+}
+
 // Gets the current working directory for the process.
 bool GetCurrentDirectory(FilePath* dir) {
   base::ThreadRestrictions::AssertIOAllowed();
 
   wchar_t system_buffer[MAX_PATH];
   system_buffer[0] = 0;
   DWORD len = ::GetCurrentDirectory(MAX_PATH, system_buffer);
   if (len == 0 || len > MAX_PATH)
     return false;
   // TODO(evanm): the old behavior of this function was to always strip the
@@ skipping 339 matching lines @@
   HANDLE cp = GetCurrentProcess();
   if (::GetMappedFileNameW(cp, file_view, mapped_file_path, kMaxPathLength)) {
     *nt_path = FilePath(mapped_file_path);
     success = true;
   }
   ::UnmapViewOfFile(file_view);
   return success;
 }
 
 }  // namespace file_util