Changeset 181816 in webkit

Timestamp:

Mar 20, 2015, 4:09:56 PM (11 years ago)

Author:

Chris Dumez

Message:

[WK2] NetworkCache retrievals sometimes fail on browser startup
​https://bugs.webkit.org/show_bug.cgi?id=142925
<rdar://problem/20245368>

Reviewed by Antti Koivisto.

NetworkCache retrievals sometimes fail on browser startup for resources
that are actually cached. The reason is that we are using a bloom filter
for performance reasons to avoid unnecessary disk I/O and this bloom
filter is populated on start up in a background thread by traversing the
cache files on disk. However, when restoring the tabs on start-up we
sometimes query this bloom filter before it is completely populated and
we thus fail to retrieve cached entries because we think they don't
exist and don't check the disk.

This patch adds an "isPopulatingContentsFilter" flag that is turned ON
on start up while we are populating the bloon filter. We then bypass
the bloom filter and send queries directly to disk on start up if this
flag is ON.

• NetworkProcess/cache/NetworkCacheStorage.cpp:

(WebKit::NetworkCache::Storage::initialize):
(WebKit::NetworkCache::Storage::retrieve):
(WebKit::NetworkCache::Storage::dispatchPendingWriteOperations):
(WebKit::NetworkCache::Storage::dispatchHeaderWriteOperation):

• NetworkProcess/cache/NetworkCacheStorage.h:

(WebKit::NetworkCache::Storage::cacheMayContain):

Location:

trunk/Source/WebKit2

Files:

• ChangeLog (modified) (1 diff)
• NetworkProcess/cache/NetworkCacheStorage.cpp (modified) (4 diffs)
• NetworkProcess/cache/NetworkCacheStorage.h (modified) (2 diffs)

trunk/Source/WebKit2/ChangeLog

@@ +1 @@
+2015-03-20  Chris Dumez  <cdumez@apple.com>
+
+        [WK2] NetworkCache retrievals sometimes fail on browser startup
+        https://bugs.webkit.org/show_bug.cgi?id=142925
+        <rdar://problem/20245368>
+
+        Reviewed by Antti Koivisto.
+
+        NetworkCache retrievals sometimes fail on browser startup for resources
+        that are actually cached. The reason is that we are using a bloom filter
+        for performance reasons to avoid unnecessary disk I/O and this bloom
+        filter is populated on start up in a background thread by traversing the
+        cache files on disk. However, when restoring the tabs on start-up we
+        sometimes query this bloom filter before it is completely populated and
+        we thus fail to retrieve cached entries because we think they don't
+        exist and don't check the disk.
+
+        This patch adds an "isPopulatingContentsFilter" flag that is turned ON
+        on start up while we are populating the bloon filter. We then bypass
+        the bloom filter and send queries directly to disk on start up if this
+        flag is ON.
+
+        * NetworkProcess/cache/NetworkCacheStorage.cpp:
+        (WebKit::NetworkCache::Storage::initialize):
+        (WebKit::NetworkCache::Storage::retrieve):
+        (WebKit::NetworkCache::Storage::dispatchPendingWriteOperations):
+        (WebKit::NetworkCache::Storage::dispatchHeaderWriteOperation):
+        * NetworkProcess/cache/NetworkCacheStorage.h:
+        (WebKit::NetworkCache::Storage::cacheMayContain):
+
 2015-03-20  Chris Dumez  <cdumez@apple.com>
 

trunk/Source/WebKit2/NetworkProcess/cache/NetworkCacheStorage.cpp

@@ -93 +93 @@
             m_approximateSize += fileSize;
         });
+        m_hasPopulatedContentsFilter = true;
     });
 }
@@ -373 +374 @@
     }
 
-    if (!m_contentsFilter.mayContain(key.shortHash())) {
+    if (!cacheMayContain(key.shortHash())) {
         completionHandler(nullptr);
         return;
@@ -461 +462 @@
         m_activeWriteOperations.add(WTF::move(writeOperation));
 
-        if (write.existingEntry && m_contentsFilter.mayContain(write.entry.key.shortHash())) {
+        if (write.existingEntry && cacheMayContain(write.entry.key.shortHash())) {
             dispatchHeaderWriteOperation(write);
             continue;
@@ -516 +517 @@
     ASSERT(write.existingEntry);
     ASSERT(m_activeWriteOperations.contains(&write));
-    ASSERT(m_contentsFilter.mayContain(write.entry.key.shortHash()));
+    ASSERT(cacheMayContain(write.entry.key.shortHash()));
 
     // Try to update the header of an existing entry.

trunk/Source/WebKit2/NetworkProcess/cache/NetworkCacheStorage.h

@@ -104 +104 @@
     WorkQueue& serialBackgroundIOQueue() { return m_serialBackgroundIOQueue.get(); }
 
+    bool cacheMayContain(unsigned shortHash) { return !m_hasPopulatedContentsFilter || m_contentsFilter.mayContain(shortHash); }
+
     const String m_baseDirectoryPath;
     const String m_directoryPath;
@@ -110 +112 @@
 
     BloomFilter<20> m_contentsFilter;
+    std::atomic<bool> m_hasPopulatedContentsFilter { false };
+
     std::atomic<size_t> m_approximateSize { 0 };
     std::atomic<bool> m_shrinkInProgress { false };