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.

Implementation

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
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */

#ifndef mozilla_dom_MemoryBlobImpl_h
#define mozilla_dom_MemoryBlobImpl_h

#include "mozilla/dom/BaseBlobImpl.h"
#include "mozilla/LinkedList.h"
#include "mozilla/StaticMutex.h"
#include "mozilla/StaticPtr.h"
#include "nsICloneableInputStream.h"
#include "nsIInputStream.h"
#include "nsIIPCSerializableInputStream.h"
#include "nsIMemoryReporter.h"
#include "nsISeekableStream.h"

namespace mozilla {
namespace dom {

class MemoryBlobImpl final : public BaseBlobImpl {
 public:
  NS_INLINE_DECL_REFCOUNTING_INHERITED(MemoryBlobImpl, BaseBlobImpl)

  MemoryBlobImpl(void* aMemoryBuffer, uint64_t aLength, const nsAString& aName,
                 const nsAString& aContentType, int64_t aLastModifiedDate)
      : BaseBlobImpl(NS_LITERAL_STRING("MemoryBlobImpl"), aName, aContentType,
                     aLength, aLastModifiedDate),
        mDataOwner(new DataOwner(aMemoryBuffer, aLength)) {
    MOZ_ASSERT(mDataOwner && mDataOwner->mData, "must have data");
  }

  MemoryBlobImpl(void* aMemoryBuffer, uint64_t aLength,
                 const nsAString& aContentType)
      : BaseBlobImpl(NS_LITERAL_STRING("MemoryBlobImpl"), aContentType,
                     aLength),
        mDataOwner(new DataOwner(aMemoryBuffer, aLength)) {
    MOZ_ASSERT(mDataOwner && mDataOwner->mData, "must have data");
  }

  virtual void CreateInputStream(nsIInputStream** aStream,
                                 ErrorResult& aRv) override;

  virtual already_AddRefed<BlobImpl> CreateSlice(uint64_t aStart,
                                                 uint64_t aLength,
                                                 const nsAString& aContentType,
                                                 ErrorResult& aRv) override;

  virtual bool IsMemoryFile() const override { return true; }

  size_t GetAllocationSize() const override { return mLength; }

  size_t GetAllocationSize(
      FallibleTArray<BlobImpl*>& aVisitedBlobImpls) const override {
    return GetAllocationSize();
  }

  class DataOwner final : public mozilla::LinkedListElement<DataOwner> {
   public:
    NS_INLINE_DECL_THREADSAFE_REFCOUNTING(DataOwner)
    DataOwner(void* aMemoryBuffer, uint64_t aLength)
        : mData(aMemoryBuffer), mLength(aLength) {
      mozilla::StaticMutexAutoLock lock(sDataOwnerMutex);

      if (!sDataOwners) {
        sDataOwners = new mozilla::LinkedList<DataOwner>();
        EnsureMemoryReporterRegistered();
      }
      sDataOwners->insertBack(this);
    }

   private:
    // Private destructor, to discourage deletion outside of Release():
    ~DataOwner() {
      mozilla::StaticMutexAutoLock lock(sDataOwnerMutex);

      remove();
      if (sDataOwners->isEmpty()) {
        // Free the linked list if it's empty.
        sDataOwners = nullptr;
      }

      free(mData);
    }

   public:
    static void EnsureMemoryReporterRegistered();

    // sDataOwners and sMemoryReporterRegistered may only be accessed while
    // holding sDataOwnerMutex!  You also must hold the mutex while touching
    // elements of the linked list that DataOwner inherits from.
    static mozilla::StaticMutex sDataOwnerMutex;
    static mozilla::StaticAutoPtr<mozilla::LinkedList<DataOwner> > sDataOwners;
    static bool sMemoryReporterRegistered;

    void* mData;
    uint64_t mLength;
  };

  class DataOwnerAdapter final : public nsIInputStream,
                                 public nsISeekableStream,
                                 public nsIIPCSerializableInputStream,
                                 public nsICloneableInputStream {
    typedef MemoryBlobImpl::DataOwner DataOwner;

   public:
    static nsresult Create(DataOwner* aDataOwner, uint32_t aStart,
                           uint32_t aLength, nsIInputStream** _retval);

    NS_DECL_THREADSAFE_ISUPPORTS

    // These are mandatory.
    NS_FORWARD_NSIINPUTSTREAM(mStream->)
    NS_FORWARD_NSISEEKABLESTREAM(mSeekableStream->)
    NS_FORWARD_NSITELLABLESTREAM(mSeekableStream->)
    NS_FORWARD_NSICLONEABLEINPUTSTREAM(mCloneableInputStream->)

    // This is optional. We use a conditional QI to keep it from being called
    // if the underlying stream doesn't support it.
    NS_FORWARD_NSIIPCSERIALIZABLEINPUTSTREAM(mSerializableInputStream->)

   private:
    ~DataOwnerAdapter() {}

    DataOwnerAdapter(DataOwner* aDataOwner, nsIInputStream* aStream)
        : mDataOwner(aDataOwner),
          mStream(aStream),
          mSeekableStream(do_QueryInterface(aStream)),
          mSerializableInputStream(do_QueryInterface(aStream)),
          mCloneableInputStream(do_QueryInterface(aStream)) {
      MOZ_ASSERT(mSeekableStream, "Somebody gave us the wrong stream!");
    }

    RefPtr<DataOwner> mDataOwner;
    nsCOMPtr<nsIInputStream> mStream;
    nsCOMPtr<nsISeekableStream> mSeekableStream;
    nsCOMPtr<nsIIPCSerializableInputStream> mSerializableInputStream;
    nsCOMPtr<nsICloneableInputStream> mCloneableInputStream;
  };

 private:
  // Create slice
  MemoryBlobImpl(const MemoryBlobImpl* aOther, uint64_t aStart,
                 uint64_t aLength, const nsAString& aContentType)
      : BaseBlobImpl(NS_LITERAL_STRING("MemoryBlobImpl"), aContentType,
                     aOther->mStart + aStart, aLength),
        mDataOwner(aOther->mDataOwner) {
    MOZ_ASSERT(mDataOwner && mDataOwner->mData, "must have data");
    mImmutable = aOther->mImmutable;
  }

  ~MemoryBlobImpl() {}

  // Used when backed by a memory store
  RefPtr<DataOwner> mDataOwner;
};

}  // namespace dom
}  // namespace mozilla

#endif  // mozilla_dom_MemoryBlobImpl_h