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/*
* Copyright 2010 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkData.h"
#include "SkFlate.h"
#include "SkStream.h"
#ifndef SK_NO_FLATE
namespace {
#ifdef ZLIB_INCLUDE
#include ZLIB_INCLUDE
#else
#include "zlib.h"
#endif
// static
const size_t kBufferSize = 1024;
// Different zlib implementations use different T.
// We've seen size_t and unsigned.
template <typename T> void* skia_alloc_func(void*, T items, T size) {
return sk_calloc_throw(SkToSizeT(items) * SkToSizeT(size));
}
static void skia_free_func(void*, void* address) { sk_free(address); }
bool doFlate(bool compress, SkStream* src, SkWStream* dst) {
uint8_t inputBuffer[kBufferSize];
uint8_t outputBuffer[kBufferSize];
z_stream flateData;
flateData.zalloc = &skia_alloc_func;
flateData.zfree = &skia_free_func;
flateData.opaque = NULL;
flateData.next_in = NULL;
flateData.avail_in = 0;
flateData.next_out = outputBuffer;
flateData.avail_out = kBufferSize;
int rc;
if (compress)
rc = deflateInit(&flateData, Z_DEFAULT_COMPRESSION);
else
rc = inflateInit(&flateData);
if (rc != Z_OK)
return false;
uint8_t* input = (uint8_t*)src->getMemoryBase();
size_t inputLength = src->getLength();
if (input == NULL || inputLength == 0) {
input = NULL;
flateData.next_in = inputBuffer;
flateData.avail_in = 0;
} else {
flateData.next_in = input;
flateData.avail_in = SkToUInt(inputLength);
}
rc = Z_OK;
while (true) {
if (flateData.avail_out < kBufferSize) {
if (!dst->write(outputBuffer, kBufferSize - flateData.avail_out)) {
rc = Z_BUF_ERROR;
break;
}
flateData.next_out = outputBuffer;
flateData.avail_out = kBufferSize;
}
if (rc != Z_OK)
break;
if (flateData.avail_in == 0) {
if (input != NULL)
break;
size_t read = src->read(&inputBuffer, kBufferSize);
if (read == 0)
break;
flateData.next_in = inputBuffer;
flateData.avail_in = SkToUInt(read);
}
if (compress)
rc = deflate(&flateData, Z_NO_FLUSH);
else
rc = inflate(&flateData, Z_NO_FLUSH);
}
while (rc == Z_OK) {
if (compress)
rc = deflate(&flateData, Z_FINISH);
else
rc = inflate(&flateData, Z_FINISH);
if (flateData.avail_out < kBufferSize) {
if (!dst->write(outputBuffer, kBufferSize - flateData.avail_out))
return false;
flateData.next_out = outputBuffer;
flateData.avail_out = kBufferSize;
}
}
if (compress)
deflateEnd(&flateData);
else
inflateEnd(&flateData);
if (rc == Z_STREAM_END)
return true;
return false;
}
}
// static
bool SkFlate::Deflate(SkStream* src, SkWStream* dst) {
return doFlate(true, src, dst);
}
bool SkFlate::Deflate(const void* ptr, size_t len, SkWStream* dst) {
SkMemoryStream stream(ptr, len);
return doFlate(true, &stream, dst);
}
bool SkFlate::Deflate(const SkData* data, SkWStream* dst) {
if (data) {
SkMemoryStream stream(data->data(), data->size());
return doFlate(true, &stream, dst);
}
return false;
}
// static
bool SkFlate::Inflate(SkStream* src, SkWStream* dst) {
return doFlate(false, src, dst);
}
#define SKDEFLATEWSTREAM_INPUT_BUFFER_SIZE 4096
#define SKDEFLATEWSTREAM_OUTPUT_BUFFER_SIZE 4224 // 4096 + 128, usually big
// enough to always do a
// single loop.
// called by both write() and finalize()
static void do_deflate(int flush,
z_stream* zStream,
SkWStream* out,
unsigned char* inBuffer,
size_t inBufferSize) {
zStream->next_in = inBuffer;
zStream->avail_in = SkToInt(inBufferSize);
unsigned char outBuffer[SKDEFLATEWSTREAM_OUTPUT_BUFFER_SIZE];
SkDEBUGCODE(int returnValue;)
do {
zStream->next_out = outBuffer;
zStream->avail_out = sizeof(outBuffer);
SkDEBUGCODE(returnValue =) deflate(zStream, flush);
SkASSERT(!zStream->msg);
out->write(outBuffer, sizeof(outBuffer) - zStream->avail_out);
} while (zStream->avail_in || !zStream->avail_out);
SkASSERT(flush == Z_FINISH
? returnValue == Z_STREAM_END
: returnValue == Z_OK);
}
// Hide all zlib impl details.
struct SkDeflateWStream::Impl {
SkWStream* fOut;
unsigned char fInBuffer[SKDEFLATEWSTREAM_INPUT_BUFFER_SIZE];
size_t fInBufferIndex;
z_stream fZStream;
};
SkDeflateWStream::SkDeflateWStream(SkWStream* out)
: fImpl(SkNEW(SkDeflateWStream::Impl)) {
fImpl->fOut = out;
fImpl->fInBufferIndex = 0;
if (!fImpl->fOut) {
return;
}
fImpl->fZStream.zalloc = &skia_alloc_func;
fImpl->fZStream.zfree = &skia_free_func;
fImpl->fZStream.opaque = NULL;
SkDEBUGCODE(int r =) deflateInit(&fImpl->fZStream, Z_DEFAULT_COMPRESSION);
SkASSERT(Z_OK == r);
}
SkDeflateWStream::~SkDeflateWStream() { this->finalize(); }
void SkDeflateWStream::finalize() {
if (!fImpl->fOut) {
return;
}
do_deflate(Z_FINISH, &fImpl->fZStream, fImpl->fOut, fImpl->fInBuffer,
fImpl->fInBufferIndex);
(void)deflateEnd(&fImpl->fZStream);
fImpl->fOut = NULL;
}
bool SkDeflateWStream::write(const void* void_buffer, size_t len) {
if (!fImpl->fOut) {
return false;
}
const char* buffer = (const char*)void_buffer;
while (len > 0) {
size_t tocopy =
SkTMin(len, sizeof(fImpl->fInBuffer) - fImpl->fInBufferIndex);
memcpy(fImpl->fInBuffer + fImpl->fInBufferIndex, buffer, tocopy);
len -= tocopy;
buffer += tocopy;
fImpl->fInBufferIndex += tocopy;
SkASSERT(fImpl->fInBufferIndex <= sizeof(fImpl->fInBuffer));
// if the buffer isn't filled, don't call into zlib yet.
if (sizeof(fImpl->fInBuffer) == fImpl->fInBufferIndex) {
do_deflate(Z_NO_FLUSH, &fImpl->fZStream, fImpl->fOut,
fImpl->fInBuffer, fImpl->fInBufferIndex);
fImpl->fInBufferIndex = 0;
}
}
return true;
}
size_t SkDeflateWStream::bytesWritten() const {
return fImpl->fZStream.total_in + fImpl->fInBufferIndex;
}
#endif // SK_NO_FLATE
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