The Tor Browser / file revision

 /*

  * Copyright 2012 Google Inc.

  *

  * Use of this source code is governed by a BSD-style license that can be

  * found in the LICENSE file.

  */

 #include "SkWriteBuffer.h"

 #include "SkBitmap.h"

 #include "SkData.h"

 #include "SkPixelRef.h"

 #include "SkPtrRecorder.h"

 #include "SkStream.h"

 #include "SkTypeface.h"

 SkWriteBuffer::SkWriteBuffer(uint32_t flags)

     : fFlags(flags)

     , fFactorySet(NULL)

     , fNamedFactorySet(NULL)

     , fBitmapHeap(NULL)

     , fTFSet(NULL)

     , fBitmapEncoder(NULL) {

 }

 SkWriteBuffer::SkWriteBuffer(void* storage, size_t storageSize, uint32_t flags)

     : fFlags(flags)

     , fFactorySet(NULL)

     , fNamedFactorySet(NULL)

     , fWriter(storage, storageSize)

     , fBitmapHeap(NULL)

     , fTFSet(NULL)

     , fBitmapEncoder(NULL) {

 }

 SkWriteBuffer::~SkWriteBuffer() {

     SkSafeUnref(fFactorySet);

     SkSafeUnref(fNamedFactorySet);

     SkSafeUnref(fBitmapHeap);

     SkSafeUnref(fTFSet);

 }

 void SkWriteBuffer::writeByteArray(const void* data, size_t size) {

     fWriter.write32(SkToU32(size));

     fWriter.writePad(data, size);

 }

 void SkWriteBuffer::writeBool(bool value) {

     fWriter.writeBool(value);

 }

 void SkWriteBuffer::writeFixed(SkFixed value) {

     fWriter.write32(value);

 }

 void SkWriteBuffer::writeScalar(SkScalar value) {

     fWriter.writeScalar(value);

 }

 void SkWriteBuffer::writeScalarArray(const SkScalar* value, uint32_t count) {

     fWriter.write32(count);

     fWriter.write(value, count * sizeof(SkScalar));

 }

 void SkWriteBuffer::writeInt(int32_t value) {

     fWriter.write32(value);

 }

 void SkWriteBuffer::writeIntArray(const int32_t* value, uint32_t count) {

     fWriter.write32(count);

     fWriter.write(value, count * sizeof(int32_t));

 }

 void SkWriteBuffer::writeUInt(uint32_t value) {

     fWriter.write32(value);

 }

 void SkWriteBuffer::write32(int32_t value) {

     fWriter.write32(value);

 }

 void SkWriteBuffer::writeString(const char* value) {

     fWriter.writeString(value);

 }

 void SkWriteBuffer::writeEncodedString(const void* value, size_t byteLength,

                                               SkPaint::TextEncoding encoding) {

     fWriter.writeInt(encoding);

     fWriter.writeInt(SkToU32(byteLength));

     fWriter.write(value, byteLength);

 }

 void SkWriteBuffer::writeColor(const SkColor& color) {

     fWriter.write32(color);

 }

 void SkWriteBuffer::writeColorArray(const SkColor* color, uint32_t count) {

     fWriter.write32(count);

     fWriter.write(color, count * sizeof(SkColor));

 }

 void SkWriteBuffer::writePoint(const SkPoint& point) {

     fWriter.writeScalar(point.fX);

     fWriter.writeScalar(point.fY);

 }

 void SkWriteBuffer::writePointArray(const SkPoint* point, uint32_t count) {

     fWriter.write32(count);

     fWriter.write(point, count * sizeof(SkPoint));

 }

 void SkWriteBuffer::writeMatrix(const SkMatrix& matrix) {

     fWriter.writeMatrix(matrix);

 }

 void SkWriteBuffer::writeIRect(const SkIRect& rect) {

     fWriter.write(&rect, sizeof(SkIRect));

 }

 void SkWriteBuffer::writeRect(const SkRect& rect) {

     fWriter.writeRect(rect);

 }

 void SkWriteBuffer::writeRegion(const SkRegion& region) {

     fWriter.writeRegion(region);

 }

 void SkWriteBuffer::writePath(const SkPath& path) {

     fWriter.writePath(path);

 }

 size_t SkWriteBuffer::writeStream(SkStream* stream, size_t length) {

     fWriter.write32(SkToU32(length));

     size_t bytesWritten = fWriter.readFromStream(stream, length);

     if (bytesWritten < length) {

         fWriter.reservePad(length - bytesWritten);

     }

     return bytesWritten;

 }

 bool SkWriteBuffer::writeToStream(SkWStream* stream) {

     return fWriter.writeToStream(stream);

 }

 static void write_encoded_bitmap(SkWriteBuffer* buffer, SkData* data,

                                  const SkIPoint& origin) {

     buffer->writeUInt(SkToU32(data->size()));

     buffer->getWriter32()->writePad(data->data(), data->size());

     buffer->write32(origin.fX);

     buffer->write32(origin.fY);

 }

 void SkWriteBuffer::writeBitmap(const SkBitmap& bitmap) {

     // Record the width and height. This way if readBitmap fails a dummy bitmap can be drawn at the

     // right size.

     this->writeInt(bitmap.width());

     this->writeInt(bitmap.height());

     // Record information about the bitmap in one of three ways, in order of priority:

     // 1. If there is an SkBitmapHeap, store it in the heap. The client can avoid serializing the

     //    bitmap entirely or serialize it later as desired. A boolean value of true will be written

     //    to the stream to signify that a heap was used.

     // 2. If there is a function for encoding bitmaps, use it to write an encoded version of the

     //    bitmap. After writing a boolean value of false, signifying that a heap was not used, write

     //    the size of the encoded data. A non-zero size signifies that encoded data was written.

     // 3. Call SkBitmap::flatten. After writing a boolean value of false, signifying that a heap was

     //    not used, write a zero to signify that the data was not encoded.

     bool useBitmapHeap = fBitmapHeap != NULL;

     // Write a bool: true if the SkBitmapHeap is to be used, in which case the reader must use an

     // SkBitmapHeapReader to read the SkBitmap. False if the bitmap was serialized another way.

     this->writeBool(useBitmapHeap);

     if (useBitmapHeap) {

         SkASSERT(NULL == fBitmapEncoder);

         int32_t slot = fBitmapHeap->insert(bitmap);

         fWriter.write32(slot);

         // crbug.com/155875

         // The generation ID is not required information. We write it to prevent collisions

         // in SkFlatDictionary.  It is possible to get a collision when a previously

         // unflattened (i.e. stale) instance of a similar flattenable is in the dictionary

         // and the instance currently being written is re-using the same slot from the

         // bitmap heap.

         fWriter.write32(bitmap.getGenerationID());

         return;

     }

     // see if the pixelref already has an encoded version

     if (bitmap.pixelRef()) {

         SkAutoDataUnref data(bitmap.pixelRef()->refEncodedData());

         if (data.get() != NULL) {

             write_encoded_bitmap(this, data, bitmap.pixelRefOrigin());

             return;

         }

     }

     // see if the caller wants to manually encode

     if (fBitmapEncoder != NULL) {

         SkASSERT(NULL == fBitmapHeap);

         size_t offset = 0;  // this parameter is deprecated/ignored

         // if we have to "encode" the bitmap, then we assume there is no

         // offset to share, since we are effectively creating a new pixelref

         SkAutoDataUnref data(fBitmapEncoder(&offset, bitmap));

         if (data.get() != NULL) {

             write_encoded_bitmap(this, data, SkIPoint::Make(0, 0));

             return;

         }

     }

     // Bitmap was not encoded. Record a zero, implying that the reader need not decode.

     this->writeUInt(0);

     bitmap.flatten(*this);

 }

 void SkWriteBuffer::writeTypeface(SkTypeface* obj) {

     if (NULL == obj || NULL == fTFSet) {

         fWriter.write32(0);

     } else {

         fWriter.write32(fTFSet->add(obj));

     }

 }

 SkFactorySet* SkWriteBuffer::setFactoryRecorder(SkFactorySet* rec) {

     SkRefCnt_SafeAssign(fFactorySet, rec);

     if (fNamedFactorySet != NULL) {

         fNamedFactorySet->unref();

         fNamedFactorySet = NULL;

     }

     return rec;

 }

 SkNamedFactorySet* SkWriteBuffer::setNamedFactoryRecorder(SkNamedFactorySet* rec) {

     SkRefCnt_SafeAssign(fNamedFactorySet, rec);

     if (fFactorySet != NULL) {

         fFactorySet->unref();

         fFactorySet = NULL;

     }

     return rec;

 }

 SkRefCntSet* SkWriteBuffer::setTypefaceRecorder(SkRefCntSet* rec) {

     SkRefCnt_SafeAssign(fTFSet, rec);

     return rec;

 }

 void SkWriteBuffer::setBitmapHeap(SkBitmapHeap* bitmapHeap) {

     SkRefCnt_SafeAssign(fBitmapHeap, bitmapHeap);

     if (bitmapHeap != NULL) {

         SkASSERT(NULL == fBitmapEncoder);

         fBitmapEncoder = NULL;

     }

 }

 void SkWriteBuffer::setBitmapEncoder(SkPicture::EncodeBitmap bitmapEncoder) {

     fBitmapEncoder = bitmapEncoder;

     if (bitmapEncoder != NULL) {

         SkASSERT(NULL == fBitmapHeap);

         SkSafeUnref(fBitmapHeap);

         fBitmapHeap = NULL;

     }

 }

 void SkWriteBuffer::writeFlattenable(const SkFlattenable* flattenable) {

     /*

      *  If we have a factoryset, then the first 32bits tell us...

      *       0: failure to write the flattenable

      *      >0: (1-based) index into the SkFactorySet or SkNamedFactorySet

      *  If we don't have a factoryset, then the first "ptr" is either the

      *  factory, or null for failure.

      *

      *  The distinction is important, since 0-index is 32bits (always), but a

      *  0-functionptr might be 32 or 64 bits.

      */

     if (NULL == flattenable) {

         if (this->isValidating()) {

             this->writeString("");

         } else if (fFactorySet != NULL || fNamedFactorySet != NULL) {

             this->write32(0);

         } else {

             this->writeFunctionPtr(NULL);

         }

         return;

     }

     SkFlattenable::Factory factory = flattenable->getFactory();

     SkASSERT(factory != NULL);

     /*

      *  We can write 1 of 3 versions of the flattenable:

      *  1.  function-ptr : this is the fastest for the reader, but assumes that

      *      the writer and reader are in the same process.

      *  2.  index into fFactorySet : This is assumes the writer will later

      *      resolve the function-ptrs into strings for its reader. SkPicture

      *      does exactly this, by writing a table of names (matching the indices)

      *      up front in its serialized form.

      *  3.  index into fNamedFactorySet. fNamedFactorySet will also store the

      *      name. SkGPipe uses this technique so it can write the name to its

      *      stream before writing the flattenable.

      */

     if (this->isValidating()) {

         this->writeString(flattenable->getTypeName());

     } else if (fFactorySet) {

         this->write32(fFactorySet->add(factory));

     } else if (fNamedFactorySet) {

         int32_t index = fNamedFactorySet->find(factory);

         this->write32(index);

         if (0 == index) {

             return;

         }

     } else {

         this->writeFunctionPtr((void*)factory);

     }

     // make room for the size of the flattened object

     (void)fWriter.reserve(sizeof(uint32_t));

     // record the current size, so we can subtract after the object writes.

     size_t offset = fWriter.bytesWritten();

     // now flatten the object

     flattenable->flatten(*this);

     size_t objSize = fWriter.bytesWritten() - offset;

     // record the obj's size

     fWriter.overwriteTAt(offset - sizeof(uint32_t), SkToU32(objSize));

 }