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 "SkPtrRecorder.h"
13#include "SkStream.h"
14#include "SkTypeface.h"
15
16SkOrderedWriteBuffer::SkOrderedWriteBuffer(size_t minSize)
17    : INHERITED()
18    , fFactorySet(NULL)
19    , fNamedFactorySet(NULL)
20    , fWriter(minSize)
21    , fBitmapHeap(NULL)
22    , fTFSet(NULL)
23    , fBitmapEncoder(NULL) {
24}
25
26SkOrderedWriteBuffer::SkOrderedWriteBuffer(size_t minSize, void* storage, size_t storageSize)
27    : INHERITED()
28    , fFactorySet(NULL)
29    , fNamedFactorySet(NULL)
30    , fWriter(minSize, storage, storageSize)
31    , fBitmapHeap(NULL)
32    , fTFSet(NULL)
33    , fBitmapEncoder(NULL) {
34}
35
36SkOrderedWriteBuffer::~SkOrderedWriteBuffer() {
37    SkSafeUnref(fFactorySet);
38    SkSafeUnref(fNamedFactorySet);
39    SkSafeUnref(fBitmapHeap);
40    SkSafeUnref(fTFSet);
41}
42
43void SkOrderedWriteBuffer::writeByteArray(const void* data, size_t size) {
44    fWriter.write32(size);
45    fWriter.writePad(data, size);
46}
47
48void SkOrderedWriteBuffer::writeBool(bool value) {
49    fWriter.writeBool(value);
50}
51
52void SkOrderedWriteBuffer::writeFixed(SkFixed value) {
53    fWriter.write32(value);
54}
55
56void SkOrderedWriteBuffer::writeScalar(SkScalar value) {
57    fWriter.writeScalar(value);
58}
59
60void SkOrderedWriteBuffer::writeScalarArray(const SkScalar* value, uint32_t count) {
61    fWriter.write32(count);
62    fWriter.write(value, count * sizeof(SkScalar));
63}
64
65void SkOrderedWriteBuffer::writeInt(int32_t value) {
66    fWriter.write32(value);
67}
68
69void SkOrderedWriteBuffer::writeIntArray(const int32_t* value, uint32_t count) {
70    fWriter.write32(count);
71    fWriter.write(value, count * sizeof(int32_t));
72}
73
74void SkOrderedWriteBuffer::writeUInt(uint32_t value) {
75    fWriter.write32(value);
76}
77
78void SkOrderedWriteBuffer::write32(int32_t value) {
79    fWriter.write32(value);
80}
81
82void SkOrderedWriteBuffer::writeString(const char* value) {
83    fWriter.writeString(value);
84}
85
86void SkOrderedWriteBuffer::writeEncodedString(const void* value, size_t byteLength,
87                                              SkPaint::TextEncoding encoding) {
88    fWriter.writeInt(encoding);
89    fWriter.writeInt(byteLength);
90    fWriter.write(value, byteLength);
91}
92
93
94void SkOrderedWriteBuffer::writeColor(const SkColor& color) {
95    fWriter.write32(color);
96}
97
98void SkOrderedWriteBuffer::writeColorArray(const SkColor* color, uint32_t count) {
99    fWriter.write32(count);
100    fWriter.write(color, count * sizeof(SkColor));
101}
102
103void SkOrderedWriteBuffer::writePoint(const SkPoint& point) {
104    fWriter.writeScalar(point.fX);
105    fWriter.writeScalar(point.fY);
106}
107
108void SkOrderedWriteBuffer::writePointArray(const SkPoint* point, uint32_t count) {
109    fWriter.write32(count);
110    fWriter.write(point, count * sizeof(SkPoint));
111}
112
113void SkOrderedWriteBuffer::writeMatrix(const SkMatrix& matrix) {
114    fWriter.writeMatrix(matrix);
115}
116
117void SkOrderedWriteBuffer::writeIRect(const SkIRect& rect) {
118    fWriter.write(&rect, sizeof(SkIRect));
119}
120
121void SkOrderedWriteBuffer::writeRect(const SkRect& rect) {
122    fWriter.writeRect(rect);
123}
124
125void SkOrderedWriteBuffer::writeRegion(const SkRegion& region) {
126    fWriter.writeRegion(region);
127}
128
129void SkOrderedWriteBuffer::writePath(const SkPath& path) {
130    fWriter.writePath(path);
131}
132
133size_t SkOrderedWriteBuffer::writeStream(SkStream* stream, size_t length) {
134    fWriter.write32(length);
135    size_t bytesWritten = fWriter.readFromStream(stream, length);
136    if (bytesWritten < length) {
137        fWriter.reservePad(length - bytesWritten);
138    }
139    return bytesWritten;
140}
141
142bool SkOrderedWriteBuffer::writeToStream(SkWStream* stream) {
143    return fWriter.writeToStream(stream);
144}
145
146// Defined in SkBitmap.cpp
147bool get_upper_left_from_offset(SkBitmap::Config config, size_t offset, size_t rowBytes,
148                            int32_t* x, int32_t* y);
149
150void SkOrderedWriteBuffer::writeBitmap(const SkBitmap& bitmap) {
151    // Record the width and height. This way if readBitmap fails a dummy bitmap can be drawn at the
152    // right size.
153    this->writeInt(bitmap.width());
154    this->writeInt(bitmap.height());
155
156    // Record information about the bitmap in one of three ways, in order of priority:
157    // 1. If there is an SkBitmapHeap, store it in the heap. The client can avoid serializing the
158    //    bitmap entirely or serialize it later as desired. A boolean value of true will be written
159    //    to the stream to signify that a heap was used.
160    // 2. If there is a function for encoding bitmaps, use it to write an encoded version of the
161    //    bitmap. After writing a boolean value of false, signifying that a heap was not used, write
162    //    the size of the encoded data. A non-zero size signifies that encoded data was written.
163    // 3. Call SkBitmap::flatten. After writing a boolean value of false, signifying that a heap was
164    //    not used, write a zero to signify that the data was not encoded.
165    bool useBitmapHeap = fBitmapHeap != NULL;
166    // Write a bool: true if the SkBitmapHeap is to be used, in which case the reader must use an
167    // SkBitmapHeapReader to read the SkBitmap. False if the bitmap was serialized another way.
168    this->writeBool(useBitmapHeap);
169    if (useBitmapHeap) {
170        SkASSERT(NULL == fBitmapEncoder);
171        int32_t slot = fBitmapHeap->insert(bitmap);
172        fWriter.write32(slot);
173        // crbug.com/155875
174        // The generation ID is not required information. We write it to prevent collisions
175        // in SkFlatDictionary.  It is possible to get a collision when a previously
176        // unflattened (i.e. stale) instance of a similar flattenable is in the dictionary
177        // and the instance currently being written is re-using the same slot from the
178        // bitmap heap.
179        fWriter.write32(bitmap.getGenerationID());
180        return;
181    }
182    if (fBitmapEncoder != NULL) {
183        SkASSERT(NULL == fBitmapHeap);
184        size_t offset = 0;
185        SkAutoDataUnref data(fBitmapEncoder(&offset, bitmap));
186        if (data.get() != NULL) {
187            // Write the length to indicate that the bitmap was encoded successfully, followed
188            // by the actual data.
189            this->writeUInt(SkToU32(data->size()));
190            fWriter.writePad(data->data(), data->size());
191            // Store the coordinate of the offset, rather than fPixelRefOffset, which may be
192            // different depending on the decoder.
193            int32_t x, y;
194            if (0 == offset || !get_upper_left_from_offset(bitmap.config(), offset,
195                                                           bitmap.rowBytes(), &x, &y)) {
196                x = y = 0;
197            }
198            this->write32(x);
199            this->write32(y);
200            return;
201        }
202    }
203    // Bitmap was not encoded. Record a zero, implying that the reader need not decode.
204    this->writeUInt(0);
205    bitmap.flatten(*this);
206}
207
208void SkOrderedWriteBuffer::writeTypeface(SkTypeface* obj) {
209    if (NULL == obj || NULL == fTFSet) {
210        fWriter.write32(0);
211    } else {
212        fWriter.write32(fTFSet->add(obj));
213    }
214}
215
216SkFactorySet* SkOrderedWriteBuffer::setFactoryRecorder(SkFactorySet* rec) {
217    SkRefCnt_SafeAssign(fFactorySet, rec);
218    if (fNamedFactorySet != NULL) {
219        fNamedFactorySet->unref();
220        fNamedFactorySet = NULL;
221    }
222    return rec;
223}
224
225SkNamedFactorySet* SkOrderedWriteBuffer::setNamedFactoryRecorder(SkNamedFactorySet* rec) {
226    SkRefCnt_SafeAssign(fNamedFactorySet, rec);
227    if (fFactorySet != NULL) {
228        fFactorySet->unref();
229        fFactorySet = NULL;
230    }
231    return rec;
232}
233
234SkRefCntSet* SkOrderedWriteBuffer::setTypefaceRecorder(SkRefCntSet* rec) {
235    SkRefCnt_SafeAssign(fTFSet, rec);
236    return rec;
237}
238
239void SkOrderedWriteBuffer::setBitmapHeap(SkBitmapHeap* bitmapHeap) {
240    SkRefCnt_SafeAssign(fBitmapHeap, bitmapHeap);
241    if (bitmapHeap != NULL) {
242        SkASSERT(NULL == fBitmapEncoder);
243        fBitmapEncoder = NULL;
244    }
245}
246
247void SkOrderedWriteBuffer::setBitmapEncoder(SkPicture::EncodeBitmap bitmapEncoder) {
248    fBitmapEncoder = bitmapEncoder;
249    if (bitmapEncoder != NULL) {
250        SkASSERT(NULL == fBitmapHeap);
251        SkSafeUnref(fBitmapHeap);
252        fBitmapHeap = NULL;
253    }
254}
255
256void SkOrderedWriteBuffer::writeFlattenable(const SkFlattenable* flattenable) {
257    /*
258     *  If we have a factoryset, then the first 32bits tell us...
259     *       0: failure to write the flattenable
260     *      >0: (1-based) index into the SkFactorySet or SkNamedFactorySet
261     *  If we don't have a factoryset, then the first "ptr" is either the
262     *  factory, or null for failure.
263     *
264     *  The distinction is important, since 0-index is 32bits (always), but a
265     *  0-functionptr might be 32 or 64 bits.
266     */
267
268    SkFlattenable::Factory factory = NULL;
269    if (flattenable) {
270        factory = flattenable->getFactory();
271    }
272    if (NULL == factory) {
273        if (this->isValidating()) {
274            this->writeString("");
275            SkASSERT(NULL == flattenable); // We shouldn't get in here in this scenario
276        } else if (fFactorySet != NULL || fNamedFactorySet != NULL) {
277            this->write32(0);
278        } else {
279            this->writeFunctionPtr(NULL);
280        }
281        return;
282    }
283
284    /*
285     *  We can write 1 of 3 versions of the flattenable:
286     *  1.  function-ptr : this is the fastest for the reader, but assumes that
287     *      the writer and reader are in the same process.
288     *  2.  index into fFactorySet : This is assumes the writer will later
289     *      resolve the function-ptrs into strings for its reader. SkPicture
290     *      does exactly this, by writing a table of names (matching the indices)
291     *      up front in its serialized form.
292     *  3.  index into fNamedFactorySet. fNamedFactorySet will also store the
293     *      name. SkGPipe uses this technique so it can write the name to its
294     *      stream before writing the flattenable.
295     */
296    if (this->isValidating()) {
297        this->writeString(flattenable->getTypeName());
298    } else if (fFactorySet) {
299        this->write32(fFactorySet->add(factory));
300    } else if (fNamedFactorySet) {
301        int32_t index = fNamedFactorySet->find(factory);
302        this->write32(index);
303        if (0 == index) {
304            return;
305        }
306    } else {
307        this->writeFunctionPtr((void*)factory);
308    }
309
310    // make room for the size of the flattened object
311    (void)fWriter.reserve(sizeof(uint32_t));
312    // record the current size, so we can subtract after the object writes.
313    uint32_t offset = fWriter.bytesWritten();
314    // now flatten the object
315    flattenObject(flattenable, *this);
316    uint32_t objSize = fWriter.bytesWritten() - offset;
317    // record the obj's size
318    *fWriter.peek32(offset - sizeof(uint32_t)) = objSize;
319}
320