1 2/* 3 * Copyright 2010 The Android Open Source Project 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 10#include "SkData.h" 11#include "SkFlate.h" 12#include "SkStream.h" 13 14namespace { 15 16#ifdef ZLIB_INCLUDE 17 #include ZLIB_INCLUDE 18#else 19 #include "zlib.h" 20#endif 21 22// static 23const size_t kBufferSize = 1024; 24 25// Different zlib implementations use different T. 26// We've seen size_t and unsigned. 27template <typename T> void* skia_alloc_func(void*, T items, T size) { 28 return sk_calloc_throw(SkToSizeT(items) * SkToSizeT(size)); 29} 30 31static void skia_free_func(void*, void* address) { sk_free(address); } 32 33bool doFlate(bool compress, SkStream* src, SkWStream* dst) { 34 uint8_t inputBuffer[kBufferSize]; 35 uint8_t outputBuffer[kBufferSize]; 36 z_stream flateData; 37 flateData.zalloc = &skia_alloc_func; 38 flateData.zfree = &skia_free_func; 39 flateData.opaque = NULL; 40 flateData.next_in = NULL; 41 flateData.avail_in = 0; 42 flateData.next_out = outputBuffer; 43 flateData.avail_out = kBufferSize; 44 int rc; 45 if (compress) 46 rc = deflateInit(&flateData, Z_DEFAULT_COMPRESSION); 47 else 48 rc = inflateInit(&flateData); 49 if (rc != Z_OK) 50 return false; 51 52 uint8_t* input = (uint8_t*)src->getMemoryBase(); 53 size_t inputLength = src->getLength(); 54 if (input == NULL || inputLength == 0) { 55 input = NULL; 56 flateData.next_in = inputBuffer; 57 flateData.avail_in = 0; 58 } else { 59 flateData.next_in = input; 60 flateData.avail_in = SkToUInt(inputLength); 61 } 62 63 rc = Z_OK; 64 while (true) { 65 if (flateData.avail_out < kBufferSize) { 66 if (!dst->write(outputBuffer, kBufferSize - flateData.avail_out)) { 67 rc = Z_BUF_ERROR; 68 break; 69 } 70 flateData.next_out = outputBuffer; 71 flateData.avail_out = kBufferSize; 72 } 73 if (rc != Z_OK) 74 break; 75 if (flateData.avail_in == 0) { 76 if (input != NULL) 77 break; 78 size_t read = src->read(&inputBuffer, kBufferSize); 79 if (read == 0) 80 break; 81 flateData.next_in = inputBuffer; 82 flateData.avail_in = SkToUInt(read); 83 } 84 if (compress) 85 rc = deflate(&flateData, Z_NO_FLUSH); 86 else 87 rc = inflate(&flateData, Z_NO_FLUSH); 88 } 89 while (rc == Z_OK) { 90 if (compress) 91 rc = deflate(&flateData, Z_FINISH); 92 else 93 rc = inflate(&flateData, Z_FINISH); 94 if (flateData.avail_out < kBufferSize) { 95 if (!dst->write(outputBuffer, kBufferSize - flateData.avail_out)) 96 return false; 97 flateData.next_out = outputBuffer; 98 flateData.avail_out = kBufferSize; 99 } 100 } 101 102 if (compress) 103 deflateEnd(&flateData); 104 else 105 inflateEnd(&flateData); 106 if (rc == Z_STREAM_END) 107 return true; 108 return false; 109} 110 111} 112 113// static 114bool SkFlate::Deflate(SkStream* src, SkWStream* dst) { 115 return doFlate(true, src, dst); 116} 117 118bool SkFlate::Deflate(const void* ptr, size_t len, SkWStream* dst) { 119 SkMemoryStream stream(ptr, len); 120 return doFlate(true, &stream, dst); 121} 122 123bool SkFlate::Deflate(const SkData* data, SkWStream* dst) { 124 if (data) { 125 SkMemoryStream stream(data->data(), data->size()); 126 return doFlate(true, &stream, dst); 127 } 128 return false; 129} 130 131// static 132bool SkFlate::Inflate(SkStream* src, SkWStream* dst) { 133 return doFlate(false, src, dst); 134} 135 136 137#define SKDEFLATEWSTREAM_INPUT_BUFFER_SIZE 4096 138#define SKDEFLATEWSTREAM_OUTPUT_BUFFER_SIZE 4224 // 4096 + 128, usually big 139 // enough to always do a 140 // single loop. 141 142// called by both write() and finalize() 143static void do_deflate(int flush, 144 z_stream* zStream, 145 SkWStream* out, 146 unsigned char* inBuffer, 147 size_t inBufferSize) { 148 zStream->next_in = inBuffer; 149 zStream->avail_in = SkToInt(inBufferSize); 150 unsigned char outBuffer[SKDEFLATEWSTREAM_OUTPUT_BUFFER_SIZE]; 151 SkDEBUGCODE(int returnValue;) 152 do { 153 zStream->next_out = outBuffer; 154 zStream->avail_out = sizeof(outBuffer); 155 SkDEBUGCODE(returnValue =) deflate(zStream, flush); 156 SkASSERT(!zStream->msg); 157 158 out->write(outBuffer, sizeof(outBuffer) - zStream->avail_out); 159 } while (zStream->avail_in || !zStream->avail_out); 160 SkASSERT(flush == Z_FINISH 161 ? returnValue == Z_STREAM_END 162 : returnValue == Z_OK); 163} 164 165// Hide all zlib impl details. 166struct SkDeflateWStream::Impl { 167 SkWStream* fOut; 168 unsigned char fInBuffer[SKDEFLATEWSTREAM_INPUT_BUFFER_SIZE]; 169 size_t fInBufferIndex; 170 z_stream fZStream; 171}; 172 173SkDeflateWStream::SkDeflateWStream(SkWStream* out) 174 : fImpl(SkNEW(SkDeflateWStream::Impl)) { 175 fImpl->fOut = out; 176 fImpl->fInBufferIndex = 0; 177 if (!fImpl->fOut) { 178 return; 179 } 180 fImpl->fZStream.zalloc = &skia_alloc_func; 181 fImpl->fZStream.zfree = &skia_free_func; 182 fImpl->fZStream.opaque = NULL; 183 SkDEBUGCODE(int r =) deflateInit(&fImpl->fZStream, Z_DEFAULT_COMPRESSION); 184 SkASSERT(Z_OK == r); 185} 186 187SkDeflateWStream::~SkDeflateWStream() { this->finalize(); } 188 189void SkDeflateWStream::finalize() { 190 if (!fImpl->fOut) { 191 return; 192 } 193 do_deflate(Z_FINISH, &fImpl->fZStream, fImpl->fOut, fImpl->fInBuffer, 194 fImpl->fInBufferIndex); 195 (void)deflateEnd(&fImpl->fZStream); 196 fImpl->fOut = NULL; 197} 198 199bool SkDeflateWStream::write(const void* void_buffer, size_t len) { 200 if (!fImpl->fOut) { 201 return false; 202 } 203 const char* buffer = (const char*)void_buffer; 204 while (len > 0) { 205 size_t tocopy = 206 SkTMin(len, sizeof(fImpl->fInBuffer) - fImpl->fInBufferIndex); 207 memcpy(fImpl->fInBuffer + fImpl->fInBufferIndex, buffer, tocopy); 208 len -= tocopy; 209 buffer += tocopy; 210 fImpl->fInBufferIndex += tocopy; 211 SkASSERT(fImpl->fInBufferIndex <= sizeof(fImpl->fInBuffer)); 212 213 // if the buffer isn't filled, don't call into zlib yet. 214 if (sizeof(fImpl->fInBuffer) == fImpl->fInBufferIndex) { 215 do_deflate(Z_NO_FLUSH, &fImpl->fZStream, fImpl->fOut, 216 fImpl->fInBuffer, fImpl->fInBufferIndex); 217 fImpl->fInBufferIndex = 0; 218 } 219 } 220 return true; 221} 222 223size_t SkDeflateWStream::bytesWritten() const { 224 return fImpl->fZStream.total_in + fImpl->fInBufferIndex; 225} 226