netwerk/base/nsBaseContentStream.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsBaseContentStream.h"
   7 #include "nsStreamUtils.h"
   8
   9 //-----------------------------------------------------------------------------
  10
  11 void nsBaseContentStream::DispatchCallback(bool async) {
  12   if (!mCallback) return;
  13
  14   // It's important to clear mCallback and mCallbackTarget up-front because the
  15   // OnInputStreamReady implementation may call our AsyncWait method.
  16
  17   nsCOMPtr<nsIInputStreamCallback> callback;
  18   if (async) {
  19     callback = NS_NewInputStreamReadyEvent(
  20         "nsBaseContentStream::DispatchCallback", mCallback, mCallbackTarget);
  21     mCallback = nullptr;
  22   } else {
  23     callback.swap(mCallback);
  24   }
  25   mCallbackTarget = nullptr;
  26
  27   callback->OnInputStreamReady(this);
  28 }
  29
  30 //-----------------------------------------------------------------------------
  31 // nsBaseContentStream::nsISupports
  32
  33 NS_IMPL_ADDREF(nsBaseContentStream)
  34 NS_IMPL_RELEASE(nsBaseContentStream)
  35
  36 // We only support nsIAsyncInputStream when we are in non-blocking mode.
  37 NS_INTERFACE_MAP_BEGIN(nsBaseContentStream)
  38   NS_INTERFACE_MAP_ENTRY(nsIInputStream)
  39   NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIAsyncInputStream, mNonBlocking)
  40   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIInputStream)
  41 NS_INTERFACE_MAP_END
  42
  43 //-----------------------------------------------------------------------------
  44 // nsBaseContentStream::nsIInputStream
  45
  46 NS_IMETHODIMP
  47 nsBaseContentStream::Close() {
  48   return IsClosed() ? NS_OK : CloseWithStatus(NS_BASE_STREAM_CLOSED);
  49 }
  50
  51 NS_IMETHODIMP
  52 nsBaseContentStream::Available(uint64_t* result) {
  53   *result = 0;
  54   return mStatus;
  55 }
  56
  57 NS_IMETHODIMP
  58 nsBaseContentStream::StreamStatus() { return mStatus; }
  59
  60 NS_IMETHODIMP
  61 nsBaseContentStream::Read(char* buf, uint32_t count, uint32_t* result) {
  62   return ReadSegments(NS_CopySegmentToBuffer, buf, count, result);
  63 }
  64
  65 NS_IMETHODIMP
  66 nsBaseContentStream::ReadSegments(nsWriteSegmentFun fun, void* closure,
  67                                   uint32_t count, uint32_t* result) {
  68   *result = 0;
  69
  70   if (mStatus == NS_BASE_STREAM_CLOSED) return NS_OK;
  71
  72   // No data yet
  73   if (!IsClosed() && IsNonBlocking()) return NS_BASE_STREAM_WOULD_BLOCK;
  74
  75   return mStatus;
  76 }
  77
  78 NS_IMETHODIMP
  79 nsBaseContentStream::IsNonBlocking(bool* result) {
  80   *result = mNonBlocking;
  81   return NS_OK;
  82 }
  83
  84 //-----------------------------------------------------------------------------
  85 // nsBaseContentStream::nsIAsyncInputStream
  86
  87 NS_IMETHODIMP
  88 nsBaseContentStream::CloseWithStatus(nsresult status) {
  89   if (IsClosed()) return NS_OK;
  90
  91   NS_ENSURE_ARG(NS_FAILED(status));
  92   mStatus = status;
  93
  94   DispatchCallback();
  95   return NS_OK;
  96 }
  97
  98 NS_IMETHODIMP
  99 nsBaseContentStream::AsyncWait(nsIInputStreamCallback* callback, uint32_t flags,
 100                                uint32_t requestedCount,
 101                                nsIEventTarget* target) {
 102   // Our _only_ consumer is nsInputStreamPump, so we simplify things here by
 103   // making assumptions about how we will be called.
 104   NS_ASSERTION(target, "unexpected parameter");
 105   NS_ASSERTION(flags == 0, "unexpected parameter");
 106   NS_ASSERTION(requestedCount == 0, "unexpected parameter");
 107
 108 #ifdef DEBUG
 109   bool correctThread;
 110   target->IsOnCurrentThread(&correctThread);
 111   NS_ASSERTION(correctThread, "event target must be on the current thread");
 112 #endif
 113
 114   mCallback = callback;
 115   mCallbackTarget = target;
 116
 117   if (!mCallback) return NS_OK;
 118
 119   // If we're already closed, then dispatch this callback immediately.
 120   if (IsClosed()) {
 121     DispatchCallback();
 122     return NS_OK;
 123   }
 124
 125   OnCallbackPending();
 126   return NS_OK;
 127 }