1
2/*
3 * Copyright 2012 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9#include "SkWriteBuffer.h"
10#include "SkBitmap.h"
11#include "SkBitmapHeap.h"
12#include "SkData.h"
13#include "SkPixelRef.h"
14#include "SkPtrRecorder.h"
15#include "SkStream.h"
16#include "SkTypeface.h"
17
18SkWriteBuffer::SkWriteBuffer(uint32_t flags)
19    : fFlags(flags)
20    , fFactorySet(NULL)
21    , fNamedFactorySet(NULL)
22    , fBitmapHeap(NULL)
23    , fTFSet(NULL) {
24}
25
26SkWriteBuffer::SkWriteBuffer(void* storage, size_t storageSize, uint32_t flags)
27    : fFlags(flags)
28    , fFactorySet(NULL)
29    , fNamedFactorySet(NULL)
30    , fWriter(storage, storageSize)
31    , fBitmapHeap(NULL)
32    , fTFSet(NULL) {
33}
34
35SkWriteBuffer::~SkWriteBuffer() {
36    SkSafeUnref(fFactorySet);
37    SkSafeUnref(fNamedFactorySet);
38    SkSafeUnref(fBitmapHeap);
39    SkSafeUnref(fTFSet);
40}
41
42void SkWriteBuffer::writeByteArray(const void* data, size_t size) {
43    fWriter.write32(SkToU32(size));
44    fWriter.writePad(data, size);
45}
46
47void SkWriteBuffer::writeBool(bool value) {
48    fWriter.writeBool(value);
49}
50
51void SkWriteBuffer::writeFixed(SkFixed value) {
52    fWriter.write32(value);
53}
54
55void SkWriteBuffer::writeScalar(SkScalar value) {
56    fWriter.writeScalar(value);
57}
58
59void SkWriteBuffer::writeScalarArray(const SkScalar* value, uint32_t count) {
60    fWriter.write32(count);
61    fWriter.write(value, count * sizeof(SkScalar));
62}
63
64void SkWriteBuffer::writeInt(int32_t value) {
65    fWriter.write32(value);
66}
67
68void SkWriteBuffer::writeIntArray(const int32_t* value, uint32_t count) {
69    fWriter.write32(count);
70    fWriter.write(value, count * sizeof(int32_t));
71}
72
73void SkWriteBuffer::writeUInt(uint32_t value) {
74    fWriter.write32(value);
75}
76
77void SkWriteBuffer::write32(int32_t value) {
78    fWriter.write32(value);
79}
80
81void SkWriteBuffer::writeString(const char* value) {
82    fWriter.writeString(value);
83}
84
85void SkWriteBuffer::writeEncodedString(const void* value, size_t byteLength,
86                                              SkPaint::TextEncoding encoding) {
87    fWriter.writeInt(encoding);
88    fWriter.writeInt(SkToU32(byteLength));
89    fWriter.write(value, byteLength);
90}
91
92
93void SkWriteBuffer::writeColor(const SkColor& color) {
94    fWriter.write32(color);
95}
96
97void SkWriteBuffer::writeColorArray(const SkColor* color, uint32_t count) {
98    fWriter.write32(count);
99    fWriter.write(color, count * sizeof(SkColor));
100}
101
102void SkWriteBuffer::writePoint(const SkPoint& point) {
103    fWriter.writeScalar(point.fX);
104    fWriter.writeScalar(point.fY);
105}
106
107void SkWriteBuffer::writePointArray(const SkPoint* point, uint32_t count) {
108    fWriter.write32(count);
109    fWriter.write(point, count * sizeof(SkPoint));
110}
111
112void SkWriteBuffer::writeMatrix(const SkMatrix& matrix) {
113    fWriter.writeMatrix(matrix);
114}
115
116void SkWriteBuffer::writeIRect(const SkIRect& rect) {
117    fWriter.write(&rect, sizeof(SkIRect));
118}
119
120void SkWriteBuffer::writeRect(const SkRect& rect) {
121    fWriter.writeRect(rect);
122}
123
124void SkWriteBuffer::writeRegion(const SkRegion& region) {
125    fWriter.writeRegion(region);
126}
127
128void SkWriteBuffer::writePath(const SkPath& path) {
129    fWriter.writePath(path);
130}
131
132size_t SkWriteBuffer::writeStream(SkStream* stream, size_t length) {
133    fWriter.write32(SkToU32(length));
134    size_t bytesWritten = fWriter.readFromStream(stream, length);
135    if (bytesWritten < length) {
136        fWriter.reservePad(length - bytesWritten);
137    }
138    return bytesWritten;
139}
140
141bool SkWriteBuffer::writeToStream(SkWStream* stream) {
142    return fWriter.writeToStream(stream);
143}
144
145static void write_encoded_bitmap(SkWriteBuffer* buffer, SkData* data,
146                                 const SkIPoint& origin) {
147    buffer->writeUInt(SkToU32(data->size()));
148    buffer->getWriter32()->writePad(data->data(), data->size());
149    buffer->write32(origin.fX);
150    buffer->write32(origin.fY);
151}
152
153void SkWriteBuffer::writeBitmap(const SkBitmap& bitmap) {
154    // Record the width and height. This way if readBitmap fails a dummy bitmap can be drawn at the
155    // right size.
156    this->writeInt(bitmap.width());
157    this->writeInt(bitmap.height());
158
159    // Record information about the bitmap in one of three ways, in order of priority:
160    // 1. If there is an SkBitmapHeap, store it in the heap. The client can avoid serializing the
161    //    bitmap entirely or serialize it later as desired. A boolean value of true will be written
162    //    to the stream to signify that a heap was used.
163    // 2. If there is a function for encoding bitmaps, use it to write an encoded version of the
164    //    bitmap. After writing a boolean value of false, signifying that a heap was not used, write
165    //    the size of the encoded data. A non-zero size signifies that encoded data was written.
166    // 3. Call SkBitmap::flatten. After writing a boolean value of false, signifying that a heap was
167    //    not used, write a zero to signify that the data was not encoded.
168    bool useBitmapHeap = fBitmapHeap != NULL;
169    // Write a bool: true if the SkBitmapHeap is to be used, in which case the reader must use an
170    // SkBitmapHeapReader to read the SkBitmap. False if the bitmap was serialized another way.
171    this->writeBool(useBitmapHeap);
172    if (useBitmapHeap) {
173        SkASSERT(NULL == fPixelSerializer);
174        int32_t slot = fBitmapHeap->insert(bitmap);
175        fWriter.write32(slot);
176        // crbug.com/155875
177        // The generation ID is not required information. We write it to prevent collisions
178        // in SkFlatDictionary.  It is possible to get a collision when a previously
179        // unflattened (i.e. stale) instance of a similar flattenable is in the dictionary
180        // and the instance currently being written is re-using the same slot from the
181        // bitmap heap.
182        fWriter.write32(bitmap.getGenerationID());
183        return;
184    }
185
186    SkPixelRef* pixelRef = bitmap.pixelRef();
187    if (pixelRef) {
188        // see if the pixelref already has an encoded version
189        SkAutoDataUnref existingData(pixelRef->refEncodedData());
190        if (existingData.get() != NULL) {
191            // Assumes that if the client did not set a serializer, they are
192            // happy to get the encoded data.
193            if (!fPixelSerializer || fPixelSerializer->useEncodedData(existingData->data(),
194                                                                      existingData->size())) {
195                write_encoded_bitmap(this, existingData, bitmap.pixelRefOrigin());
196                return;
197            }
198        }
199
200        // see if the caller wants to manually encode
201        if (fPixelSerializer) {
202            SkASSERT(NULL == fBitmapHeap);
203            SkAutoLockPixels alp(bitmap);
204            SkAutoDataUnref data(fPixelSerializer->encodePixels(bitmap.info(),
205                                                                bitmap.getPixels(),
206                                                                bitmap.rowBytes()));
207            if (data.get() != NULL) {
208                // if we have to "encode" the bitmap, then we assume there is no
209                // offset to share, since we are effectively creating a new pixelref
210                write_encoded_bitmap(this, data, SkIPoint::Make(0, 0));
211                return;
212            }
213        }
214    }
215
216    this->writeUInt(0); // signal raw pixels
217    SkBitmap::WriteRawPixels(this, bitmap);
218}
219
220void SkWriteBuffer::writeTypeface(SkTypeface* obj) {
221    if (NULL == obj || NULL == fTFSet) {
222        fWriter.write32(0);
223    } else {
224        fWriter.write32(fTFSet->add(obj));
225    }
226}
227
228SkFactorySet* SkWriteBuffer::setFactoryRecorder(SkFactorySet* rec) {
229    SkRefCnt_SafeAssign(fFactorySet, rec);
230    if (fNamedFactorySet != NULL) {
231        fNamedFactorySet->unref();
232        fNamedFactorySet = NULL;
233    }
234    return rec;
235}
236
237SkNamedFactorySet* SkWriteBuffer::setNamedFactoryRecorder(SkNamedFactorySet* rec) {
238    SkRefCnt_SafeAssign(fNamedFactorySet, rec);
239    if (fFactorySet != NULL) {
240        fFactorySet->unref();
241        fFactorySet = NULL;
242    }
243    return rec;
244}
245
246SkRefCntSet* SkWriteBuffer::setTypefaceRecorder(SkRefCntSet* rec) {
247    SkRefCnt_SafeAssign(fTFSet, rec);
248    return rec;
249}
250
251void SkWriteBuffer::setBitmapHeap(SkBitmapHeap* bitmapHeap) {
252    SkRefCnt_SafeAssign(fBitmapHeap, bitmapHeap);
253    if (bitmapHeap != NULL) {
254        SkASSERT(NULL == fPixelSerializer);
255        fPixelSerializer.reset(NULL);
256    }
257}
258
259void SkWriteBuffer::setPixelSerializer(SkPixelSerializer* serializer) {
260    fPixelSerializer.reset(serializer);
261    if (serializer) {
262        serializer->ref();
263        SkASSERT(NULL == fBitmapHeap);
264        SkSafeUnref(fBitmapHeap);
265        fBitmapHeap = NULL;
266    }
267}
268
269void SkWriteBuffer::writeFlattenable(const SkFlattenable* flattenable) {
270    /*
271     *  If we have a factoryset, then the first 32bits tell us...
272     *       0: failure to write the flattenable
273     *      >0: (1-based) index into the SkFactorySet or SkNamedFactorySet
274     *  If we don't have a factoryset, then the first "ptr" is either the
275     *  factory, or null for failure.
276     *
277     *  The distinction is important, since 0-index is 32bits (always), but a
278     *  0-functionptr might be 32 or 64 bits.
279     */
280    if (NULL == flattenable) {
281        if (this->isValidating()) {
282            this->writeString("");
283        } else if (fFactorySet != NULL || fNamedFactorySet != NULL) {
284            this->write32(0);
285        } else {
286            this->writeFunctionPtr(NULL);
287        }
288        return;
289    }
290
291    SkFlattenable::Factory factory = flattenable->getFactory();
292    SkASSERT(factory != NULL);
293
294    /*
295     *  We can write 1 of 3 versions of the flattenable:
296     *  1.  function-ptr : this is the fastest for the reader, but assumes that
297     *      the writer and reader are in the same process.
298     *  2.  index into fFactorySet : This is assumes the writer will later
299     *      resolve the function-ptrs into strings for its reader. SkPicture
300     *      does exactly this, by writing a table of names (matching the indices)
301     *      up front in its serialized form.
302     *  3.  index into fNamedFactorySet. fNamedFactorySet will also store the
303     *      name. SkGPipe uses this technique so it can write the name to its
304     *      stream before writing the flattenable.
305     */
306    if (this->isValidating()) {
307        this->writeString(flattenable->getTypeName());
308    } else if (fFactorySet) {
309        this->write32(fFactorySet->add(factory));
310    } else if (fNamedFactorySet) {
311        int32_t index = fNamedFactorySet->find(factory);
312        this->write32(index);
313        if (0 == index) {
314            return;
315        }
316    } else {
317        this->writeFunctionPtr((void*)factory);
318    }
319
320    // make room for the size of the flattened object
321    (void)fWriter.reserve(sizeof(uint32_t));
322    // record the current size, so we can subtract after the object writes.
323    size_t offset = fWriter.bytesWritten();
324    // now flatten the object
325    flattenable->flatten(*this);
326    size_t objSize = fWriter.bytesWritten() - offset;
327    // record the obj's size
328    fWriter.overwriteTAt(offset - sizeof(uint32_t), SkToU32(objSize));
329}
330