Refactor language detection logic to allow non-static CLD data sources.

components/translate/content/browser/data_file_browser_cld_data_provider.cc

 // Copyright 2014 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 "data_file_browser_cld_data_provider.h"
+#include "components/translate/content/browser/data_file_browser_cld_data_provider.h"
 
 #include "base/basictypes.h"
 #include "base/files/file.h"
 #include "base/files/file_path.h"
+#include "base/files/file_util.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/memory/weak_ptr.h"
 #include "base/synchronization/lock.h"
 #include "base/task_runner.h"
+#include "components/translate/content/common/cld_data_source.h"
 #include "components/translate/content/common/data_file_cld_data_provider_messages.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 #include "ipc/ipc_message.h"
 #include "ipc/ipc_message_macros.h"
 #include "ipc/ipc_platform_file.h"
 
 namespace {
 // The data file,  cached as long as the process stays alive.
 // We also track the offset at which the data starts, and its length.
 base::FilePath g_cached_filepath;  // guarded by g_file_lock_
 base::File* g_cached_file = NULL;  // guarded by g_file_lock_
-uint64 g_cached_data_offset = -1;  // guarded by g_file_lock_
-uint64 g_cached_data_length = -1;  // guarded by g_file_lock_
+uint64 g_cached_data_offset = 0;  // guarded by g_file_lock_
+uint64 g_cached_data_length = 0;  // guarded by g_file_lock_
 
 // Guards g_cached_filepath
 base::LazyInstance<base::Lock> g_file_lock_;
 }  // namespace
 
 namespace translate {
 
-// Implementation of the static factory method from BrowserCldDataProvider,
-// hooking up this specific implementation for all of Chromium.
-BrowserCldDataProvider* CreateBrowserCldDataProviderFor(
-    content::WebContents* web_contents) {
-  VLOG(1) << "Creating DataFileBrowserCldDataProvider";
-  return new DataFileBrowserCldDataProvider(web_contents);
-}
-
 void SetCldDataFilePath(const base::FilePath& path) {
   VLOG(1) << "Setting CLD data file path to: " << path.value();
   base::AutoLock lock(g_file_lock_.Get());
   if (g_cached_filepath == path)
     return;  // no change necessary
   g_cached_filepath = path;
   // For sanity, clean these other values up just in case.
   g_cached_file = NULL;
-  g_cached_data_length = -1;
-  g_cached_data_offset = -1;
+  g_cached_data_length = 0;
+  g_cached_data_offset = 0;
 }
 
 base::FilePath GetCldDataFilePath() {
   base::AutoLock lock(g_file_lock_.Get());
+  if (g_cached_filepath.empty()) {
+    g_cached_filepath = translate::CldDataSource::Get()->GetCldDataFilePath();
+  }
   return g_cached_filepath;
 }
 
 DataFileBrowserCldDataProvider::DataFileBrowserCldDataProvider(
     content::WebContents* web_contents)
     : web_contents_(web_contents), weak_pointer_factory_() {
 }
 
 DataFileBrowserCldDataProvider::~DataFileBrowserCldDataProvider() {
+  // web_contents_ outlives this object
 }
 
 bool DataFileBrowserCldDataProvider::OnMessageReceived(
     const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(DataFileBrowserCldDataProvider, message)
   IPC_MESSAGE_HANDLER(ChromeViewHostMsg_NeedCldDataFile, OnCldDataRequest)
   IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
@@ skipping 72 matching lines @@
 
   content::RenderProcessHost* render_process_host =
       render_view_host->GetProcess();
   if (render_process_host == NULL) {
     // Render process destroyed, render view not yet dead. No need to bother.
     VLOG(1) << "Lost render process, giving up";
     return;
   }
 
   // Data available, respond to the request.
-  const int render_process_handle = render_process_host->GetHandle();
+  base::ProcessHandle render_process_handle = render_process_host->GetHandle();
   IPC::PlatformFileForTransit ipc_platform_file =
       IPC::GetFileHandleForProcess(handle->GetPlatformFile(),
                                    render_process_handle, false);
 
   // In general, sending a response from within the code path that is processing
   // a request is discouraged because there is potential for deadlock (if the
   // methods are sent synchronously) or loops (if the response can trigger a
   // new request). Neither of these concerns is relevant in this code, so
   // sending the response from within the code path of the request handler is
   // safe.
@@ skipping 61 matching lines @@
       // Else, this request has taken care of it all. Cache all info.
       VLOG(1) << "Caching CLD data file information.";
       g_cached_file = file.release();
       g_cached_data_offset = data_offset;
       g_cached_data_length = data_length;
     }
   }
 }
 
 }  // namespace translate