From a04905c2bb5caac9c9c0a3d0928f6fdfb4600cb9 Mon Sep 17 00:00:00 2001
From: Shane Kearns <shane.kearns@accenture.com>
Date: Fri, 1 Apr 2011 11:08:39 +0100
Subject: Implement cache support for the async resolver

Add additional check when starting a queued request, as the cache may
have been populated while the request was queued.
Put completed requests in the cache (note cache code internally discards
errored results and only caches successful results)

Reviewed-by: Aaron Tunney
Reviewed-by: Markus Goetz
---
 src/network/kernel/qhostinfo_p.h         |  2 +-
 src/network/kernel/qhostinfo_symbian.cpp | 29 +++++++++++++++++++++++++++--
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/src/network/kernel/qhostinfo_p.h b/src/network/kernel/qhostinfo_p.h
index ab3e809..ceec04d 100644
--- a/src/network/kernel/qhostinfo_p.h
+++ b/src/network/kernel/qhostinfo_p.h
@@ -274,7 +274,7 @@ private:
         EIdle,
         EGetByName,
         EGetByAddress,
-        EGetMoreNames,
+        ECompleteFromCache,
         EError
     } iState;
 };
diff --git a/src/network/kernel/qhostinfo_symbian.cpp b/src/network/kernel/qhostinfo_symbian.cpp
index 73fed16..a38a845 100644
--- a/src/network/kernel/qhostinfo_symbian.cpp
+++ b/src/network/kernel/qhostinfo_symbian.cpp
@@ -108,6 +108,9 @@ QHostInfo QHostInfoAgent::fromName(const QString &hostName, QSharedPointer<QNetw
     QHostAddress address;
     if (address.setAddress(hostName)) {
         // Reverse lookup
+#if defined(QHOSTINFO_DEBUG)
+        qDebug("(reverse lookup)");
+#endif
         TInetAddr IpAdd;
         IpAdd.Input(qt_QString2TPtrC(hostName));
 
@@ -233,6 +236,24 @@ void QSymbianHostResolver::requestHostLookup()
         iHostName.toLatin1().constData(), id());
 #endif
 
+    QSymbianHostInfoLookupManger *manager = QSymbianHostInfoLookupManger::globalInstance();
+    if (manager->cache.isEnabled()) {
+        //check if name has been put in the cache while this request was queued
+        bool valid;
+        QHostInfo cachedResult = manager->cache.get(iHostName, &valid);
+        if (valid) {
+#if defined(QHOSTINFO_DEBUG)
+            qDebug("...found in cache");
+#endif
+            iResults = cachedResult;
+            iState = ECompleteFromCache;
+            SetActive();
+            TRequestStatus* stat = &iStatus;
+            User::RequestComplete(stat, KErrNone);
+            return;
+        }
+    }
+
     int err;
     if (iNetworkSession) {
         err = QNetworkSessionPrivate::nativeOpenHostResolver(*iNetworkSession, iHostResolver, KAfInet, KProtocolInetUdp);
@@ -295,12 +316,12 @@ void QSymbianHostResolver::DoCancel()
 #if defined(QHOSTINFO_DEBUG)
     qDebug() << "QSymbianHostResolver::DoCancel" << QThread::currentThreadId() << id() << (int)iState << this;
 #endif
-    if (iState == EGetByAddress || iState == EGetByName || iState == EGetMoreNames) {
+    if (iState == EGetByAddress || iState == EGetByName) {
         //these states have made an async request to host resolver
         iHostResolver.Cancel();
     } else {
         //for the self completing states there is nothing to cancel
-        Q_ASSERT(iState == EError);
+        Q_ASSERT(iState == EError || iState == ECompleteFromCache);
     }
 }
 
@@ -318,6 +339,7 @@ void QSymbianHostResolver::run()
     case EGetByAddress:
         processAddressResult();
         break;
+    case ECompleteFromCache:
     case EError:
         returnResults();
         break;
@@ -339,6 +361,9 @@ void QSymbianHostResolver::returnResults()
     iState = EIdle;
 
     QSymbianHostInfoLookupManger *manager = QSymbianHostInfoLookupManger::globalInstance();
+    if (manager->cache.isEnabled()) {
+        manager->cache.put(iHostName, iResults);
+    }
     manager->lookupFinished(this);
 
     resultEmitter.emitResultsReady(iResults);
-- 
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