WebCore/platform/SharedBuffer.h
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/platform/SharedBuffer.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
+ * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+#ifndef SharedBuffer_h
+#define SharedBuffer_h
+
+#include "PlatformString.h"
+#include <wtf/Forward.h>
+#include <wtf/OwnPtr.h>
+#include <wtf/RefCounted.h>
+#include <wtf/Vector.h>
+
+#if PLATFORM(CF)
+#include <wtf/RetainPtr.h>
+#endif
+
+#if PLATFORM(MAC)
+#ifdef __OBJC__
+@class NSData;
+#else
+class NSData;
+#endif
+
+#endif
+
+namespace WebCore {
+    
+class PurgeableBuffer;
+
+class SharedBuffer : public RefCounted<SharedBuffer> {
+public:
+    static PassRefPtr<SharedBuffer> create() { return adoptRef(new SharedBuffer); }
+    static PassRefPtr<SharedBuffer> create(const char* c, int i) { return adoptRef(new SharedBuffer(c, i)); }
+    static PassRefPtr<SharedBuffer> create(const unsigned char* c, int i) { return adoptRef(new SharedBuffer(c, i)); }
+
+    static PassRefPtr<SharedBuffer> createWithContentsOfFile(const String& filePath);
+
+    static PassRefPtr<SharedBuffer> adoptVector(Vector<char>& vector);
+    
+    // The buffer must be in non-purgeable state before adopted to a SharedBuffer. 
+    // It will stay that way until released.
+    static PassRefPtr<SharedBuffer> adoptPurgeableBuffer(PassOwnPtr<PurgeableBuffer>);
+    
+    ~SharedBuffer();
+    
+#if PLATFORM(MAC)
+    NSData *createNSData();
+    static PassRefPtr<SharedBuffer> wrapNSData(NSData *data);
+#endif
+#if PLATFORM(CF)
+    CFDataRef createCFData();
+    static PassRefPtr<SharedBuffer> wrapCFData(CFDataRef);
+#endif
+
+    // Calling this function will force internal segmented buffers
+    // to be merged into a flat buffer. Use getSomeData() whenever possible
+    // for better performance.
+    const char* data() const;
+
+    unsigned size() const;
+
+    // Calling this function will force internal segmented buffers
+    // to be merged into a flat buffer. Use getSomeData() whenever possible
+    // for better performance.
+    const Vector<char>& buffer() const;
+
+    bool isEmpty() const { return !size(); }
+
+    void append(const char*, unsigned);
+    void clear();
+    const char* platformData() const;
+    unsigned platformDataSize() const;
+
+    PassRefPtr<SharedBuffer> copy() const;
+    
+    bool hasPurgeableBuffer() const { return m_purgeableBuffer.get(); }
+
+    // Ensure this buffer has no other clients before calling this.
+    PassOwnPtr<PurgeableBuffer> releasePurgeableBuffer();
+
+    // Return the number of consecutive bytes after "position". "data"
+    // points to the first byte.
+    // Return 0 when no more data left.
+    // When extracting all data with getSomeData(), the caller should
+    // repeat calling it until it returns 0.
+    // Usage:
+    //      const char* segment;
+    //      unsigned pos = 0;
+    //      while (unsigned length = sharedBuffer->getSomeData(segment, pos)) {
+    //          // Use the data. for example: decoder->decode(segment, length);
+    //          pos += length;
+    //      }
+    unsigned getSomeData(const char*& data, unsigned position = 0) const;
+
+private:
+    SharedBuffer();
+    SharedBuffer(const char*, int);
+    SharedBuffer(const unsigned char*, int);
+    
+    void clearPlatformData();
+    void maybeTransferPlatformData();
+    bool hasPlatformData() const;
+    
+    unsigned m_size;
+    mutable Vector<char> m_buffer;
+    mutable Vector<char*> m_segments;
+    OwnPtr<PurgeableBuffer> m_purgeableBuffer;
+#if PLATFORM(CF)
+    SharedBuffer(CFDataRef);
+    RetainPtr<CFDataRef> m_cfData;
+#endif
+};
+    
+}
+
+#endif // SharedBuffer_h