table_session_connect.cc 9.74 KB
Newer Older
Sergei Golubchik's avatar
Sergei Golubchik committed
1
/* Copyright (c) 2008, 2015, Oracle and/or its affiliates. All rights reserved.
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44

  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,
  51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */

#include "table_session_connect.h"

static const TABLE_FIELD_TYPE field_types[]=
{
  {
    { C_STRING_WITH_LEN("PROCESSLIST_ID") },
    { C_STRING_WITH_LEN("int(11)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("ATTR_NAME") },
    { C_STRING_WITH_LEN("varchar(32)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("ATTR_VALUE") },
    { C_STRING_WITH_LEN("varchar(1024)") },
    { NULL, 0}
  },
  {
    { C_STRING_WITH_LEN("ORDINAL_POSITION") },
    { C_STRING_WITH_LEN("int(11)") },
    { NULL, 0}
  }
};

TABLE_FIELD_DEF table_session_connect::m_field_def=
{ 4, field_types };

Sergei Golubchik's avatar
Sergei Golubchik committed
45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64
table_session_connect::table_session_connect(const PFS_engine_table_share *share)
 : cursor_by_thread_connect_attr(share)
{
  if (session_connect_attrs_size_per_thread > 0)
  {
    m_copy_session_connect_attrs= (char *) my_malloc(/* 5.7: PSI_INSTRUMENT_ME, */
                                             session_connect_attrs_size_per_thread,
                                             MYF(0));
  }
  else
  {
    m_copy_session_connect_attrs= NULL;
  }
  m_copy_session_connect_attrs_length= 0;
}

table_session_connect::~table_session_connect()
{
  my_free(m_copy_session_connect_attrs);
}
65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194

/**
  Take a length encoded string

  @arg ptr  inout       the input string array
  @arg dest             where to store the result
  @arg dest_size        max size of @c dest
  @arg copied_len       the actual length of the data copied
  @arg start_ptr        pointer to the start of input
  @arg input_length     the length of the incoming data
  @arg copy_data        copy the data or just skip the input
  @arg from_cs          character set in which @c ptr is encoded
  @arg nchars_max       maximum number of characters to read
  @return status
    @retval true    parsing failed
    @retval false   parsing succeeded
*/
bool parse_length_encoded_string(const char **ptr,
                 char *dest, uint dest_size,
                 uint *copied_len,
                 const char *start_ptr, uint input_length,
                 bool copy_data,
                 const CHARSET_INFO *from_cs,
                 uint nchars_max)
{
  ulong copy_length, data_length;
  const char *well_formed_error_pos= NULL, *cannot_convert_error_pos= NULL,
        *from_end_pos= NULL;

  copy_length= data_length= net_field_length((uchar **) ptr);

  /* we don't tolerate NULL as a length */
  if (data_length == NULL_LENGTH)
    return true;

  if (*ptr - start_ptr + data_length > input_length)
    return true;

  copy_length= well_formed_copy_nchars(&my_charset_utf8_bin, dest, dest_size,
                                       from_cs, *ptr, data_length, nchars_max,
                                       &well_formed_error_pos,
                                       &cannot_convert_error_pos,
                                       &from_end_pos);
  *copied_len= copy_length;
  (*ptr)+= data_length;

  return false;
}

/**
  Take the nth attribute name/value pair

  Parse the attributes blob form the beginning, skipping the attributes
  whose number is lower than the one we seek.
  When we reach the attribute at an index we're looking for the values
  are copied to the output parameters.
  If parsing fails or no more attributes are found the function stops
  and returns an error code.

  @arg connect_attrs            pointer to the connect attributes blob
  @arg connect_attrs_length     length of @c connect_attrs
  @arg connect_attrs_cs         character set used to encode @c connect_attrs
  @arg ordinal                  index of the attribute we need
  @arg attr_name [out]          buffer to receive the attribute name
  @arg max_attr_name            max size of @c attr_name in bytes
  @arg attr_name_length [out]   number of bytes written in @attr_name
  @arg attr_value [out]         buffer to receive the attribute name
  @arg max_attr_value           max size of @c attr_value in bytes
  @arg attr_value_length [out]  number of bytes written in @attr_value
  @return status
    @retval true    requested attribute pair is found and copied
    @retval false   error. Either because of parsing or too few attributes.
*/
bool read_nth_attr(const char *connect_attrs,
                   uint connect_attrs_length,
                   const CHARSET_INFO *connect_attrs_cs,
                   uint ordinal,
                   char *attr_name, uint max_attr_name,
                   uint *attr_name_length,
                   char *attr_value, uint max_attr_value,
                   uint *attr_value_length)
{
  uint idx;
  const char *ptr;

  for (ptr= connect_attrs, idx= 0;
       (uint)(ptr - connect_attrs) < connect_attrs_length && idx <= ordinal;
      idx++)
  {
    uint copy_length;
    /* do the copying only if we absolutely have to */
    bool fill_in_attr_name= idx == ordinal;
    bool fill_in_attr_value= idx == ordinal;

    /* read the key */
    if (parse_length_encoded_string(&ptr,
                                    attr_name, max_attr_name, &copy_length,
                                    connect_attrs,
                                    connect_attrs_length,
                                    fill_in_attr_name,
                                    connect_attrs_cs, 32) ||
        !copy_length
        )
      return false;

    if (idx == ordinal)
      *attr_name_length= copy_length;
      
    /* read the value */
    if (parse_length_encoded_string(&ptr,
                                    attr_value, max_attr_value, &copy_length,
                                    connect_attrs,
                                    connect_attrs_length,
                                    fill_in_attr_value,
                                    connect_attrs_cs, 1024))
      return false;

    if (idx == ordinal)
      *attr_value_length= copy_length;

    if (idx == ordinal)
      return true;
  }

  return false;
}

void table_session_connect::make_row(PFS_thread *pfs, uint ordinal)
{
  pfs_lock lock;
Sergei Golubchik's avatar
Sergei Golubchik committed
195
  pfs_lock session_lock;
196
  PFS_thread_class *safe_class;
Sergei Golubchik's avatar
Sergei Golubchik committed
197
  const CHARSET_INFO *cs;
198 199 200 201 202

  m_row_exists= false;

  /* Protect this reader against thread termination */
  pfs->m_lock.begin_optimistic_lock(&lock);
Sergei Golubchik's avatar
Sergei Golubchik committed
203 204 205
  /* Protect this reader against writing on session attributes */
  pfs->m_session_lock.begin_optimistic_lock(&session_lock);

206 207 208 209 210 211 212 213
  safe_class= sanitize_thread_class(pfs->m_class);
  if (unlikely(safe_class == NULL))
    return;

  /* Filtering threads must be done under the protection of the optimistic lock. */
  if (! thread_fits(pfs))
    return;

Sergei Golubchik's avatar
Sergei Golubchik committed
214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242
  /* Make a safe copy of the session attributes */

  if (m_copy_session_connect_attrs == NULL)
    return;

  m_copy_session_connect_attrs_length= pfs->m_session_connect_attrs_length;

  if (m_copy_session_connect_attrs_length > session_connect_attrs_size_per_thread)
    return;

  memcpy(m_copy_session_connect_attrs,
         pfs->m_session_connect_attrs,
         m_copy_session_connect_attrs_length);

  cs= get_charset(pfs->m_session_connect_attrs_cs_number, MYF(0));
  if (cs == NULL)
    return;

  if (! pfs->m_session_lock.end_optimistic_lock(& session_lock))
    return;

  if (! pfs->m_lock.end_optimistic_lock(& lock))
    return;

  /*
    Now we have a safe copy of the data,
    that will not change while parsing it
  */

243
  /* populate the row */
Sergei Golubchik's avatar
Sergei Golubchik committed
244 245 246
  if (read_nth_attr(m_copy_session_connect_attrs,
                    m_copy_session_connect_attrs_length,
                    cs,
247 248 249 250 251 252 253
                    ordinal,
                    m_row.m_attr_name, (uint) sizeof(m_row.m_attr_name),
                    &m_row.m_attr_name_length,
                    m_row.m_attr_value, (uint) sizeof(m_row.m_attr_value),
                    &m_row.m_attr_value_length))
  {
    /* we don't expect internal threads to have connection attributes */
Sergei Golubchik's avatar
Sergei Golubchik committed
254 255
    if (pfs->m_processlist_id == 0)
	return;
256 257 258 259 260

    m_row.m_ordinal_position= ordinal;
    m_row.m_process_id= pfs->m_processlist_id;

    m_row_exists= true;
Sergei Golubchik's avatar
Sergei Golubchik committed
261
  }
262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317
}

int table_session_connect::read_row_values(TABLE *table,
                                         unsigned char *buf,
                                         Field **fields,
                                         bool read_all)
{
  Field *f;

  if (unlikely(!m_row_exists))
    return HA_ERR_RECORD_DELETED;

  /* Set the null bits */
  DBUG_ASSERT(table->s->null_bytes == 1);
  buf[0]= 0;

  for (; (f= *fields) ; fields++)
  {
    if (read_all || bitmap_is_set(table->read_set, f->field_index))
    {
      switch(f->field_index)
      {
      case FO_PROCESS_ID:
        if (m_row.m_process_id != 0)
          set_field_ulong(f, m_row.m_process_id);
        else
          f->set_null();
        break;
      case FO_ATTR_NAME:
        set_field_varchar_utf8(f, m_row.m_attr_name,
                               m_row.m_attr_name_length);
        break;
      case FO_ATTR_VALUE:
        if (m_row.m_attr_value_length)
          set_field_varchar_utf8(f, m_row.m_attr_value,
                                 m_row.m_attr_value_length);
        else
          f->set_null();
        break;
      case FO_ORDINAL_POSITION:
        set_field_ulong(f, m_row.m_ordinal_position);
        break;
      default:
        DBUG_ASSERT(false);
      }
    }
  }
  return 0;
}

bool
table_session_connect::thread_fits(PFS_thread *thread)
{
  return true;
}