michael@0: /*
michael@0:  * Copyright 2012 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #include "SkTypes.h"
michael@0: #include "SkDWriteFontFileStream.h"
michael@0: #include "SkHRESULT.h"
michael@0: #include "SkTemplates.h"
michael@0: #include "SkTFitsIn.h"
michael@0: #include "SkTScopedComPtr.h"
michael@0: 
michael@0: #include <dwrite.h>
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: //  SkIDWriteFontFileStream
michael@0: 
michael@0: SkDWriteFontFileStream::SkDWriteFontFileStream(IDWriteFontFileStream* fontFileStream)
michael@0:     : fFontFileStream(SkRefComPtr(fontFileStream))
michael@0:     , fPos(0)
michael@0:     , fLockedMemory(NULL)
michael@0:     , fFragmentLock(NULL) {
michael@0: }
michael@0: 
michael@0: SkDWriteFontFileStream::~SkDWriteFontFileStream() {
michael@0:     if (fFragmentLock) {
michael@0:         fFontFileStream->ReleaseFileFragment(fFragmentLock);
michael@0:     }
michael@0: }
michael@0: 
michael@0: size_t SkDWriteFontFileStream::read(void* buffer, size_t size) {
michael@0:     HRESULT hr = S_OK;
michael@0: 
michael@0:     if (NULL == buffer) {
michael@0:         size_t fileSize = this->getLength();
michael@0: 
michael@0:         if (fPos + size > fileSize) {
michael@0:             size_t skipped = fileSize - fPos;
michael@0:             fPos = fileSize;
michael@0:             return skipped;
michael@0:         } else {
michael@0:             fPos += size;
michael@0:             return size;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     const void* start;
michael@0:     void* fragmentLock;
michael@0:     hr = fFontFileStream->ReadFileFragment(&start, fPos, size, &fragmentLock);
michael@0:     if (SUCCEEDED(hr)) {
michael@0:         memcpy(buffer, start, size);
michael@0:         fFontFileStream->ReleaseFileFragment(fragmentLock);
michael@0:         fPos += size;
michael@0:         return size;
michael@0:     }
michael@0: 
michael@0:     //The read may have failed because we asked for too much data.
michael@0:     size_t fileSize = this->getLength();
michael@0:     if (fPos + size <= fileSize) {
michael@0:         //This means we were within bounds, but failed for some other reason.
michael@0:         return 0;
michael@0:     }
michael@0: 
michael@0:     size_t read = fileSize - fPos;
michael@0:     hr = fFontFileStream->ReadFileFragment(&start, fPos, read, &fragmentLock);
michael@0:     if (SUCCEEDED(hr)) {
michael@0:         memcpy(buffer, start, read);
michael@0:         fFontFileStream->ReleaseFileFragment(fragmentLock);
michael@0:         fPos = fileSize;
michael@0:         return read;
michael@0:     }
michael@0: 
michael@0:     return 0;
michael@0: }
michael@0: 
michael@0: bool SkDWriteFontFileStream::isAtEnd() const {
michael@0:     return fPos == this->getLength();
michael@0: }
michael@0: 
michael@0: bool SkDWriteFontFileStream::rewind() {
michael@0:     fPos = 0;
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: SkDWriteFontFileStream* SkDWriteFontFileStream::duplicate() const {
michael@0:     return SkNEW_ARGS(SkDWriteFontFileStream, (fFontFileStream.get()));
michael@0: }
michael@0: 
michael@0: size_t SkDWriteFontFileStream::getPosition() const {
michael@0:     return fPos;
michael@0: }
michael@0: 
michael@0: bool SkDWriteFontFileStream::seek(size_t position) {
michael@0:     size_t length = this->getLength();
michael@0:     fPos = (position > length) ? length : position;
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: bool SkDWriteFontFileStream::move(long offset) {
michael@0:     return seek(fPos + offset);
michael@0: }
michael@0: 
michael@0: SkDWriteFontFileStream* SkDWriteFontFileStream::fork() const {
michael@0:     SkAutoTUnref<SkDWriteFontFileStream> that(this->duplicate());
michael@0:     that->seek(fPos);
michael@0:     return that.detach();
michael@0: }
michael@0: 
michael@0: size_t SkDWriteFontFileStream::getLength() const {
michael@0:     HRESULT hr = S_OK;
michael@0:     UINT64 realFileSize = 0;
michael@0:     hr = fFontFileStream->GetFileSize(&realFileSize);
michael@0:     if (!SkTFitsIn<size_t>(realFileSize)) {
michael@0:         return 0;
michael@0:     }
michael@0:     return static_cast<size_t>(realFileSize);
michael@0: }
michael@0: 
michael@0: const void* SkDWriteFontFileStream::getMemoryBase() {
michael@0:     if (fLockedMemory) {
michael@0:         return fLockedMemory;
michael@0:     }
michael@0: 
michael@0:     UINT64 fileSize;
michael@0:     HRNM(fFontFileStream->GetFileSize(&fileSize), "Could not get file size");
michael@0:     HRNM(fFontFileStream->ReadFileFragment(&fLockedMemory, 0, fileSize, &fFragmentLock),
michael@0:          "Could not lock file fragment.");
michael@0:     return fLockedMemory;
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: //  SkIDWriteFontFileStreamWrapper
michael@0: 
michael@0: HRESULT SkDWriteFontFileStreamWrapper::Create(SkStream* stream, SkDWriteFontFileStreamWrapper** streamFontFileStream) {
michael@0:     *streamFontFileStream = new SkDWriteFontFileStreamWrapper(stream);
michael@0:     if (NULL == streamFontFileStream) {
michael@0:         return E_OUTOFMEMORY;
michael@0:     }
michael@0:     return S_OK;
michael@0: }
michael@0: 
michael@0: SkDWriteFontFileStreamWrapper::SkDWriteFontFileStreamWrapper(SkStream* stream)
michael@0:     : fRefCount(1), fStream(SkRef(stream)) {
michael@0: }
michael@0: 
michael@0: HRESULT STDMETHODCALLTYPE SkDWriteFontFileStreamWrapper::QueryInterface(REFIID iid, void** ppvObject) {
michael@0:     if (iid == IID_IUnknown || iid == __uuidof(IDWriteFontFileStream)) {
michael@0:         *ppvObject = this;
michael@0:         AddRef();
michael@0:         return S_OK;
michael@0:     } else {
michael@0:         *ppvObject = NULL;
michael@0:         return E_NOINTERFACE;
michael@0:     }
michael@0: }
michael@0: 
michael@0: ULONG STDMETHODCALLTYPE SkDWriteFontFileStreamWrapper::AddRef() {
michael@0:     return InterlockedIncrement(&fRefCount);
michael@0: }
michael@0: 
michael@0: ULONG STDMETHODCALLTYPE SkDWriteFontFileStreamWrapper::Release() {
michael@0:     ULONG newCount = InterlockedDecrement(&fRefCount);
michael@0:     if (0 == newCount) {
michael@0:         delete this;
michael@0:     }
michael@0:     return newCount;
michael@0: }
michael@0: 
michael@0: HRESULT STDMETHODCALLTYPE SkDWriteFontFileStreamWrapper::ReadFileFragment(
michael@0:     void const** fragmentStart,
michael@0:     UINT64 fileOffset,
michael@0:     UINT64 fragmentSize,
michael@0:     void** fragmentContext)
michael@0: {
michael@0:     // The loader is responsible for doing a bounds check.
michael@0:     UINT64 fileSize;
michael@0:     this->GetFileSize(&fileSize);
michael@0:     if (fileOffset > fileSize || fragmentSize > fileSize - fileOffset) {
michael@0:         *fragmentStart = NULL;
michael@0:         *fragmentContext = NULL;
michael@0:         return E_FAIL;
michael@0:     }
michael@0: 
michael@0:     if (!SkTFitsIn<size_t>(fileOffset + fragmentSize)) {
michael@0:         return E_FAIL;
michael@0:     }
michael@0: 
michael@0:     const void* data = fStream->getMemoryBase();
michael@0:     if (NULL != data) {
michael@0:         *fragmentStart = static_cast<BYTE const*>(data) + static_cast<size_t>(fileOffset);
michael@0:         *fragmentContext = NULL;
michael@0: 
michael@0:     } else {
michael@0:         //May be called from multiple threads.
michael@0:         SkAutoMutexAcquire ama(fStreamMutex);
michael@0: 
michael@0:         *fragmentStart = NULL;
michael@0:         *fragmentContext = NULL;
michael@0: 
michael@0:         if (!fStream->rewind()) {
michael@0:             return E_FAIL;
michael@0:         }
michael@0:         if (fStream->skip(static_cast<size_t>(fileOffset)) != fileOffset) {
michael@0:             return E_FAIL;
michael@0:         }
michael@0:         SkAutoTMalloc<uint8_t> streamData(static_cast<size_t>(fragmentSize));
michael@0:         if (fStream->read(streamData.get(), static_cast<size_t>(fragmentSize)) != fragmentSize) {
michael@0:             return E_FAIL;
michael@0:         }
michael@0: 
michael@0:         *fragmentStart = streamData.get();
michael@0:         *fragmentContext = streamData.detach();
michael@0:     }
michael@0:     return S_OK;
michael@0: }
michael@0: 
michael@0: void STDMETHODCALLTYPE SkDWriteFontFileStreamWrapper::ReleaseFileFragment(void* fragmentContext) {
michael@0:     sk_free(fragmentContext);
michael@0: }
michael@0: 
michael@0: HRESULT STDMETHODCALLTYPE SkDWriteFontFileStreamWrapper::GetFileSize(UINT64* fileSize) {
michael@0:     *fileSize = fStream->getLength();
michael@0:     return S_OK;
michael@0: }
michael@0: 
michael@0: HRESULT STDMETHODCALLTYPE SkDWriteFontFileStreamWrapper::GetLastWriteTime(UINT64* lastWriteTime) {
michael@0:     // The concept of last write time does not apply to this loader.
michael@0:     *lastWriteTime = 0;
michael@0:     return E_NOTIMPL;
michael@0: }