Add a visualizer for the HostCache (DNS cache) on the network internals page.

BUG=http://crbug.com/14478

Review URL: http://codereview.chromium.org/172100

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@25227 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 92 insertions, 3 deletions

diff --git a/net/base/host_cache.h b/net/base/host_cache.h
index d5b9511..ab01c86 100644
--- a/net/base/host_cache.h
+++ b/net/base/host_cache.h
@@ -31,6 +31,8 @@ class HostCache {
     base::TimeTicks expiration;
   };
 
+  typedef base::hash_map<std::string, scoped_refptr<Entry> > EntryMap;
+
   // Constructs a HostCache whose entries are valid for |cache_duration_ms|
   // milliseconds. The cache will store up to |max_entries|.
   HostCache(size_t max_entries, size_t cache_duration_ms);
@@ -60,12 +62,23 @@ class HostCache {
     return entries_.size();
   }
 
+  size_t max_entries() const {
+    return max_entries_;
+  }
+
+  size_t cache_duration_ms() const {
+    return cache_duration_ms_;
+  }
+
+  // Note that this map may contain expired entries.
+  const EntryMap& entries() const {
+    return entries_;
+  }
+
  private:
   FRIEND_TEST(HostCacheTest, Compact);
   FRIEND_TEST(HostCacheTest, NoCache);
 
-  typedef base::hash_map<std::string, scoped_refptr<Entry> > EntryMap;
-
   // Returns true if this cache entry's result is valid at time |now|.
   static bool CanUseEntry(const Entry* entry, const base::TimeTicks now);
 
diff --git a/net/base/host_resolver.h b/net/base/host_resolver.h
index eecf394..e5c46a3 100644
--- a/net/base/host_resolver.h
+++ b/net/base/host_resolver.h
@@ -16,6 +16,7 @@ class MessageLoop;
 namespace net {
 
 class AddressList;
+class HostCache;
 class LoadLog;
 
 // This class represents the task of resolving hostnames (or IP address
@@ -130,6 +131,10 @@ class HostResolver : public base::RefCounted<HostResolver> {
   // Unregisters an observer previously added by AddObserver().
   virtual void RemoveObserver(Observer* observer) = 0;
 
+  // Returns the host cache, or NULL if this implementation does not use
+  // a HostCache.
+  virtual HostCache* GetHostCache() = 0;
+
   // TODO(eroman): temp hack for http://crbug.com/18373
   virtual void Shutdown() = 0;
 
diff --git a/net/base/host_resolver_impl.cc b/net/base/host_resolver_impl.cc
index eed116a..61f075e 100644
--- a/net/base/host_resolver_impl.cc
+++ b/net/base/host_resolver_impl.cc
@@ -414,6 +414,10 @@ void HostResolverImpl::RemoveObserver(Observer* observer) {
   observers_.erase(it);
 }
 
+HostCache* HostResolverImpl::GetHostCache() {
+  return &cache_;
+}
+
 void HostResolverImpl::Shutdown() {
   shutdown_ = true;
 
diff --git a/net/base/host_resolver_impl.h b/net/base/host_resolver_impl.h
index 45c8841..74dea08 100644
--- a/net/base/host_resolver_impl.h
+++ b/net/base/host_resolver_impl.h
@@ -65,6 +65,7 @@ class HostResolverImpl : public HostResolver {
   virtual void CancelRequest(RequestHandle req);
   virtual void AddObserver(Observer* observer);
   virtual void RemoveObserver(Observer* observer);
+  virtual HostCache* GetHostCache();
 
   // TODO(eroman): temp hack for http://crbug.com/15513
   virtual void Shutdown();
diff --git a/net/base/mock_host_resolver.cc b/net/base/mock_host_resolver.cc
index 3c09e15..addccd0f 100644
--- a/net/base/mock_host_resolver.cc
+++ b/net/base/mock_host_resolver.cc
@@ -66,6 +66,10 @@ void MockHostResolverBase::RemoveObserver(Observer* observer) {
   impl_->RemoveObserver(observer);
 }
 
+HostCache* MockHostResolverBase::GetHostCache() {
+  return impl_->GetHostCache();
+}
+
 void MockHostResolverBase::Shutdown() {
   impl_->Shutdown();
 }
diff --git a/net/base/mock_host_resolver.h b/net/base/mock_host_resolver.h
index 548cd0a..01a2eab 100644
--- a/net/base/mock_host_resolver.h
+++ b/net/base/mock_host_resolver.h
@@ -49,6 +49,7 @@ class MockHostResolverBase : public HostResolver {
   virtual void CancelRequest(RequestHandle req);
   virtual void AddObserver(Observer* observer);
   virtual void RemoveObserver(Observer* observer);
+  virtual HostCache* GetHostCache();
   // TODO(eroman): temp hack for http://crbug.com/18373
   virtual void Shutdown();
 
diff --git a/net/url_request/url_request_view_net_internal_job.cc b/net/url_request/url_request_view_net_internal_job.cc
index dba83b1..d2185c4 100644
--- a/net/url_request/url_request_view_net_internal_job.cc
+++ b/net/url_request/url_request_view_net_internal_job.cc
@@ -9,8 +9,10 @@
 #include "base/stl_util-inl.h"
 #include "base/string_util.h"
 #include "net/base/escape.h"
+#include "net/base/host_cache.h"
 #include "net/base/load_log_util.h"
 #include "net/base/net_errors.h"
+#include "net/base/net_util.h"
 #include "net/proxy/proxy_service.h"
 #include "net/url_request/url_request_context.h"
 
@@ -189,7 +191,66 @@ class HostResolverCacheSubSection : public SubSection {
   }
 
   virtual void OutputBody(URLRequestContext* context, std::string* out) {
-    out->append("TODO");
+    const net::HostCache* host_cache = context->host_resolver()->GetHostCache();
+
+    if (!host_cache || host_cache->caching_is_disabled()) {
+      out->append("<i>Caching is disabled.</i>");
+      return;
+    }
+
+    out->append(StringPrintf("<ul><li>Size: %u</li>"
+                             "<li>Capacity: %u</li>"
+                             "<li>Time to live (ms): %u</li></ul>",
+                             host_cache->size(),
+                             host_cache->max_entries(),
+                             host_cache->cache_duration_ms()));
+
+    out->append("<table border=1>"
+                "<tr>"
+                "<th>Host</th>"
+                "<th>First address</th>"
+                "<th>Time to live (ms)</th>"
+                "</tr>");
+
+    for (net::HostCache::EntryMap::const_iterator it =
+             host_cache->entries().begin();
+         it != host_cache->entries().end();
+         ++it) {
+      const std::string& host = it->first;
+      const net::HostCache::Entry* entry = it->second.get();
+
+      if (entry->error == net::OK) {
+        // Note that ttl_ms may be negative, for the cases where entries have
+        // expired but not been garbage collected yet.
+        int ttl_ms = static_cast<int>(
+            (entry->expiration - base::TimeTicks::Now()).InMilliseconds());
+
+        // Color expired entries blue.
+        if (ttl_ms > 0) {
+          out->append("<tr>");
+        } else {
+          out->append("<tr style='color:blue'>");
+        }
+
+        std::string address_str =
+            net::NetAddressToString(entry->addrlist.head());
+
+        out->append(StringPrintf("<td>%s</td><td>%s</td><td>%d</td></tr>",
+                                 EscapeForHTML(host).c_str(),
+                                 EscapeForHTML(address_str).c_str(),
+                                 ttl_ms));
+      } else {
+        // This was an entry that failed to be resolved.
+        // Color negative entries red.
+        out->append(StringPrintf(
+            "<tr style='color:red'><td>%s</td>"
+            "<td colspan=2>%s</td></tr>",
+            EscapeForHTML(host).c_str(),
+            EscapeForHTML(net::ErrorToString(entry->error)).c_str()));
+      }
+    }
+
+    out->append("</table>");
   }
 };