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     openRedoFile();
  27 }
  28 DbRetVal FileSend::openRedoFile()
  29 {
  30     char fileName[MAX_FILE_LEN];
  31     sprintf(fileName, "%s/csql.db.cur", Conf::config.getDbFile());
  32     int durableMode = Conf::config.getDurableMode();
  33     switch(durableMode) {
  34         case 1:
  35         case 2:
  36             fdRedoLog = os::openFileForAppend(fileName, O_CREAT);
  37             break;
  38         case 3:
  39             fdRedoLog = os::openFileForAppend(fileName, O_CREAT|O_SYNC);
  40             break;
  41         case 4:
  42 #ifdef SOLARIS
  43             fdRedoLog = os::openFileForAppend(fileName, O_CREAT|O_DSYNC);
  44 #else
  45             fdRedoLog = os::openFileForAppend(fileName, O_CREAT|O_DIRECT);
  46 #endif
  47             break;
  48         default:
  49             fdRedoLog = os::openFileForAppend(fileName, O_CREAT);
  50             break;
  51     }
  52     if (-1 == fdRedoLog) {
  53         printError(ErrSysInternal, "Unable to open redo log file");
  54         return ErrSysInternal;
  55     }
  56     return OK;
  57 }
  58
  59 FileSend::~FileSend() { if (fdRedoLog > 0) os::closeFile(fdRedoLog); fdRedoLog = -1; }
  60
  61 DbRetVal FileSend::prepare(int txnId, int stmtId, int len, char *stmt, char *tblName)
  62 {
  63     if (fdRedoLog < 0) return ErrBadArg;
  64     //The following structure needs strlen after stmt id for traversal in
  65     //redolog file unlike msg queue structure where string is the last element
  66     //and is not a continuous piece of memory.
  67     int datalen = os::align(5 * sizeof(int) + len); // for len + txnId + msg type + stmtId + tableName + stmtstrlen + stmtstring
  68     char *buf = (char*) malloc(datalen);
  69     char *msg = buf;
  70     //Note:: msg type is taken as -ve as we need to differentiate between
  71     //statement id and logtype during recovery.
  72     *(int*) msg = -1;
  73     if (strlen(stmt) > 6 && ( strncasecmp(stmt,"CREATE", 6) == 0 || strncasecmp(stmt,"DROP", 4) == 0 ))
  74         *(int*)msg = -4; //means prepare and execute the stmt
  75     msg = msg+sizeof(int);
  76     *(int *)msg = datalen;
  77     msg = msg+sizeof(int);
  78     *(int *)msg = txnId;
  79     msg = msg+sizeof(int);
  80     *(int *)msg = stmtId;
  81     msg = msg+ sizeof(int);
  82     *(int *)msg = os::align(len);
  83     msg = msg+ sizeof(int);
  84     msg[len-1] = '\0';
  85     strcpy(msg, stmt);
  86     int ret =0;
  87     bool firstTime=true;
  88 retry:
  89     if (Conf::config.getDurableMode() != 1) {
  90         ret = os::lockFile(fdRedoLog);
  91         if (-1 == ret) {
  92             ::free(buf);
  93             printError(ErrLockTimeOut,"Unable to get exclusive lock on redo log file");
  94             return ErrLockTimeOut;
  95         }
  96     }
  97     ret = os::write(fdRedoLog, buf, datalen);
  98     if (Conf::config.getDurableMode() != 1) {
  99         os::unlockFile(fdRedoLog);
 100     }
 101     if (-1 == ret) {
 102         DbRetVal rv = openRedoFile();
 103         if (OK == rv) {
 104             logFine(Conf::logger, "Reopening redo log file");
 105             if(firstTime) { firstTime = false; goto retry; }
 106         }
 107         printError(ErrOS, "Unable to write undo log");
 108         ::free(buf);
 109         return ErrOS;
 110     }
 111     ::free(buf);
 112     return OK;
 113 };
 114
 115 DbRetVal FileSend::commit(int len, void *data)
 116 {
 117     if (fdRedoLog < 0) return ErrBadArg;
 118     char *dat=(char*)data - sizeof(int);
 119     *(int*)dat = -2; //type 2->commit
 120     bool firstTime = true;
 121 retry:
 122     if (Conf::config.getDurableMode() != 1) {
 123         int ret = os::lockFile(fdRedoLog);
 124         if (-1 == ret) {
 125             printError(ErrLockTimeOut,"Unable to get exclusive lock on redo log file");
 126             return ErrLockTimeOut;
 127         }
 128     }
 129     int ret = os::write(fdRedoLog, dat, len+sizeof(int));
 130     if (Conf::config.getDurableMode() != 1) {
 131         os::unlockFile(fdRedoLog);
 132     }
 133     if (-1 == ret) {
 134         DbRetVal rv = openRedoFile();
 135         if (OK == rv) {
 136             logFine(Conf::logger, "Reopening redo log file");
 137             if(firstTime) { firstTime = false; goto retry; }
 138         }
 139         printError(ErrOS, "Unable to write undo log");
 140         return ErrOS;
 141     }
 142     return OK;
 143 }
 144 DbRetVal FileSend::free(int txnId, int stmtId)
 145 {
 146     int buflen =  4 *sizeof(int);
 147     char *msg = (char *) malloc(buflen);
 148     char *ptr = msg;
 149     *(int*)ptr = -3;
 150     ptr += sizeof(int);
 151     *(int *)ptr = 3 * sizeof(int); // for len + txnId + stmtId
 152     ptr += sizeof(int);
 153     *(int *)ptr = txnId;
 154     ptr += sizeof(int);
 155     *(int *)ptr = stmtId;
 156     printDebug(DM_SqlLog, "stmtID sent = %d\n", *(int *)ptr);
 157     bool firstTime = false;
 158 retry:
 159     if (Conf::config.getDurableMode() != 1) {
 160         int ret = os::lockFile(fdRedoLog);
 161         if (-1 == ret) {
 162             ::free(msg);
 163             printError(ErrLockTimeOut,"Unable to get exclusive lock on redo log file");
 164             return ErrLockTimeOut;
 165         }
 166     }
 167     int ret = os::write(fdRedoLog, msg, buflen);
 168     if (Conf::config.getDurableMode() != 1) {
 169         os::unlockFile(fdRedoLog);
 170     }
 171     if (-1 == ret) {
 172         DbRetVal rv = openRedoFile();
 173         if (OK == rv) {
 174             logFine(Conf::logger, "Reopening redo log file");
 175             if(firstTime) { firstTime = false; goto retry; }
 176         }
 177         printError(ErrOS, "Unable to write undo log");
 178         ::free(msg);
 179         return ErrOS;
 180     }
 181     ::free(msg);
 182     return OK;
 183 }