Changeset 288463 in webkit

Timestamp:

Jan 24, 2022 1:12:37 PM (6 months ago)

Author:

youenn@apple.com

Message:

file.stream() is slow and CPU-bound
​https://bugs.webkit.org/show_bug.cgi?id=235448

Reviewed by Alex Christensen.

We introduce a ReadAsBinaryChunks mode to prevent storing the whole file in memory.
Use this in Blob stream implementation.
The new implementation is much faster for big files given it does not need to keep in memory the whole file.
Covered by existing tests.

• fileapi/Blob.cpp:
• fileapi/FileReaderLoader.cpp:
• fileapi/FileReaderLoader.h:
• fileapi/FileReaderLoaderClient.h:

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• fileapi/Blob.cpp (modified) (3 diffs)
• fileapi/FileReaderLoader.cpp (modified) (2 diffs)
• fileapi/FileReaderLoader.h (modified) (1 diff)
• fileapi/FileReaderLoaderClient.h (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2022-01-24  Youenn Fablet  <youenn@apple.com>
+
+        file.stream() is slow and CPU-bound
+        https://bugs.webkit.org/show_bug.cgi?id=235448
+
+        Reviewed by Alex Christensen.
+
+        We introduce a ReadAsBinaryChunks mode to prevent storing the whole file in memory.
+        Use this in Blob stream implementation.
+        The new implementation is much faster for big files given it does not need to keep in memory the whole file.
+        Covered by existing tests.
+
+        * fileapi/Blob.cpp:
+        * fileapi/FileReaderLoader.cpp:
+        * fileapi/FileReaderLoader.h:
+        * fileapi/FileReaderLoaderClient.h:
+
 2022-01-24  Youenn Fablet  <youenn@apple.com>
 

trunk/Source/WebCore/fileapi/Blob.cpp

@@ -242 +242 @@
     public:
         BlobStreamSource(ScriptExecutionContext& scriptExecutionContext, Blob& blob)
-            : m_loader(makeUniqueRef<FileReaderLoader>(FileReaderLoader::ReadType::ReadAsArrayBuffer, this))
+            : m_loader(makeUniqueRef<FileReaderLoader>(FileReaderLoader::ReadType::ReadAsBinaryChunks, this))
         {
             m_loader->start(&scriptExecutionContext, blob);
@@ -266 +266 @@
         // FileReaderLoaderClient
         void didStartLoading() final { }
-        void didReceiveData() final
-        {
-            auto result = m_loader->arrayBufferResult();
-            if (!result)
-                return;
-
-            if (m_loader->isCompleted() && !m_bytesRead)
-                controller().enqueue(WTFMove(result));
-            else {
-                auto bytesLoaded = m_loader->bytesLoaded();
-                controller().enqueue(result->slice(m_bytesRead, bytesLoaded));
-                m_bytesRead = bytesLoaded;
-            }
+        void didReceiveData() final { }
+        void didReceiveBinaryChunk(const SharedBuffer& buffer) final
+        {
+            if (!controller().enqueue(buffer.tryCreateArrayBuffer()))
+                doCancel();
         }
         void didFinishLoading() final
@@ -295 +287 @@
 
         UniqueRef<FileReaderLoader> m_loader;
-        size_t m_bytesRead { 0 };
         bool m_isStarted { false };
         std::optional<Exception> m_exception;

trunk/Source/WebCore/fileapi/FileReaderLoader.cpp

@@ -178 +178 @@
         return;
 
+    if (m_readType == ReadType::ReadAsBinaryChunks) {
+        if (m_client)
+            m_client->didReceiveBinaryChunk(buffer);
+        return;
+    }
+
     int length = buffer.size();
     unsigned remainingBufferSpace = m_totalBytes - m_bytesLoaded;
@@ -312 +318 @@
             convertToDataURL();
         break;
-    default:
+    case ReadAsBlob:
+    case ReadAsBinaryChunks:
         ASSERT_NOT_REACHED();
     }

trunk/Source/WebCore/fileapi/FileReaderLoader.h

@@ -59 +59 @@
         ReadAsBlob,
         ReadAsText,
-        ReadAsDataURL
+        ReadAsDataURL,
+        ReadAsBinaryChunks
     };
 

trunk/Source/WebCore/fileapi/FileReaderLoaderClient.h

@@ -42 +42 @@
     virtual void didStartLoading() = 0;
     virtual void didReceiveData() = 0;
+    virtual void didReceiveBinaryChunk(const SharedBuffer&) { }
     virtual void didFinishLoading() = 0;
     virtual void didFail(ExceptionCode errorCode) = 0;