/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* vim:set ts=2 sw=2 sts=2 et cindent: */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #include "MP4Stream.h" #include "MediaResource.h" namespace mozilla { MP4Stream::MP4Stream(MediaResource* aResource) : mResource(aResource) , mPinCount(0) { MOZ_COUNT_CTOR(MP4Stream); MOZ_ASSERT(aResource); } MP4Stream::~MP4Stream() { MOZ_COUNT_DTOR(MP4Stream); MOZ_ASSERT(mPinCount == 0); } bool MP4Stream::BlockingReadIntoCache(int64_t aOffset, size_t aCount, Monitor* aToUnlock) { MOZ_ASSERT(mPinCount > 0); CacheBlock block(aOffset, aCount); if (!block.Init()) { return false; } uint32_t bytesRead = 0; { MonitorAutoUnlock unlock(*aToUnlock); nsresult rv = mResource.ReadAt(aOffset, block.Buffer(), aCount, &bytesRead); if (NS_FAILED(rv)) { return false; } } MOZ_ASSERT(block.mCount >= bytesRead); block.mCount = bytesRead; mCache.AppendElement(Move(block)); return true; } // We surreptitiously reimplement the supposedly-blocking ReadAt as a non- // blocking CachedReadAt, and record when it fails. This allows MP4Reader // to retry the read as an actual blocking read without holding the lock. bool MP4Stream::ReadAt(int64_t aOffset, void* aBuffer, size_t aCount, size_t* aBytesRead) { if (mFailedRead.isSome()) { mFailedRead.reset(); } if (!CachedReadAt(aOffset, aBuffer, aCount, aBytesRead)) { mFailedRead.emplace(aOffset, aCount); return false; } return true; } bool MP4Stream::CachedReadAt(int64_t aOffset, void* aBuffer, size_t aCount, size_t* aBytesRead) { // First, check our local cache. for (size_t i = 0; i < mCache.Length(); ++i) { if (mCache[i].mOffset == aOffset && mCache[i].mCount >= aCount) { memcpy(aBuffer, mCache[i].Buffer(), aCount); *aBytesRead = aCount; return true; } } nsresult rv = mResource.GetResource()->ReadFromCache(reinterpret_cast<char*>(aBuffer), aOffset, aCount); if (NS_FAILED(rv)) { *aBytesRead = 0; return false; } *aBytesRead = aCount; return true; } bool MP4Stream::Length(int64_t* aSize) { if (mResource.GetLength() < 0) return false; *aSize = mResource.GetLength(); return true; } } // namespace mozilla