palemoon-dev/platform/toolkit/components/url-classifier/nsCheckSummedOutputStream.h

//* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */

#ifndef nsCheckSummedOutputStream_h__
#define nsCheckSummedOutputStream_h__

#include "nsILocalFile.h"
#include "nsIFile.h"
#include "nsIOutputStream.h"
#include "nsICryptoHash.h"
#include "nsNetCID.h"
#include "nsString.h"
#include "nsToolkitCompsCID.h"
#include "../../../netwerk/base/nsBufferedStreams.h"
#include "prio.h"

class nsCheckSummedOutputStream : public nsBufferedOutputStream
{
public:
  NS_DECL_ISUPPORTS_INHERITED

  // Size of MD5 hash in bytes
  static const uint32_t CHECKSUM_SIZE = 16;
  static const uint32_t MAX_BUFFER_SIZE = 64 * 1024;

  nsCheckSummedOutputStream() {}

  NS_IMETHOD Finish() override;
  NS_IMETHOD Write(const char *buf, uint32_t count, uint32_t *result) override;
  NS_IMETHOD Init(nsIOutputStream* stream, uint32_t bufferSize) override;

protected:
  virtual ~nsCheckSummedOutputStream() { nsBufferedOutputStream::Close(); }

  nsCOMPtr<nsICryptoHash> mHash;
  nsCString mCheckSum;
};

// returns a file output stream which can be QI'ed to nsIFileOutputStream.
inline nsresult
NS_NewCheckSummedOutputStream(nsIOutputStream **result,
                              nsIFile         *file)
{
    nsCOMPtr<nsIOutputStream> localOutFile;
    nsresult rv = NS_NewSafeLocalFileOutputStream(getter_AddRefs(localOutFile), file,
                                                  PR_WRONLY | PR_TRUNCATE | PR_CREATE_FILE);
    NS_ENSURE_SUCCESS(rv, rv);

    nsCOMPtr<nsIBufferedOutputStream> out = new nsCheckSummedOutputStream();
    rv = out->Init(localOutFile, nsCheckSummedOutputStream::CHECKSUM_SIZE);
    if (NS_SUCCEEDED(rv)) {
      out.forget(result);
    }
    return rv;
}

#endif