Bug 1046109: Add |SocketConsumerBase| and inherit |UnixSocketConsumer| from it, r=kyle

|SocketConsumerBase| handles connection state for |UnixSocketConsumer|
and its derived classes. Implementing classes must override a number of
virtual methods, to handle notifications about changes to the state of
the connection.

ipc/unixsocket/SocketBase.cpp

@@ -0,0 +1,126 @@
+/* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 40 -*- */
+/* vim: set ts=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/.
+ */
+
+#include "SocketBase.h"
+#include <string.h>
+#include "nsThreadUtils.h"
+
+namespace mozilla {
+namespace ipc {
+
+//
+// UnixSocketRawData
+//
+
+UnixSocketRawData::UnixSocketRawData(size_t aSize)
+: mSize(aSize)
+, mCurrentWriteOffset(0)
+{
+  mData = new uint8_t[mSize];
+}
+
+UnixSocketRawData::UnixSocketRawData(const void* aData, size_t aSize)
+: mSize(aSize)
+, mCurrentWriteOffset(0)
+{
+  MOZ_ASSERT(aData || !mSize);
+
+  mData = new uint8_t[mSize];
+  memcpy(mData, aData, mSize);
+}
+
+//
+// SocketConsumerBase
+//
+
+SocketConsumerBase::~SocketConsumerBase()
+{
+  MOZ_ASSERT(mConnectionStatus == SOCKET_DISCONNECTED);
+}
+
+SocketConnectionStatus
+SocketConsumerBase::GetConnectionStatus() const
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  return mConnectionStatus;
+}
+
+int
+SocketConsumerBase::GetSuggestedConnectDelayMs() const
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  return mConnectDelayMs;
+}
+
+void
+SocketConsumerBase::NotifySuccess()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  mConnectionStatus = SOCKET_CONNECTED;
+  mConnectTimestamp = PR_IntervalNow();
+  OnConnectSuccess();
+}
+
+void
+SocketConsumerBase::NotifyError()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  mConnectionStatus = SOCKET_DISCONNECTED;
+  mConnectDelayMs = CalculateConnectDelayMs();
+  OnConnectError();
+}
+
+void
+SocketConsumerBase::NotifyDisconnect()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  mConnectionStatus = SOCKET_DISCONNECTED;
+  mConnectDelayMs = CalculateConnectDelayMs();
+  OnDisconnect();
+}
+
+uint32_t
+SocketConsumerBase::CalculateConnectDelayMs() const
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  uint32_t connectDelayMs = mConnectDelayMs;
+
+  if ((PR_IntervalNow()-mConnectTimestamp) > connectDelayMs) {
+    // reset delay if connection has been opened for a while, or...
+    connectDelayMs = 0;
+  } else if (!connectDelayMs) {
+    // ...start with a delay of ~1 sec, or...
+    connectDelayMs = 1<<10;
+  } else if (connectDelayMs < (1<<16)) {
+    // ...otherwise increase delay by a factor of 2
+    connectDelayMs <<= 1;
+  }
+  return connectDelayMs;
+}
+
+SocketConsumerBase::SocketConsumerBase()
+: mConnectionStatus(SOCKET_DISCONNECTED)
+, mConnectTimestamp(0)
+, mConnectDelayMs(0)
+{ }
+
+void
+SocketConsumerBase::SetConnectionStatus(
+  SocketConnectionStatus aConnectionStatus)
+{
+  mConnectionStatus = aConnectionStatus;
+}
+
+}
+}