src/sqllog/FileSend.cxx

   1 /***************************************************************************
   2  *   Copyright (C) 2007 by Prabakaran Thirumalai   *
   3  *   praba_tuty@yahoo.com   *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  19  ***************************************************************************/
  20 #include <os.h>
  21 #include <SqlLogConnection.h>
  22 #include <CSql.h>
  23
  24 FileSend::FileSend()
  25 {
  26     char fileName[1024];
  27     sprintf(fileName, "%s/csql.db.cur", Conf::config.getDbFile());
  28     int durableMode = Conf::config.getDurableMode();
  29     switch(durableMode) {
  30         case 1:
  31         case 2:
  32             fdRedoLog = os::openFileForAppend(fileName, O_CREAT);
  33             break;
  34         case 3:
  35             fdRedoLog = os::openFileForAppend(fileName, O_CREAT|O_SYNC);
  36             break;
  37         case 4:
  38 #ifdef SOLARIS
  39             fdRedoLog = os::openFileForAppend(fileName, O_CREAT|O_DSYNC);
  40 #else
  41             fdRedoLog = os::openFileForAppend(fileName, O_CREAT|O_DIRECT);
  42 #endif
  43             break;
  44         default:
  45             fdRedoLog = os::openFileForAppend(fileName, O_CREAT);
  46             break;
  47     }
  48 }
  49
  50 FileSend::~FileSend() { if (fdRedoLog > 0) os::closeFile(fdRedoLog); fdRedoLog = -1; }
  51
  52 DbRetVal FileSend::prepare(int txnId, int stmtId, int len, char *stmt, char *tblName)
  53 {
  54     if (fdRedoLog < 0) return ErrBadArg;
  55     //The following structure needs strlen after stmt id for traversal in
  56     //redolog file unlike msg queue structure where string is the last element
  57     //and is not a continuous piece of memory.
  58     int datalen = os::align(5 * sizeof(int) + len); // for len + txnId + msg type + stmtId + tableName + stmtstrlen + stmtstring
  59     char *buf = (char*) malloc(datalen);
  60     char *msg = buf;
  61     //Note:: msg type is taken as -ve as we need to differentiate between
  62     //statement id and logtype during recovery.
  63     *(int*) msg = -1;
  64     if (strlen(stmt) > 6 && ( strncasecmp(stmt,"CREATE", 6) == 0 || strncasecmp(stmt,"DROP", 4) == 0 ))
  65         *(int*)msg = -4; //means prepare and execute the stmt
  66     msg = msg+sizeof(int);
  67     *(int *)msg = datalen;
  68     msg = msg+sizeof(int);
  69     *(int *)msg = txnId;
  70     msg = msg+sizeof(int);
  71     *(int *)msg = stmtId;
  72     msg = msg+ sizeof(int);
  73     *(int *)msg = os::align(len);
  74     msg = msg+ sizeof(int);
  75     msg[len-1] = '\0';
  76     strcpy(msg, stmt);
  77     int ret =0;
  78     if (Conf::config.getDurableMode() != 1) {
  79         ret = os::lockFile(fdRedoLog);
  80         if (-1 == ret) {
  81             ::free(buf);
  82             printError(ErrLockTimeOut,"Unable to get exclusive lock on redo log file");
  83             return ErrLockTimeOut;
  84         }
  85     }
  86     ret = os::write(fdRedoLog, buf, datalen);
  87     if (Conf::config.getDurableMode() != 1) {
  88         os::unlockFile(fdRedoLog);
  89     }
  90     ::free(buf);
  91     //if (ret == datalen) { printf("log written successfully %d\n", ret); return OK; }
  92     if (ret == datalen) { return OK; }
  93     return ErrOS;
  94 };
  95
  96 DbRetVal FileSend::commit(int len, void *data)
  97 {
  98     if (fdRedoLog < 0) return ErrBadArg;
  99     char *dat=(char*)data - sizeof(int);
 100     *(int*)dat = -2; //type 2->commit
 101     if (Conf::config.getDurableMode() != 1) {
 102         int ret = os::lockFile(fdRedoLog);
 103         if (-1 == ret) {
 104             printError(ErrLockTimeOut,"Unable to get exclusive lock on redo log file");
 105             return ErrLockTimeOut;
 106         }
 107     }
 108     int ret = os::write(fdRedoLog, dat, len+sizeof(int));
 109     if (Conf::config.getDurableMode() != 1) {
 110         os::unlockFile(fdRedoLog);
 111     }
 112     //if (ret == len+sizeof(int)) { printf("log written successfully %d\n", ret); return OK; }
 113     if (ret == len+sizeof(int)) { return OK; }
 114     return ErrOS;
 115 }
 116 DbRetVal FileSend::free(int txnId, int stmtId)
 117 {
 118     int buflen =  4 *sizeof(int);
 119     char *msg = (char *) malloc(buflen);
 120     char *ptr = msg;
 121     *(int*)ptr = -3;
 122     ptr += sizeof(int);
 123     *(int *)ptr = 3 * sizeof(int); // for len + txnId + stmtId
 124     ptr += sizeof(int);
 125     *(int *)ptr = txnId;
 126     ptr += sizeof(int);
 127     *(int *)ptr = stmtId;
 128     printDebug(DM_SqlLog, "stmtID sent = %d\n", *(int *)ptr);
 129     if (Conf::config.getDurableMode() != 1) {
 130         int ret = os::lockFile(fdRedoLog);
 131         if (-1 == ret) {
 132             ::free(msg);
 133             printError(ErrLockTimeOut,"Unable to get exclusive lock on redo log file");
 134             return ErrLockTimeOut;
 135         }
 136     }
 137     int ret = os::write(fdRedoLog, msg, buflen);
 138     if (Conf::config.getDurableMode() != 1) {
 139         os::unlockFile(fdRedoLog);
 140     }
 141     //if (ret == buflen) { printf("log written successfully %d\n", ret); return OK; }
 142     ::free(msg);
 143     if (ret == buflen) { return OK; }
 144     return ErrOS;
 145 }