SkWriteBuffer.cpp revision 7c9d539d8843ad75a1c249633bbc8bb331f5035e 
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 "SkOrderedWriteBuffer.h"
10#include "SkBitmap.h"
11#include "SkData.h"
12#include "SkPixelRef.h"
13#include "SkPtrRecorder.h"
14#include "SkStream.h"
15#include "SkTypeface.h"
16
17SkOrderedWriteBuffer::SkOrderedWriteBuffer(size_t minSize)
18    : INHERITED()
19    , fFactorySet(NULL)
20    , fNamedFactorySet(NULL)
21    , fWriter(minSize)
22    , fBitmapHeap(NULL)
23    , fTFSet(NULL)
24    , fBitmapEncoder(NULL) {
25}
26
27SkOrderedWriteBuffer::SkOrderedWriteBuffer(size_t minSize, void* storage, size_t storageSize)
28    : INHERITED()
29    , fFactorySet(NULL)
30    , fNamedFactorySet(NULL)
31    , fWriter(minSize, storage, storageSize)
32    , fBitmapHeap(NULL)
33    , fTFSet(NULL)
34    , fBitmapEncoder(NULL) {
35}
36
37SkOrderedWriteBuffer::~SkOrderedWriteBuffer() {
38    SkSafeUnref(fFactorySet);
39    SkSafeUnref(fNamedFactorySet);
40    SkSafeUnref(fBitmapHeap);
41    SkSafeUnref(fTFSet);
42}
43
44void SkOrderedWriteBuffer::writeByteArray(const void* data, size_t size) {
45    fWriter.write32(size);
46    fWriter.writePad(data, size);
47}
48
49void SkOrderedWriteBuffer::writeBool(bool value) {
50    fWriter.writeBool(value);
51}
52
53void SkOrderedWriteBuffer::writeFixed(SkFixed value) {
54    fWriter.write32(value);
55}
56
57void SkOrderedWriteBuffer::writeScalar(SkScalar value) {
58    fWriter.writeScalar(value);
59}
60
61void SkOrderedWriteBuffer::writeScalarArray(const SkScalar* value, uint32_t count) {
62    fWriter.write32(count);
63    fWriter.write(value, count * sizeof(SkScalar));
64}
65
66void SkOrderedWriteBuffer::writeInt(int32_t value) {
67    fWriter.write32(value);
68}
69
70void SkOrderedWriteBuffer::writeIntArray(const int32_t* value, uint32_t count) {
71    fWriter.write32(count);
72    fWriter.write(value, count * sizeof(int32_t));
73}
74
75void SkOrderedWriteBuffer::writeUInt(uint32_t value) {
76    fWriter.write32(value);
77}
78
79void SkOrderedWriteBuffer::write32(int32_t value) {
80    fWriter.write32(value);
81}
82
83void SkOrderedWriteBuffer::writeString(const char* value) {
84    fWriter.writeString(value);
85}
86
87void SkOrderedWriteBuffer::writeEncodedString(const void* value, size_t byteLength,
88                                              SkPaint::TextEncoding encoding) {
89    fWriter.writeInt(encoding);
90    fWriter.writeInt(byteLength);
91    fWriter.write(value, byteLength);
92}
93
94
95void SkOrderedWriteBuffer::writeColor(const SkColor& color) {
96    fWriter.write32(color);
97}
98
99void SkOrderedWriteBuffer::writeColorArray(const SkColor* color, uint32_t count) {
100    fWriter.write32(count);
101    fWriter.write(color, count * sizeof(SkColor));
102}
103
104void SkOrderedWriteBuffer::writePoint(const SkPoint& point) {
105    fWriter.writeScalar(point.fX);
106    fWriter.writeScalar(point.fY);
107}
108
109void SkOrderedWriteBuffer::writePointArray(const SkPoint* point, uint32_t count) {
110    fWriter.write32(count);
111    fWriter.write(point, count * sizeof(SkPoint));
112}
113
114void SkOrderedWriteBuffer::writeMatrix(const SkMatrix& matrix) {
115    fWriter.writeMatrix(matrix);
116}
117
118void SkOrderedWriteBuffer::writeIRect(const SkIRect& rect) {
119    fWriter.write(&rect, sizeof(SkIRect));
120}
121
122void SkOrderedWriteBuffer::writeRect(const SkRect& rect) {
123    fWriter.writeRect(rect);
124}
125
126void SkOrderedWriteBuffer::writeRegion(const SkRegion& region) {
127    fWriter.writeRegion(region);
128}
129
130void SkOrderedWriteBuffer::writePath(const SkPath& path) {
131    fWriter.writePath(path);
132}
133
134size_t SkOrderedWriteBuffer::writeStream(SkStream* stream, size_t length) {
135    return fWriter.readFromStream(stream, length);
136}
137
138bool SkOrderedWriteBuffer::writeToStream(SkWStream* stream) {
139    return fWriter.writeToStream(stream);
140}
141
142void SkOrderedWriteBuffer::writeBitmap(const SkBitmap& bitmap) {
143    // Record information about the bitmap in one of three ways, in order of priority:
144    // 1. If there is an SkBitmapHeap, store it in the heap. The client can avoid serializing the
145    //    bitmap entirely or serialize it later as desired.
146    // 2. Write an encoded version of the bitmap. Afterwards the width and height are written, so
147    //    a reader without a decoder can draw a dummy bitmap of the right size.
148    //    A. If the bitmap has an encoded representation, write it to the stream.
149    //    B. If there is a function for encoding bitmaps, use it.
150    // 3. Call SkBitmap::flatten.
151    // For an encoded bitmap, write the size first. Otherwise store a 0 so the reader knows not to
152    // decode.
153    if (fBitmapHeap != NULL) {
154        SkASSERT(NULL == fBitmapEncoder);
155        // Bitmap was not encoded. Record a zero, implying that the reader need not decode.
156        this->writeUInt(0);
157        int32_t slot = fBitmapHeap->insert(bitmap);
158        fWriter.write32(slot);
159        // crbug.com/155875
160        // The generation ID is not required information. We write it to prevent collisions
161        // in SkFlatDictionary.  It is possible to get a collision when a previously
162        // unflattened (i.e. stale) instance of a similar flattenable is in the dictionary
163        // and the instance currently being written is re-using the same slot from the
164        // bitmap heap.
165        fWriter.write32(bitmap.getGenerationID());
166        return;
167    }
168    bool encoded = false;
169    // Before attempting to encode the SkBitmap, check to see if there is already an encoded
170    // version.
171    SkPixelRef* ref = bitmap.pixelRef();
172    if (ref != NULL) {
173        SkAutoDataUnref data(ref->refEncodedData());
174        if (data.get() != NULL) {
175            // Write the length to indicate that the bitmap was encoded successfully, followed
176            // by the actual data. This must match the case where fBitmapEncoder is used so the
177            // reader need not know the difference.
178            this->writeUInt(data->size());
179            fWriter.writePad(data->data(), data->size());
180            encoded = true;
181        }
182    }
183    if (fBitmapEncoder != NULL && !encoded) {
184        SkASSERT(NULL == fBitmapHeap);
185        SkDynamicMemoryWStream stream;
186        if (fBitmapEncoder(&stream, bitmap)) {
187            uint32_t offset = fWriter.bytesWritten();
188            // Write the length to indicate that the bitmap was encoded successfully, followed
189            // by the actual data. This must match the case where the original data is used so the
190            // reader need not know the difference.
191            size_t length = stream.getOffset();
192            this->writeUInt(length);
193            if (stream.read(fWriter.reservePad(length), 0, length)) {
194                encoded = true;
195            } else {
196                // Writing the stream failed, so go back to original state to store another way.
197                fWriter.rewindToOffset(offset);
198            }
199        }
200    }
201    if (encoded) {
202        // Write the width and height in case the reader does not have a decoder.
203        this->writeInt(bitmap.width());
204        this->writeInt(bitmap.height());
205    } else {
206        // Bitmap was not encoded. Record a zero, implying that the reader need not decode.
207        this->writeUInt(0);
208        bitmap.flatten(*this);
209    }
210}
211
212void SkOrderedWriteBuffer::writeTypeface(SkTypeface* obj) {
213    if (NULL == obj || NULL == fTFSet) {
214        fWriter.write32(0);
215    } else {
216        fWriter.write32(fTFSet->add(obj));
217    }
218}
219
220SkFactorySet* SkOrderedWriteBuffer::setFactoryRecorder(SkFactorySet* rec) {
221    SkRefCnt_SafeAssign(fFactorySet, rec);
222    if (fNamedFactorySet != NULL) {
223        fNamedFactorySet->unref();
224        fNamedFactorySet = NULL;
225    }
226    return rec;
227}
228
229SkNamedFactorySet* SkOrderedWriteBuffer::setNamedFactoryRecorder(SkNamedFactorySet* rec) {
230    SkRefCnt_SafeAssign(fNamedFactorySet, rec);
231    if (fFactorySet != NULL) {
232        fFactorySet->unref();
233        fFactorySet = NULL;
234    }
235    return rec;
236}
237
238SkRefCntSet* SkOrderedWriteBuffer::setTypefaceRecorder(SkRefCntSet* rec) {
239    SkRefCnt_SafeAssign(fTFSet, rec);
240    return rec;
241}
242
243void SkOrderedWriteBuffer::setBitmapHeap(SkBitmapHeap* bitmapHeap) {
244    SkRefCnt_SafeAssign(fBitmapHeap, bitmapHeap);
245    if (bitmapHeap != NULL) {
246        SkASSERT(NULL == fBitmapEncoder);
247        fBitmapEncoder = NULL;
248    }
249}
250
251void SkOrderedWriteBuffer::setBitmapEncoder(SkSerializationHelpers::EncodeBitmap bitmapEncoder) {
252    fBitmapEncoder = bitmapEncoder;
253    if (bitmapEncoder != NULL) {
254        SkASSERT(NULL == fBitmapHeap);
255        SkSafeUnref(fBitmapHeap);
256        fBitmapHeap = NULL;
257    }
258}
259
260void SkOrderedWriteBuffer::writeFlattenable(SkFlattenable* flattenable) {
261    /*
262     *  If we have a factoryset, then the first 32bits tell us...
263     *       0: failure to write the flattenable
264     *      >0: (1-based) index into the SkFactorySet or SkNamedFactorySet
265     *  If we don't have a factoryset, then the first "ptr" is either the
266     *  factory, or null for failure.
267     *
268     *  The distinction is important, since 0-index is 32bits (always), but a
269     *  0-functionptr might be 32 or 64 bits.
270     */
271
272    SkFlattenable::Factory factory = NULL;
273    if (flattenable) {
274        factory = flattenable->getFactory();
275    }
276    if (NULL == factory) {
277        if (fFactorySet != NULL || fNamedFactorySet != NULL) {
278            this->write32(0);
279        } else {
280            this->writeFunctionPtr(NULL);
281        }
282        return;
283    }
284
285    /*
286     *  We can write 1 of 3 versions of the flattenable:
287     *  1.  function-ptr : this is the fastest for the reader, but assumes that
288     *      the writer and reader are in the same process.
289     *  2.  index into fFactorySet : This is assumes the writer will later
290     *      resolve the function-ptrs into strings for its reader. SkPicture
291     *      does exactly this, by writing a table of names (matching the indices)
292     *      up front in its serialized form.
293     *  3.  index into fNamedFactorySet. fNamedFactorySet will also store the
294     *      name. SkGPipe uses this technique so it can write the name to its
295     *      stream before writing the flattenable.
296     */
297    if (fFactorySet) {
298        this->write32(fFactorySet->add(factory));
299    } else if (fNamedFactorySet) {
300        int32_t index = fNamedFactorySet->find(factory);
301        this->write32(index);
302        if (0 == index) {
303            return;
304        }
305    } else {
306        this->writeFunctionPtr((void*)factory);
307    }
308
309    // make room for the size of the flattened object
310    (void)fWriter.reserve(sizeof(uint32_t));
311    // record the current size, so we can subtract after the object writes.
312    uint32_t offset = fWriter.size();
313    // now flatten the object
314    flattenObject(flattenable, *this);
315    uint32_t objSize = fWriter.size() - offset;
316    // record the obj's size
317    *fWriter.peek32(offset - sizeof(uint32_t)) = objSize;
318}
319