michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim: set ts=8 sts=2 et sw=2 tw=80: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "nsGZFileWriter.h"
michael@0: #include "nsIFile.h"
michael@0: #include "nsString.h"
michael@0: #include "zlib.h"
michael@0: 
michael@0: #ifdef XP_WIN
michael@0: #include <io.h>
michael@0: #define _dup dup
michael@0: #else
michael@0: #include <unistd.h>
michael@0: #endif
michael@0: 
michael@0: NS_IMPL_ISUPPORTS(nsGZFileWriter, nsIGZFileWriter)
michael@0: 
michael@0: nsGZFileWriter::nsGZFileWriter()
michael@0:   : mInitialized(false)
michael@0:   , mFinished(false)
michael@0: {}
michael@0: 
michael@0: nsGZFileWriter::~nsGZFileWriter()
michael@0: {
michael@0:   if (mInitialized && !mFinished) {
michael@0:     Finish();
michael@0:   }
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsGZFileWriter::Init(nsIFile* aFile)
michael@0: {
michael@0:   if (NS_WARN_IF(mInitialized) ||
michael@0:       NS_WARN_IF(mFinished))
michael@0:     return NS_ERROR_FAILURE;
michael@0: 
michael@0:   // Get a FILE out of our nsIFile.  Convert that into a file descriptor which
michael@0:   // gzip can own.  Then close our FILE, leaving only gzip's fd open.
michael@0: 
michael@0:   FILE* file;
michael@0:   nsresult rv = aFile->OpenANSIFileDesc("wb", &file);
michael@0:   if (NS_WARN_IF(NS_FAILED(rv)))
michael@0:     return rv;
michael@0: 
michael@0:   mGZFile = gzdopen(dup(fileno(file)), "wb");
michael@0:   fclose(file);
michael@0: 
michael@0:   // gzdopen returns nullptr on error.
michael@0:   if (NS_WARN_IF(!mGZFile))
michael@0:     return NS_ERROR_FAILURE;
michael@0: 
michael@0:   mInitialized = true;
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsGZFileWriter::Write(const nsACString& aStr)
michael@0: {
michael@0:   if (NS_WARN_IF(!mInitialized) ||
michael@0:       NS_WARN_IF(mFinished))
michael@0:     return NS_ERROR_FAILURE;
michael@0: 
michael@0:   // gzwrite uses a return value of 0 to indicate failure.  Otherwise, it
michael@0:   // returns the number of uncompressed bytes written.  To ensure we can
michael@0:   // distinguish between success and failure, don't call gzwrite when we have 0
michael@0:   // bytes to write.
michael@0:   if (aStr.IsEmpty()) {
michael@0:     return NS_OK;
michael@0:   }
michael@0: 
michael@0:   // gzwrite never does a short write -- that is, the return value should
michael@0:   // always be either 0 or aStr.Length(), and we shouldn't have to call it
michael@0:   // multiple times in order to get it to read the whole buffer.
michael@0:   int rv = gzwrite(mGZFile, aStr.BeginReading(), aStr.Length());
michael@0:   if (NS_WARN_IF(rv != static_cast<int>(aStr.Length())))
michael@0:     return NS_ERROR_FAILURE;
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsGZFileWriter::Finish()
michael@0: {
michael@0:   if (NS_WARN_IF(!mInitialized) ||
michael@0:       NS_WARN_IF(mFinished))
michael@0:     return NS_ERROR_FAILURE;
michael@0: 
michael@0:   mFinished = true;
michael@0:   gzclose(mGZFile);
michael@0: 
michael@0:   // Ignore errors from gzclose; it's not like there's anything we can do about
michael@0:   // it, at this point!
michael@0:   return NS_OK;
michael@0: }