The Tor Browser: xpcom/base/nsGZFileWriter.cpp@6474c204b198

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     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/. */

     7 #include "nsGZFileWriter.h"

     8 #include "nsIFile.h"

     9 #include "nsString.h"

    10 #include "zlib.h"

    12 #ifdef XP_WIN

    13 #include <io.h>

    14 #define _dup dup

    15 #else

    16 #include <unistd.h>

    17 #endif

    19 NS_IMPL_ISUPPORTS(nsGZFileWriter, nsIGZFileWriter)

    21 nsGZFileWriter::nsGZFileWriter()

    22   : mInitialized(false)

    23   , mFinished(false)

    24 {}

    26 nsGZFileWriter::~nsGZFileWriter()

    27 {

    28   if (mInitialized && !mFinished) {

    29     Finish();

    30   }

    31 }

    33 NS_IMETHODIMP

    34 nsGZFileWriter::Init(nsIFile* aFile)

    35 {

    36   if (NS_WARN_IF(mInitialized) ||

    37       NS_WARN_IF(mFinished))

    38     return NS_ERROR_FAILURE;

    40   // Get a FILE out of our nsIFile.  Convert that into a file descriptor which

    41   // gzip can own.  Then close our FILE, leaving only gzip's fd open.

    43   FILE* file;

    44   nsresult rv = aFile->OpenANSIFileDesc("wb", &file);

    45   if (NS_WARN_IF(NS_FAILED(rv)))

    46     return rv;

    48   mGZFile = gzdopen(dup(fileno(file)), "wb");

    49   fclose(file);

    51   // gzdopen returns nullptr on error.

    52   if (NS_WARN_IF(!mGZFile))

    53     return NS_ERROR_FAILURE;

    55   mInitialized = true;

    57   return NS_OK;

    58 }

    60 NS_IMETHODIMP

    61 nsGZFileWriter::Write(const nsACString& aStr)

    62 {

    63   if (NS_WARN_IF(!mInitialized) ||

    64       NS_WARN_IF(mFinished))

    65     return NS_ERROR_FAILURE;

    67   // gzwrite uses a return value of 0 to indicate failure.  Otherwise, it

    68   // returns the number of uncompressed bytes written.  To ensure we can

    69   // distinguish between success and failure, don't call gzwrite when we have 0

    70   // bytes to write.

    71   if (aStr.IsEmpty()) {

    72     return NS_OK;

    73   }

    75   // gzwrite never does a short write -- that is, the return value should

    76   // always be either 0 or aStr.Length(), and we shouldn't have to call it

    77   // multiple times in order to get it to read the whole buffer.

    78   int rv = gzwrite(mGZFile, aStr.BeginReading(), aStr.Length());

    79   if (NS_WARN_IF(rv != static_cast<int>(aStr.Length())))

    80     return NS_ERROR_FAILURE;

    82   return NS_OK;

    83 }

    85 NS_IMETHODIMP

    86 nsGZFileWriter::Finish()

    87 {

    88   if (NS_WARN_IF(!mInitialized) ||

    89       NS_WARN_IF(mFinished))

    90     return NS_ERROR_FAILURE;

    92   mFinished = true;

    93   gzclose(mGZFile);

    95   // Ignore errors from gzclose; it's not like there's anything we can do about

    96   // it, at this point!

    97   return NS_OK;

    98 }

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