********** WebCore blob hacking

WebCore/platform/network/BlobRegistryImpl.cpp

Index: WebCore/platform/network/BlobRegistryImpl.cpp
===================================================================
--- WebCore/platform/network/BlobRegistryImpl.cpp	(revision 136547)
+++ WebCore/platform/network/BlobRegistryImpl.cpp	(working copy)
@@ -40,26 +40,28 @@
 #include "ResourceLoader.h"
 #include "ResourceRequest.h"
 #include "ResourceResponse.h"
+#include "SecurityOrigin.h"
 #include <wtf/MainThread.h>
 #include <wtf/StdLibExtras.h>
 
 namespace WebCore {
 
-#if !PLATFORM(CHROMIUM)
 BlobRegistry& blobRegistry()
 {
-    ASSERT(isMainThread());
-    DEFINE_STATIC_LOCAL(BlobRegistryImpl, instance, ());
-    return instance;
+    // TODO: would be nice to ensure that this is first accessed on the main thread.
+    AtomicallyInitializedStatic(BlobRegistryImpl&, intance = *new BlobRegistryImpl);
+    return intance;
 }
 
 static PassRefPtr<ResourceHandle> createResourceHandle(const ResourceRequest& request, ResourceHandleClient* client)
 {
+    ASSERT(isMainThread());
     return static_cast<BlobRegistryImpl&>(blobRegistry()).createResourceHandle(request, client);
 }
 
 static void registerBlobResourceHandleConstructor()
 {
+    ASSERT(isMainThread());
     static bool didRegister = false;
     if (!didRegister) {
         ResourceHandle::registerBuiltinConstructor("blob", createResourceHandle);
@@ -67,15 +69,9 @@
     }
 }
 
-#else
-
-static void registerBlobResourceHandleConstructor()
-{
-}
-#endif
-
 bool BlobRegistryImpl::shouldLoadResource(const ResourceRequest& request) const
 {
+    ASSERT(isMainThread());
     // If the resource is not fetched using the GET method, bail out.
     if (!equalIgnoringCase(request.httpMethod(), "GET"))
         return false;
@@ -88,7 +84,7 @@
     if (!shouldLoadResource(request))
         return 0;
 
-    RefPtr<BlobResourceHandle> handle = BlobResourceHandle::create(m_blobs.get(request.url().string()), request, client);
+    RefPtr<BlobResourceHandle> handle = BlobResourceHandle::create(getBlobDataFromURL(request.url()), request, client);
     handle->start();
     return handle.release();
 }
@@ -98,26 +94,10 @@
     if (!shouldLoadResource(request))
         return false;
 
-    BlobResourceHandle::loadResourceSynchronously(m_blobs.get(request.url().string()), request, error, response, data);
+    BlobResourceHandle::loadResourceSynchronously(getBlobDataFromURL(request.url()), request, error, response, data);
     return true;
 }
 
-void BlobRegistryImpl::appendStorageItems(BlobStorageData* blobStorageData, const BlobDataItemList& items)
-{
-    for (BlobDataItemList::const_iterator iter = items.begin(); iter != items.end(); ++iter) {
-        if (iter->type == BlobDataItem::Data)
-            blobStorageData->m_data.appendData(iter->data, iter->offset, iter->length);
-#if ENABLE(FILE_SYSTEM)
-        else if (iter->type == BlobDataItem::URL)
-            blobStorageData->m_data.appendURL(iter->url, iter->offset, iter->length, iter->expectedModificationTime);
-#endif
-        else {
-            ASSERT(iter->type == BlobDataItem::File);
-            blobStorageData->m_data.appendFile(iter->path, iter->offset, iter->length, iter->expectedModificationTime);
-        }
-    }
-}
-
 void BlobRegistryImpl::appendStorageItems(BlobStorageData* blobStorageData, const BlobDataItemList& items, long long offset, long long length)
 {
     ASSERT(length != BlobDataItem::toEndOfFile);
@@ -139,76 +119,154 @@
             blobStorageData->m_data.appendData(iter->data, iter->offset + offset, newLength);
 #if ENABLE(FILE_SYSTEM)
         else if (iter->type == BlobDataItem::URL)
-            blobStorageData->m_data.appendURL(iter->url, iter->offset + offset, newLength, iter->expectedModificationTime);
+            blobStorageData->m_data.appendURL(iter->url.copy(), iter->offset + offset, newLength, iter->expectedModificationTime);
 #endif
         else {
             ASSERT(iter->type == BlobDataItem::File);
-            blobStorageData->m_data.appendFile(iter->path, iter->offset + offset, newLength, iter->expectedModificationTime);
+            blobStorageData->m_data.appendFile(iter->path.isolatedCopy(), iter->offset + offset, newLength, iter->expectedModificationTime);
         }
         length -= newLength;
         offset = 0;
     }
 }
 
-void BlobRegistryImpl::registerBlobURL(const KURL& url, PassOwnPtr<BlobData> blobData)
+void BlobRegistryImpl::registerBlobData(const String& uuid, PassOwnPtr<BlobData> blobData)
 {
-    ASSERT(isMainThread());
-    registerBlobResourceHandleConstructor();
-
-    RefPtr<BlobStorageData> blobStorageData = BlobStorageData::create(blobData->contentType(), blobData->contentDisposition());
-
     // The blob data is stored in the "canonical" way. That is, it only contains a list of Data and File items.
     // 1) The Data item is denoted by the raw data and the range.
     // 2) The File item is denoted by the file path, the range and the expected modification time.
     // 3) The URL item is denoted by the URL, the range and the expected modification time.
     // All the Blob items in the passing blob data are resolved and expanded into a set of Data and File items.
 
+    RefPtr<BlobStorageData> blobStorageData = BlobStorageData::create(blobData->contentType(), blobData->contentDisposition());
     for (BlobDataItemList::const_iterator iter = blobData->items().begin(); iter != blobData->items().end(); ++iter) {
         switch (iter->type) {
         case BlobDataItem::Data:
+            // FIXME: Can we avoid making this copy of the data?
             blobStorageData->m_data.appendData(iter->data, 0, iter->data->length());
             break;
         case BlobDataItem::File:
-            blobStorageData->m_data.appendFile(iter->path, iter->offset, iter->length, iter->expectedModificationTime);
+            blobStorageData->m_data.appendFile(iter->path.isolatedCopy(), iter->offset, iter->length, iter->expectedModificationTime);
             break;
 #if ENABLE(FILE_SYSTEM)
         case BlobDataItem::URL:
-            blobStorageData->m_data.appendURL(iter->url, iter->offset, iter->length, iter->expectedModificationTime);
+            blobStorageData->m_data.appendURL(iter->url.copy(), iter->offset, iter->length, iter->expectedModificationTime);
             break;
 #endif
-        case BlobDataItem::Blob:
-            if (m_blobs.contains(iter->url.string()))
-                appendStorageItems(blobStorageData.get(), m_blobs.get(iter->url.string())->items(), iter->offset, iter->length);
+        case BlobDataItem::Blob: {
+                RefPtr<BlobStorageData> other = getBlobDataFromUUID(iter->blobDataHandle->uuid());
+                if (other)
+                    appendStorageItems(blobStorageData.get(), other->items(), iter->offset, iter->length);
+            }
             break;
         }
     }
 
-    m_blobs.set(url.string(), blobStorageData);
+
+    MutexLocker locker(m_mutex);
+    ASSERT(m_blobs.find(uuid) == m_blobs.end());
+    m_blobs.set(uuid.isolatedCopy(), std::make_pair(1, blobStorageData));
 }
 
-void BlobRegistryImpl::registerBlobURL(const KURL& url, const KURL& srcURL)
+void BlobRegistryImpl::addBlobDataRef(const String& uuid)
 {
-    ASSERT(isMainThread());
-    registerBlobResourceHandleConstructor();
+    MutexLocker locker(m_mutex);
+    BlobMap::iterator found = m_blobs.find(uuid);
+    ASSERT(found != m_blobs.end());
+    found->value.first += 1;
+}
 
-    RefPtr<BlobStorageData> src = m_blobs.get(srcURL.string());
-    ASSERT(src);
-    if (!src)
-        return;
+void BlobRegistryImpl::removeBlobDataRef(const String& uuid)
+{
+    MutexLocker locker(m_mutex);
+    BlobMap::iterator found = m_blobs.find(uuid);
+    ASSERT(found != m_blobs.end());
+    found->value.first -= 1;
+    if (found->value.first == 0)
+        m_blobs.remove(found);
+}
 
-    m_blobs.set(url.string(), src);
+// Helper to access the blob url map on the main thread only when registering/revoking urls.
+class BlobRegistryImpl::URLRegistrationHelper {
+public:
+  URLRegistrationHelper(BlobRegistryImpl* registry, const KURL& url, PassRefPtr<BlobDataHandle> dataHandle = 0)
+      : registry(registry)
+      , url(url.copy())
+      , dataHandle(dataHandle)
+  {
+  }
+
+  static void registerURLTask(void* context)
+  {
+      OwnPtr<URLRegistrationHelper> helper = adoptPtr(static_cast<URLRegistrationHelper*>(context));
+      helper->registerURL();
+  }
+
+  static void revokeURLTask(void* context)
+  {
+      OwnPtr<URLRegistrationHelper> helper = adoptPtr(static_cast<URLRegistrationHelper*>(context));
+      helper->revokeURL();
+  }
+
+  void registerURL()
+  {

[kinuko, 2013/01/07 09:38:06]

nit: can we have ASSERT(isMainThread()) here? (though we seem to call it in
registerBlobResourceHandleConstructor())

[michaeln, 2013/01/25 21:19:26]

Done.

+      registerBlobResourceHandleConstructor();
+      registry->m_publicURLs.set(url, dataHandle);
+  }
+
+  void revokeURL()
+  {
+      registry->m_publicURLs.remove(url);

[kinuko, 2013/01/07 09:38:06]

nit: can we have ASSERT(isMainThread()) here?

[michaeln, 2013/01/25 21:19:26]

Done.

+  }
+
+  BlobRegistryImpl* registry;
+  KURL url;
+  RefPtr<BlobDataHandle> dataHandle; // NULL for revoke tasks.
+};
+
+
+void BlobRegistryImpl::registerPublicBlobURL(SecurityOrigin* origin, const KURL& url, PassRefPtr<BlobDataHandle> dataHandle)
+{
+    // The cached origin has thread affinity so we must fiddle with it's registration on the current thread.
+    BlobRegistry::setCachedUniqueOrigin(url, origin);  
+
+    // But the blob map is only accessed on the main thread.
+    OwnPtr<URLRegistrationHelper> helper = adoptPtr(new URLRegistrationHelper(this, url, dataHandle));
+    if (isMainThread())
+        helper->registerURL();
+    else
+        callOnMainThread(&URLRegistrationHelper::registerURLTask, helper.leakPtr());
 }
 
-void BlobRegistryImpl::unregisterBlobURL(const KURL& url)
+void BlobRegistryImpl::revokePublicBlobURL(const KURL& url)
 {
-    ASSERT(isMainThread());
-    m_blobs.remove(url.string());
+    BlobRegistry::clearCachedUniqueOrigin(url);
+
+    OwnPtr<URLRegistrationHelper> helper = adoptPtr(new URLRegistrationHelper(this, url));
+    if (isMainThread())
+        helper->revokeURL();
+    else
+        callOnMainThread(&URLRegistrationHelper::revokeURLTask, helper.leakPtr());
 }
 
+PassRefPtr<SecurityOrigin> BlobRegistryImpl::cachedUniqueOrigin(const KURL& url)
+{
+    return BlobRegistry::getCachedUniqueOrigin(url);
+}
+
+PassRefPtr<BlobStorageData> BlobRegistryImpl::getBlobDataFromUUID(const String& uuid) const
+{
+    MutexLocker locker(m_mutex);
+    return m_blobs.get(uuid).second;
+}
+
 PassRefPtr<BlobStorageData> BlobRegistryImpl::getBlobDataFromURL(const KURL& url) const
 {
     ASSERT(isMainThread());
-    return m_blobs.get(url.string());
+    RefPtr<BlobDataHandle> dataHandle = m_publicURLs.get(url.string());
+    if (!dataHandle)
+        return 0;
+    return getBlobDataFromUUID(dataHandle->uuid());
 }
 
 } // namespace WebCore