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 (d38398e5144e)

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
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "nsIncrementalStreamLoader.h"
#include "nsIInputStream.h"
#include "nsIChannel.h"
#include "nsError.h"
#include "GeckoProfiler.h"

#include <limits>

nsIncrementalStreamLoader::nsIncrementalStreamLoader()
  : mData(), mBytesConsumed(0)
{
}

nsIncrementalStreamLoader::~nsIncrementalStreamLoader()
{
}

NS_IMETHODIMP
nsIncrementalStreamLoader::Init(nsIIncrementalStreamLoaderObserver* observer)
{
  NS_ENSURE_ARG_POINTER(observer);
  mObserver = observer;
  return NS_OK;
}

nsresult
nsIncrementalStreamLoader::Create(nsISupports *aOuter, REFNSIID aIID, void **aResult)
{
  if (aOuter) return NS_ERROR_NO_AGGREGATION;

  nsIncrementalStreamLoader* it = new nsIncrementalStreamLoader();
  if (it == nullptr)
    return NS_ERROR_OUT_OF_MEMORY;
  NS_ADDREF(it);
  nsresult rv = it->QueryInterface(aIID, aResult);
  NS_RELEASE(it);
  return rv;
}

NS_IMPL_ISUPPORTS(nsIncrementalStreamLoader, nsIIncrementalStreamLoader,
                  nsIRequestObserver, nsIStreamListener,
                  nsIThreadRetargetableStreamListener)

NS_IMETHODIMP
nsIncrementalStreamLoader::GetNumBytesRead(uint32_t* aNumBytes)
{
  *aNumBytes = mBytesConsumed + mData.length();
  return NS_OK;
}

/* readonly attribute nsIRequest request; */
NS_IMETHODIMP
nsIncrementalStreamLoader::GetRequest(nsIRequest **aRequest)
{
  NS_IF_ADDREF(*aRequest = mRequest);
  return NS_OK;
}

NS_IMETHODIMP
nsIncrementalStreamLoader::OnStartRequest(nsIRequest* request, nsISupports *ctxt)
{
  nsCOMPtr<nsIChannel> chan( do_QueryInterface(request) );
  if (chan) {
    int64_t contentLength = -1;
    chan->GetContentLength(&contentLength);
    if (contentLength >= 0) {
      if (uint64_t(contentLength) > std::numeric_limits<size_t>::max()) {
        // Too big to fit into size_t, so let's bail.
        return NS_ERROR_OUT_OF_MEMORY;
      }
      // preallocate buffer
      if (!mData.initCapacity(contentLength)) {
        return NS_ERROR_OUT_OF_MEMORY;
      }
    }
  }
  mContext = ctxt;
  return NS_OK;
}

NS_IMETHODIMP
nsIncrementalStreamLoader::OnStopRequest(nsIRequest* request, nsISupports *ctxt,
                                         nsresult aStatus)
{
  PROFILER_LABEL("nsIncrementalStreamLoader", "OnStopRequest",
    js::ProfileEntry::Category::NETWORK);

  if (mObserver) {
    // provide nsIIncrementalStreamLoader::request during call to OnStreamComplete
    mRequest = request;
    size_t length = mData.length();
    uint8_t* elems = mData.extractOrCopyRawBuffer();
    nsresult rv = mObserver->OnStreamComplete(this, mContext, aStatus,
                                              length, elems);
    if (rv != NS_SUCCESS_ADOPTED_DATA) {
      // The observer didn't take ownership of the extracted data buffer, so
      // put it back into mData.
      mData.replaceRawBuffer(elems, length);
    }
    // done.. cleanup
    ReleaseData();
    mRequest = nullptr;
    mObserver = nullptr;
    mContext = nullptr;
  }
  return NS_OK;
}

nsresult
nsIncrementalStreamLoader::WriteSegmentFun(nsIInputStream *inStr,
                                           void *closure,
                                           const char *fromSegment,
                                           uint32_t toOffset,
                                           uint32_t count,
                                           uint32_t *writeCount)
{
  nsIncrementalStreamLoader *self = (nsIncrementalStreamLoader *) closure;

  const uint8_t *data = reinterpret_cast<const uint8_t *>(fromSegment);
  uint32_t consumedCount = 0;
  nsresult rv;
  if (self->mData.empty()) {
    // Shortcut when observer wants to keep the listener's buffer empty.
    rv = self->mObserver->OnIncrementalData(self, self->mContext,
                                            count, data, &consumedCount);

    if (rv != NS_OK) {
      return rv;
    }

    if (consumedCount > count) {
      return NS_ERROR_INVALID_ARG;
    }

    if (consumedCount < count) {
      if (!self->mData.append(fromSegment + consumedCount,
                              count - consumedCount)) {
        self->mData.clearAndFree();
        return NS_ERROR_OUT_OF_MEMORY;
      }
    }
  } else {
    // We have some non-consumed data from previous OnIncrementalData call,
    // appending new data and reporting combined data.
    if (!self->mData.append(fromSegment, count)) {
      self->mData.clearAndFree();
      return NS_ERROR_OUT_OF_MEMORY;
    }
    size_t length = self->mData.length();
    uint32_t reportCount = length > UINT32_MAX ? UINT32_MAX : (uint32_t)length;
    uint8_t* elems = self->mData.extractOrCopyRawBuffer();

    rv = self->mObserver->OnIncrementalData(self, self->mContext,
                                            reportCount, elems, &consumedCount);

    // We still own elems, freeing its memory when exiting scope.
    if (rv != NS_OK) {
      free(elems);
      return rv;
    }

    if (consumedCount > reportCount) {
      free(elems);
      return NS_ERROR_INVALID_ARG;
    }

    if (consumedCount == length) {
      free(elems); // good case -- fully consumed data
    } else {
      // Adopting elems back (at least its portion).
      self->mData.replaceRawBuffer(elems, length);
      if (consumedCount > 0) {
        self->mData.erase(self->mData.begin() + consumedCount);
      }
    }
  }

  self->mBytesConsumed += consumedCount;
  *writeCount = count;

  return NS_OK;
}

NS_IMETHODIMP
nsIncrementalStreamLoader::OnDataAvailable(nsIRequest* request, nsISupports *ctxt,
                                nsIInputStream *inStr,
                                uint64_t sourceOffset, uint32_t count)
{
  if (mObserver) {
    // provide nsIIncrementalStreamLoader::request during call to OnStreamComplete
    mRequest = request;
  }
  uint32_t countRead;
  nsresult rv = inStr->ReadSegments(WriteSegmentFun, this, count, &countRead);
  mRequest = nullptr;
  return rv;
}

void
nsIncrementalStreamLoader::ReleaseData()
{
  mData.clearAndFree();
}

NS_IMETHODIMP
nsIncrementalStreamLoader::CheckListenerChain()
{
  return NS_OK;
}