DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (b6d82b1a6b02)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsAsyncStreamCopier.h"
#include "nsIOService.h"
#include "nsIEventTarget.h"
#include "nsStreamUtils.h"
#include "nsThreadUtils.h"
#include "nsNetUtil.h"
#include "nsNetCID.h"
#include "nsIBufferedStreams.h"
#include "nsIRequestObserver.h"
#include "mozilla/Logging.h"

using namespace mozilla;
using namespace mozilla::net;

#undef LOG
//
// MOZ_LOG=nsStreamCopier:5
//
static LazyLogModule gStreamCopierLog("nsStreamCopier");
#define LOG(args) MOZ_LOG(gStreamCopierLog, mozilla::LogLevel::Debug, args)

/**
 * An event used to perform initialization off the main thread.
 */
class AsyncApplyBufferingPolicyEvent final : public Runnable {
 public:
  /**
   * @param aCopier
   *        The nsAsyncStreamCopier requesting the information.
   */
  explicit AsyncApplyBufferingPolicyEvent(nsAsyncStreamCopier* aCopier)
      : mozilla::Runnable("AsyncApplyBufferingPolicyEvent"),
        mCopier(aCopier),
        mTarget(GetCurrentThreadEventTarget()) {}

  NS_IMETHOD Run() override {
    nsresult rv = mCopier->ApplyBufferingPolicy();
    if (NS_FAILED(rv)) {
      mCopier->Cancel(rv);
      return NS_OK;
    }

    rv = mTarget->Dispatch(
        NewRunnableMethod("nsAsyncStreamCopier::AsyncCopyInternal", mCopier,
                          &nsAsyncStreamCopier::AsyncCopyInternal),
        NS_DISPATCH_NORMAL);
    MOZ_ASSERT(NS_SUCCEEDED(rv));

    if (NS_FAILED(rv)) {
      mCopier->Cancel(rv);
    }
    return NS_OK;
  }

 private:
  RefPtr<nsAsyncStreamCopier> mCopier;
  nsCOMPtr<nsIEventTarget> mTarget;
};

//-----------------------------------------------------------------------------

nsAsyncStreamCopier::nsAsyncStreamCopier()
    : mLock("nsAsyncStreamCopier.mLock"),
      mMode(NS_ASYNCCOPY_VIA_READSEGMENTS),
      mChunkSize(nsIOService::gDefaultSegmentSize),
      mStatus(NS_OK),
      mIsPending(false),
      mCloseSource{false},
      mCloseSink{false},
      mShouldSniffBuffering(false) {
  LOG(("Creating nsAsyncStreamCopier @%p\n", this));
}

nsAsyncStreamCopier::~nsAsyncStreamCopier() {
  LOG(("Destroying nsAsyncStreamCopier @%p\n", this));
}

bool nsAsyncStreamCopier::IsComplete(nsresult* status) {
  MutexAutoLock lock(mLock);
  if (status) *status = mStatus;
  return !mIsPending;
}

nsIRequest* nsAsyncStreamCopier::AsRequest() {
  return static_cast<nsIRequest*>(static_cast<nsIAsyncStreamCopier*>(this));
}

void nsAsyncStreamCopier::Complete(nsresult status) {
  LOG(("nsAsyncStreamCopier::Complete [this=%p status=%" PRIx32 "]\n", this,
       static_cast<uint32_t>(status)));

  nsCOMPtr<nsIRequestObserver> observer;
  nsCOMPtr<nsISupports> ctx;
  {
    MutexAutoLock lock(mLock);
    mCopierCtx = nullptr;

    if (mIsPending) {
      mIsPending = false;
      mStatus = status;

      // setup OnStopRequest callback and release references...
      observer = mObserver;
      mObserver = nullptr;
    }
  }

  if (observer) {
    LOG(("  calling OnStopRequest [status=%" PRIx32 "]\n",
         static_cast<uint32_t>(status)));
    observer->OnStopRequest(AsRequest(), status);
  }
}

void nsAsyncStreamCopier::OnAsyncCopyComplete(void* closure, nsresult status) {
  // AddRef'd in AsyncCopy. Will be released at the end of the method.
  RefPtr<nsAsyncStreamCopier> self = dont_AddRef((nsAsyncStreamCopier*)closure);
  self->Complete(status);
}

//-----------------------------------------------------------------------------
// nsISupports

// We cannot use simply NS_IMPL_ISUPPORTSx as both
// nsIAsyncStreamCopier and nsIAsyncStreamCopier2 implement nsIRequest

NS_IMPL_ADDREF(nsAsyncStreamCopier)
NS_IMPL_RELEASE(nsAsyncStreamCopier)
NS_INTERFACE_TABLE_HEAD(nsAsyncStreamCopier)
  NS_INTERFACE_TABLE_BEGIN
    NS_INTERFACE_TABLE_ENTRY(nsAsyncStreamCopier, nsIAsyncStreamCopier)
    NS_INTERFACE_TABLE_ENTRY(nsAsyncStreamCopier, nsIAsyncStreamCopier2)
    NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(nsAsyncStreamCopier, nsIRequest,
                                       nsIAsyncStreamCopier)
    NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(nsAsyncStreamCopier, nsISupports,
                                       nsIAsyncStreamCopier)
  NS_INTERFACE_TABLE_END
NS_INTERFACE_TABLE_TAIL

//-----------------------------------------------------------------------------
// nsIRequest

NS_IMETHODIMP
nsAsyncStreamCopier::GetName(nsACString& name) {
  name.Truncate();
  return NS_OK;
}

NS_IMETHODIMP
nsAsyncStreamCopier::IsPending(bool* result) {
  *result = !IsComplete();
  return NS_OK;
}

NS_IMETHODIMP
nsAsyncStreamCopier::GetStatus(nsresult* status) {
  IsComplete(status);
  return NS_OK;
}

NS_IMETHODIMP
nsAsyncStreamCopier::Cancel(nsresult status) {
  nsCOMPtr<nsISupports> copierCtx;
  {
    MutexAutoLock lock(mLock);
    if (!mIsPending) return NS_OK;
    copierCtx.swap(mCopierCtx);
  }

  if (NS_SUCCEEDED(status)) {
    NS_WARNING("cancel with non-failure status code");
    status = NS_BASE_STREAM_CLOSED;
  }

  if (copierCtx) NS_CancelAsyncCopy(copierCtx, status);

  return NS_OK;
}

NS_IMETHODIMP
nsAsyncStreamCopier::Suspend() {
  MOZ_ASSERT_UNREACHABLE("nsAsyncStreamCopier::Suspend");
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP
nsAsyncStreamCopier::Resume() {
  MOZ_ASSERT_UNREACHABLE("nsAsyncStreamCopier::Resume");
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP
nsAsyncStreamCopier::GetLoadFlags(nsLoadFlags* aLoadFlags) {
  *aLoadFlags = LOAD_NORMAL;
  return NS_OK;
}

NS_IMETHODIMP
nsAsyncStreamCopier::SetLoadFlags(nsLoadFlags aLoadFlags) { return NS_OK; }

NS_IMETHODIMP
nsAsyncStreamCopier::GetLoadGroup(nsILoadGroup** aLoadGroup) {
  *aLoadGroup = nullptr;
  return NS_OK;
}

NS_IMETHODIMP
nsAsyncStreamCopier::SetLoadGroup(nsILoadGroup* aLoadGroup) { return NS_OK; }

nsresult nsAsyncStreamCopier::InitInternal(nsIInputStream* source,
                                           nsIOutputStream* sink,
                                           nsIEventTarget* target,
                                           uint32_t chunkSize, bool closeSource,
                                           bool closeSink) {
  NS_ASSERTION(!mSource && !mSink, "Init() called more than once");
  if (chunkSize == 0) {
    chunkSize = nsIOService::gDefaultSegmentSize;
  }
  mChunkSize = chunkSize;

  mSource = source;
  mSink = sink;
  mCloseSource = closeSource;
  mCloseSink = closeSink;

  if (target) {
    mTarget = target;
  } else {
    nsresult rv;
    mTarget = do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID, &rv);
    if (NS_FAILED(rv)) {
      return rv;
    }
  }

  return NS_OK;
}

//-----------------------------------------------------------------------------
// nsIAsyncStreamCopier

NS_IMETHODIMP
nsAsyncStreamCopier::Init(nsIInputStream* source, nsIOutputStream* sink,
                          nsIEventTarget* target, bool sourceBuffered,
                          bool sinkBuffered, uint32_t chunkSize,
                          bool closeSource, bool closeSink) {
  NS_ASSERTION(sourceBuffered || sinkBuffered,
               "at least one stream must be buffered");
  mMode = sourceBuffered ? NS_ASYNCCOPY_VIA_READSEGMENTS
                         : NS_ASYNCCOPY_VIA_WRITESEGMENTS;

  return InitInternal(source, sink, target, chunkSize, closeSource, closeSink);
}

//-----------------------------------------------------------------------------
// nsIAsyncStreamCopier2

NS_IMETHODIMP
nsAsyncStreamCopier::Init(nsIInputStream* source, nsIOutputStream* sink,
                          nsIEventTarget* target, uint32_t chunkSize,
                          bool closeSource, bool closeSink) {
  mShouldSniffBuffering = true;

  return InitInternal(source, sink, target, chunkSize, closeSource, closeSink);
}

/**
 * Detect whether the input or the output stream is buffered,
 * bufferize one of them if neither is buffered.
 */
nsresult nsAsyncStreamCopier::ApplyBufferingPolicy() {
  // This function causes I/O, it must not be executed on the main
  // thread.
  MOZ_ASSERT(!NS_IsMainThread());

  if (NS_OutputStreamIsBuffered(mSink)) {
    // Sink is buffered, no need to perform additional buffering
    mMode = NS_ASYNCCOPY_VIA_WRITESEGMENTS;
    return NS_OK;
  }
  if (NS_InputStreamIsBuffered(mSource)) {
    // Source is buffered, no need to perform additional buffering
    mMode = NS_ASYNCCOPY_VIA_READSEGMENTS;
    return NS_OK;
  }

  // No buffering, let's buffer the sink
  nsresult rv;
  nsCOMPtr<nsIBufferedOutputStream> sink =
      do_CreateInstance(NS_BUFFEREDOUTPUTSTREAM_CONTRACTID, &rv);
  if (NS_FAILED(rv)) {
    return rv;
  }

  rv = sink->Init(mSink, mChunkSize);
  if (NS_FAILED(rv)) {
    return rv;
  }

  mMode = NS_ASYNCCOPY_VIA_WRITESEGMENTS;
  mSink = sink;
  return NS_OK;
}

//-----------------------------------------------------------------------------
// Both nsIAsyncStreamCopier and nsIAsyncStreamCopier2

NS_IMETHODIMP
nsAsyncStreamCopier::AsyncCopy(nsIRequestObserver* observer, nsISupports* ctx) {
  LOG(("nsAsyncStreamCopier::AsyncCopy [this=%p observer=%p]\n", this,
       observer));

  NS_ASSERTION(mSource && mSink, "not initialized");
  nsresult rv;

  if (observer) {
    // build proxy for observer events
    rv = NS_NewRequestObserverProxy(getter_AddRefs(mObserver), observer, ctx);
    if (NS_FAILED(rv)) return rv;
  }

  // from this point forward, AsyncCopy is going to return NS_OK.  any errors
  // will be reported via OnStopRequest.
  mIsPending = true;

  if (mObserver) {
    rv = mObserver->OnStartRequest(AsRequest());
    if (NS_FAILED(rv)) Cancel(rv);
  }

  if (!mShouldSniffBuffering) {
    // No buffer sniffing required, let's proceed
    AsyncCopyInternal();
    return NS_OK;
  }

  if (NS_IsMainThread()) {
    // Don't perform buffer sniffing on the main thread
    nsCOMPtr<nsIRunnable> event = new AsyncApplyBufferingPolicyEvent(this);
    rv = mTarget->Dispatch(event, NS_DISPATCH_NORMAL);
    if (NS_FAILED(rv)) {
      Cancel(rv);
    }
    return NS_OK;
  }

  // We're not going to block the main thread, so let's sniff here
  rv = ApplyBufferingPolicy();
  if (NS_FAILED(rv)) {
    Cancel(rv);
  }
  AsyncCopyInternal();
  return NS_OK;
}

// Launch async copy.
// All errors are reported through the observer.
void nsAsyncStreamCopier::AsyncCopyInternal() {
  MOZ_ASSERT(mMode == NS_ASYNCCOPY_VIA_READSEGMENTS ||
             mMode == NS_ASYNCCOPY_VIA_WRITESEGMENTS);

  nsresult rv;
  // We want to receive progress notifications; release happens in
  // OnAsyncCopyComplete.
  RefPtr<nsAsyncStreamCopier> self = this;
  {
    MutexAutoLock lock(mLock);
    rv = NS_AsyncCopy(mSource, mSink, mTarget, mMode, mChunkSize,
                      OnAsyncCopyComplete, this, mCloseSource, mCloseSink,
                      getter_AddRefs(mCopierCtx));
  }
  if (NS_FAILED(rv)) {
    Cancel(rv);
    return;  // release self
  }

  Unused << self.forget();  // Will be released in OnAsyncCopyComplete
}