* 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

3 files changed, 21 insertions, 5 deletions

diff --git a/net/url_request/url_request_context.h b/net/url_request/url_request_context.h
index 8e32c97..2c9f6fa 100644
--- a/net/url_request/url_request_context.h
+++ b/net/url_request/url_request_context.h
@@ -19,6 +19,7 @@ namespace net {
 class CookieMonster;
 class ForceTLSState;
 class FtpTransactionFactory;
+class HostResolver;
 class HttpTransactionFactory;
 class ProxyService;
 }
@@ -28,13 +29,18 @@ class URLRequestContext :
     public base::RefCountedThreadSafe<URLRequestContext> {
  public:
   URLRequestContext()
-      : proxy_service_(NULL),
+      : host_resolver_(NULL),
+        proxy_service_(NULL),
         http_transaction_factory_(NULL),
         ftp_transaction_factory_(NULL),
         cookie_store_(NULL),
         force_tls_state_(NULL) {
   }
 
+  net::HostResolver* host_resolver() const {
+    return host_resolver_;
+  }
+
   // Get the proxy service for this context.
   net::ProxyService* proxy_service() const {
     return proxy_service_;
@@ -88,6 +94,7 @@ class URLRequestContext :
 
   // The following members are expected to be initialized and owned by
   // subclasses.
+  net::HostResolver* host_resolver_;
   net::ProxyService* proxy_service_;
   net::HttpTransactionFactory* http_transaction_factory_;
   net::FtpTransactionFactory* ftp_transaction_factory_;
diff --git a/net/url_request/url_request_unittest.cc b/net/url_request/url_request_unittest.cc
index 6551df1..18ff111 100644
--- a/net/url_request/url_request_unittest.cc
+++ b/net/url_request/url_request_unittest.cc
@@ -45,10 +45,12 @@ namespace {
 class URLRequestHttpCacheContext : public URLRequestContext {
  public:
   URLRequestHttpCacheContext() {
+    host_resolver_ = new net::HostResolver;
     proxy_service_ = net::ProxyService::CreateNull();
     http_transaction_factory_ =
-        new net::HttpCache(net::HttpNetworkLayer::CreateFactory(proxy_service_),
-                           disk_cache::CreateInMemoryCacheBackend(0));
+        new net::HttpCache(
+          net::HttpNetworkLayer::CreateFactory(host_resolver_, proxy_service_),
+          disk_cache::CreateInMemoryCacheBackend(0));
     // In-memory cookie store.
     cookie_store_ = new net::CookieMonster();
   }
@@ -57,6 +59,7 @@ class URLRequestHttpCacheContext : public URLRequestContext {
     delete cookie_store_;
     delete http_transaction_factory_;
     delete proxy_service_;
+    delete host_resolver_;
   }
 };
 
diff --git a/net/url_request/url_request_unittest.h b/net/url_request/url_request_unittest.h
index d4e2b82..1c880fd 100644
--- a/net/url_request/url_request_unittest.h
+++ b/net/url_request/url_request_unittest.h
@@ -21,6 +21,7 @@
 #include "base/thread.h"
 #include "base/time.h"
 #include "base/waitable_event.h"
+#include "net/base/host_resolver.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/base/ssl_test_util.h"
@@ -42,22 +43,27 @@ using base::TimeDelta;
 class TestURLRequestContext : public URLRequestContext {
  public:
   TestURLRequestContext() {
+    host_resolver_ = new net::HostResolver;
     proxy_service_ = net::ProxyService::CreateNull();
     http_transaction_factory_ =
-        net::HttpNetworkLayer::CreateFactory(proxy_service_);
+        net::HttpNetworkLayer::CreateFactory(host_resolver_,
+            proxy_service_);
   }
 
   explicit TestURLRequestContext(const std::string& proxy) {
+    host_resolver_ = new net::HostResolver;
     net::ProxyConfig proxy_config;
     proxy_config.proxy_rules.ParseFromString(proxy);
     proxy_service_ = net::ProxyService::CreateFixed(proxy_config);
     http_transaction_factory_ =
-        net::HttpNetworkLayer::CreateFactory(proxy_service_);
+        net::HttpNetworkLayer::CreateFactory(host_resolver_,
+            proxy_service_);
   }
 
   virtual ~TestURLRequestContext() {
     delete http_transaction_factory_;
     delete proxy_service_;
+    delete host_resolver_;
   }
 };