import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

netwerk/base/SimpleBuffer.cpp

@@ -0,0 +1,95 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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 "SimpleBuffer.h"
+#include <algorithm>
+
+namespace mozilla {
+namespace net {
+
+SimpleBuffer::SimpleBuffer()
+  : mStatus(NS_OK)
+  , mAvailable(0)
+{
+  mOwningThread = PR_GetCurrentThread();
+}
+
+nsresult SimpleBuffer::Write(char *src, size_t len)
+{
+  MOZ_ASSERT(PR_GetCurrentThread() == mOwningThread);
+  if (NS_FAILED(mStatus)) {
+    return mStatus;
+  }
+
+  while (len > 0) {
+    SimpleBufferPage *p = mBufferList.getLast();
+    if (p && (p->mWriteOffset == SimpleBufferPage::kSimpleBufferPageSize)) {
+      // no room.. make a new page
+      p = nullptr;
+    }
+    if (!p) {
+      p = new (fallible) SimpleBufferPage();
+      if (!p) {
+        mStatus = NS_ERROR_OUT_OF_MEMORY;
+        return mStatus;
+      }
+      mBufferList.insertBack(p);
+    }
+    size_t roomOnPage = SimpleBufferPage::kSimpleBufferPageSize - p->mWriteOffset;
+    size_t toWrite = std::min(roomOnPage, len);
+    memcpy(p->mBuffer + p->mWriteOffset, src, toWrite);
+    src += toWrite;
+    len -= toWrite;
+    p->mWriteOffset += toWrite;
+    mAvailable += toWrite;
+  }
+  return NS_OK;
+}
+
+size_t SimpleBuffer::Read(char *dest, size_t maxLen)
+{
+  MOZ_ASSERT(PR_GetCurrentThread() == mOwningThread);
+  if (NS_FAILED(mStatus)) {
+    return 0;
+  }
+
+  size_t rv = 0;
+  for (SimpleBufferPage *p = mBufferList.getFirst();
+       p && (rv < maxLen); p = mBufferList.getFirst()) {
+    size_t avail = p->mWriteOffset - p->mReadOffset;
+    size_t toRead = std::min(avail, (maxLen - rv));
+    memcpy(dest + rv, p->mBuffer + p->mReadOffset, toRead);
+    rv += toRead;
+    p->mReadOffset += toRead;
+    if (p->mReadOffset == p->mWriteOffset) {
+      p->remove();
+      delete p;
+    }
+  }
+
+  MOZ_ASSERT(mAvailable >= rv);
+  mAvailable -= rv;
+  return rv;
+}
+
+size_t SimpleBuffer::Available()
+{
+  MOZ_ASSERT(PR_GetCurrentThread() == mOwningThread);
+  return NS_SUCCEEDED(mStatus) ? mAvailable : 0;
+}
+
+void SimpleBuffer::Clear()
+{
+  MOZ_ASSERT(PR_GetCurrentThread() == mOwningThread);
+  SimpleBufferPage *p;
+  while ((p = mBufferList.popFirst())) {
+    delete p;
+  }
+  mAvailable = 0;
+}
+
+} // namespace net
+} // namespace mozilla