NuCachedSource2.cpp revision 6f5aae1bcba130d5b8092a19fca3627aa565df56
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 mLooper->registerHandler(mReflector); 183 mLooper->start(); 184 185 Mutex::Autolock autoLock(mLock); 186 (new AMessage(kWhatFetchMore, mReflector->id()))->post(); 187} 188 189NuCachedSource2::~NuCachedSource2() { 190 mLooper->stop(); 191 mLooper->unregisterHandler(mReflector->id()); 192 193 delete mCache; 194 mCache = NULL; 195} 196 197status_t NuCachedSource2::initCheck() const { 198 return mSource->initCheck(); 199} 200 201status_t NuCachedSource2::getSize(off_t *size) { 202 return mSource->getSize(size); 203} 204 205uint32_t NuCachedSource2::flags() { 206 return mSource->flags(); 207} 208 209void NuCachedSource2::onMessageReceived(const sp<AMessage> &msg) { 210 switch (msg->what()) { 211 case kWhatFetchMore: 212 { 213 onFetch(); 214 break; 215 } 216 217 case kWhatRead: 218 { 219 onRead(msg); 220 break; 221 } 222 223 default: 224 TRESPASS(); 225 } 226} 227 228void NuCachedSource2::fetchInternal() { 229 LOG(VERBOSE) << "fetchInternal"; 230 231 CHECK_EQ(mFinalStatus, (status_t)OK); 232 233 PageCache::Page *page = mCache->acquirePage(); 234 235 ssize_t n = mSource->readAt( 236 mCacheOffset + mCache->totalSize(), page->mData, kPageSize); 237 238 Mutex::Autolock autoLock(mLock); 239 240 if (n < 0) { 241 LOG(ERROR) << "source returned error " << n; 242 mFinalStatus = n; 243 mCache->releasePage(page); 244 } else if (n == 0) { 245 LOG(INFO) << "ERROR_END_OF_STREAM"; 246 mFinalStatus = ERROR_END_OF_STREAM; 247 mCache->releasePage(page); 248 } else { 249 page->mSize = n; 250 mCache->appendPage(page); 251 } 252} 253 254void NuCachedSource2::onFetch() { 255 LOG(VERBOSE) << "onFetch"; 256 257 if (mFinalStatus != OK) { 258 LOG(VERBOSE) << "EOS reached, done prefetching for now"; 259 mFetching = false; 260 } 261 262 if (mFetching) { 263 fetchInternal(); 264 265 if (mCache->totalSize() >= kHighWaterThreshold) { 266 LOG(INFO) << "Cache full, done prefetching for now"; 267 mFetching = false; 268 } 269 } else { 270 restartPrefetcherIfNecessary_l(); 271 } 272 273 (new AMessage(kWhatFetchMore, mReflector->id()))->post( 274 mFetching ? 0 : 100000ll); 275} 276 277void NuCachedSource2::onRead(const sp<AMessage> &msg) { 278 LOG(VERBOSE) << "onRead"; 279 280 int64_t offset; 281 CHECK(msg->findInt64("offset", &offset)); 282 283 void *data; 284 CHECK(msg->findPointer("data", &data)); 285 286 size_t size; 287 CHECK(msg->findSize("size", &size)); 288 289 ssize_t result = readInternal(offset, data, size); 290 291 if (result == -EAGAIN) { 292 msg->post(50000); 293 return; 294 } 295 296 Mutex::Autolock autoLock(mLock); 297 298 CHECK(mAsyncResult == NULL); 299 300 mAsyncResult = new AMessage; 301 mAsyncResult->setInt32("result", result); 302 303 mCondition.signal(); 304} 305 306void NuCachedSource2::restartPrefetcherIfNecessary_l() { 307 static const size_t kGrayArea = 256 * 1024; 308 309 if (mFetching || mFinalStatus != OK) { 310 return; 311 } 312 313 if (mCacheOffset + mCache->totalSize() - mLastAccessPos 314 >= kLowWaterThreshold) { 315 return; 316 } 317 318 size_t maxBytes = mLastAccessPos - mCacheOffset; 319 if (maxBytes < kGrayArea) { 320 return; 321 } 322 323 maxBytes -= kGrayArea; 324 325 size_t actualBytes = mCache->releaseFromStart(maxBytes); 326 mCacheOffset += actualBytes; 327 328 LOG(INFO) << "restarting prefetcher, totalSize = " << mCache->totalSize(); 329 mFetching = true; 330} 331 332ssize_t NuCachedSource2::readAt(off_t offset, void *data, size_t size) { 333 Mutex::Autolock autoSerializer(mSerializer); 334 335 LOG(VERBOSE) << "readAt offset " << offset << " size " << size; 336 337 Mutex::Autolock autoLock(mLock); 338 339 // If the request can be completely satisfied from the cache, do so. 340 341 if (offset >= mCacheOffset 342 && offset + size <= mCacheOffset + mCache->totalSize()) { 343 size_t delta = offset - mCacheOffset; 344 mCache->copy(delta, data, size); 345 346 mLastAccessPos = offset + size; 347 348 return size; 349 } 350 351 sp<AMessage> msg = new AMessage(kWhatRead, mReflector->id()); 352 msg->setInt64("offset", offset); 353 msg->setPointer("data", data); 354 msg->setSize("size", size); 355 356 CHECK(mAsyncResult == NULL); 357 msg->post(); 358 359 while (mAsyncResult == NULL) { 360 mCondition.wait(mLock); 361 } 362 363 int32_t result; 364 CHECK(mAsyncResult->findInt32("result", &result)); 365 366 mAsyncResult.clear(); 367 368 if (result > 0) { 369 mLastAccessPos = offset + result; 370 } 371 372 return (ssize_t)result; 373} 374 375size_t NuCachedSource2::cachedSize() { 376 Mutex::Autolock autoLock(mLock); 377 return mCacheOffset + mCache->totalSize(); 378} 379 380size_t NuCachedSource2::approxDataRemaining(bool *eos) { 381 Mutex::Autolock autoLock(mLock); 382 return approxDataRemaining_l(eos); 383} 384 385size_t NuCachedSource2::approxDataRemaining_l(bool *eos) { 386 *eos = (mFinalStatus != OK); 387 off_t lastBytePosCached = mCacheOffset + mCache->totalSize(); 388 if (mLastAccessPos < lastBytePosCached) { 389 return lastBytePosCached - mLastAccessPos; 390 } 391 return 0; 392} 393 394ssize_t NuCachedSource2::readInternal(off_t offset, void *data, size_t size) { 395 LOG(VERBOSE) << "readInternal offset " << offset << " size " << size; 396 397 Mutex::Autolock autoLock(mLock); 398 399 if (offset < mCacheOffset 400 || offset >= (off_t)(mCacheOffset + mCache->totalSize())) { 401 static const off_t kPadding = 32768; 402 403 // In the presence of multiple decoded streams, once of them will 404 // trigger this seek request, the other one will request data "nearby" 405 // soon, adjust the seek position so that that subsequent request 406 // does not trigger another seek. 407 off_t seekOffset = (offset > kPadding) ? offset - kPadding : 0; 408 409 seekInternal_l(seekOffset); 410 } 411 412 size_t delta = offset - mCacheOffset; 413 414 if (mFinalStatus != OK) { 415 if (delta >= mCache->totalSize()) { 416 return mFinalStatus; 417 } 418 419 size_t avail = mCache->totalSize() - delta; 420 mCache->copy(delta, data, avail); 421 422 return avail; 423 } 424 425 if (offset + size <= mCacheOffset + mCache->totalSize()) { 426 mCache->copy(delta, data, size); 427 428 return size; 429 } 430 431 LOG(VERBOSE) << "deferring read"; 432 433 return -EAGAIN; 434} 435 436status_t NuCachedSource2::seekInternal_l(off_t offset) { 437 mLastAccessPos = offset; 438 439 if (offset >= mCacheOffset 440 && offset <= (off_t)(mCacheOffset + mCache->totalSize())) { 441 return OK; 442 } 443 444 LOG(INFO) << "new range: offset= " << offset; 445 446 mCacheOffset = offset; 447 448 size_t totalSize = mCache->totalSize(); 449 CHECK_EQ(mCache->releaseFromStart(totalSize), totalSize); 450 451 mFinalStatus = OK; 452 mFetching = true; 453 454 return OK; 455} 456 457} // namespace android 458 459