~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2008, 2009 Sun Microsystems, Inc.

 *

 *  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; version 2 of the License.

 *

 *  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/logging.h>

#include <drizzled/gettext.h>

#include <drizzled/session.h>

#include PCRE_HEADER

#include <limits.h>

#include <sys/time.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <string>

#include <boost/format.hpp>

#include <boost/program_options.hpp>

#include <drizzled/module/option_map.h>

#include <cstdio>

#include <cerrno>

namespace po= boost::program_options;

using namespace drizzled;

using namespace std;

#define ESCAPE_CHAR      '\\'

#define SEPARATOR_CHAR   ','

namespace drizzle_plugin

{

static bool sysvar_logging_query_enable= false;

/* TODO fix these to not be unsigned long once we have sensible sys_var system */

static uint32_constraint sysvar_logging_query_threshold_slow;

static uint32_constraint sysvar_logging_query_threshold_big_resultset;

static uint32_constraint sysvar_logging_query_threshold_big_examined;

/* quote a string to be safe to include in a CSV line

   that means backslash quoting all commas, doublequotes, backslashes,

   and all the ASCII unprintable characters

   as long as we pass the high-bit bytes unchanged

   this is safe to do to a UTF8 string

   we dont allow overrunning the targetbuffer

   to avoid having a very long query overwrite memory

   TODO consider remapping the unprintables instead to "Printable

   Representation", the Unicode characters from the area U+2400 to

   U+2421 reserved for representing control characters when it is

   necessary to print or display them rather than have them perform

   their intended function.

*/

static void quotify(const string &src, string &dst)

{

  static const char hexit[]= { '0', '1', '2', '3', '4', '5', '6', '7',

			  '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };

  string::const_iterator src_iter;

  for (src_iter= src.begin(); src_iter < src.end(); ++src_iter)

  {

    if (static_cast<unsigned char>(*src_iter) > 0x7f)

    {

      dst.push_back(*src_iter);

    }

    else if (*src_iter == 0x00)  // null

    {

      dst.push_back(ESCAPE_CHAR); dst.push_back('0');

    }

    else if (*src_iter == 0x07)  // bell

    {

      dst.push_back(ESCAPE_CHAR); dst.push_back('a');

    }

    else if (*src_iter == 0x08)  // backspace

    {

      dst.push_back(ESCAPE_CHAR); dst.push_back('b');

    }

    else if (*src_iter == 0x09)  // horiz tab

    {

      dst.push_back(ESCAPE_CHAR); dst.push_back('t');

    }

    else if (*src_iter == 0x0a)  // line feed

    {

      dst.push_back(ESCAPE_CHAR); dst.push_back('n');

    }

    else if (*src_iter == 0x0b)  // vert tab

    {

      dst.push_back(ESCAPE_CHAR); dst.push_back('v');

    }

    else if (*src_iter == 0x0c)  // formfeed

    {

      dst.push_back(ESCAPE_CHAR); dst.push_back('f');

    }

    else if (*src_iter == 0x0d)  // carrage return

    {

      dst.push_back(ESCAPE_CHAR); dst.push_back('r');

    }

    else if (*src_iter == 0x1b)  // escape

    {

      dst.push_back(ESCAPE_CHAR); dst.push_back('e');

    }

    else if (*src_iter == 0x22)  // quotation mark

    {

      dst.push_back(ESCAPE_CHAR); dst.push_back(0x22);

    }

    else if (*src_iter == SEPARATOR_CHAR)

    {

      dst.push_back(ESCAPE_CHAR); dst.push_back(SEPARATOR_CHAR);

    }

    else if (*src_iter == ESCAPE_CHAR)

    {

      dst.push_back(ESCAPE_CHAR); dst.push_back(ESCAPE_CHAR);

    }

    else if ((*src_iter < 0x20) || (*src_iter == 0x7F))  // other unprintable ASCII

    {

      dst.push_back(ESCAPE_CHAR);

      dst.push_back('x');

      dst.push_back(hexit[(*src_iter >> 4) & 0x0f]);

      dst.push_back(hexit[*src_iter & 0x0f]);

    }

    else  // everything else

    {

      dst.push_back(*src_iter);

    }

  }

}

class Logging_query: public drizzled::plugin::Logging

{

  const std::string _filename;

  const std::string _query_pcre;

  int fd;

  pcre *re;

  pcre_extra *pe;

  /** Format of the output string */

  boost::format formatter;

public:

  Logging_query(const std::string &filename,

                const std::string &query_pcre) :

    drizzled::plugin::Logging("Logging_query"),

    _filename(filename),

    _query_pcre(query_pcre),

    fd(-1), re(NULL), pe(NULL),

    formatter("%1%,%2%,%3%,\"%4%\",\"%5%\",\"%6%\",%7%,%8%,"

              "%9%,%10%,%11%,%12%,%13%,%14%,\"%15%\"\n")

  {

    /* if there is no destination filename, dont bother doing anything */

    if (_filename.empty())

      return;

    fd= open(_filename.c_str(),

             O_WRONLY | O_APPEND | O_CREAT,

             S_IRUSR|S_IWUSR);

    if (fd < 0)

    {

      char errmsg[STRERROR_MAX];

      strerror_r(errno, errmsg, sizeof(errmsg));

      errmsg_printf(ERRMSG_LVL_ERROR, _("fail open() fn=%s er=%s\n"),

                    _filename.c_str(),

                    errmsg);

      return;

    }

    if (not _query_pcre.empty())

    {

      const char *this_pcre_error;

      int this_pcre_erroffset;

      re= pcre_compile(_query_pcre.c_str(), 0, &this_pcre_error,

                       &this_pcre_erroffset, NULL);

      pe= pcre_study(re, 0, &this_pcre_error);

      /* TODO emit error messages if there is a problem */

    }

  }

  ~Logging_query()

  {

    if (fd >= 0)

    {

      close(fd);

    }

    if (pe != NULL)

    {

      pcre_free(pe);

    }

    if (re != NULL)

    {

      pcre_free(re);

    }

  }

  virtual bool post (Session *session)

  {

    size_t wrv;

    assert(session != NULL);

    if (fd < 0)

      return false;

    /* Yes, we know that checking sysvar_logging_query_enable,

       sysvar_logging_query_threshold_big_resultset, and

       sysvar_logging_query_threshold_big_examined is not threadsafe,

       because some other thread might change these sysvars.  But we

       don't care.  We might start logging a little late as it spreads

       to other threads.  Big deal. */

    // return if not enabled or query was too fast or resultset was too small

    if (sysvar_logging_query_enable == false)

      return false;

    if (session->sent_row_count < sysvar_logging_query_threshold_big_resultset.get())

      return false;

    if (session->examined_row_count < sysvar_logging_query_threshold_big_examined.get())

      return false;

    /*

      TODO, the session object should have a "utime command completed"

      inside itself, so be more accurate, and so this doesnt have to

      keep calling current_utime, which can be slow.

    */

    uint64_t t_mark= session->getCurrentTimestamp(false);

    if (session->getElapsedTime() < (sysvar_logging_query_threshold_slow.get()))

      return false;

    Session::QueryString query_string(session->getQueryString());

    if (re)

    {

      int this_pcre_rc;

      this_pcre_rc= pcre_exec(re, pe, query_string->c_str(), query_string->length(), 0, 0, NULL, 0);

      if (this_pcre_rc < 0)

        return false;

    }

    // buffer to quotify the query

    string qs;

    // Since quotify() builds the quoted string incrementally, we can

    // avoid some reallocating if we reserve some space up front.

    qs.reserve(query_string->length());

    quotify(*query_string, qs);

    // to avoid trying to printf %s something that is potentially NULL

    util::string::const_shared_ptr schema(session->schema());

    const char *dbs= (schema and not schema->empty()) ? schema->c_str() : "";

    formatter % t_mark

              % session->thread_id

              % session->getQueryId()

              % dbs

              % qs

              % command_name[session->command].str

              % (t_mark - session->getConnectMicroseconds())

              % session->getElapsedTime()

              % (t_mark - session->utime_after_lock)

              % session->sent_row_count

              % session->examined_row_count

              % session->tmp_table

              % session->total_warn_count

              % session->getServerId()

              % glob_hostname;

    string msgbuf= formatter.str();

    // a single write has a kernel thread lock, thus no need mutex guard this

    wrv= write(fd, msgbuf.c_str(), msgbuf.length());

    assert(wrv == msgbuf.length());

    return false;

  }

};

static int logging_query_plugin_init(drizzled::module::Context &context)

{

  const module::option_map &vm= context.getOptions();

  if (vm.count("filename") > 0)

  {

    context.add(new Logging_query(vm["filename"].as<string>(),

                                  vm["pcre"].as<string>()));

    context.registerVariable(new sys_var_bool_ptr("enable", &sysvar_logging_query_enable));

    context.registerVariable(new sys_var_const_string_val("filename", vm["filename"].as<string>()));

    context.registerVariable(new sys_var_const_string_val("pcre", vm["pcre"].as<string>()));

    context.registerVariable(new sys_var_constrained_value<uint32_t>("threshold_slow", sysvar_logging_query_threshold_slow));

    context.registerVariable(new sys_var_constrained_value<uint32_t>("threshold_big_resultset", sysvar_logging_query_threshold_big_resultset));

    context.registerVariable(new sys_var_constrained_value<uint32_t>("threshold_big_examined", sysvar_logging_query_threshold_big_examined));

  }

  return 0;

}

static void init_options(drizzled::module::option_context &context)

{

  context("enable",

          po::value<bool>(&sysvar_logging_query_enable)->default_value(false)->zero_tokens(),

          _("Enable logging to CSV file"));

  context("filename",

          po::value<string>(),

          _("File to log to"));

  context("pcre",

          po::value<string>()->default_value(""),

          _("PCRE to match the query against"));

  context("threshold-slow",

          po::value<uint32_constraint>(&sysvar_logging_query_threshold_slow)->default_value(0),

          _("Threshold for logging slow queries, in microseconds"));

  context("threshold-big-resultset",

          po::value<uint32_constraint>(&sysvar_logging_query_threshold_big_resultset)->default_value(0),

          _("Threshold for logging big queries, for rows returned"));

  context("threshold-big-examined",

          po::value<uint32_constraint>(&sysvar_logging_query_threshold_big_examined)->default_value(0),

          _("Threshold for logging big queries, for rows examined"));

}

} /* namespace drizzle_plugin */

DRIZZLE_DECLARE_PLUGIN

{

  DRIZZLE_VERSION_ID,

  "logging-query",

  "0.2",

  "Mark Atwood <mark@fallenpegasus.com>",

  N_("Log queries to a CSV file"),

  PLUGIN_LICENSE_GPL,

  drizzle_plugin::logging_query_plugin_init,

  NULL,

  drizzle_plugin::init_options

}

DRIZZLE_DECLARE_PLUGIN_END;