Line data    Source code

       1             : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2             : /* vim: set ts=8 sts=2 et sw=2 tw=80: */
       3             : /* This Source Code Form is subject to the terms of the Mozilla Public
       4             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       5             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       6             : 
       7             : #include "nsGZFileWriter.h"
       8             : #include "nsIFile.h"
       9             : #include "nsString.h"
      10             : #include "zlib.h"
      11             : 
      12             : #ifdef XP_WIN
      13             : #include <io.h>
      14             : #define _dup dup
      15             : #else
      16             : #include <unistd.h>
      17             : #endif
      18             : 
      19           0 : NS_IMPL_ISUPPORTS(nsGZFileWriter, nsIGZFileWriter)
      20             : 
      21           0 : nsGZFileWriter::nsGZFileWriter(Operation aMode)
      22             :   : mMode(aMode)
      23             :   , mInitialized(false)
      24           0 :   , mFinished(false)
      25             : {
      26           0 : }
      27             : 
      28           0 : nsGZFileWriter::~nsGZFileWriter()
      29             : {
      30           0 :   if (mInitialized && !mFinished) {
      31           0 :     Finish();
      32             :   }
      33           0 : }
      34             : 
      35             : NS_IMETHODIMP
      36           0 : nsGZFileWriter::Init(nsIFile* aFile)
      37             : {
      38           0 :   if (NS_WARN_IF(mInitialized) ||
      39           0 :       NS_WARN_IF(mFinished)) {
      40           0 :     return NS_ERROR_FAILURE;
      41             :   }
      42             : 
      43             :   // Get a FILE out of our nsIFile.  Convert that into a file descriptor which
      44             :   // gzip can own.  Then close our FILE, leaving only gzip's fd open.
      45             : 
      46             :   FILE* file;
      47           0 :   nsresult rv = aFile->OpenANSIFileDesc(mMode == Create ? "wb" : "ab", &file);
      48           0 :   if (NS_WARN_IF(NS_FAILED(rv))) {
      49           0 :     return rv;
      50             :   }
      51           0 :   return InitANSIFileDesc(file);
      52             : }
      53             : 
      54             : NS_IMETHODIMP
      55           0 : nsGZFileWriter::InitANSIFileDesc(FILE* aFile)
      56             : {
      57           0 :   mGZFile = gzdopen(dup(fileno(aFile)), mMode == Create ? "wb" : "ab");
      58           0 :   fclose(aFile);
      59             : 
      60             :   // gzdopen returns nullptr on error.
      61           0 :   if (NS_WARN_IF(!mGZFile)) {
      62           0 :     return NS_ERROR_FAILURE;
      63             :   }
      64             : 
      65           0 :   mInitialized = true;
      66             : 
      67           0 :   return NS_OK;
      68             : }
      69             : 
      70             : NS_IMETHODIMP
      71           0 : nsGZFileWriter::Write(const nsACString& aStr)
      72             : {
      73           0 :   if (NS_WARN_IF(!mInitialized) ||
      74           0 :       NS_WARN_IF(mFinished)) {
      75           0 :     return NS_ERROR_FAILURE;
      76             :   }
      77             : 
      78             :   // gzwrite uses a return value of 0 to indicate failure.  Otherwise, it
      79             :   // returns the number of uncompressed bytes written.  To ensure we can
      80             :   // distinguish between success and failure, don't call gzwrite when we have 0
      81             :   // bytes to write.
      82           0 :   if (aStr.IsEmpty()) {
      83           0 :     return NS_OK;
      84             :   }
      85             : 
      86             :   // gzwrite never does a short write -- that is, the return value should
      87             :   // always be either 0 or aStr.Length(), and we shouldn't have to call it
      88             :   // multiple times in order to get it to read the whole buffer.
      89           0 :   int rv = gzwrite(mGZFile, aStr.BeginReading(), aStr.Length());
      90           0 :   if (NS_WARN_IF(rv != static_cast<int>(aStr.Length()))) {
      91           0 :     return NS_ERROR_FAILURE;
      92             :   }
      93             : 
      94           0 :   return NS_OK;
      95             : }
      96             : 
      97             : NS_IMETHODIMP
      98           0 : nsGZFileWriter::Finish()
      99             : {
     100           0 :   if (NS_WARN_IF(!mInitialized) ||
     101           0 :       NS_WARN_IF(mFinished)) {
     102           0 :     return NS_ERROR_FAILURE;
     103             :   }
     104             : 
     105           0 :   mFinished = true;
     106           0 :   gzclose(mGZFile);
     107             : 
     108             :   // Ignore errors from gzclose; it's not like there's anything we can do about
     109             :   // it, at this point!
     110           0 :   return NS_OK;
     111             : }