* Avoid doing concurrent DNS resolves of the same hostname in HostResolver.

* Add a 1 minute cache for host resolves.

* Refactor HostResolver to handle multiple requests.

* Make HostResolver a dependency of URLRequestContext. operate the HostResolver
in async mode for proxy resolver (bridging to IO thread).

TEST=unittests
BUG=13163

Review URL: http://codereview.chromium.org/118100

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@18236 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 18 insertions, 9 deletions

diff --git a/net/ftp/ftp_network_layer.cc b/net/ftp/ftp_network_layer.cc
index e05b67f..fa0e87c 100644
--- a/net/ftp/ftp_network_layer.cc
+++ b/net/ftp/ftp_network_layer.cc
@@ -10,17 +10,18 @@
 
 namespace net {
 
-FtpNetworkLayer::FtpNetworkLayer()
-    : suspended_(false) {
-  session_ = new FtpNetworkSession();
+FtpNetworkLayer::FtpNetworkLayer(HostResolver* host_resolver)
+    : session_(new FtpNetworkSession(host_resolver)),
+      suspended_(false) {
 }
 
 FtpNetworkLayer::~FtpNetworkLayer() {
 }
 
 // static
-FtpTransactionFactory* FtpNetworkLayer::CreateFactory() {
-  return new FtpNetworkLayer();
+FtpTransactionFactory* FtpNetworkLayer::CreateFactory(
+    HostResolver* host_resolver) {
+  return new FtpNetworkLayer(host_resolver);
 }
 
 FtpTransaction* FtpNetworkLayer::CreateTransaction() {
diff --git a/net/ftp/ftp_network_layer.h b/net/ftp/ftp_network_layer.h
index 71bd3b9..2d37eae 100644
--- a/net/ftp/ftp_network_layer.h
+++ b/net/ftp/ftp_network_layer.h
@@ -12,13 +12,14 @@ namespace net {
 
 class FtpNetworkSession;
 class FtpAuthCache;
+class HostResolver;
 
 class FtpNetworkLayer : public FtpTransactionFactory {
  public:
-  FtpNetworkLayer();
+  explicit FtpNetworkLayer(HostResolver* host_resolver);
   ~FtpNetworkLayer();
 
-  static FtpTransactionFactory* CreateFactory();
+  static FtpTransactionFactory* CreateFactory(HostResolver* host_resolver);
 
   // FtpTransactionFactory methods:
   virtual FtpTransaction* CreateTransaction();
diff --git a/net/ftp/ftp_network_session.h b/net/ftp/ftp_network_session.h
index 13ab216..29c34d2 100644
--- a/net/ftp/ftp_network_session.h
+++ b/net/ftp/ftp_network_session.h
@@ -10,14 +10,19 @@
 
 namespace net {
 
+class HostResolver;
+
 // This class holds session objects used by FtpNetworkTransaction objects.
 class FtpNetworkSession : public base::RefCounted<FtpNetworkSession> {
  public:
-  FtpNetworkSession() {}
+  explicit FtpNetworkSession(HostResolver* host_resolver)
+      : host_resolver_(host_resolver) {}
 
+  HostResolver* host_resolver() { return host_resolver_; }
   FtpAuthCache* auth_cache() { return &auth_cache_; }
 
  private:
+  HostResolver* host_resolver_;
   FtpAuthCache auth_cache_;
 };
 
diff --git a/net/ftp/ftp_network_transaction.cc b/net/ftp/ftp_network_transaction.cc
index ae6e4fc..87f9217 100644
--- a/net/ftp/ftp_network_transaction.cc
+++ b/net/ftp/ftp_network_transaction.cc
@@ -34,6 +34,7 @@ FtpNetworkTransaction::FtpNetworkTransaction(
       user_callback_(NULL),
       session_(session),
       request_(NULL),
+      resolver_(session->host_resolver()),
       read_ctrl_buf_size_(kCtrlBufLen),
       response_message_buf_len_(0),
       read_data_buf_len_(0),
diff --git a/net/ftp/ftp_network_transaction.h b/net/ftp/ftp_network_transaction.h
index 0bb67e5..53f0b29 100644
--- a/net/ftp/ftp_network_transaction.h
+++ b/net/ftp/ftp_network_transaction.h
@@ -142,7 +142,8 @@ class FtpNetworkTransaction : public FtpTransaction {
   const FtpRequestInfo* request_;
   FtpResponseInfo response_;
 
-  HostResolver resolver_;
+  // Cancels the outstanding request on destruction.
+  SingleRequestHostResolver resolver_;
   AddressList addresses_;
 
   // User buffer and length passed to the Read method.