media/libstagefright/NuCachedSource2.cpp - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2010 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #define LOG_TAG "NuCachedSource2"
 #include <utils/Log.h>

 #include "include/NuCachedSource2.h"

 #include <media/stagefright/foundation/ADebug.h>
 #include <media/stagefright/foundation/AMessage.h>
 #include <media/stagefright/MediaErrors.h>

 namespace android {

 struct PageCache {
     PageCache(size_t pageSize);
     ~PageCache();

     struct Page {
         void *mData;
         size_t mSize;
     };

     Page *acquirePage();
     void releasePage(Page *page);

     void appendPage(Page *page);
     size_t releaseFromStart(size_t maxBytes);

     size_t totalSize() const {
         return mTotalSize;
     }

     void copy(size_t from, void *data, size_t size);

 private:
     size_t mPageSize;
     size_t mTotalSize;

     List<Page *> mActivePages;
     List<Page *> mFreePages;

     void freePages(List<Page *> *list);

     DISALLOW_EVIL_CONSTRUCTORS(PageCache);
 };

 PageCache::PageCache(size_t pageSize)
     : mPageSize(pageSize),
       mTotalSize(0) {
 }

 PageCache::~PageCache() {
     freePages(&mActivePages);
     freePages(&mFreePages);
 }

 void PageCache::freePages(List<Page *> *list) {
     List<Page *>::iterator it = list->begin();
     while (it != list->end()) {
         Page *page = *it;

         free(page->mData);
         delete page;
         page = NULL;

         ++it;
     }
 }

 PageCache::Page *PageCache::acquirePage() {
     if (!mFreePages.empty()) {
         List<Page *>::iterator it = mFreePages.begin();
         Page *page = *it;
         mFreePages.erase(it);

         return page;
     }

     Page *page = new Page;
     page->mData = malloc(mPageSize);
     page->mSize = 0;

     return page;
 }

 void PageCache::releasePage(Page *page) {
     page->mSize = 0;
     mFreePages.push_back(page);
 }

 void PageCache::appendPage(Page *page) {
     mTotalSize += page->mSize;
     mActivePages.push_back(page);
 }

 size_t PageCache::releaseFromStart(size_t maxBytes) {
     size_t bytesReleased = 0;

     while (maxBytes > 0 && !mActivePages.empty()) {
         List<Page *>::iterator it = mActivePages.begin();

         Page *page = *it;

         if (maxBytes < page->mSize) {
             break;
         }

         mActivePages.erase(it);

         maxBytes -= page->mSize;
         bytesReleased += page->mSize;

         releasePage(page);
     }

     mTotalSize -= bytesReleased;
     return bytesReleased;
 }

 void PageCache::copy(size_t from, void *data, size_t size) {
     LOGV("copy from %d size %d", from, size);

     CHECK_LE(from + size, mTotalSize);

     size_t offset = 0;
     List<Page *>::iterator it = mActivePages.begin();
     while (from >= offset + (*it)->mSize) {
         offset += (*it)->mSize;
         ++it;
     }

     size_t delta = from - offset;
     size_t avail = (*it)->mSize - delta;

     if (avail >= size) {
         memcpy(data, (const uint8_t *)(*it)->mData + delta, size);
         return;
     }

     memcpy(data, (const uint8_t *)(*it)->mData + delta, avail);
     ++it;
     data = (uint8_t *)data + avail;
     size -= avail;

     while (size > 0) {
         size_t copy = (*it)->mSize;
         if (copy > size) {
             copy = size;
         }
         memcpy(data, (*it)->mData, copy);
         data = (uint8_t *)data + copy;
         size -= copy;
         ++it;
     }
 }

 ////////////////////////////////////////////////////////////////////////////////

 NuCachedSource2::NuCachedSource2(const sp<DataSource> &source)
     : mSource(source),
       mReflector(new AHandlerReflector<NuCachedSource2>(this)),
       mLooper(new ALooper),
       mCache(new PageCache(kPageSize)),
       mCacheOffset(0),
       mFinalStatus(OK),
       mLastAccessPos(0),
       mFetching(true),
       mLastFetchTimeUs(-1),
       mSuspended(false) {
     mLooper->setName("NuCachedSource2");
     mLooper->registerHandler(mReflector);
     mLooper->start();

     Mutex::Autolock autoLock(mLock);
     (new AMessage(kWhatFetchMore, mReflector->id()))->post();
 }

 NuCachedSource2::~NuCachedSource2() {
     mLooper->stop();
     mLooper->unregisterHandler(mReflector->id());

     delete mCache;
     mCache = NULL;
 }

 status_t NuCachedSource2::initCheck() const {
     return mSource->initCheck();
 }

 status_t NuCachedSource2::getSize(off_t *size) {
     return mSource->getSize(size);
 }

 uint32_t NuCachedSource2::flags() {
     return (mSource->flags() & ~kWantsPrefetching) | kIsCachingDataSource;
 }

 void NuCachedSource2::onMessageReceived(const sp<AMessage> &msg) {
     switch (msg->what()) {
         case kWhatFetchMore:
         {
             onFetch();
             break;
         }

         case kWhatRead:
         {
             onRead(msg);
             break;
         }

         case kWhatSuspend:
         {
             onSuspend();
             break;
         }

         default:
             TRESPASS();
     }
 }

 void NuCachedSource2::fetchInternal() {
     LOGV("fetchInternal");

     CHECK_EQ(mFinalStatus, (status_t)OK);

     PageCache::Page *page = mCache->acquirePage();

     ssize_t n = mSource->readAt(
             mCacheOffset + mCache->totalSize(), page->mData, kPageSize);

     Mutex::Autolock autoLock(mLock);

     if (n < 0) {
         LOGE("source returned error %ld", n);
         mFinalStatus = n;
         mCache->releasePage(page);
     } else if (n == 0) {
         LOGI("ERROR_END_OF_STREAM");
         mFinalStatus = ERROR_END_OF_STREAM;
         mCache->releasePage(page);
     } else {
         page->mSize = n;
         mCache->appendPage(page);
     }
 }

 void NuCachedSource2::onFetch() {
     LOGV("onFetch");

     if (mFinalStatus != OK) {
         LOGV("EOS reached, done prefetching for now");
         mFetching = false;
     }

     bool keepAlive =
         !mFetching
             && !mSuspended
             && mFinalStatus == OK
             && ALooper::GetNowUs() >= mLastFetchTimeUs + kKeepAliveIntervalUs;

     if (mFetching || keepAlive) {
         if (keepAlive) {
             LOGI("Keep alive");
         }

         fetchInternal();

         mLastFetchTimeUs = ALooper::GetNowUs();

         if (mFetching && mCache->totalSize() >= kHighWaterThreshold) {
             LOGI("Cache full, done prefetching for now");
             mFetching = false;
         }
     } else if (!mSuspended) {
         Mutex::Autolock autoLock(mLock);
         restartPrefetcherIfNecessary_l();
     }

     (new AMessage(kWhatFetchMore, mReflector->id()))->post(
             mFetching ? 0 : 100000ll);
 }

 void NuCachedSource2::onRead(const sp<AMessage> &msg) {
     LOGV("onRead");

     int64_t offset;
     CHECK(msg->findInt64("offset", &offset));

     void *data;
     CHECK(msg->findPointer("data", &data));

     size_t size;
     CHECK(msg->findSize("size", &size));

     ssize_t result = readInternal(offset, data, size);

     if (result == -EAGAIN) {
         msg->post(50000);
         return;
     }

     Mutex::Autolock autoLock(mLock);

     CHECK(mAsyncResult == NULL);

     mAsyncResult = new AMessage;
     mAsyncResult->setInt32("result", result);

     mCondition.signal();
 }

 void NuCachedSource2::restartPrefetcherIfNecessary_l() {
     static const size_t kGrayArea = 256 * 1024;

     if (mFetching || mFinalStatus != OK) {
         return;
     }

     if (mCacheOffset + mCache->totalSize() - mLastAccessPos
             >= kLowWaterThreshold) {
         return;
     }

     size_t maxBytes = mLastAccessPos - mCacheOffset;
     if (maxBytes < kGrayArea) {
         return;
     }

     maxBytes -= kGrayArea;

     size_t actualBytes = mCache->releaseFromStart(maxBytes);
     mCacheOffset += actualBytes;

     LOGI("restarting prefetcher, totalSize = %d", mCache->totalSize());
     mFetching = true;
 }

 ssize_t NuCachedSource2::readAt(off_t offset, void *data, size_t size) {
     Mutex::Autolock autoSerializer(mSerializer);

     LOGV("readAt offset %ld, size %d", offset, size);

     Mutex::Autolock autoLock(mLock);

     // If the request can be completely satisfied from the cache, do so.

     if (offset >= mCacheOffset
             && offset + size <= mCacheOffset + mCache->totalSize()) {
         size_t delta = offset - mCacheOffset;
         mCache->copy(delta, data, size);

         mLastAccessPos = offset + size;

         return size;
     }

     sp<AMessage> msg = new AMessage(kWhatRead, mReflector->id());
     msg->setInt64("offset", offset);
     msg->setPointer("data", data);
     msg->setSize("size", size);

     CHECK(mAsyncResult == NULL);
     msg->post();

     while (mAsyncResult == NULL) {
         mCondition.wait(mLock);
     }

     int32_t result;
     CHECK(mAsyncResult->findInt32("result", &result));

     mAsyncResult.clear();

     if (result > 0) {
         mLastAccessPos = offset + result;
     }

     return (ssize_t)result;
 }

 size_t NuCachedSource2::cachedSize() {
     Mutex::Autolock autoLock(mLock);
     return mCacheOffset + mCache->totalSize();
 }

 size_t NuCachedSource2::approxDataRemaining(bool *eos) {
     Mutex::Autolock autoLock(mLock);
     return approxDataRemaining_l(eos);
 }

 size_t NuCachedSource2::approxDataRemaining_l(bool *eos) {
     *eos = (mFinalStatus != OK);
     off_t lastBytePosCached = mCacheOffset + mCache->totalSize();
     if (mLastAccessPos < lastBytePosCached) {
         return lastBytePosCached - mLastAccessPos;
     }
     return 0;
 }

 ssize_t NuCachedSource2::readInternal(off_t offset, void *data, size_t size) {
     LOGV("readInternal offset %ld size %d", offset, size);

     Mutex::Autolock autoLock(mLock);

     if (offset < mCacheOffset
             || offset >= (off_t)(mCacheOffset + mCache->totalSize())) {
         static const off_t kPadding = 32768;

         // In the presence of multiple decoded streams, once of them will
         // trigger this seek request, the other one will request data "nearby"
         // soon, adjust the seek position so that that subsequent request
         // does not trigger another seek.
         off_t seekOffset = (offset > kPadding) ? offset - kPadding : 0;

         seekInternal_l(seekOffset);
     }

     size_t delta = offset - mCacheOffset;

     if (mFinalStatus != OK) {
         if (delta >= mCache->totalSize()) {
             return mFinalStatus;
         }

         size_t avail = mCache->totalSize() - delta;
         mCache->copy(delta, data, avail);

         return avail;
     }

     if (offset + size <= mCacheOffset + mCache->totalSize()) {
         mCache->copy(delta, data, size);

         return size;
     }

     LOGV("deferring read");

     return -EAGAIN;
 }

 status_t NuCachedSource2::seekInternal_l(off_t offset) {
     mLastAccessPos = offset;

     if (offset >= mCacheOffset
             && offset <= (off_t)(mCacheOffset + mCache->totalSize())) {
         return OK;
     }

     LOGI("new range: offset= %ld", offset);

     mCacheOffset = offset;

     size_t totalSize = mCache->totalSize();
     CHECK_EQ(mCache->releaseFromStart(totalSize), totalSize);

     mFinalStatus = OK;
     mFetching = true;

     return OK;
 }

 void NuCachedSource2::clearCacheAndResume() {
     LOGV("clearCacheAndResume");

     Mutex::Autolock autoLock(mLock);

     CHECK(mSuspended);

     mCacheOffset = 0;
     mFinalStatus = OK;
     mLastAccessPos = 0;
     mLastFetchTimeUs = -1;

     size_t totalSize = mCache->totalSize();
     CHECK_EQ(mCache->releaseFromStart(totalSize), totalSize);

     mFetching = true;
     mSuspended = false;
 }

 void NuCachedSource2::suspend() {
     (new AMessage(kWhatSuspend, mReflector->id()))->post();

     while (!mSuspended) {
         usleep(10000);
     }
 }

 void NuCachedSource2::onSuspend() {
     Mutex::Autolock autoLock(mLock);

     mFetching = false;
     mSuspended = true;
 }

 }  // namespace android
	/*
	* Copyright (C) 2010 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#define LOG_TAG "NuCachedSource2"
	#include <utils/Log.h>

	#include "include/NuCachedSource2.h"

	#include <media/stagefright/foundation/ADebug.h>
	#include <media/stagefright/foundation/AMessage.h>
	#include <media/stagefright/MediaErrors.h>

	namespace android {

	struct PageCache {
	PageCache(size_t pageSize);
	~PageCache();

	struct Page {
	void *mData;
	size_t mSize;
	};

	Page *acquirePage();
	void releasePage(Page *page);

	void appendPage(Page *page);
	size_t releaseFromStart(size_t maxBytes);

	size_t totalSize() const {
	return mTotalSize;
	}

	void copy(size_t from, void *data, size_t size);

	private:
	size_t mPageSize;
	size_t mTotalSize;

	List<Page *> mActivePages;
	List<Page *> mFreePages;

	void freePages(List<Page > list);

	DISALLOW_EVIL_CONSTRUCTORS(PageCache);
	};

	PageCache::PageCache(size_t pageSize)
	: mPageSize(pageSize),
	mTotalSize(0) {
	}

	PageCache::~PageCache() {
	freePages(&mActivePages);
	freePages(&mFreePages);
	}

	void PageCache::freePages(List<Page > list) {
	List<Page *>::iterator it = list->begin();
	while (it != list->end()) {
	Page page = it;

	free(page->mData);
	delete page;
	page = NULL;

	++it;
	}
	}

	PageCache::Page *PageCache::acquirePage() {
	if (!mFreePages.empty()) {
	List<Page *>::iterator it = mFreePages.begin();
	Page page = it;
	mFreePages.erase(it);

	return page;
	}

	Page *page = new Page;
	page->mData = malloc(mPageSize);
	page->mSize = 0;

	return page;
	}

	void PageCache::releasePage(Page *page) {
	page->mSize = 0;
	mFreePages.push_back(page);
	}

	void PageCache::appendPage(Page *page) {
	mTotalSize += page->mSize;
	mActivePages.push_back(page);
	}

	size_t PageCache::releaseFromStart(size_t maxBytes) {
	size_t bytesReleased = 0;

	while (maxBytes > 0 && !mActivePages.empty()) {
	List<Page *>::iterator it = mActivePages.begin();

	Page page = it;

	if (maxBytes < page->mSize) {
	break;
	}

	mActivePages.erase(it);

	maxBytes -= page->mSize;
	bytesReleased += page->mSize;

	releasePage(page);
	}

	mTotalSize -= bytesReleased;
	return bytesReleased;
	}

	void PageCache::copy(size_t from, void *data, size_t size) {
	LOGV("copy from %d size %d", from, size);

	CHECK_LE(from + size, mTotalSize);

	size_t offset = 0;
	List<Page *>::iterator it = mActivePages.begin();
	while (from >= offset + (*it)->mSize) {
	offset += (*it)->mSize;
	++it;
	}

	size_t delta = from - offset;
	size_t avail = (*it)->mSize - delta;

	if (avail >= size) {
	memcpy(data, (const uint8_t )(it)->mData + delta, size);
	return;
	}

	memcpy(data, (const uint8_t )(it)->mData + delta, avail);
	++it;
	data = (uint8_t *)data + avail;
	size -= avail;

	while (size > 0) {
	size_t copy = (*it)->mSize;
	if (copy > size) {
	copy = size;
	}
	memcpy(data, (*it)->mData, copy);
	data = (uint8_t *)data + copy;
	size -= copy;
	++it;
	}
	}

	////////////////////////////////////////////////////////////////////////////////

	NuCachedSource2::NuCachedSource2(const sp<DataSource> &source)
	: mSource(source),
	mReflector(new AHandlerReflector<NuCachedSource2>(this)),
	mLooper(new ALooper),
	mCache(new PageCache(kPageSize)),
	mCacheOffset(0),
	mFinalStatus(OK),
	mLastAccessPos(0),
	mFetching(true),
	mLastFetchTimeUs(-1),
	mSuspended(false) {
	mLooper->setName("NuCachedSource2");
	mLooper->registerHandler(mReflector);
	mLooper->start();

	Mutex::Autolock autoLock(mLock);
	(new AMessage(kWhatFetchMore, mReflector->id()))->post();
	}

	NuCachedSource2::~NuCachedSource2() {
	mLooper->stop();
	mLooper->unregisterHandler(mReflector->id());

	delete mCache;
	mCache = NULL;
	}

	status_t NuCachedSource2::initCheck() const {
	return mSource->initCheck();
	}

	status_t NuCachedSource2::getSize(off_t *size) {
	return mSource->getSize(size);
	}

	uint32_t NuCachedSource2::flags() {
	return (mSource->flags() & ~kWantsPrefetching) \| kIsCachingDataSource;
	}

	void NuCachedSource2::onMessageReceived(const sp<AMessage> &msg) {
	switch (msg->what()) {
	case kWhatFetchMore:
	{
	onFetch();
	break;
	}

	case kWhatRead:
	{
	onRead(msg);
	break;
	}

	case kWhatSuspend:
	{
	onSuspend();
	break;
	}

	default:
	TRESPASS();
	}
	}

	void NuCachedSource2::fetchInternal() {
	LOGV("fetchInternal");

	CHECK_EQ(mFinalStatus, (status_t)OK);

	PageCache::Page *page = mCache->acquirePage();

	ssize_t n = mSource->readAt(
	mCacheOffset + mCache->totalSize(), page->mData, kPageSize);

	Mutex::Autolock autoLock(mLock);

	if (n < 0) {
	LOGE("source returned error %ld", n);
	mFinalStatus = n;
	mCache->releasePage(page);
	} else if (n == 0) {
	LOGI("ERROR_END_OF_STREAM");
	mFinalStatus = ERROR_END_OF_STREAM;
	mCache->releasePage(page);
	} else {
	page->mSize = n;
	mCache->appendPage(page);
	}
	}

	void NuCachedSource2::onFetch() {
	LOGV("onFetch");

	if (mFinalStatus != OK) {
	LOGV("EOS reached, done prefetching for now");
	mFetching = false;
	}

	bool keepAlive =
	!mFetching
	&& !mSuspended
	&& mFinalStatus == OK
	&& ALooper::GetNowUs() >= mLastFetchTimeUs + kKeepAliveIntervalUs;

	if (mFetching \|\| keepAlive) {
	if (keepAlive) {
	LOGI("Keep alive");
	}

	fetchInternal();

	mLastFetchTimeUs = ALooper::GetNowUs();

	if (mFetching && mCache->totalSize() >= kHighWaterThreshold) {
	LOGI("Cache full, done prefetching for now");
	mFetching = false;
	}
	} else if (!mSuspended) {
	Mutex::Autolock autoLock(mLock);
	restartPrefetcherIfNecessary_l();
	}

	(new AMessage(kWhatFetchMore, mReflector->id()))->post(
	mFetching ? 0 : 100000ll);
	}

	void NuCachedSource2::onRead(const sp<AMessage> &msg) {
	LOGV("onRead");

	int64_t offset;
	CHECK(msg->findInt64("offset", &offset));

	void *data;
	CHECK(msg->findPointer("data", &data));

	size_t size;
	CHECK(msg->findSize("size", &size));

	ssize_t result = readInternal(offset, data, size);

	if (result == -EAGAIN) {
	msg->post(50000);
	return;
	}

	Mutex::Autolock autoLock(mLock);

	CHECK(mAsyncResult == NULL);

	mAsyncResult = new AMessage;
	mAsyncResult->setInt32("result", result);

	mCondition.signal();
	}

	void NuCachedSource2::restartPrefetcherIfNecessary_l() {
	static const size_t kGrayArea = 256 * 1024;

	if (mFetching \|\| mFinalStatus != OK) {
	return;
	}

	if (mCacheOffset + mCache->totalSize() - mLastAccessPos
	>= kLowWaterThreshold) {
	return;
	}

	size_t maxBytes = mLastAccessPos - mCacheOffset;
	if (maxBytes < kGrayArea) {
	return;
	}

	maxBytes -= kGrayArea;

	size_t actualBytes = mCache->releaseFromStart(maxBytes);
	mCacheOffset += actualBytes;

	LOGI("restarting prefetcher, totalSize = %d", mCache->totalSize());
	mFetching = true;
	}

	ssize_t NuCachedSource2::readAt(off_t offset, void *data, size_t size) {
	Mutex::Autolock autoSerializer(mSerializer);

	LOGV("readAt offset %ld, size %d", offset, size);

	Mutex::Autolock autoLock(mLock);

	// If the request can be completely satisfied from the cache, do so.

	if (offset >= mCacheOffset
	&& offset + size <= mCacheOffset + mCache->totalSize()) {
	size_t delta = offset - mCacheOffset;
	mCache->copy(delta, data, size);

	mLastAccessPos = offset + size;

	return size;
	}

	sp<AMessage> msg = new AMessage(kWhatRead, mReflector->id());
	msg->setInt64("offset", offset);
	msg->setPointer("data", data);
	msg->setSize("size", size);

	CHECK(mAsyncResult == NULL);
	msg->post();

	while (mAsyncResult == NULL) {
	mCondition.wait(mLock);
	}

	int32_t result;
	CHECK(mAsyncResult->findInt32("result", &result));

	mAsyncResult.clear();

	if (result > 0) {
	mLastAccessPos = offset + result;
	}

	return (ssize_t)result;
	}

	size_t NuCachedSource2::cachedSize() {
	Mutex::Autolock autoLock(mLock);
	return mCacheOffset + mCache->totalSize();
	}

	size_t NuCachedSource2::approxDataRemaining(bool *eos) {
	Mutex::Autolock autoLock(mLock);
	return approxDataRemaining_l(eos);
	}

	size_t NuCachedSource2::approxDataRemaining_l(bool *eos) {
	*eos = (mFinalStatus != OK);
	off_t lastBytePosCached = mCacheOffset + mCache->totalSize();
	if (mLastAccessPos < lastBytePosCached) {
	return lastBytePosCached - mLastAccessPos;
	}
	return 0;
	}

	ssize_t NuCachedSource2::readInternal(off_t offset, void *data, size_t size) {
	LOGV("readInternal offset %ld size %d", offset, size);

	Mutex::Autolock autoLock(mLock);

	if (offset < mCacheOffset
	\|\| offset >= (off_t)(mCacheOffset + mCache->totalSize())) {
	static const off_t kPadding = 32768;

	// In the presence of multiple decoded streams, once of them will
	// trigger this seek request, the other one will request data "nearby"
	// soon, adjust the seek position so that that subsequent request
	// does not trigger another seek.
	off_t seekOffset = (offset > kPadding) ? offset - kPadding : 0;

	seekInternal_l(seekOffset);
	}

	size_t delta = offset - mCacheOffset;

	if (mFinalStatus != OK) {
	if (delta >= mCache->totalSize()) {
	return mFinalStatus;
	}

	size_t avail = mCache->totalSize() - delta;
	mCache->copy(delta, data, avail);

	return avail;
	}

	if (offset + size <= mCacheOffset + mCache->totalSize()) {
	mCache->copy(delta, data, size);

	return size;
	}

	LOGV("deferring read");

	return -EAGAIN;
	}

	status_t NuCachedSource2::seekInternal_l(off_t offset) {
	mLastAccessPos = offset;

	if (offset >= mCacheOffset
	&& offset <= (off_t)(mCacheOffset + mCache->totalSize())) {
	return OK;
	}

	LOGI("new range: offset= %ld", offset);

	mCacheOffset = offset;

	size_t totalSize = mCache->totalSize();
	CHECK_EQ(mCache->releaseFromStart(totalSize), totalSize);

	mFinalStatus = OK;
	mFetching = true;

	return OK;
	}

	void NuCachedSource2::clearCacheAndResume() {
	LOGV("clearCacheAndResume");

	Mutex::Autolock autoLock(mLock);

	CHECK(mSuspended);

	mCacheOffset = 0;
	mFinalStatus = OK;
	mLastAccessPos = 0;
	mLastFetchTimeUs = -1;

	size_t totalSize = mCache->totalSize();
	CHECK_EQ(mCache->releaseFromStart(totalSize), totalSize);

	mFetching = true;
	mSuspended = false;
	}

	void NuCachedSource2::suspend() {
	(new AMessage(kWhatSuspend, mReflector->id()))->post();

	while (!mSuspended) {
	usleep(10000);
	}
	}

	void NuCachedSource2::onSuspend() {
	Mutex::Autolock autoLock(mLock);

	mFetching = false;
	mSuspended = true;
	}

	} // namespace android