NuCachedSource2.cpp revision a5273ebd1746368662a597643d6701a5046d5c7b
1/* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#define LOG_TAG "NuCachedSource2" 18#include <utils/Log.h> 19 20#include "include/NuCachedSource2.h" 21 22#include <media/stagefright/foundation/ADebug.h> 23#include <media/stagefright/foundation/AMessage.h> 24#include <media/stagefright/MediaErrors.h> 25 26namespace android { 27 28struct PageCache { 29 PageCache(size_t pageSize); 30 ~PageCache(); 31 32 struct Page { 33 void *mData; 34 size_t mSize; 35 }; 36 37 Page *acquirePage(); 38 void releasePage(Page *page); 39 40 void appendPage(Page *page); 41 size_t releaseFromStart(size_t maxBytes); 42 43 size_t totalSize() const { 44 return mTotalSize; 45 } 46 47 void copy(size_t from, void *data, size_t size); 48 49private: 50 size_t mPageSize; 51 size_t mTotalSize; 52 53 List<Page *> mActivePages; 54 List<Page *> mFreePages; 55 56 void freePages(List<Page *> *list); 57 58 DISALLOW_EVIL_CONSTRUCTORS(PageCache); 59}; 60 61PageCache::PageCache(size_t pageSize) 62 : mPageSize(pageSize), 63 mTotalSize(0) { 64} 65 66PageCache::~PageCache() { 67 freePages(&mActivePages); 68 freePages(&mFreePages); 69} 70 71void PageCache::freePages(List<Page *> *list) { 72 List<Page *>::iterator it = list->begin(); 73 while (it != list->end()) { 74 Page *page = *it; 75 76 free(page->mData); 77 delete page; 78 page = NULL; 79 80 ++it; 81 } 82} 83 84PageCache::Page *PageCache::acquirePage() { 85 if (!mFreePages.empty()) { 86 List<Page *>::iterator it = mFreePages.begin(); 87 Page *page = *it; 88 mFreePages.erase(it); 89 90 return page; 91 } 92 93 Page *page = new Page; 94 page->mData = malloc(mPageSize); 95 page->mSize = 0; 96 97 return page; 98} 99 100void PageCache::releasePage(Page *page) { 101 page->mSize = 0; 102 mFreePages.push_back(page); 103} 104 105void PageCache::appendPage(Page *page) { 106 mTotalSize += page->mSize; 107 mActivePages.push_back(page); 108} 109 110size_t PageCache::releaseFromStart(size_t maxBytes) { 111 size_t bytesReleased = 0; 112 113 while (maxBytes > 0 && !mActivePages.empty()) { 114 List<Page *>::iterator it = mActivePages.begin(); 115 116 Page *page = *it; 117 118 if (maxBytes < page->mSize) { 119 break; 120 } 121 122 mActivePages.erase(it); 123 124 maxBytes -= page->mSize; 125 bytesReleased += page->mSize; 126 127 releasePage(page); 128 } 129 130 mTotalSize -= bytesReleased; 131 return bytesReleased; 132} 133 134void PageCache::copy(size_t from, void *data, size_t size) { 135 LOG(VERBOSE) << "copy from " << from << " size " << size; 136 137 CHECK_LE(from + size, mTotalSize); 138 139 size_t offset = 0; 140 List<Page *>::iterator it = mActivePages.begin(); 141 while (from >= offset + (*it)->mSize) { 142 offset += (*it)->mSize; 143 ++it; 144 } 145 146 size_t delta = from - offset; 147 size_t avail = (*it)->mSize - delta; 148 149 if (avail >= size) { 150 memcpy(data, (const uint8_t *)(*it)->mData + delta, size); 151 return; 152 } 153 154 memcpy(data, (const uint8_t *)(*it)->mData + delta, avail); 155 ++it; 156 data = (uint8_t *)data + avail; 157 size -= avail; 158 159 while (size > 0) { 160 size_t copy = (*it)->mSize; 161 if (copy > size) { 162 copy = size; 163 } 164 memcpy(data, (*it)->mData, copy); 165 data = (uint8_t *)data + copy; 166 size -= copy; 167 ++it; 168 } 169} 170 171//////////////////////////////////////////////////////////////////////////////// 172 173NuCachedSource2::NuCachedSource2(const sp<DataSource> &source) 174 : mSource(source), 175 mReflector(new AHandlerReflector<NuCachedSource2>(this)), 176 mLooper(new ALooper), 177 mCache(new PageCache(kPageSize)), 178 mCacheOffset(0), 179 mFinalStatus(OK), 180 mLastAccessPos(0), 181 mFetching(true), 182 mLastFetchTimeUs(-1) { 183 mLooper->registerHandler(mReflector); 184 mLooper->start(); 185 186 Mutex::Autolock autoLock(mLock); 187 (new AMessage(kWhatFetchMore, mReflector->id()))->post(); 188} 189 190NuCachedSource2::~NuCachedSource2() { 191 mLooper->stop(); 192 mLooper->unregisterHandler(mReflector->id()); 193 194 delete mCache; 195 mCache = NULL; 196} 197 198status_t NuCachedSource2::initCheck() const { 199 return mSource->initCheck(); 200} 201 202status_t NuCachedSource2::getSize(off_t *size) { 203 return mSource->getSize(size); 204} 205 206uint32_t NuCachedSource2::flags() { 207 return mSource->flags(); 208} 209 210void NuCachedSource2::onMessageReceived(const sp<AMessage> &msg) { 211 switch (msg->what()) { 212 case kWhatFetchMore: 213 { 214 onFetch(); 215 break; 216 } 217 218 case kWhatRead: 219 { 220 onRead(msg); 221 break; 222 } 223 224 default: 225 TRESPASS(); 226 } 227} 228 229void NuCachedSource2::fetchInternal() { 230 LOG(VERBOSE) << "fetchInternal"; 231 232 CHECK_EQ(mFinalStatus, (status_t)OK); 233 234 PageCache::Page *page = mCache->acquirePage(); 235 236 ssize_t n = mSource->readAt( 237 mCacheOffset + mCache->totalSize(), page->mData, kPageSize); 238 239 Mutex::Autolock autoLock(mLock); 240 241 if (n < 0) { 242 LOG(ERROR) << "source returned error " << n; 243 mFinalStatus = n; 244 mCache->releasePage(page); 245 } else if (n == 0) { 246 LOG(INFO) << "ERROR_END_OF_STREAM"; 247 mFinalStatus = ERROR_END_OF_STREAM; 248 mCache->releasePage(page); 249 } else { 250 page->mSize = n; 251 mCache->appendPage(page); 252 } 253} 254 255void NuCachedSource2::onFetch() { 256 LOG(VERBOSE) << "onFetch"; 257 258 if (mFinalStatus != OK) { 259 LOG(VERBOSE) << "EOS reached, done prefetching for now"; 260 mFetching = false; 261 } 262 263 bool keepAlive = 264 !mFetching 265 && mFinalStatus == OK 266 && ALooper::GetNowUs() >= mLastFetchTimeUs + kKeepAliveIntervalUs; 267 268 if (mFetching || keepAlive) { 269 if (keepAlive) { 270 LOG(INFO) << "Keep alive"; 271 } 272 273 fetchInternal(); 274 275 mLastFetchTimeUs = ALooper::GetNowUs(); 276 277 if (mFetching && mCache->totalSize() >= kHighWaterThreshold) { 278 LOG(INFO) << "Cache full, done prefetching for now"; 279 mFetching = false; 280 } 281 } else { 282 Mutex::Autolock autoLock(mLock); 283 restartPrefetcherIfNecessary_l(); 284 } 285 286 (new AMessage(kWhatFetchMore, mReflector->id()))->post( 287 mFetching ? 0 : 100000ll); 288} 289 290void NuCachedSource2::onRead(const sp<AMessage> &msg) { 291 LOG(VERBOSE) << "onRead"; 292 293 int64_t offset; 294 CHECK(msg->findInt64("offset", &offset)); 295 296 void *data; 297 CHECK(msg->findPointer("data", &data)); 298 299 size_t size; 300 CHECK(msg->findSize("size", &size)); 301 302 ssize_t result = readInternal(offset, data, size); 303 304 if (result == -EAGAIN) { 305 msg->post(50000); 306 return; 307 } 308 309 Mutex::Autolock autoLock(mLock); 310 311 CHECK(mAsyncResult == NULL); 312 313 mAsyncResult = new AMessage; 314 mAsyncResult->setInt32("result", result); 315 316 mCondition.signal(); 317} 318 319void NuCachedSource2::restartPrefetcherIfNecessary_l() { 320 static const size_t kGrayArea = 256 * 1024; 321 322 if (mFetching || mFinalStatus != OK) { 323 return; 324 } 325 326 if (mCacheOffset + mCache->totalSize() - mLastAccessPos 327 >= kLowWaterThreshold) { 328 return; 329 } 330 331 size_t maxBytes = mLastAccessPos - mCacheOffset; 332 if (maxBytes < kGrayArea) { 333 return; 334 } 335 336 maxBytes -= kGrayArea; 337 338 size_t actualBytes = mCache->releaseFromStart(maxBytes); 339 mCacheOffset += actualBytes; 340 341 LOG(INFO) << "restarting prefetcher, totalSize = " << mCache->totalSize(); 342 mFetching = true; 343} 344 345ssize_t NuCachedSource2::readAt(off_t offset, void *data, size_t size) { 346 Mutex::Autolock autoSerializer(mSerializer); 347 348 LOG(VERBOSE) << "readAt offset " << offset << " size " << size; 349 350 Mutex::Autolock autoLock(mLock); 351 352 // If the request can be completely satisfied from the cache, do so. 353 354 if (offset >= mCacheOffset 355 && offset + size <= mCacheOffset + mCache->totalSize()) { 356 size_t delta = offset - mCacheOffset; 357 mCache->copy(delta, data, size); 358 359 mLastAccessPos = offset + size; 360 361 return size; 362 } 363 364 sp<AMessage> msg = new AMessage(kWhatRead, mReflector->id()); 365 msg->setInt64("offset", offset); 366 msg->setPointer("data", data); 367 msg->setSize("size", size); 368 369 CHECK(mAsyncResult == NULL); 370 msg->post(); 371 372 while (mAsyncResult == NULL) { 373 mCondition.wait(mLock); 374 } 375 376 int32_t result; 377 CHECK(mAsyncResult->findInt32("result", &result)); 378 379 mAsyncResult.clear(); 380 381 if (result > 0) { 382 mLastAccessPos = offset + result; 383 } 384 385 return (ssize_t)result; 386} 387 388size_t NuCachedSource2::cachedSize() { 389 Mutex::Autolock autoLock(mLock); 390 return mCacheOffset + mCache->totalSize(); 391} 392 393size_t NuCachedSource2::approxDataRemaining(bool *eos) { 394 Mutex::Autolock autoLock(mLock); 395 return approxDataRemaining_l(eos); 396} 397 398size_t NuCachedSource2::approxDataRemaining_l(bool *eos) { 399 *eos = (mFinalStatus != OK); 400 off_t lastBytePosCached = mCacheOffset + mCache->totalSize(); 401 if (mLastAccessPos < lastBytePosCached) { 402 return lastBytePosCached - mLastAccessPos; 403 } 404 return 0; 405} 406 407ssize_t NuCachedSource2::readInternal(off_t offset, void *data, size_t size) { 408 LOG(VERBOSE) << "readInternal offset " << offset << " size " << size; 409 410 Mutex::Autolock autoLock(mLock); 411 412 if (offset < mCacheOffset 413 || offset >= (off_t)(mCacheOffset + mCache->totalSize())) { 414 static const off_t kPadding = 32768; 415 416 // In the presence of multiple decoded streams, once of them will 417 // trigger this seek request, the other one will request data "nearby" 418 // soon, adjust the seek position so that that subsequent request 419 // does not trigger another seek. 420 off_t seekOffset = (offset > kPadding) ? offset - kPadding : 0; 421 422 seekInternal_l(seekOffset); 423 } 424 425 size_t delta = offset - mCacheOffset; 426 427 if (mFinalStatus != OK) { 428 if (delta >= mCache->totalSize()) { 429 return mFinalStatus; 430 } 431 432 size_t avail = mCache->totalSize() - delta; 433 mCache->copy(delta, data, avail); 434 435 return avail; 436 } 437 438 if (offset + size <= mCacheOffset + mCache->totalSize()) { 439 mCache->copy(delta, data, size); 440 441 return size; 442 } 443 444 LOG(VERBOSE) << "deferring read"; 445 446 return -EAGAIN; 447} 448 449status_t NuCachedSource2::seekInternal_l(off_t offset) { 450 mLastAccessPos = offset; 451 452 if (offset >= mCacheOffset 453 && offset <= (off_t)(mCacheOffset + mCache->totalSize())) { 454 return OK; 455 } 456 457 LOG(INFO) << "new range: offset= " << offset; 458 459 mCacheOffset = offset; 460 461 size_t totalSize = mCache->totalSize(); 462 CHECK_EQ(mCache->releaseFromStart(totalSize), totalSize); 463 464 mFinalStatus = OK; 465 mFetching = true; 466 467 return OK; 468} 469 470} // namespace android 471 472