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| 1 // Copyright 2013 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #include "media/blink/buffered_resource_loader.h" | |
| 6 | |
| 7 #include <stddef.h> | |
| 8 #include <stdint.h> | |
| 9 #include <limits> | |
| 10 #include <utility> | |
| 11 | |
| 12 #include "base/bits.h" | |
| 13 #include "base/callback_helpers.h" | |
| 14 #include "base/metrics/histogram.h" | |
| 15 #include "base/strings/string_number_conversions.h" | |
| 16 #include "base/strings/string_util.h" | |
| 17 #include "media/base/media_log.h" | |
| 18 #include "media/blink/cache_util.h" | |
| 19 #include "net/http/http_byte_range.h" | |
| 20 #include "net/http/http_request_headers.h" | |
| 21 #include "third_party/WebKit/public/platform/WebString.h" | |
| 22 #include "third_party/WebKit/public/platform/WebURLError.h" | |
| 23 #include "third_party/WebKit/public/platform/WebURLResponse.h" | |
| 24 #include "third_party/WebKit/public/web/WebKit.h" | |
| 25 #include "third_party/WebKit/public/web/WebURLLoaderOptions.h" | |
| 26 | |
| 27 using blink::WebFrame; | |
| 28 using blink::WebString; | |
| 29 using blink::WebURLError; | |
| 30 using blink::WebURLLoader; | |
| 31 using blink::WebURLLoaderOptions; | |
| 32 using blink::WebURLRequest; | |
| 33 using blink::WebURLResponse; | |
| 34 | |
| 35 namespace media { | |
| 36 | |
| 37 static const int kHttpOK = 200; | |
| 38 static const int kHttpPartialContent = 206; | |
| 39 | |
| 40 // Define the number of bytes in a megabyte. | |
| 41 static const int kMegabyte = 1024 * 1024; | |
| 42 | |
| 43 // Minimum capacity of the buffer in forward or backward direction. | |
| 44 // | |
| 45 // 2MB is an arbitrary limit; it just seems to be "good enough" in practice. | |
| 46 static const int kMinBufferCapacity = 2 * kMegabyte; | |
| 47 | |
| 48 // Maximum capacity of the buffer in forward or backward direction. This is | |
| 49 // effectively the largest single read the code path can handle. | |
| 50 // 20MB is an arbitrary limit; it just seems to be "good enough" in practice. | |
| 51 static const int kMaxBufferCapacity = 20 * kMegabyte; | |
| 52 | |
| 53 // Maximum number of bytes outside the buffer we will wait for in order to | |
| 54 // fulfill a read. If a read starts more than 2MB away from the data we | |
| 55 // currently have in the buffer, we will not wait for buffer to reach the read's | |
| 56 // location and will instead reset the request. | |
| 57 static const int kForwardWaitThreshold = 2 * kMegabyte; | |
| 58 | |
| 59 // Computes the suggested backward and forward capacity for the buffer | |
| 60 // if one wants to play at |playback_rate| * the natural playback speed. | |
| 61 // Use a value of 0 for |bitrate| if it is unknown. | |
| 62 static void ComputeTargetBufferWindow(double playback_rate, int bitrate, | |
| 63 int* out_backward_capacity, | |
| 64 int* out_forward_capacity) { | |
| 65 static const int kDefaultBitrate = 200 * 1024 * 8; // 200 Kbps. | |
| 66 static const int kMaxBitrate = 20 * kMegabyte * 8; // 20 Mbps. | |
| 67 static const double kMaxPlaybackRate = 25.0; | |
| 68 static const int kTargetSecondsBufferedAhead = 10; | |
| 69 static const int kTargetSecondsBufferedBehind = 2; | |
| 70 | |
| 71 // Use a default bit rate if unknown and clamp to prevent overflow. | |
| 72 if (bitrate <= 0) | |
| 73 bitrate = kDefaultBitrate; | |
| 74 bitrate = std::min(bitrate, kMaxBitrate); | |
| 75 | |
| 76 // Only scale the buffer window for playback rates greater than 1.0 in | |
| 77 // magnitude and clamp to prevent overflow. | |
| 78 bool backward_playback = false; | |
| 79 if (playback_rate < 0.0) { | |
| 80 backward_playback = true; | |
| 81 playback_rate *= -1.0; | |
| 82 } | |
| 83 | |
| 84 playback_rate = std::max(playback_rate, 1.0); | |
| 85 playback_rate = std::min(playback_rate, kMaxPlaybackRate); | |
| 86 | |
| 87 int bytes_per_second = (bitrate / 8.0) * playback_rate; | |
| 88 | |
| 89 // Clamp between kMinBufferCapacity and kMaxBufferCapacity. | |
| 90 *out_forward_capacity = std::max( | |
| 91 kTargetSecondsBufferedAhead * bytes_per_second, kMinBufferCapacity); | |
| 92 *out_backward_capacity = std::max( | |
| 93 kTargetSecondsBufferedBehind * bytes_per_second, kMinBufferCapacity); | |
| 94 | |
| 95 *out_forward_capacity = std::min(*out_forward_capacity, kMaxBufferCapacity); | |
| 96 *out_backward_capacity = std::min(*out_backward_capacity, kMaxBufferCapacity); | |
| 97 | |
| 98 if (backward_playback) | |
| 99 std::swap(*out_forward_capacity, *out_backward_capacity); | |
| 100 } | |
| 101 | |
| 102 BufferedResourceLoader::BufferedResourceLoader(const GURL& url, | |
| 103 CORSMode cors_mode, | |
| 104 int64_t first_byte_position, | |
| 105 int64_t last_byte_position, | |
| 106 DeferStrategy strategy, | |
| 107 int bitrate, | |
| 108 double playback_rate, | |
| 109 MediaLog* media_log) | |
| 110 : buffer_(kMinBufferCapacity, kMinBufferCapacity), | |
| 111 loader_failed_(false), | |
| 112 defer_strategy_(strategy), | |
| 113 might_be_reused_from_cache_in_future_(true), | |
| 114 range_supported_(false), | |
| 115 saved_forward_capacity_(0), | |
| 116 url_(url), | |
| 117 cors_mode_(cors_mode), | |
| 118 first_byte_position_(first_byte_position), | |
| 119 last_byte_position_(last_byte_position), | |
| 120 single_origin_(true), | |
| 121 offset_(0), | |
| 122 content_length_(kPositionNotSpecified), | |
| 123 instance_size_(kPositionNotSpecified), | |
| 124 read_position_(0), | |
| 125 read_size_(0), | |
| 126 read_buffer_(NULL), | |
| 127 first_offset_(0), | |
| 128 last_offset_(0), | |
| 129 bitrate_(bitrate), | |
| 130 playback_rate_(playback_rate), | |
| 131 media_log_(media_log), | |
| 132 cancel_upon_deferral_(false) { | |
| 133 // Set the initial capacity of |buffer_| based on |bitrate_| and | |
| 134 // |playback_rate_|. | |
| 135 UpdateBufferWindow(); | |
| 136 } | |
| 137 | |
| 138 BufferedResourceLoader::~BufferedResourceLoader() {} | |
| 139 | |
| 140 void BufferedResourceLoader::Start( | |
| 141 const StartCB& start_cb, | |
| 142 const LoadingStateChangedCB& loading_cb, | |
| 143 const ProgressCB& progress_cb, | |
| 144 WebFrame* frame) { | |
| 145 // Make sure we have not started. | |
| 146 DCHECK(start_cb_.is_null()); | |
| 147 DCHECK(loading_cb_.is_null()); | |
| 148 DCHECK(progress_cb_.is_null()); | |
| 149 DCHECK(!start_cb.is_null()); | |
| 150 DCHECK(!loading_cb.is_null()); | |
| 151 DCHECK(!progress_cb.is_null()); | |
| 152 CHECK(frame); | |
| 153 | |
| 154 start_cb_ = start_cb; | |
| 155 loading_cb_ = loading_cb; | |
| 156 progress_cb_ = progress_cb; | |
| 157 | |
| 158 if (first_byte_position_ != kPositionNotSpecified) { | |
| 159 // TODO(hclam): server may not support range request so |offset_| may not | |
| 160 // equal to |first_byte_position_|. | |
| 161 offset_ = first_byte_position_; | |
| 162 } | |
| 163 | |
| 164 // Prepare the request. | |
| 165 WebURLRequest request(url_); | |
| 166 // TODO(mkwst): Split this into video/audio. | |
| 167 request.setRequestContext(WebURLRequest::RequestContextVideo); | |
| 168 | |
| 169 if (IsRangeRequest()) { | |
| 170 request.setHTTPHeaderField( | |
| 171 WebString::fromUTF8(net::HttpRequestHeaders::kRange), | |
| 172 WebString::fromUTF8(net::HttpByteRange::Bounded( | |
| 173 first_byte_position_, last_byte_position_).GetHeaderValue())); | |
| 174 } | |
| 175 | |
| 176 frame->setReferrerForRequest(request, blink::WebURL()); | |
| 177 | |
| 178 // Disable compression, compression for audio/video doesn't make sense... | |
| 179 request.setHTTPHeaderField( | |
| 180 WebString::fromUTF8(net::HttpRequestHeaders::kAcceptEncoding), | |
| 181 WebString::fromUTF8("identity;q=1, *;q=0")); | |
| 182 | |
| 183 // Check for our test WebURLLoader. | |
| 184 std::unique_ptr<WebURLLoader> loader; | |
| 185 if (test_loader_) { | |
| 186 loader = std::move(test_loader_); | |
| 187 } else { | |
| 188 WebURLLoaderOptions options; | |
| 189 if (cors_mode_ == kUnspecified) { | |
| 190 options.allowCredentials = true; | |
| 191 options.crossOriginRequestPolicy = | |
| 192 WebURLLoaderOptions::CrossOriginRequestPolicyAllow; | |
| 193 } else { | |
| 194 options.exposeAllResponseHeaders = true; | |
| 195 // The author header set is empty, no preflight should go ahead. | |
| 196 options.preflightPolicy = WebURLLoaderOptions::PreventPreflight; | |
| 197 options.crossOriginRequestPolicy = | |
| 198 WebURLLoaderOptions::CrossOriginRequestPolicyUseAccessControl; | |
| 199 if (cors_mode_ == kUseCredentials) | |
| 200 options.allowCredentials = true; | |
| 201 } | |
| 202 loader.reset(frame->createAssociatedURLLoader(options)); | |
| 203 } | |
| 204 | |
| 205 // Start the resource loading. | |
| 206 loader->loadAsynchronously(request, this); | |
| 207 active_loader_.reset(new ActiveLoader(std::move(loader))); | |
| 208 loading_cb_.Run(kLoading); | |
| 209 } | |
| 210 | |
| 211 void BufferedResourceLoader::Stop() { | |
| 212 // Reset callbacks. | |
| 213 start_cb_.Reset(); | |
| 214 loading_cb_.Reset(); | |
| 215 progress_cb_.Reset(); | |
| 216 read_cb_.Reset(); | |
| 217 | |
| 218 // Cancel and reset any active loaders. | |
| 219 active_loader_.reset(); | |
| 220 } | |
| 221 | |
| 222 void BufferedResourceLoader::Read(int64_t position, | |
| 223 int read_size, | |
| 224 uint8_t* buffer, | |
| 225 const ReadCB& read_cb) { | |
| 226 DCHECK(start_cb_.is_null()); | |
| 227 DCHECK(read_cb_.is_null()); | |
| 228 DCHECK(!read_cb.is_null()); | |
| 229 DCHECK(buffer); | |
| 230 DCHECK_GT(read_size, 0); | |
| 231 | |
| 232 // Save the parameter of reading. | |
| 233 read_cb_ = read_cb; | |
| 234 read_position_ = position; | |
| 235 read_size_ = read_size; | |
| 236 read_buffer_ = buffer; | |
| 237 | |
| 238 // Reads should immediately fail if the loader also failed. | |
| 239 if (loader_failed_) { | |
| 240 DoneRead(kFailed, 0); | |
| 241 return; | |
| 242 } | |
| 243 | |
| 244 // If we're attempting to read past the end of the file, return a zero | |
| 245 // indicating EOF. | |
| 246 // | |
| 247 // This can happen with callees that read in fixed-sized amounts for parsing | |
| 248 // or at the end of chunked 200 responses when we discover the actual length | |
| 249 // of the file. | |
| 250 if (instance_size_ != kPositionNotSpecified && | |
| 251 instance_size_ <= read_position_) { | |
| 252 DVLOG(1) << "Appear to have seeked beyond EOS; returning 0."; | |
| 253 DoneRead(kOk, 0); | |
| 254 return; | |
| 255 } | |
| 256 | |
| 257 // Make sure |offset_| and |read_position_| does not differ by a large | |
| 258 // amount. | |
| 259 if (read_position_ > offset_ + std::numeric_limits<int32_t>::max() || | |
| 260 read_position_ < offset_ + std::numeric_limits<int32_t>::min()) { | |
| 261 DoneRead(kCacheMiss, 0); | |
| 262 return; | |
| 263 } | |
| 264 | |
| 265 // Make sure |read_size_| is not too large for the buffer to ever be able to | |
| 266 // fulfill the read request. | |
| 267 if (read_size_ > kMaxBufferCapacity) { | |
| 268 DoneRead(kFailed, 0); | |
| 269 return; | |
| 270 } | |
| 271 | |
| 272 // Prepare the parameters. | |
| 273 first_offset_ = read_position_ - offset_; | |
| 274 last_offset_ = first_offset_ + read_size_; | |
| 275 | |
| 276 // If we can serve the request now, do the actual read. | |
| 277 if (CanFulfillRead()) { | |
| 278 ReadInternal(); | |
| 279 UpdateDeferBehavior(); | |
| 280 return; | |
| 281 } | |
| 282 | |
| 283 // If we expect the read request to be fulfilled later, expand capacity as | |
| 284 // necessary and disable deferring. | |
| 285 if (WillFulfillRead()) { | |
| 286 // Advance offset as much as possible to create additional capacity. | |
| 287 int advance = std::min(first_offset_, buffer_.forward_bytes()); | |
| 288 bool ret = buffer_.Seek(advance); | |
| 289 DCHECK(ret); | |
| 290 | |
| 291 offset_ += advance; | |
| 292 first_offset_ -= advance; | |
| 293 last_offset_ -= advance; | |
| 294 | |
| 295 // Expand capacity to accomodate a read that extends past the normal | |
| 296 // capacity. | |
| 297 // | |
| 298 // This can happen when reading in a large seek index or when the | |
| 299 // first byte of a read request falls within kForwardWaitThreshold. | |
| 300 if (last_offset_ > buffer_.forward_capacity()) { | |
| 301 saved_forward_capacity_ = buffer_.forward_capacity(); | |
| 302 buffer_.set_forward_capacity(last_offset_); | |
| 303 } | |
| 304 | |
| 305 // Make sure we stop deferring now that there's additional capacity. | |
| 306 DCHECK(!ShouldDefer()) | |
| 307 << "Capacity was not adjusted properly to prevent deferring."; | |
| 308 UpdateDeferBehavior(); | |
| 309 | |
| 310 return; | |
| 311 } | |
| 312 | |
| 313 // Make a callback to report failure. | |
| 314 DoneRead(kCacheMiss, 0); | |
| 315 } | |
| 316 | |
| 317 int64_t BufferedResourceLoader::content_length() { | |
| 318 return content_length_; | |
| 319 } | |
| 320 | |
| 321 int64_t BufferedResourceLoader::instance_size() { | |
| 322 return instance_size_; | |
| 323 } | |
| 324 | |
| 325 bool BufferedResourceLoader::range_supported() { | |
| 326 return range_supported_; | |
| 327 } | |
| 328 | |
| 329 ///////////////////////////////////////////////////////////////////////////// | |
| 330 // blink::WebURLLoaderClient implementation. | |
| 331 void BufferedResourceLoader::willFollowRedirect( | |
| 332 WebURLLoader* loader, | |
| 333 WebURLRequest& newRequest, | |
| 334 const WebURLResponse& redirectResponse, | |
| 335 int64_t encodedDataLength) { | |
| 336 // The load may have been stopped and |start_cb| is destroyed. | |
| 337 // In this case we shouldn't do anything. | |
| 338 if (start_cb_.is_null()) { | |
| 339 // Set the url in the request to an invalid value (empty url). | |
| 340 newRequest.setURL(blink::WebURL()); | |
| 341 return; | |
| 342 } | |
| 343 | |
| 344 // Only allow |single_origin_| if we haven't seen a different origin yet. | |
| 345 if (single_origin_) | |
| 346 single_origin_ = url_.GetOrigin() == GURL(newRequest.url()).GetOrigin(); | |
| 347 | |
| 348 url_ = newRequest.url(); | |
| 349 } | |
| 350 | |
| 351 void BufferedResourceLoader::didSendData( | |
| 352 WebURLLoader* loader, | |
| 353 unsigned long long bytes_sent, | |
| 354 unsigned long long total_bytes_to_be_sent) { | |
| 355 NOTIMPLEMENTED(); | |
| 356 } | |
| 357 | |
| 358 void BufferedResourceLoader::didReceiveResponse( | |
| 359 WebURLLoader* loader, | |
| 360 const WebURLResponse& response) { | |
| 361 DVLOG(1) << "didReceiveResponse: HTTP/" | |
| 362 << (response.httpVersion() == WebURLResponse::HTTPVersion_0_9 | |
| 363 ? "0.9" | |
| 364 : response.httpVersion() == WebURLResponse::HTTPVersion_1_0 | |
| 365 ? "1.0" | |
| 366 : response.httpVersion() == | |
| 367 WebURLResponse::HTTPVersion_1_1 | |
| 368 ? "1.1" | |
| 369 : response.httpVersion() == | |
| 370 WebURLResponse::HTTPVersion_2_0 | |
| 371 ? "2.0" | |
| 372 : "Unknown") | |
| 373 << " " << response.httpStatusCode(); | |
| 374 DCHECK(active_loader_.get()); | |
| 375 response_original_url_ = response.wasFetchedViaServiceWorker() | |
| 376 ? response.originalURLViaServiceWorker() | |
| 377 : response.url(); | |
| 378 | |
| 379 // The loader may have been stopped and |start_cb| is destroyed. | |
| 380 // In this case we shouldn't do anything. | |
| 381 if (start_cb_.is_null()) | |
| 382 return; | |
| 383 | |
| 384 uint32_t reasons = GetReasonsForUncacheability(response); | |
| 385 might_be_reused_from_cache_in_future_ = reasons == 0; | |
| 386 UMA_HISTOGRAM_BOOLEAN("Media.CacheUseful", reasons == 0); | |
| 387 int shift = 0; | |
| 388 int max_enum = base::bits::Log2Ceiling(kMaxReason); | |
| 389 while (reasons) { | |
| 390 DCHECK_LT(shift, max_enum); // Sanity check. | |
| 391 if (reasons & 0x1) { | |
| 392 UMA_HISTOGRAM_ENUMERATION("Media.UncacheableReason", | |
| 393 shift, | |
| 394 max_enum); // PRESUBMIT_IGNORE_UMA_MAX | |
| 395 } | |
| 396 | |
| 397 reasons >>= 1; | |
| 398 ++shift; | |
| 399 } | |
| 400 | |
| 401 // Expected content length can be |kPositionNotSpecified|, in that case | |
| 402 // |content_length_| is not specified and this is a streaming response. | |
| 403 content_length_ = response.expectedContentLength(); | |
| 404 | |
| 405 // We make a strong assumption that when we reach here we have either | |
| 406 // received a response from HTTP/HTTPS protocol or the request was | |
| 407 // successful (in particular range request). So we only verify the partial | |
| 408 // response for HTTP and HTTPS protocol. | |
| 409 if (url_.SchemeIsHTTPOrHTTPS()) { | |
| 410 bool partial_response = (response.httpStatusCode() == kHttpPartialContent); | |
| 411 bool ok_response = (response.httpStatusCode() == kHttpOK); | |
| 412 | |
| 413 if (IsRangeRequest()) { | |
| 414 // Check to see whether the server supports byte ranges. | |
| 415 std::string accept_ranges = | |
| 416 response.httpHeaderField("Accept-Ranges").utf8(); | |
| 417 range_supported_ = (accept_ranges.find("bytes") != std::string::npos); | |
| 418 | |
| 419 // If we have verified the partial response and it is correct, we will | |
| 420 // return kOk. It's also possible for a server to support range requests | |
| 421 // without advertising "Accept-Ranges: bytes". | |
| 422 if (partial_response && VerifyPartialResponse(response)) { | |
| 423 range_supported_ = true; | |
| 424 } else if (ok_response && first_byte_position_ == 0 && | |
| 425 last_byte_position_ == kPositionNotSpecified) { | |
| 426 // We accept a 200 response for a Range:0- request, trusting the | |
| 427 // Accept-Ranges header, because Apache thinks that's a reasonable thing | |
| 428 // to return. | |
| 429 instance_size_ = content_length_; | |
| 430 } else { | |
| 431 MEDIA_LOG(ERROR, media_log_) | |
| 432 << "Failed loading buffered resource using range request due to " | |
| 433 "invalid server response. HTTP status code=" | |
| 434 << response.httpStatusCode(); | |
| 435 DoneStart(kFailed); | |
| 436 return; | |
| 437 } | |
| 438 } else { | |
| 439 instance_size_ = content_length_; | |
| 440 if (response.httpStatusCode() != kHttpOK) { | |
| 441 // We didn't request a range but server didn't reply with "200 OK". | |
| 442 MEDIA_LOG(ERROR, media_log_) | |
| 443 << "Failed loading buffered resource due to invalid server " | |
| 444 "response. HTTP status code=" << response.httpStatusCode(); | |
| 445 DoneStart(kFailed); | |
| 446 return; | |
| 447 } | |
| 448 } | |
| 449 | |
| 450 } else { | |
| 451 CHECK_EQ(instance_size_, kPositionNotSpecified); | |
| 452 if (content_length_ != kPositionNotSpecified) { | |
| 453 if (first_byte_position_ == kPositionNotSpecified) | |
| 454 instance_size_ = content_length_; | |
| 455 else if (last_byte_position_ == kPositionNotSpecified) | |
| 456 instance_size_ = content_length_ + first_byte_position_; | |
| 457 } | |
| 458 } | |
| 459 | |
| 460 // Calls with a successful response. | |
| 461 DoneStart(kOk); | |
| 462 } | |
| 463 | |
| 464 void BufferedResourceLoader::didReceiveData(WebURLLoader* loader, | |
| 465 const char* data, | |
| 466 int data_length, | |
| 467 int encoded_data_length, | |
| 468 int encoded_body_length) { | |
| 469 DVLOG(1) << "didReceiveData: " << data_length << " bytes"; | |
| 470 DCHECK(active_loader_.get()); | |
| 471 DCHECK_GT(data_length, 0); | |
| 472 | |
| 473 buffer_.Append(reinterpret_cast<const uint8_t*>(data), data_length); | |
| 474 | |
| 475 // If there is an active read request, try to fulfill the request. | |
| 476 if (HasPendingRead() && CanFulfillRead()) | |
| 477 ReadInternal(); | |
| 478 | |
| 479 // At last see if the buffer is full and we need to defer the downloading. | |
| 480 UpdateDeferBehavior(); | |
| 481 | |
| 482 // Consume excess bytes from our in-memory buffer if necessary. | |
| 483 if (buffer_.forward_bytes() > buffer_.forward_capacity()) { | |
| 484 int excess = buffer_.forward_bytes() - buffer_.forward_capacity(); | |
| 485 bool success = buffer_.Seek(excess); | |
| 486 DCHECK(success); | |
| 487 offset_ += first_offset_ + excess; | |
| 488 } | |
| 489 | |
| 490 // Notify latest progress and buffered offset. | |
| 491 progress_cb_.Run(offset_ + buffer_.forward_bytes() - 1); | |
| 492 Log(); | |
| 493 } | |
| 494 | |
| 495 void BufferedResourceLoader::didDownloadData( | |
| 496 blink::WebURLLoader* loader, | |
| 497 int dataLength, | |
| 498 int encoded_data_length) { | |
| 499 NOTIMPLEMENTED(); | |
| 500 } | |
| 501 | |
| 502 void BufferedResourceLoader::didReceiveCachedMetadata( | |
| 503 WebURLLoader* loader, | |
| 504 const char* data, | |
| 505 int data_length) { | |
| 506 NOTIMPLEMENTED(); | |
| 507 } | |
| 508 | |
| 509 void BufferedResourceLoader::didFinishLoading( | |
| 510 WebURLLoader* loader, | |
| 511 double finishTime, | |
| 512 int64_t total_encoded_data_length) { | |
| 513 DVLOG(1) << "didFinishLoading"; | |
| 514 DCHECK(active_loader_.get()); | |
| 515 | |
| 516 // We're done with the loader. | |
| 517 active_loader_.reset(); | |
| 518 loading_cb_.Run(kLoadingFinished); | |
| 519 | |
| 520 // If we didn't know the |instance_size_| we do now. | |
| 521 if (instance_size_ == kPositionNotSpecified) { | |
| 522 instance_size_ = offset_ + buffer_.forward_bytes(); | |
| 523 } | |
| 524 | |
| 525 // If there is a start callback, run it. | |
| 526 if (!start_cb_.is_null()) { | |
| 527 DCHECK(read_cb_.is_null()) | |
| 528 << "Shouldn't have a read callback during start"; | |
| 529 DoneStart(kOk); | |
| 530 return; | |
| 531 } | |
| 532 | |
| 533 // Don't leave read callbacks hanging around. | |
| 534 if (HasPendingRead()) { | |
| 535 // Try to fulfill with what is in the buffer. | |
| 536 if (CanFulfillRead()) | |
| 537 ReadInternal(); | |
| 538 else | |
| 539 DoneRead(kCacheMiss, 0); | |
| 540 } | |
| 541 } | |
| 542 | |
| 543 void BufferedResourceLoader::didFail( | |
| 544 WebURLLoader* loader, | |
| 545 const WebURLError& error) { | |
| 546 DVLOG(1) << "didFail: reason=" << error.reason | |
| 547 << ", isCancellation=" << error.isCancellation | |
| 548 << ", domain=" << error.domain.utf8().data() | |
| 549 << ", localizedDescription=" | |
| 550 << error.localizedDescription.utf8().data(); | |
| 551 DCHECK(active_loader_.get()); | |
| 552 MEDIA_LOG(ERROR, media_log_) | |
| 553 << "Failed loading buffered resource. Error code=" << error.reason; | |
| 554 | |
| 555 // We don't need to continue loading after failure. | |
| 556 // | |
| 557 // Keep it alive until we exit this method so that |error| remains valid. | |
| 558 std::unique_ptr<ActiveLoader> active_loader = std::move(active_loader_); | |
| 559 loader_failed_ = true; | |
| 560 loading_cb_.Run(kLoadingFailed); | |
| 561 | |
| 562 // Don't leave start callbacks hanging around. | |
| 563 if (!start_cb_.is_null()) { | |
| 564 DCHECK(read_cb_.is_null()) | |
| 565 << "Shouldn't have a read callback during start"; | |
| 566 DoneStart(kFailed); | |
| 567 return; | |
| 568 } | |
| 569 | |
| 570 // Don't leave read callbacks hanging around. | |
| 571 if (HasPendingRead()) { | |
| 572 DoneRead(kFailed, 0); | |
| 573 } | |
| 574 } | |
| 575 | |
| 576 bool BufferedResourceLoader::HasSingleOrigin() const { | |
| 577 DCHECK(start_cb_.is_null()) | |
| 578 << "Start() must complete before calling HasSingleOrigin()"; | |
| 579 return single_origin_; | |
| 580 } | |
| 581 | |
| 582 bool BufferedResourceLoader::DidPassCORSAccessCheck() const { | |
| 583 // Until Start() is done we don't know, assume no until we know. | |
| 584 if (!start_cb_.is_null()) | |
| 585 return false; | |
| 586 return !loader_failed_ && cors_mode_ != kUnspecified; | |
| 587 } | |
| 588 | |
| 589 void BufferedResourceLoader::UpdateDeferStrategy(DeferStrategy strategy) { | |
| 590 if (!might_be_reused_from_cache_in_future_ && strategy == kNeverDefer) | |
| 591 strategy = kCapacityDefer; | |
| 592 defer_strategy_ = strategy; | |
| 593 UpdateDeferBehavior(); | |
| 594 } | |
| 595 | |
| 596 void BufferedResourceLoader::SetPlaybackRate(double playback_rate) { | |
| 597 playback_rate_ = playback_rate; | |
| 598 | |
| 599 // This is a pause so don't bother updating the buffer window as we'll likely | |
| 600 // get unpaused in the future. | |
| 601 if (playback_rate_ == 0.0) | |
| 602 return; | |
| 603 | |
| 604 // Abort any cancellations in progress if playback starts. | |
| 605 if (playback_rate_ > 0 && cancel_upon_deferral_) | |
| 606 cancel_upon_deferral_ = false; | |
| 607 | |
| 608 UpdateBufferWindow(); | |
| 609 } | |
| 610 | |
| 611 void BufferedResourceLoader::SetBitrate(int bitrate) { | |
| 612 DCHECK(bitrate >= 0); | |
| 613 bitrate_ = bitrate; | |
| 614 UpdateBufferWindow(); | |
| 615 } | |
| 616 | |
| 617 ///////////////////////////////////////////////////////////////////////////// | |
| 618 // Helper methods. | |
| 619 | |
| 620 void BufferedResourceLoader::UpdateBufferWindow() { | |
| 621 int backward_capacity; | |
| 622 int forward_capacity; | |
| 623 ComputeTargetBufferWindow( | |
| 624 playback_rate_, bitrate_, &backward_capacity, &forward_capacity); | |
| 625 | |
| 626 // This does not evict data from the buffer if the new capacities are less | |
| 627 // than the current capacities; the new limits will be enforced after the | |
| 628 // existing excess buffered data is consumed. | |
| 629 buffer_.set_backward_capacity(backward_capacity); | |
| 630 buffer_.set_forward_capacity(forward_capacity); | |
| 631 } | |
| 632 | |
| 633 void BufferedResourceLoader::UpdateDeferBehavior() { | |
| 634 if (!active_loader_) | |
| 635 return; | |
| 636 | |
| 637 SetDeferred(ShouldDefer()); | |
| 638 } | |
| 639 | |
| 640 void BufferedResourceLoader::SetDeferred(bool deferred) { | |
| 641 if (active_loader_->deferred() == deferred) | |
| 642 return; | |
| 643 | |
| 644 active_loader_->SetDeferred(deferred); | |
| 645 loading_cb_.Run(deferred ? kLoadingDeferred : kLoading); | |
| 646 | |
| 647 if (deferred && cancel_upon_deferral_) | |
| 648 CancelUponDeferral(); | |
| 649 } | |
| 650 | |
| 651 bool BufferedResourceLoader::ShouldDefer() const { | |
| 652 switch(defer_strategy_) { | |
| 653 case kNeverDefer: | |
| 654 return false; | |
| 655 | |
| 656 case kReadThenDefer: | |
| 657 DCHECK(read_cb_.is_null() || last_offset_ > buffer_.forward_bytes()) | |
| 658 << "We shouldn't stop deferring if we can fulfill the read"; | |
| 659 return read_cb_.is_null(); | |
| 660 | |
| 661 case kCapacityDefer: | |
| 662 return buffer_.forward_bytes() >= buffer_.forward_capacity(); | |
| 663 } | |
| 664 NOTREACHED(); | |
| 665 return false; | |
| 666 } | |
| 667 | |
| 668 bool BufferedResourceLoader::CanFulfillRead() const { | |
| 669 // If we are reading too far in the backward direction. | |
| 670 if (first_offset_ < 0 && (first_offset_ + buffer_.backward_bytes()) < 0) | |
| 671 return false; | |
| 672 | |
| 673 // If the start offset is too far ahead. | |
| 674 if (first_offset_ >= buffer_.forward_bytes()) | |
| 675 return false; | |
| 676 | |
| 677 // At the point, we verified that first byte requested is within the buffer. | |
| 678 // If the request has completed, then just returns with what we have now. | |
| 679 if (!active_loader_) | |
| 680 return true; | |
| 681 | |
| 682 // If the resource request is still active, make sure the whole requested | |
| 683 // range is covered. | |
| 684 if (last_offset_ > buffer_.forward_bytes()) | |
| 685 return false; | |
| 686 | |
| 687 return true; | |
| 688 } | |
| 689 | |
| 690 bool BufferedResourceLoader::WillFulfillRead() const { | |
| 691 // Trying to read too far behind. | |
| 692 if (first_offset_ < 0 && (first_offset_ + buffer_.backward_bytes()) < 0) | |
| 693 return false; | |
| 694 | |
| 695 // Trying to read too far ahead. | |
| 696 if ((first_offset_ - buffer_.forward_bytes()) >= kForwardWaitThreshold) | |
| 697 return false; | |
| 698 | |
| 699 // The resource request has completed, there's no way we can fulfill the | |
| 700 // read request. | |
| 701 if (!active_loader_) | |
| 702 return false; | |
| 703 | |
| 704 return true; | |
| 705 } | |
| 706 | |
| 707 void BufferedResourceLoader::ReadInternal() { | |
| 708 // Seek to the first byte requested. | |
| 709 bool ret = buffer_.Seek(first_offset_); | |
| 710 DCHECK(ret); | |
| 711 | |
| 712 // Then do the read. | |
| 713 int read = buffer_.Read(read_buffer_, read_size_); | |
| 714 offset_ += first_offset_ + read; | |
| 715 | |
| 716 // And report with what we have read. | |
| 717 DoneRead(kOk, read); | |
| 718 } | |
| 719 | |
| 720 int64_t BufferedResourceLoader::first_byte_position() const { | |
| 721 return first_byte_position_; | |
| 722 } | |
| 723 | |
| 724 // static | |
| 725 bool BufferedResourceLoader::ParseContentRange( | |
| 726 const std::string& content_range_str, | |
| 727 int64_t* first_byte_position, | |
| 728 int64_t* last_byte_position, | |
| 729 int64_t* instance_size) { | |
| 730 const std::string kUpThroughBytesUnit = "bytes "; | |
| 731 if (!base::StartsWith(content_range_str, kUpThroughBytesUnit, | |
| 732 base::CompareCase::SENSITIVE)) { | |
| 733 return false; | |
| 734 } | |
| 735 std::string range_spec = | |
| 736 content_range_str.substr(kUpThroughBytesUnit.length()); | |
| 737 size_t dash_offset = range_spec.find("-"); | |
| 738 size_t slash_offset = range_spec.find("/"); | |
| 739 | |
| 740 if (dash_offset == std::string::npos || slash_offset == std::string::npos || | |
| 741 slash_offset < dash_offset || slash_offset + 1 == range_spec.length()) { | |
| 742 return false; | |
| 743 } | |
| 744 if (!base::StringToInt64(range_spec.substr(0, dash_offset), | |
| 745 first_byte_position) || | |
| 746 !base::StringToInt64(range_spec.substr(dash_offset + 1, | |
| 747 slash_offset - dash_offset - 1), | |
| 748 last_byte_position)) { | |
| 749 return false; | |
| 750 } | |
| 751 if (slash_offset == range_spec.length() - 2 && | |
| 752 range_spec[slash_offset + 1] == '*') { | |
| 753 *instance_size = kPositionNotSpecified; | |
| 754 } else { | |
| 755 if (!base::StringToInt64(range_spec.substr(slash_offset + 1), | |
| 756 instance_size)) { | |
| 757 return false; | |
| 758 } | |
| 759 } | |
| 760 if (*last_byte_position < *first_byte_position || | |
| 761 (*instance_size != kPositionNotSpecified && | |
| 762 *last_byte_position >= *instance_size)) { | |
| 763 return false; | |
| 764 } | |
| 765 | |
| 766 return true; | |
| 767 } | |
| 768 | |
| 769 void BufferedResourceLoader::CancelUponDeferral() { | |
| 770 cancel_upon_deferral_ = true; | |
| 771 if (active_loader_ && active_loader_->deferred()) | |
| 772 active_loader_.reset(); | |
| 773 } | |
| 774 | |
| 775 int64_t BufferedResourceLoader::GetMemoryUsage() const { | |
| 776 return buffer_.forward_bytes() + buffer_.backward_bytes(); | |
| 777 } | |
| 778 | |
| 779 bool BufferedResourceLoader::VerifyPartialResponse( | |
| 780 const WebURLResponse& response) { | |
| 781 int64_t first_byte_position, last_byte_position, instance_size; | |
| 782 if (!ParseContentRange(response.httpHeaderField("Content-Range").utf8(), | |
| 783 &first_byte_position, &last_byte_position, | |
| 784 &instance_size)) { | |
| 785 return false; | |
| 786 } | |
| 787 | |
| 788 if (instance_size != kPositionNotSpecified) { | |
| 789 instance_size_ = instance_size; | |
| 790 } | |
| 791 | |
| 792 if (first_byte_position_ != kPositionNotSpecified && | |
| 793 first_byte_position_ != first_byte_position) { | |
| 794 return false; | |
| 795 } | |
| 796 | |
| 797 // TODO(hclam): I should also check |last_byte_position|, but since | |
| 798 // we will never make such a request that it is ok to leave it unimplemented. | |
| 799 return true; | |
| 800 } | |
| 801 | |
| 802 void BufferedResourceLoader::DoneRead(Status status, int bytes_read) { | |
| 803 if (saved_forward_capacity_) { | |
| 804 buffer_.set_forward_capacity(saved_forward_capacity_); | |
| 805 saved_forward_capacity_ = 0; | |
| 806 } | |
| 807 read_position_ = 0; | |
| 808 read_size_ = 0; | |
| 809 read_buffer_ = NULL; | |
| 810 first_offset_ = 0; | |
| 811 last_offset_ = 0; | |
| 812 Log(); | |
| 813 | |
| 814 base::ResetAndReturn(&read_cb_).Run(status, bytes_read); | |
| 815 } | |
| 816 | |
| 817 | |
| 818 void BufferedResourceLoader::DoneStart(Status status) { | |
| 819 base::ResetAndReturn(&start_cb_).Run(status); | |
| 820 } | |
| 821 | |
| 822 bool BufferedResourceLoader::IsRangeRequest() const { | |
| 823 return first_byte_position_ != kPositionNotSpecified; | |
| 824 } | |
| 825 | |
| 826 void BufferedResourceLoader::Log() { | |
| 827 media_log_->AddEvent( | |
| 828 media_log_->CreateBufferedExtentsChangedEvent( | |
| 829 offset_ - buffer_.backward_bytes(), | |
| 830 offset_, | |
| 831 offset_ + buffer_.forward_bytes())); | |
| 832 } | |
| 833 | |
| 834 } // namespace media | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 2272163002:
Delete now deprecated BufferedDataSource and friends. (Closed)
