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| 1 // Copyright (c) 2011 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 "webkit/glue/media/buffered_resource_loader.h" | |
| 6 | |
| 7 #include "base/format_macros.h" | |
| 8 #include "base/stringprintf.h" | |
| 9 #include "base/string_util.h" | |
| 10 #include "media/base/media_log.h" | |
| 11 #include "net/base/net_errors.h" | |
| 12 #include "net/http/http_request_headers.h" | |
| 13 #include "third_party/WebKit/Source/WebKit/chromium/public/WebKit.h" | |
| 14 #include "third_party/WebKit/Source/WebKit/chromium/public/WebKitPlatformSupport
.h" | |
| 15 #include "third_party/WebKit/Source/WebKit/chromium/public/WebString.h" | |
| 16 #include "third_party/WebKit/Source/WebKit/chromium/public/WebURLError.h" | |
| 17 #include "third_party/WebKit/Source/WebKit/chromium/public/WebURLLoaderOptions.h
" | |
| 18 #include "webkit/glue/multipart_response_delegate.h" | |
| 19 #include "webkit/glue/webkit_glue.h" | |
| 20 | |
| 21 using WebKit::WebFrame; | |
| 22 using WebKit::WebString; | |
| 23 using WebKit::WebURLError; | |
| 24 using WebKit::WebURLLoader; | |
| 25 using WebKit::WebURLLoaderOptions; | |
| 26 using WebKit::WebURLRequest; | |
| 27 using WebKit::WebURLResponse; | |
| 28 using webkit_glue::MultipartResponseDelegate; | |
| 29 | |
| 30 namespace webkit_glue { | |
| 31 | |
| 32 static const int kHttpOK = 200; | |
| 33 static const int kHttpPartialContent = 206; | |
| 34 | |
| 35 // Define the number of bytes in a megabyte. | |
| 36 static const size_t kMegabyte = 1024 * 1024; | |
| 37 | |
| 38 // Minimum capacity of the buffer in forward or backward direction. | |
| 39 // | |
| 40 // 2MB is an arbitrary limit; it just seems to be "good enough" in practice. | |
| 41 static const size_t kMinBufferCapacity = 2 * kMegabyte; | |
| 42 | |
| 43 // Maximum capacity of the buffer in forward or backward direction. This is | |
| 44 // effectively the largest single read the code path can handle. | |
| 45 // 20MB is an arbitrary limit; it just seems to be "good enough" in practice. | |
| 46 static const size_t kMaxBufferCapacity = 20 * kMegabyte; | |
| 47 | |
| 48 // Maximum number of bytes outside the buffer we will wait for in order to | |
| 49 // fulfill a read. If a read starts more than 2MB away from the data we | |
| 50 // currently have in the buffer, we will not wait for buffer to reach the read's | |
| 51 // location and will instead reset the request. | |
| 52 static const int kForwardWaitThreshold = 2 * kMegabyte; | |
| 53 | |
| 54 // Computes the suggested backward and forward capacity for the buffer | |
| 55 // if one wants to play at |playback_rate| * the natural playback speed. | |
| 56 // Use a value of 0 for |bitrate| if it is unknown. | |
| 57 static void ComputeTargetBufferWindow(float playback_rate, int bitrate, | |
| 58 size_t* out_backward_capacity, | |
| 59 size_t* out_forward_capacity) { | |
| 60 static const size_t kDefaultBitrate = 200 * 1024 * 8; // 200 Kbps. | |
| 61 static const size_t kMaxBitrate = 20 * kMegabyte * 8; // 20 Mbps. | |
| 62 static const float kMaxPlaybackRate = 25.0; | |
| 63 static const size_t kTargetSecondsBufferedAhead = 10; | |
| 64 static const size_t kTargetSecondsBufferedBehind = 2; | |
| 65 | |
| 66 // Use a default bit rate if unknown and clamp to prevent overflow. | |
| 67 if (bitrate <= 0) | |
| 68 bitrate = kDefaultBitrate; | |
| 69 bitrate = std::min(static_cast<size_t>(bitrate), kMaxBitrate); | |
| 70 | |
| 71 // Only scale the buffer window for playback rates greater than 1.0 in | |
| 72 // magnitude and clamp to prevent overflow. | |
| 73 bool backward_playback = false; | |
| 74 if (playback_rate < 0.0f) { | |
| 75 backward_playback = true; | |
| 76 playback_rate *= -1.0f; | |
| 77 } | |
| 78 | |
| 79 playback_rate = std::max(playback_rate, 1.0f); | |
| 80 playback_rate = std::min(playback_rate, kMaxPlaybackRate); | |
| 81 | |
| 82 size_t bytes_per_second = static_cast<size_t>(playback_rate * bitrate / 8.0); | |
| 83 | |
| 84 // Clamp between kMinBufferCapacity and kMaxBufferCapacity. | |
| 85 *out_forward_capacity = std::max( | |
| 86 kTargetSecondsBufferedAhead * bytes_per_second, kMinBufferCapacity); | |
| 87 *out_backward_capacity = std::max( | |
| 88 kTargetSecondsBufferedBehind * bytes_per_second, kMinBufferCapacity); | |
| 89 | |
| 90 *out_forward_capacity = std::min(*out_forward_capacity, kMaxBufferCapacity); | |
| 91 *out_backward_capacity = std::min(*out_backward_capacity, kMaxBufferCapacity); | |
| 92 | |
| 93 if (backward_playback) | |
| 94 std::swap(*out_forward_capacity, *out_backward_capacity); | |
| 95 } | |
| 96 | |
| 97 | |
| 98 BufferedResourceLoader::BufferedResourceLoader( | |
| 99 const GURL& url, | |
| 100 int64 first_byte_position, | |
| 101 int64 last_byte_position, | |
| 102 DeferStrategy strategy, | |
| 103 int bitrate, | |
| 104 float playback_rate, | |
| 105 media::MediaLog* media_log) | |
| 106 : deferred_(false), | |
| 107 defer_strategy_(strategy), | |
| 108 completed_(false), | |
| 109 range_requested_(false), | |
| 110 range_supported_(false), | |
| 111 saved_forward_capacity_(0), | |
| 112 url_(url), | |
| 113 first_byte_position_(first_byte_position), | |
| 114 last_byte_position_(last_byte_position), | |
| 115 single_origin_(true), | |
| 116 start_callback_(NULL), | |
| 117 offset_(0), | |
| 118 content_length_(kPositionNotSpecified), | |
| 119 instance_size_(kPositionNotSpecified), | |
| 120 read_callback_(NULL), | |
| 121 read_position_(0), | |
| 122 read_size_(0), | |
| 123 read_buffer_(NULL), | |
| 124 first_offset_(0), | |
| 125 last_offset_(0), | |
| 126 keep_test_loader_(false), | |
| 127 bitrate_(bitrate), | |
| 128 playback_rate_(playback_rate), | |
| 129 media_log_(media_log) { | |
| 130 | |
| 131 size_t backward_capacity; | |
| 132 size_t forward_capacity; | |
| 133 ComputeTargetBufferWindow( | |
| 134 playback_rate_, bitrate_, &backward_capacity, &forward_capacity); | |
| 135 buffer_.reset(new media::SeekableBuffer(backward_capacity, forward_capacity)); | |
| 136 } | |
| 137 | |
| 138 BufferedResourceLoader::~BufferedResourceLoader() { | |
| 139 if (!completed_ && url_loader_.get()) | |
| 140 url_loader_->cancel(); | |
| 141 } | |
| 142 | |
| 143 void BufferedResourceLoader::Start(net::OldCompletionCallback* start_callback, | |
| 144 const base::Closure& event_callback, | |
| 145 WebFrame* frame) { | |
| 146 // Make sure we have not started. | |
| 147 DCHECK(!start_callback_.get()); | |
| 148 DCHECK(event_callback_.is_null()); | |
| 149 DCHECK(start_callback); | |
| 150 DCHECK(!event_callback.is_null()); | |
| 151 CHECK(frame); | |
| 152 | |
| 153 start_callback_.reset(start_callback); | |
| 154 event_callback_ = event_callback; | |
| 155 | |
| 156 if (first_byte_position_ != kPositionNotSpecified) { | |
| 157 // TODO(hclam): server may not support range request so |offset_| may not | |
| 158 // equal to |first_byte_position_|. | |
| 159 offset_ = first_byte_position_; | |
| 160 } | |
| 161 | |
| 162 // Increment the reference count right before we start the request. This | |
| 163 // reference will be release when this request has ended. | |
| 164 AddRef(); | |
| 165 | |
| 166 // Prepare the request. | |
| 167 WebURLRequest request(url_); | |
| 168 request.setTargetType(WebURLRequest::TargetIsMedia); | |
| 169 | |
| 170 if (IsRangeRequest()) { | |
| 171 range_requested_ = true; | |
| 172 request.setHTTPHeaderField( | |
| 173 WebString::fromUTF8(net::HttpRequestHeaders::kRange), | |
| 174 WebString::fromUTF8(GenerateHeaders(first_byte_position_, | |
| 175 last_byte_position_))); | |
| 176 } | |
| 177 frame->setReferrerForRequest(request, WebKit::WebURL()); | |
| 178 | |
| 179 // Disable compression, compression for audio/video doesn't make sense... | |
| 180 request.setHTTPHeaderField( | |
| 181 WebString::fromUTF8(net::HttpRequestHeaders::kAcceptEncoding), | |
| 182 WebString::fromUTF8("identity;q=1, *;q=0")); | |
| 183 | |
| 184 // This flag is for unittests as we don't want to reset |url_loader| | |
| 185 if (!keep_test_loader_) { | |
| 186 WebURLLoaderOptions options; | |
| 187 options.allowCredentials = true; | |
| 188 options.crossOriginRequestPolicy = | |
| 189 WebURLLoaderOptions::CrossOriginRequestPolicyAllow; | |
| 190 url_loader_.reset(frame->createAssociatedURLLoader(options)); | |
| 191 } | |
| 192 | |
| 193 // Start the resource loading. | |
| 194 url_loader_->loadAsynchronously(request, this); | |
| 195 } | |
| 196 | |
| 197 void BufferedResourceLoader::Stop() { | |
| 198 // Reset callbacks. | |
| 199 start_callback_.reset(); | |
| 200 event_callback_.Reset(); | |
| 201 read_callback_.reset(); | |
| 202 | |
| 203 // Use the internal buffer to signal that we have been stopped. | |
| 204 // TODO(hclam): Not so pretty to do this. | |
| 205 if (!buffer_.get()) | |
| 206 return; | |
| 207 | |
| 208 // Destroy internal buffer. | |
| 209 buffer_.reset(); | |
| 210 | |
| 211 if (url_loader_.get()) { | |
| 212 if (deferred_) | |
| 213 url_loader_->setDefersLoading(false); | |
| 214 deferred_ = false; | |
| 215 | |
| 216 if (!completed_) { | |
| 217 url_loader_->cancel(); | |
| 218 completed_ = true; | |
| 219 } | |
| 220 } | |
| 221 } | |
| 222 | |
| 223 void BufferedResourceLoader::Read(int64 position, | |
| 224 int read_size, | |
| 225 uint8* buffer, | |
| 226 net::OldCompletionCallback* read_callback) { | |
| 227 DCHECK(!read_callback_.get()); | |
| 228 DCHECK(buffer_.get()); | |
| 229 DCHECK(read_callback); | |
| 230 DCHECK(buffer); | |
| 231 DCHECK_GT(read_size, 0); | |
| 232 | |
| 233 // Save the parameter of reading. | |
| 234 read_callback_.reset(read_callback); | |
| 235 read_position_ = position; | |
| 236 read_size_ = read_size; | |
| 237 read_buffer_ = buffer; | |
| 238 | |
| 239 // If read position is beyond the instance size, we cannot read there. | |
| 240 if (instance_size_ != kPositionNotSpecified && | |
| 241 instance_size_ <= read_position_) { | |
| 242 DoneRead(0); | |
| 243 return; | |
| 244 } | |
| 245 | |
| 246 // Make sure |offset_| and |read_position_| does not differ by a large | |
| 247 // amount. | |
| 248 if (read_position_ > offset_ + kint32max || | |
| 249 read_position_ < offset_ + kint32min) { | |
| 250 DoneRead(net::ERR_CACHE_MISS); | |
| 251 return; | |
| 252 } | |
| 253 | |
| 254 // Make sure |read_size_| is not too large for the buffer to ever be able to | |
| 255 // fulfill the read request. | |
| 256 if (read_size_ > kMaxBufferCapacity) { | |
| 257 DoneRead(net::ERR_FAILED); | |
| 258 return; | |
| 259 } | |
| 260 | |
| 261 // Prepare the parameters. | |
| 262 first_offset_ = static_cast<int>(read_position_ - offset_); | |
| 263 last_offset_ = first_offset_ + read_size_; | |
| 264 | |
| 265 // If we can serve the request now, do the actual read. | |
| 266 if (CanFulfillRead()) { | |
| 267 ReadInternal(); | |
| 268 UpdateDeferBehavior(); | |
| 269 return; | |
| 270 } | |
| 271 | |
| 272 // If we expect the read request to be fulfilled later, expand capacity as | |
| 273 // necessary and disable deferring. | |
| 274 if (WillFulfillRead()) { | |
| 275 // Advance offset as much as possible to create additional capacity. | |
| 276 int advance = std::min(first_offset_, | |
| 277 static_cast<int>(buffer_->forward_bytes())); | |
| 278 bool ret = buffer_->Seek(advance); | |
| 279 DCHECK(ret); | |
| 280 | |
| 281 offset_ += advance; | |
| 282 first_offset_ -= advance; | |
| 283 last_offset_ -= advance; | |
| 284 | |
| 285 // Expand capacity to accomodate a read that extends past the normal | |
| 286 // capacity. | |
| 287 // | |
| 288 // This can happen when reading in a large seek index or when the | |
| 289 // first byte of a read request falls within kForwardWaitThreshold. | |
| 290 if (last_offset_ > static_cast<int>(buffer_->forward_capacity())) { | |
| 291 saved_forward_capacity_ = buffer_->forward_capacity(); | |
| 292 buffer_->set_forward_capacity(last_offset_); | |
| 293 } | |
| 294 | |
| 295 // Make sure we stop deferring now that there's additional capacity. | |
| 296 // | |
| 297 // XXX: can we DCHECK(url_loader_.get()) at this point in time? | |
| 298 if (deferred_) | |
| 299 SetDeferred(false); | |
| 300 | |
| 301 DCHECK(!ShouldEnableDefer()) | |
| 302 << "Capacity was not adjusted properly to prevent deferring."; | |
| 303 | |
| 304 return; | |
| 305 } | |
| 306 | |
| 307 // Make a callback to report failure. | |
| 308 DoneRead(net::ERR_CACHE_MISS); | |
| 309 } | |
| 310 | |
| 311 int64 BufferedResourceLoader::GetBufferedPosition() { | |
| 312 if (buffer_.get()) | |
| 313 return offset_ + static_cast<int>(buffer_->forward_bytes()) - 1; | |
| 314 return kPositionNotSpecified; | |
| 315 } | |
| 316 | |
| 317 int64 BufferedResourceLoader::content_length() { | |
| 318 return content_length_; | |
| 319 } | |
| 320 | |
| 321 int64 BufferedResourceLoader::instance_size() { | |
| 322 return instance_size_; | |
| 323 } | |
| 324 | |
| 325 bool BufferedResourceLoader::range_supported() { | |
| 326 return range_supported_; | |
| 327 } | |
| 328 | |
| 329 bool BufferedResourceLoader::is_downloading_data() { | |
| 330 return !completed_ && !deferred_; | |
| 331 } | |
| 332 | |
| 333 const GURL& BufferedResourceLoader::url() { | |
| 334 return url_; | |
| 335 } | |
| 336 | |
| 337 void BufferedResourceLoader::SetURLLoaderForTest(WebURLLoader* mock_loader) { | |
| 338 url_loader_.reset(mock_loader); | |
| 339 keep_test_loader_ = true; | |
| 340 } | |
| 341 | |
| 342 ///////////////////////////////////////////////////////////////////////////// | |
| 343 // WebKit::WebURLLoaderClient implementation. | |
| 344 void BufferedResourceLoader::willSendRequest( | |
| 345 WebURLLoader* loader, | |
| 346 WebURLRequest& newRequest, | |
| 347 const WebURLResponse& redirectResponse) { | |
| 348 | |
| 349 // The load may have been stopped and |start_callback| is destroyed. | |
| 350 // In this case we shouldn't do anything. | |
| 351 if (!start_callback_.get()) { | |
| 352 // Set the url in the request to an invalid value (empty url). | |
| 353 newRequest.setURL(WebKit::WebURL()); | |
| 354 return; | |
| 355 } | |
| 356 | |
| 357 // Only allow |single_origin_| if we haven't seen a different origin yet. | |
| 358 if (single_origin_) | |
| 359 single_origin_ = url_.GetOrigin() == GURL(newRequest.url()).GetOrigin(); | |
| 360 | |
| 361 if (!IsProtocolSupportedForMedia(newRequest.url())) { | |
| 362 // Set the url in the request to an invalid value (empty url). | |
| 363 newRequest.setURL(WebKit::WebURL()); | |
| 364 DoneStart(net::ERR_ADDRESS_INVALID); | |
| 365 return; | |
| 366 } | |
| 367 | |
| 368 url_ = newRequest.url(); | |
| 369 } | |
| 370 | |
| 371 void BufferedResourceLoader::didSendData( | |
| 372 WebURLLoader* loader, | |
| 373 unsigned long long bytes_sent, | |
| 374 unsigned long long total_bytes_to_be_sent) { | |
| 375 NOTIMPLEMENTED(); | |
| 376 } | |
| 377 | |
| 378 void BufferedResourceLoader::didReceiveResponse( | |
| 379 WebURLLoader* loader, | |
| 380 const WebURLResponse& response) { | |
| 381 VLOG(1) << "didReceiveResponse: " << response.httpStatusCode(); | |
| 382 | |
| 383 // The loader may have been stopped and |start_callback| is destroyed. | |
| 384 // In this case we shouldn't do anything. | |
| 385 if (!start_callback_.get()) | |
| 386 return; | |
| 387 | |
| 388 bool partial_response = false; | |
| 389 | |
| 390 // We make a strong assumption that when we reach here we have either | |
| 391 // received a response from HTTP/HTTPS protocol or the request was | |
| 392 // successful (in particular range request). So we only verify the partial | |
| 393 // response for HTTP and HTTPS protocol. | |
| 394 if (url_.SchemeIs(kHttpScheme) || url_.SchemeIs(kHttpsScheme)) { | |
| 395 int error = net::OK; | |
| 396 | |
| 397 // Check to see whether the server supports byte ranges. | |
| 398 std::string accept_ranges = | |
| 399 response.httpHeaderField("Accept-Ranges").utf8(); | |
| 400 range_supported_ = (accept_ranges.find("bytes") != std::string::npos); | |
| 401 | |
| 402 partial_response = (response.httpStatusCode() == kHttpPartialContent); | |
| 403 | |
| 404 if (range_requested_) { | |
| 405 // If we have verified the partial response and it is correct, we will | |
| 406 // return net::OK. It's also possible for a server to support range | |
| 407 // requests without advertising Accept-Ranges: bytes. | |
| 408 if (partial_response && VerifyPartialResponse(response)) | |
| 409 range_supported_ = true; | |
| 410 else | |
| 411 error = net::ERR_INVALID_RESPONSE; | |
| 412 } else if (response.httpStatusCode() != kHttpOK) { | |
| 413 // We didn't request a range but server didn't reply with "200 OK". | |
| 414 error = net::ERR_FAILED; | |
| 415 } | |
| 416 | |
| 417 if (error != net::OK) { | |
| 418 DoneStart(error); | |
| 419 Stop(); | |
| 420 return; | |
| 421 } | |
| 422 } else { | |
| 423 // For any protocol other than HTTP and HTTPS, assume range request is | |
| 424 // always fulfilled. | |
| 425 partial_response = range_requested_; | |
| 426 } | |
| 427 | |
| 428 // Expected content length can be |kPositionNotSpecified|, in that case | |
| 429 // |content_length_| is not specified and this is a streaming response. | |
| 430 content_length_ = response.expectedContentLength(); | |
| 431 | |
| 432 // If we have not requested a range, then the size of the instance is equal | |
| 433 // to the content length. | |
| 434 if (!partial_response) | |
| 435 instance_size_ = content_length_; | |
| 436 | |
| 437 // Calls with a successful response. | |
| 438 DoneStart(net::OK); | |
| 439 } | |
| 440 | |
| 441 void BufferedResourceLoader::didReceiveData( | |
| 442 WebURLLoader* loader, | |
| 443 const char* data, | |
| 444 int data_length, | |
| 445 int encoded_data_length) { | |
| 446 VLOG(1) << "didReceiveData: " << data_length << " bytes"; | |
| 447 | |
| 448 DCHECK(!completed_); | |
| 449 DCHECK_GT(data_length, 0); | |
| 450 | |
| 451 // If this loader has been stopped, |buffer_| would be destroyed. | |
| 452 // In this case we shouldn't do anything. | |
| 453 if (!buffer_.get()) | |
| 454 return; | |
| 455 | |
| 456 // Writes more data to |buffer_|. | |
| 457 buffer_->Append(reinterpret_cast<const uint8*>(data), data_length); | |
| 458 | |
| 459 // If there is an active read request, try to fulfill the request. | |
| 460 if (HasPendingRead() && CanFulfillRead()) | |
| 461 ReadInternal(); | |
| 462 | |
| 463 // At last see if the buffer is full and we need to defer the downloading. | |
| 464 UpdateDeferBehavior(); | |
| 465 | |
| 466 // Consume excess bytes from our in-memory buffer if necessary. | |
| 467 if (buffer_->forward_bytes() > buffer_->forward_capacity()) { | |
| 468 size_t excess = buffer_->forward_bytes() - buffer_->forward_capacity(); | |
| 469 bool success = buffer_->Seek(excess); | |
| 470 DCHECK(success); | |
| 471 offset_ += first_offset_ + excess; | |
| 472 } | |
| 473 | |
| 474 // Notify that we have received some data. | |
| 475 NotifyNetworkEvent(); | |
| 476 Log(); | |
| 477 } | |
| 478 | |
| 479 void BufferedResourceLoader::didDownloadData( | |
| 480 WebKit::WebURLLoader* loader, | |
| 481 int dataLength) { | |
| 482 NOTIMPLEMENTED(); | |
| 483 } | |
| 484 | |
| 485 void BufferedResourceLoader::didReceiveCachedMetadata( | |
| 486 WebURLLoader* loader, | |
| 487 const char* data, | |
| 488 int data_length) { | |
| 489 NOTIMPLEMENTED(); | |
| 490 } | |
| 491 | |
| 492 void BufferedResourceLoader::didFinishLoading( | |
| 493 WebURLLoader* loader, | |
| 494 double finishTime) { | |
| 495 VLOG(1) << "didFinishLoading"; | |
| 496 | |
| 497 DCHECK(!completed_); | |
| 498 completed_ = true; | |
| 499 | |
| 500 // If we didn't know the |instance_size_| we do now. | |
| 501 if (instance_size_ == kPositionNotSpecified) { | |
| 502 instance_size_ = offset_ + buffer_->forward_bytes(); | |
| 503 } | |
| 504 | |
| 505 // If there is a start callback, calls it. | |
| 506 if (start_callback_.get()) { | |
| 507 DoneStart(net::OK); | |
| 508 } | |
| 509 | |
| 510 // If there is a pending read but the request has ended, returns with what | |
| 511 // we have. | |
| 512 if (HasPendingRead()) { | |
| 513 // Make sure we have a valid buffer before we satisfy a read request. | |
| 514 DCHECK(buffer_.get()); | |
| 515 | |
| 516 // Try to fulfill with what is in the buffer. | |
| 517 if (CanFulfillRead()) | |
| 518 ReadInternal(); | |
| 519 else | |
| 520 DoneRead(net::ERR_CACHE_MISS); | |
| 521 } | |
| 522 | |
| 523 // There must not be any outstanding read request. | |
| 524 DCHECK(!HasPendingRead()); | |
| 525 | |
| 526 // Notify that network response is completed. | |
| 527 NotifyNetworkEvent(); | |
| 528 | |
| 529 url_loader_.reset(); | |
| 530 Release(); | |
| 531 } | |
| 532 | |
| 533 void BufferedResourceLoader::didFail( | |
| 534 WebURLLoader* loader, | |
| 535 const WebURLError& error) { | |
| 536 VLOG(1) << "didFail: " << error.reason; | |
| 537 | |
| 538 DCHECK(!completed_); | |
| 539 completed_ = true; | |
| 540 | |
| 541 // If there is a start callback, calls it. | |
| 542 if (start_callback_.get()) { | |
| 543 DoneStart(error.reason); | |
| 544 } | |
| 545 | |
| 546 // If there is a pending read but the request failed, return with the | |
| 547 // reason for the error. | |
| 548 if (HasPendingRead()) { | |
| 549 DoneRead(error.reason); | |
| 550 } | |
| 551 | |
| 552 // Notify that network response is completed. | |
| 553 NotifyNetworkEvent(); | |
| 554 | |
| 555 url_loader_.reset(); | |
| 556 Release(); | |
| 557 } | |
| 558 | |
| 559 bool BufferedResourceLoader::HasSingleOrigin() const { | |
| 560 return single_origin_; | |
| 561 } | |
| 562 | |
| 563 void BufferedResourceLoader::UpdateDeferStrategy(DeferStrategy strategy) { | |
| 564 defer_strategy_ = strategy; | |
| 565 UpdateDeferBehavior(); | |
| 566 } | |
| 567 | |
| 568 void BufferedResourceLoader::SetPlaybackRate(float playback_rate) { | |
| 569 playback_rate_ = playback_rate; | |
| 570 | |
| 571 // This is a pause so don't bother updating the buffer window as we'll likely | |
| 572 // get unpaused in the future. | |
| 573 if (playback_rate_ == 0.0) | |
| 574 return; | |
| 575 | |
| 576 UpdateBufferWindow(); | |
| 577 } | |
| 578 | |
| 579 void BufferedResourceLoader::SetBitrate(int bitrate) { | |
| 580 DCHECK(bitrate >= 0); | |
| 581 bitrate_ = bitrate; | |
| 582 UpdateBufferWindow(); | |
| 583 } | |
| 584 | |
| 585 ///////////////////////////////////////////////////////////////////////////// | |
| 586 // Helper methods. | |
| 587 | |
| 588 void BufferedResourceLoader::UpdateBufferWindow() { | |
| 589 if (!buffer_.get()) | |
| 590 return; | |
| 591 | |
| 592 size_t backward_capacity; | |
| 593 size_t forward_capacity; | |
| 594 ComputeTargetBufferWindow( | |
| 595 playback_rate_, bitrate_, &backward_capacity, &forward_capacity); | |
| 596 | |
| 597 // This does not evict data from the buffer if the new capacities are less | |
| 598 // than the current capacities; the new limits will be enforced after the | |
| 599 // existing excess buffered data is consumed. | |
| 600 buffer_->set_backward_capacity(backward_capacity); | |
| 601 buffer_->set_forward_capacity(forward_capacity); | |
| 602 } | |
| 603 | |
| 604 void BufferedResourceLoader::UpdateDeferBehavior() { | |
| 605 if (!url_loader_.get() || !buffer_.get()) | |
| 606 return; | |
| 607 | |
| 608 // If necessary, toggle defer state and continue/pause downloading data | |
| 609 // accordingly. | |
| 610 if (ShouldEnableDefer() || ShouldDisableDefer()) | |
| 611 SetDeferred(!deferred_); | |
| 612 } | |
| 613 | |
| 614 void BufferedResourceLoader::SetDeferred(bool deferred) { | |
| 615 deferred_ = deferred; | |
| 616 if (url_loader_.get()) { | |
| 617 url_loader_->setDefersLoading(deferred); | |
| 618 NotifyNetworkEvent(); | |
| 619 } | |
| 620 } | |
| 621 | |
| 622 bool BufferedResourceLoader::ShouldEnableDefer() { | |
| 623 // If we're already deferring, then enabling makes no sense. | |
| 624 if (deferred_) | |
| 625 return false; | |
| 626 | |
| 627 switch(defer_strategy_) { | |
| 628 // Never defer at all, so never enable defer. | |
| 629 case kNeverDefer: | |
| 630 return false; | |
| 631 | |
| 632 // Defer if nothing is being requested. | |
| 633 case kReadThenDefer: | |
| 634 return !read_callback_.get(); | |
| 635 | |
| 636 // Defer if we've reached the max capacity of the threshold. | |
| 637 case kThresholdDefer: | |
| 638 return buffer_->forward_bytes() >= buffer_->forward_capacity(); | |
| 639 } | |
| 640 // Otherwise don't enable defer. | |
| 641 return false; | |
| 642 } | |
| 643 | |
| 644 bool BufferedResourceLoader::ShouldDisableDefer() { | |
| 645 // If we're not deferring, then disabling makes no sense. | |
| 646 if (!deferred_) | |
| 647 return false; | |
| 648 | |
| 649 switch(defer_strategy_) { | |
| 650 // Always disable deferring. | |
| 651 case kNeverDefer: | |
| 652 return true; | |
| 653 | |
| 654 // We have an outstanding read request, and we have not buffered enough | |
| 655 // yet to fulfill the request; disable defer to get more data. | |
| 656 case kReadThenDefer: | |
| 657 return read_callback_.get() && | |
| 658 last_offset_ > static_cast<int>(buffer_->forward_bytes()); | |
| 659 | |
| 660 // We have less than half the capacity of our threshold, so | |
| 661 // disable defer to get more data. | |
| 662 case kThresholdDefer: { | |
| 663 size_t amount_buffered = buffer_->forward_bytes(); | |
| 664 size_t half_capacity = buffer_->forward_capacity() / 2; | |
| 665 return amount_buffered < half_capacity; | |
| 666 } | |
| 667 } | |
| 668 | |
| 669 // Otherwise keep deferring. | |
| 670 return false; | |
| 671 } | |
| 672 | |
| 673 bool BufferedResourceLoader::CanFulfillRead() { | |
| 674 // If we are reading too far in the backward direction. | |
| 675 if (first_offset_ < 0 && | |
| 676 first_offset_ + static_cast<int>(buffer_->backward_bytes()) < 0) | |
| 677 return false; | |
| 678 | |
| 679 // If the start offset is too far ahead. | |
| 680 if (first_offset_ >= static_cast<int>(buffer_->forward_bytes())) | |
| 681 return false; | |
| 682 | |
| 683 // At the point, we verified that first byte requested is within the buffer. | |
| 684 // If the request has completed, then just returns with what we have now. | |
| 685 if (completed_) | |
| 686 return true; | |
| 687 | |
| 688 // If the resource request is still active, make sure the whole requested | |
| 689 // range is covered. | |
| 690 if (last_offset_ > static_cast<int>(buffer_->forward_bytes())) | |
| 691 return false; | |
| 692 | |
| 693 return true; | |
| 694 } | |
| 695 | |
| 696 bool BufferedResourceLoader::WillFulfillRead() { | |
| 697 // Trying to read too far behind. | |
| 698 if (first_offset_ < 0 && | |
| 699 first_offset_ + static_cast<int>(buffer_->backward_bytes()) < 0) | |
| 700 return false; | |
| 701 | |
| 702 // Trying to read too far ahead. | |
| 703 if (first_offset_ - static_cast<int>(buffer_->forward_bytes()) >= | |
| 704 kForwardWaitThreshold) | |
| 705 return false; | |
| 706 | |
| 707 // The resource request has completed, there's no way we can fulfill the | |
| 708 // read request. | |
| 709 if (completed_) | |
| 710 return false; | |
| 711 | |
| 712 return true; | |
| 713 } | |
| 714 | |
| 715 void BufferedResourceLoader::ReadInternal() { | |
| 716 // Seek to the first byte requested. | |
| 717 bool ret = buffer_->Seek(first_offset_); | |
| 718 DCHECK(ret); | |
| 719 | |
| 720 // Then do the read. | |
| 721 int read = static_cast<int>(buffer_->Read(read_buffer_, read_size_)); | |
| 722 offset_ += first_offset_ + read; | |
| 723 | |
| 724 // And report with what we have read. | |
| 725 DoneRead(read); | |
| 726 } | |
| 727 | |
| 728 bool BufferedResourceLoader::VerifyPartialResponse( | |
| 729 const WebURLResponse& response) { | |
| 730 int64 first_byte_position, last_byte_position, instance_size; | |
| 731 | |
| 732 if (!MultipartResponseDelegate::ReadContentRanges(response, | |
| 733 &first_byte_position, | |
| 734 &last_byte_position, | |
| 735 &instance_size)) { | |
| 736 return false; | |
| 737 } | |
| 738 | |
| 739 if (instance_size != kPositionNotSpecified) { | |
| 740 instance_size_ = instance_size; | |
| 741 } | |
| 742 | |
| 743 if (first_byte_position_ != kPositionNotSpecified && | |
| 744 first_byte_position_ != first_byte_position) { | |
| 745 return false; | |
| 746 } | |
| 747 | |
| 748 // TODO(hclam): I should also check |last_byte_position|, but since | |
| 749 // we will never make such a request that it is ok to leave it unimplemented. | |
| 750 return true; | |
| 751 } | |
| 752 | |
| 753 std::string BufferedResourceLoader::GenerateHeaders( | |
| 754 int64 first_byte_position, | |
| 755 int64 last_byte_position) { | |
| 756 // Construct the value for the range header. | |
| 757 std::string header; | |
| 758 if (first_byte_position > kPositionNotSpecified && | |
| 759 last_byte_position > kPositionNotSpecified) { | |
| 760 if (first_byte_position <= last_byte_position) { | |
| 761 header = base::StringPrintf("bytes=%" PRId64 "-%" PRId64, | |
| 762 first_byte_position, | |
| 763 last_byte_position); | |
| 764 } | |
| 765 } else if (first_byte_position > kPositionNotSpecified) { | |
| 766 header = base::StringPrintf("bytes=%" PRId64 "-", | |
| 767 first_byte_position); | |
| 768 } else if (last_byte_position > kPositionNotSpecified) { | |
| 769 NOTIMPLEMENTED() << "Suffix range not implemented"; | |
| 770 } | |
| 771 return header; | |
| 772 } | |
| 773 | |
| 774 void BufferedResourceLoader::DoneRead(int error) { | |
| 775 read_callback_->RunWithParams(Tuple1<int>(error)); | |
| 776 read_callback_.reset(); | |
| 777 if (buffer_.get() && saved_forward_capacity_) { | |
| 778 buffer_->set_forward_capacity(saved_forward_capacity_); | |
| 779 saved_forward_capacity_ = 0; | |
| 780 } | |
| 781 read_position_ = 0; | |
| 782 read_size_ = 0; | |
| 783 read_buffer_ = NULL; | |
| 784 first_offset_ = 0; | |
| 785 last_offset_ = 0; | |
| 786 Log(); | |
| 787 } | |
| 788 | |
| 789 void BufferedResourceLoader::DoneStart(int error) { | |
| 790 start_callback_->RunWithParams(Tuple1<int>(error)); | |
| 791 start_callback_.reset(); | |
| 792 } | |
| 793 | |
| 794 void BufferedResourceLoader::NotifyNetworkEvent() { | |
| 795 if (!event_callback_.is_null()) | |
| 796 event_callback_.Run(); | |
| 797 } | |
| 798 | |
| 799 bool BufferedResourceLoader::IsRangeRequest() const { | |
| 800 return first_byte_position_ != kPositionNotSpecified; | |
| 801 } | |
| 802 | |
| 803 void BufferedResourceLoader::Log() { | |
| 804 if (buffer_.get()) { | |
| 805 media_log_->AddEvent( | |
| 806 media_log_->CreateBufferedExtentsChangedEvent( | |
| 807 offset_ - buffer_->backward_bytes(), | |
| 808 offset_, | |
| 809 offset_ + buffer_->forward_bytes())); | |
| 810 } | |
| 811 } | |
| 812 | |
| 813 } // namespace webkit_glue | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 8570010:
Moving media-related files from webkit/glue/ to webkit/media/. (Closed)
Base URL: svn://chrome-svn/chrome/trunk/src