Teach the network service to clear its disk cache if requested.

mojo/services/network/network_context.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 "mojo/services/network/network_context.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/base_paths.h"
 #include "base/bind.h"
 #include "base/command_line.h"
+#include "base/files/file_util.h"
 #include "base/path_service.h"
 #include "mojo/common/user_agent.h"
 #include "mojo/services/network/url_loader_impl.h"
 #include "net/log/net_log_util.h"
 #include "net/log/write_to_file_net_log_observer.h"
 #include "net/proxy/proxy_service.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_builder.h"
 
 namespace mojo {
 
 namespace {
 // Logs network information to the specified file.
 const char kLogNetLog[] = "log-net-log";
+
+base::FilePath GetCacheDirectory(const base::FilePath& base_path) {
+  return base_path.Append(FILE_PATH_LITERAL("Cache"));
+}
 }
 
 class NetworkContext::MojoNetLog : public net::NetLog {
  public:
   MojoNetLog() {
     const base::CommandLine* command_line =
         base::CommandLine::ForCurrentProcess();
     if (!command_line->HasSwitch(kLogNetLog))
       return;
 
@@ skipping 20 matching lines @@
     if (write_to_file_observer_)
       write_to_file_observer_->StopObserving(nullptr);
   }
 
  private:
   scoped_ptr<net::WriteToFileNetLogObserver> write_to_file_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(MojoNetLog);
 };
 
+// static
+void NetworkContext::ClearCache(const base::FilePath& base_path,
+                                scoped_refptr<base::TaskRunner> task_runner) {
+  base::FilePath trash_dir = base_path.Append(FILE_PATH_LITERAL("Trash"));
+  base::CreateDirectory(trash_dir);
+  base::FilePath dest_dir;
+  base::CreateTemporaryDirInDir(trash_dir, "", &dest_dir);
+
+  // Move the current cache directory, if present, into trash.
+  base::FilePath cache_dir = GetCacheDirectory(base_path);
+  if (PathExists(cache_dir)) {
+    base::File::Error error;
+    if (!base::ReplaceFile(cache_dir, dest_dir, &error)) {
+      LOG(ERROR) << "Failed to clear cache content: " << error;
+    }
+  }
+  // Recreate the cache directory.
+  base::CreateDirectory(cache_dir);
+
+  task_runner->PostTask(
+      FROM_HERE,
+      base::Bind(base::IgnoreResult(&base::DeleteFile), trash_dir, true));
+}
+
 NetworkContext::NetworkContext(
     scoped_ptr<net::URLRequestContext> url_request_context)
     : net_log_(new MojoNetLog),
       url_request_context_(url_request_context.Pass()),
       in_shutdown_(false) {
   url_request_context_->set_net_log(net_log_.get());
 }
 
 NetworkContext::NetworkContext(const base::FilePath& base_path)
     : NetworkContext(MakeURLRequestContext(base_path)) {
@@ skipping 36 matching lines @@
   builder.set_user_agent(mojo::common::GetUserAgent());
   builder.set_proxy_service(net::ProxyService::CreateDirect());
   builder.set_transport_security_persister_path(base_path);
   builder.set_data_enabled(true);
 
   net::URLRequestContextBuilder::HttpCacheParams cache_params;
 #if defined(OS_ANDROID)
   // On Android, we store the cache on disk becase we can run only a single
   // instance of the shell at a time.
   cache_params.type = net::URLRequestContextBuilder::HttpCacheParams::DISK;
-  cache_params.path = base_path.Append(FILE_PATH_LITERAL("Cache"));
+  cache_params.path = GetCacheDirectory(base_path);
 #else
   // On desktop, we store the cache in memory so we can run many shells
   // in parallel when running tests, otherwise the network services in each
   // shell will corrupt the disk cache.
   cache_params.type = net::URLRequestContextBuilder::HttpCacheParams::IN_MEMORY;
 #endif
 
   builder.EnableHttpCache(cache_params);
   builder.set_file_enabled(true);
 
   return make_scoped_ptr(builder.Build());
 }
 
 }  // namespace mojo