hexdump_transaction_message.cc

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/* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
 *
 *  Copyright (C) 2009 Sun Microsystems, Inc.
 *
 *  Authors:
 *
 *  Jay Pipes <joinfu@sun.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <config.h>
#include <drizzled/plugin/function.h>
#include <drizzled/item/func.h>
#include <drizzled/function/str/strfunc.h>
#include <drizzled/error.h>
#include <drizzled/internal/my_sys.h>
#include <drizzled/charset.h>
#include <drizzled/errmsg_print.h>
#include <drizzled/gettext.h>

#include <fcntl.h>
#include <errno.h>

#include "transaction_log.h"
#include "hexdump_transaction_message.h"

#include <drizzled/message/transaction.pb.h>
#include <drizzled/util/convert.h>
#include <google/protobuf/io/zero_copy_stream.h>
#include <google/protobuf/io/zero_copy_stream_impl.h>
#include <google/protobuf/io/coded_stream.h>
#include <google/protobuf/text_format.h>

using namespace std;
using namespace drizzled;
using namespace google;

extern TransactionLog *transaction_log;

plugin::Create_function<HexdumpTransactionMessageFunction> *hexdump_transaction_message_func_factory= NULL;

void HexdumpTransactionMessageFunction::fix_length_and_dec()
{
  max_length= 2 * 1024 * 1024; /* 2MB size limit seems ok... */
  args[0]->collation.set(
    get_charset_by_csname(args[0]->collation.collation->csname,
                          MY_CS_BINSORT), DERIVATION_COERCIBLE);
}

String *HexdumpTransactionMessageFunction::val_str(String *str)
{
  assert(fixed == true);

  String *filename_arg= args[0]->val_str(str);
  off_t offset_arg= static_cast<int64_t>(args[1]->val_int());

  if (filename_arg == NULL || args[1]->null_value == true)
  {
    my_error(ER_INVALID_NULL_ARGUMENT, MYF(0), func_name());
    null_value= true;
    return NULL;
  }

  if (transaction_log == NULL)
  {
    my_error(ER_INVALID_NULL_ARGUMENT, MYF(0), func_name());
    null_value= true;
    return NULL;
  }

  null_value= false;

  message::Transaction transaction_message;

  const string &filename= transaction_log->getLogFilename();
  int log_file= open(filename.c_str(), O_RDONLY);
  if (log_file == -1)
  {
    drizzled::sql_perror(_("Failed to open transaction log file"), filename);
    null_value= true;

    return NULL;
  }

  (void) lseek(log_file, offset_arg, SEEK_SET);

  protobuf::io::FileInputStream *file_input= new protobuf::io::FileInputStream(log_file);
  file_input->SetCloseOnDelete(true);

  protobuf::io::CodedInputStream *coded_input= new protobuf::io::CodedInputStream(file_input);

  /* Grab our message type and length */
  uint32_t message_type;
  if (! coded_input->ReadLittleEndian32(&message_type))
  {
    delete file_input;

    null_value= true;
    return NULL;
  }

  uint32_t message_size;
  if (! coded_input->ReadLittleEndian32(&message_size))
  {
    delete file_input;

    null_value= true;
    return NULL;
  }

  uint8_t *buffer= (uint8_t *) malloc(message_size);

  bool result= coded_input->ReadRaw(buffer, message_size);
  if (result == false)
  {
    char errmsg[STRERROR_MAX];
    strerror_r(errno, errmsg, sizeof(errmsg));
    fprintf(stderr, _("Could not read transaction message.\n"));
    fprintf(stderr, _("GPB ERROR: %s.\n"), errmsg);
    fprintf(stderr, _("Raw buffer read: %s.\n"), buffer);
  }

  /*
   * Convert raw bytes to a hex representation and store back into
   * the return String.
   */
  string hexdump;
  hexdump.reserve(message_size * 4);
  bytesToHexdumpFormat(hexdump, reinterpret_cast<const unsigned char *>(buffer), message_size);

  /* 
   * Check that the transaction message is actually not corrupt before
   * printing out the raw byte representation of the transaction message...
   */
  result= transaction_message.ParseFromArray(buffer, static_cast<int32_t>(message_size));
  if (result == false)
  {
    fprintf(stderr, _("Unable to parse transaction. Got error: %s.\n"), transaction_message.InitializationErrorString().c_str());
    if (buffer != NULL)
      fprintf(stderr, _("BUFFER: %s\n"), buffer);
  }

  str->alloc(message_size * 4); /* Hex representation is ~4 times number of bytes */

  strncpy(str->ptr(), hexdump.c_str(), hexdump.length());
  str->length(hexdump.length());

  free(buffer);

  delete coded_input;
  delete file_input;

  return str;
}