ext/rbu/rbu.c

   1 /*
   2 ** 2014 August 30
   3 **
   4 ** The author disclaims copyright to this source code.  In place of
   5 ** a legal notice, here is a blessing:
   6 **
   7 **    May you do good and not evil.
   8 **    May you find forgiveness for yourself and forgive others.
   9 **    May you share freely, never taking more than you give.
  10 **
  11 *************************************************************************
  12 **
  13 ** This file contains a command-line application that uses the RBU
  14 ** extension. See the usage() function below for an explanation.
  15 */
  16
  17 #include "sqlite3rbu.h"
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <string.h>
  21
  22 /*
  23 ** Print a usage message and exit.
  24 */
  25 void usage(const char *zArgv0){
  26   fprintf(stderr,
  27 "Usage: %s ?OPTIONS? TARGET-DB RBU-DB\n"
  28 "\n"
  29 "Where options are:\n"
  30 "\n"
  31 "    -step NSTEP\n"
  32 "    -vacuum\n"
  33 "\n"
  34 "  If the -vacuum switch is not present, argument RBU-DB must be an RBU\n"
  35 "  database containing an update suitable for target database TARGET-DB.\n"
  36 "  Or, if -vacuum is specified, then TARGET-DB is a database to vacuum using\n"
  37 "  RBU, and RBU-DB is used as the state database for the vacuum (refer to\n"
  38 "  API documentation for details).\n"
  39 "\n"
  40 "  If NSTEP is set to less than or equal to zero (the default value), this \n"
  41 "  program attempts to perform the entire update or vacuum operation before\n"
  42 "  exiting\n"
  43 "\n"
  44 "  If NSTEP is greater than zero, then a maximum of NSTEP calls are made\n"
  45 "  to sqlite3rbu_step(). If the RBU update has not been completely applied\n"
  46 "  after the NSTEP'th call is made, the state is saved in the database RBU-DB\n"
  47 "  and the program exits. Subsequent invocations of this (or any other RBU)\n"
  48 "  application will use this state to resume applying the RBU update to the\n"
  49 "  target db.\n"
  50 "\n"
  51 , zArgv0);
  52   exit(1);
  53 }
  54
  55 void report_default_vfs(){
  56   sqlite3_vfs *pVfs = sqlite3_vfs_find(0);
  57   fprintf(stdout, "default vfs is \"%s\"\n", pVfs->zName);
  58 }
  59
  60 void report_rbu_vfs(sqlite3rbu *pRbu){
  61   sqlite3 *db = sqlite3rbu_db(pRbu, 0);
  62   if( db ){
  63     char *zName = 0;
  64     sqlite3_file_control(db, "main", SQLITE_FCNTL_VFSNAME, &zName);
  65     if( zName ){
  66       fprintf(stdout, "using vfs \"%s\"\n", zName);
  67     }else{
  68       fprintf(stdout, "vfs name not available\n");
  69     }
  70     sqlite3_free(zName);
  71   }
  72 }
  73
  74 int main(int argc, char **argv){
  75   int i;
  76   const char *zTarget;            /* Target database to apply RBU to */
  77   const char *zRbu;               /* Database containing RBU */
  78   char zBuf[200];                 /* Buffer for printf() */
  79   char *zErrmsg;                  /* Error message, if any */
  80   sqlite3rbu *pRbu;               /* RBU handle */
  81   int nStep = 0;                  /* Maximum number of step() calls */
  82   int bVacuum = 0;
  83   int rc;
  84   sqlite3_int64 nProgress = 0;
  85   int nArgc = argc-2;
  86
  87   if( argc<3 ) usage(argv[0]);
  88   for(i=1; i<nArgc; i++){
  89     const char *zArg = argv[i];
  90     int nArg = strlen(zArg);
  91     if( nArg>1 && nArg<=8 && 0==memcmp(zArg, "-vacuum", nArg) ){
  92       bVacuum = 1;
  93     }else if( nArg>1 && nArg<=5 && 0==memcmp(zArg, "-step", nArg) && i<nArg-1 ){
  94       i++;
  95       nStep = atoi(argv[i]);
  96     }else{
  97       usage(argv[0]);
  98     }
  99   }
 100
 101   zTarget = argv[argc-2];
 102   zRbu = argv[argc-1];
 103
 104   report_default_vfs();
 105
 106   /* Open an RBU handle. A vacuum handle if -vacuum was specified, or a
 107   ** regular RBU update handle otherwise.  */
 108   if( bVacuum ){
 109     pRbu = sqlite3rbu_vacuum(zTarget, zRbu);
 110   }else{
 111     pRbu = sqlite3rbu_open(zTarget, zRbu, 0);
 112   }
 113   report_rbu_vfs(pRbu);
 114
 115   /* If nStep is less than or equal to zero, call
 116   ** sqlite3rbu_step() until either the RBU has been completely applied
 117   ** or an error occurs. Or, if nStep is greater than zero, call
 118   ** sqlite3rbu_step() a maximum of nStep times.  */
 119   for(i=0; (nStep<=0 || i<nStep) && sqlite3rbu_step(pRbu)==SQLITE_OK; i++);
 120   nProgress = sqlite3rbu_progress(pRbu);
 121   rc = sqlite3rbu_close(pRbu, &zErrmsg);
 122
 123   /* Let the user know what happened. */
 124   switch( rc ){
 125     case SQLITE_OK:
 126       sqlite3_snprintf(sizeof(zBuf), zBuf,
 127           "SQLITE_OK: rbu update incomplete (%lld operations so far)\n",
 128           nProgress
 129       );
 130       fprintf(stdout, "%s", zBuf);
 131       break;
 132
 133     case SQLITE_DONE:
 134       sqlite3_snprintf(sizeof(zBuf), zBuf,
 135           "SQLITE_DONE: rbu update completed (%lld operations)\n",
 136           nProgress
 137       );
 138       fprintf(stdout, "%s", zBuf);
 139       break;
 140
 141     default:
 142       fprintf(stderr, "error=%d: %s\n", rc, zErrmsg);
 143       break;
 144   }
 145
 146   sqlite3_free(zErrmsg);
 147   return (rc==SQLITE_OK || rc==SQLITE_DONE) ? 0 : 1;
 148 }