Line data    Source code

       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 "mozilla/devtools/ZeroCopyNSIOutputStream.h"
       7             : 
       8             : #include "mozilla/DebugOnly.h"
       9             : #include "mozilla/Unused.h"
      10             : 
      11             : namespace mozilla {
      12             : namespace devtools {
      13             : 
      14           0 : ZeroCopyNSIOutputStream::ZeroCopyNSIOutputStream(nsCOMPtr<nsIOutputStream>& out)
      15             :   : out(out)
      16             :   , result_(NS_OK)
      17             :   , amountUsed(0)
      18           0 :   , writtenCount(0)
      19             : {
      20           0 :   DebugOnly<bool> nonBlocking = false;
      21           0 :   MOZ_ASSERT(out->IsNonBlocking(&nonBlocking) == NS_OK);
      22           0 :   MOZ_ASSERT(!nonBlocking);
      23           0 : }
      24             : 
      25           0 : ZeroCopyNSIOutputStream::~ZeroCopyNSIOutputStream()
      26             : {
      27           0 :   if (!failed())
      28           0 :     Unused << NS_WARN_IF(NS_FAILED(writeBuffer()));
      29           0 : }
      30             : 
      31             : nsresult
      32           0 : ZeroCopyNSIOutputStream::writeBuffer()
      33             : {
      34           0 :   if (failed())
      35           0 :     return result_;
      36             : 
      37           0 :   if (amountUsed == 0)
      38           0 :     return NS_OK;
      39             : 
      40           0 :   int32_t amountWritten = 0;
      41           0 :   while (amountWritten < amountUsed) {
      42           0 :     uint32_t justWritten = 0;
      43             : 
      44           0 :     result_ = out->Write(buffer + amountWritten,
      45           0 :                          amountUsed - amountWritten,
      46           0 :                          &justWritten);
      47           0 :     if (NS_WARN_IF(NS_FAILED(result_)))
      48           0 :       return result_;
      49             : 
      50           0 :     amountWritten += justWritten;
      51             :   }
      52             : 
      53           0 :   writtenCount += amountUsed;
      54           0 :   amountUsed = 0;
      55           0 :   return NS_OK;
      56             : }
      57             : 
      58             : // ZeroCopyOutputStream Interface
      59             : 
      60             : bool
      61           0 : ZeroCopyNSIOutputStream::Next(void** data, int* size)
      62             : {
      63           0 :   MOZ_ASSERT(data != nullptr);
      64           0 :   MOZ_ASSERT(size != nullptr);
      65             : 
      66           0 :   if (failed())
      67           0 :     return false;
      68             : 
      69           0 :   if (amountUsed == BUFFER_SIZE) {
      70           0 :     if (NS_FAILED(writeBuffer()))
      71           0 :       return false;
      72             :   }
      73             : 
      74           0 :   *data = buffer + amountUsed;
      75           0 :   *size = BUFFER_SIZE - amountUsed;
      76           0 :   amountUsed = BUFFER_SIZE;
      77           0 :   return true;
      78             : }
      79             : 
      80             : void
      81           0 : ZeroCopyNSIOutputStream::BackUp(int count)
      82             : {
      83           0 :   MOZ_ASSERT(count >= 0,
      84             :              "Cannot back up a negative amount of bytes.");
      85           0 :   MOZ_ASSERT(amountUsed == BUFFER_SIZE,
      86             :              "Can only call BackUp directly after calling Next.");
      87           0 :   MOZ_ASSERT(count <= amountUsed,
      88             :              "Can't back up further than we've given out.");
      89             : 
      90           0 :   amountUsed -= count;
      91           0 : }
      92             : 
      93             : ::google::protobuf::int64
      94           0 : ZeroCopyNSIOutputStream::ByteCount() const
      95             : {
      96           0 :   return writtenCount + amountUsed;
      97             : }
      98             : 
      99             : } // namespace devtools
     100             : } // namespace mozilla