ext/session/changeset.c

   1 /*
   2 ** 2014-08-18
   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 ** This file contains code to implement the "changeset" command line
  13 ** utility for displaying and transforming changesets generated by
  14 ** the Sessions extension.
  15 */
  16 #include "sqlite3.h"
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20 #include <assert.h>
  21 #include <ctype.h>
  22
  23
  24 /*
  25 ** Show a usage message on stderr then quit.
  26 */
  27 static void usage(const char *argv0){
  28   fprintf(stderr, "Usage: %s FILENAME COMMAND ...\n", argv0);
  29   fprintf(stderr,
  30     "COMMANDs:\n"
  31     "   apply DB           Apply the changeset to database file DB\n"
  32     "   concat FILE2 OUT   Concatenate FILENAME and FILE2 into OUT\n"
  33     "   dump               Show the complete content of the changeset\n"
  34     "   invert OUT         Write an inverted changeset into file OUT\n"
  35     "   sql                Give a pseudo-SQL rendering of the changeset\n"
  36   );
  37   exit(1);
  38 }
  39
  40 /*
  41 ** Read the content of a disk file into an in-memory buffer
  42 */
  43 static void readFile(const char *zFilename, int *pSz, void **ppBuf){
  44   FILE *f;
  45   int sz;
  46   void *pBuf;
  47   f = fopen(zFilename, "rb");
  48   if( f==0 ){
  49     fprintf(stderr, "cannot open \"%s\" for reading\n", zFilename);
  50     exit(1);
  51   }
  52   fseek(f, 0, SEEK_END);
  53   sz = (int)ftell(f);
  54   rewind(f);
  55   pBuf = sqlite3_malloc( sz ? sz : 1 );
  56   if( pBuf==0 ){
  57     fprintf(stderr, "cannot allocate %d to hold content of \"%s\"\n",
  58             sz, zFilename);
  59     exit(1);
  60   }
  61   if( sz>0 ){
  62     if( fread(pBuf, sz, 1, f)!=1 ){
  63       fprintf(stderr, "cannot read all %d bytes of \"%s\"\n", sz, zFilename);
  64       exit(1);
  65     }
  66     fclose(f);
  67   }
  68   *pSz = sz;
  69   *ppBuf = pBuf;
  70 }
  71
  72 /* Array for converting from half-bytes (nybbles) into ASCII hex
  73 ** digits. */
  74 static const char hexdigits[] = {
  75   '0', '1', '2', '3', '4', '5', '6', '7',
  76   '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
  77 };
  78
  79 /*
  80 ** Render an sqlite3_value as an SQL string.
  81 */
  82 static void renderValue(sqlite3_value *pVal){
  83   switch( sqlite3_value_type(pVal) ){
  84     case SQLITE_FLOAT: {
  85       double r1;
  86       char zBuf[50];
  87       r1 = sqlite3_value_double(pVal);
  88       sqlite3_snprintf(sizeof(zBuf), zBuf, "%!.15g", r1);
  89       printf("%s", zBuf);
  90       break;
  91     }
  92     case SQLITE_INTEGER: {
  93       printf("%lld", sqlite3_value_int64(pVal));
  94       break;
  95     }
  96     case SQLITE_BLOB: {
  97       char const *zBlob = sqlite3_value_blob(pVal);
  98       int nBlob = sqlite3_value_bytes(pVal);
  99       int i;
 100       printf("x'");
 101       for(i=0; i<nBlob; i++){
 102         putchar(hexdigits[(zBlob[i]>>4)&0x0F]);
 103         putchar(hexdigits[(zBlob[i])&0x0F]);
 104       }
 105       putchar('\'');
 106       break;
 107     }
 108     case SQLITE_TEXT: {
 109       const unsigned char *zArg = sqlite3_value_text(pVal);
 110       putchar('\'');
 111       while( zArg[0] ){
 112         putchar(zArg[0]);
 113         if( zArg[0]=='\'' ) putchar(zArg[0]);
 114         zArg++;
 115       }
 116       putchar('\'');
 117       break;
 118     }
 119     default: {
 120       assert( sqlite3_value_type(pVal)==SQLITE_NULL );
 121       printf("NULL");
 122       break;
 123     }
 124   }
 125 }
 126
 127 /*
 128 ** Number of conflicts seen
 129 */
 130 static int nConflict = 0;
 131
 132 /*
 133 ** The conflict callback
 134 */
 135 static int conflictCallback(
 136   void *pCtx,
 137   int eConflict,
 138   sqlite3_changeset_iter *pIter
 139 ){
 140   int op, bIndirect, nCol, i;
 141   const char *zTab;
 142   unsigned char *abPK;
 143   const char *zType = "";
 144   const char *zOp = "";
 145   const char *zSep = " ";
 146
 147   nConflict++;
 148   sqlite3changeset_op(pIter, &zTab, &nCol, &op, &bIndirect);
 149   sqlite3changeset_pk(pIter, &abPK, 0);
 150   switch( eConflict ){
 151     case SQLITE_CHANGESET_DATA:         zType = "DATA";         break;
 152     case SQLITE_CHANGESET_NOTFOUND:     zType = "NOTFOUND";     break;
 153     case SQLITE_CHANGESET_CONFLICT:     zType = "PRIMARY KEY";  break;
 154     case SQLITE_CHANGESET_FOREIGN_KEY:  zType = "FOREIGN KEY";  break;
 155     case SQLITE_CHANGESET_CONSTRAINT:   zType = "CONSTRAINT";   break;
 156   }
 157   switch( op ){
 158     case SQLITE_UPDATE:     zOp = "UPDATE of";     break;
 159     case SQLITE_INSERT:     zOp = "INSERT into";   break;
 160     case SQLITE_DELETE:     zOp = "DELETE from";   break;
 161   }
 162   printf("%s conflict on %s table %s with primary key", zType, zOp, zTab);
 163   for(i=0; i<nCol; i++){
 164     sqlite3_value *pVal;
 165     if( abPK[i]==0 ) continue;
 166     printf("%s", zSep);
 167     if( op==SQLITE_INSERT ){
 168       sqlite3changeset_new(pIter, i, &pVal);
 169     }else{
 170       sqlite3changeset_old(pIter, i, &pVal);
 171     }
 172     renderValue(pVal);
 173     zSep = ",";
 174   }
 175   printf("\n");
 176   return SQLITE_CHANGESET_OMIT;
 177 }
 178
 179 int main(int argc, char **argv){
 180   int sz, rc;
 181   void *pBuf = 0;
 182   if( argc<3 ) usage(argv[0]);
 183   readFile(argv[1], &sz, &pBuf);
 184
 185   /* changeset FILENAME apply DB
 186   ** Apply the changeset in FILENAME to the database file DB
 187   */
 188   if( strcmp(argv[2],"apply")==0 ){
 189     sqlite3 *db;
 190     if( argc!=4 ) usage(argv[0]);
 191     rc = sqlite3_open(argv[3], &db);
 192     if( rc!=SQLITE_OK ){
 193       fprintf(stderr, "unable to open database file \"%s\": %s\n",
 194               argv[3], sqlite3_errmsg(db));
 195       sqlite3_close(db);
 196       exit(1);
 197     }
 198     sqlite3_exec(db, "BEGIN", 0, 0, 0);
 199     nConflict = 0;
 200     rc = sqlite3changeset_apply(db, sz, pBuf, 0, conflictCallback, 0);
 201     if( rc ){
 202       fprintf(stderr, "sqlite3changeset_apply() returned %d\n", rc);
 203     }
 204     if( nConflict ){
 205       fprintf(stderr, "%d conflicts - no changes applied\n", nConflict);
 206       sqlite3_exec(db, "ROLLBACK", 0, 0, 0);
 207     }else if( rc ){
 208       fprintf(stderr, "sqlite3changeset_apply() returns %d "
 209                       "- no changes applied\n", rc);
 210       sqlite3_exec(db, "ROLLBACK", 0, 0, 0);
 211     }else{
 212       sqlite3_exec(db, "COMMIT", 0, 0, 0);
 213     }
 214     sqlite3_close(db);
 215   }else
 216
 217   /* changeset FILENAME concat FILE2 OUT
 218   ** Add changeset FILE2 onto the end of the changeset in FILENAME
 219   ** and write the result into OUT.
 220   */
 221   if( strcmp(argv[2],"concat")==0 ){
 222     int szB;
 223     void *pB;
 224     int szOut;
 225     void *pOutBuf;
 226     FILE *out;
 227     const char *zOut = argv[4];
 228     if( argc!=5 ) usage(argv[0]);
 229     out = fopen(zOut, "wb");
 230     if( out==0 ){
 231       fprintf(stderr, "cannot open \"%s\" for writing\n", zOut);
 232       exit(1);
 233     }
 234     readFile(argv[3], &szB, &pB);
 235     rc = sqlite3changeset_concat(sz, pBuf, szB, pB, &szOut, &pOutBuf);
 236     if( rc!=SQLITE_OK ){
 237       fprintf(stderr, "sqlite3changeset_concat() returns %d\n", rc);
 238     }else if( szOut>0 && fwrite(pOutBuf, szOut, 1, out)!=1 ){
 239       fprintf(stderr, "unable to write all %d bytes of output to \"%s\"\n",
 240               szOut, zOut);
 241     }
 242     fclose(out);
 243     sqlite3_free(pOutBuf);
 244     sqlite3_free(pB);
 245   }else
 246
 247   /* changeset FILENAME dump
 248   ** Show the complete content of the changeset in FILENAME
 249   */
 250   if( strcmp(argv[2],"dump")==0 ){
 251     int cnt = 0;
 252     int i;
 253     sqlite3_changeset_iter *pIter;
 254     rc = sqlite3changeset_start(&pIter, sz, pBuf);
 255     if( rc!=SQLITE_OK ){
 256       fprintf(stderr, "sqlite3changeset_start() returns %d\n", rc);
 257       exit(1);
 258     }
 259     while( sqlite3changeset_next(pIter)==SQLITE_ROW ){
 260       int op, bIndirect, nCol;
 261       const char *zTab;
 262       unsigned char *abPK;
 263       sqlite3changeset_op(pIter, &zTab, &nCol, &op, &bIndirect);
 264       cnt++;
 265       printf("%d: %s table=[%s] indirect=%d nColumn=%d\n",
 266              cnt, op==SQLITE_INSERT ? "INSERT" :
 267                        op==SQLITE_UPDATE ? "UPDATE" : "DELETE",
 268              zTab, bIndirect, nCol);
 269       sqlite3changeset_pk(pIter, &abPK, 0);
 270       for(i=0; i<nCol; i++){
 271         sqlite3_value *pVal;
 272         pVal = 0;
 273         sqlite3changeset_old(pIter, i, &pVal);
 274         if( pVal ){
 275           printf("    old[%d]%s = ", i, abPK[i] ? "pk" : "  ");
 276           renderValue(pVal);
 277           printf("\n");
 278         }
 279         pVal = 0;
 280         sqlite3changeset_new(pIter, i, &pVal);
 281         if( pVal ){
 282           printf("    new[%d]%s = ", i, abPK[i] ? "pk" : "  ");
 283           renderValue(pVal);
 284           printf("\n");
 285         }
 286       }
 287     }
 288     sqlite3changeset_finalize(pIter);
 289   }else
 290
 291   /* changeset FILENAME invert OUT
 292   ** Invert the changes in FILENAME and writes the result on OUT
 293   */
 294   if( strcmp(argv[2],"invert")==0 ){
 295     FILE *out;
 296     int szOut = 0;
 297     void *pOutBuf = 0;
 298     const char *zOut = argv[3];
 299     if( argc!=4 ) usage(argv[0]);
 300     out = fopen(zOut, "wb");
 301     if( out==0 ){
 302       fprintf(stderr, "cannot open \"%s\" for writing\n", zOut);
 303       exit(1);
 304     }
 305     rc = sqlite3changeset_invert(sz, pBuf, &szOut, &pOutBuf);
 306     if( rc!=SQLITE_OK ){
 307       fprintf(stderr, "sqlite3changeset_invert() returns %d\n", rc);
 308     }else if( szOut>0 && fwrite(pOutBuf, szOut, 1, out)!=1 ){
 309       fprintf(stderr, "unable to write all %d bytes of output to \"%s\"\n",
 310               szOut, zOut);
 311     }
 312     fclose(out);
 313     sqlite3_free(pOutBuf);
 314   }else
 315
 316   /* changeset FILE sql
 317   ** Show the content of the changeset as pseudo-SQL
 318   */
 319   if( strcmp(argv[2],"sql")==0 ){
 320     int cnt = 0;
 321     char *zPrevTab = 0;
 322     char *zSQLTabName = 0;
 323     sqlite3_changeset_iter *pIter = 0;
 324     rc = sqlite3changeset_start(&pIter, sz, pBuf);
 325     if( rc!=SQLITE_OK ){
 326       fprintf(stderr, "sqlite3changeset_start() returns %d\n", rc);
 327       exit(1);
 328     }
 329     printf("BEGIN;\n");
 330     while( sqlite3changeset_next(pIter)==SQLITE_ROW ){
 331       int op, bIndirect, nCol;
 332       const char *zTab;
 333       sqlite3changeset_op(pIter, &zTab, &nCol, &op, &bIndirect);
 334       cnt++;
 335       if( zPrevTab==0 || strcmp(zPrevTab,zTab)!=0 ){
 336         sqlite3_free(zPrevTab);
 337         sqlite3_free(zSQLTabName);
 338         zPrevTab = sqlite3_mprintf("%s", zTab);
 339         if( !isalnum(zTab[0]) || sqlite3_strglob("*[^a-zA-Z0-9]*",zTab)==0 ){
 340           zSQLTabName = sqlite3_mprintf("\"%w\"", zTab);
 341         }else{
 342           zSQLTabName = sqlite3_mprintf("%s", zTab);
 343         }
 344         printf("/****** Changes for table %s ***************/\n", zSQLTabName);
 345       }
 346       switch( op ){
 347         case SQLITE_DELETE: {
 348           unsigned char *abPK;
 349           int i;
 350           const char *zSep = " ";
 351           sqlite3changeset_pk(pIter, &abPK, 0);
 352           printf("/* %d */ DELETE FROM %s WHERE", cnt, zSQLTabName);
 353           for(i=0; i<nCol; i++){
 354             sqlite3_value *pVal;
 355             if( abPK[i]==0 ) continue;
 356             printf("%sc%d=", zSep, i+1);
 357             zSep = " AND ";
 358             sqlite3changeset_old(pIter, i, &pVal);
 359             renderValue(pVal);
 360           }
 361           printf(";\n");
 362           break;
 363         }
 364         case SQLITE_UPDATE: {
 365           unsigned char *abPK;
 366           int i;
 367           const char *zSep = " ";
 368           sqlite3changeset_pk(pIter, &abPK, 0);
 369           printf("/* %d */ UPDATE %s SET", cnt, zSQLTabName);
 370           for(i=0; i<nCol; i++){
 371             sqlite3_value *pVal = 0;
 372             sqlite3changeset_new(pIter, i, &pVal);
 373             if( pVal ){
 374               printf("%sc%d=", zSep, i+1);
 375               zSep = ", ";
 376               renderValue(pVal);
 377             }
 378           }
 379           printf(" WHERE");
 380           zSep = " ";
 381           for(i=0; i<nCol; i++){
 382             sqlite3_value *pVal;
 383             if( abPK[i]==0 ) continue;
 384             printf("%sc%d=", zSep, i+1);
 385             zSep = " AND ";
 386             sqlite3changeset_old(pIter, i, &pVal);
 387             renderValue(pVal);
 388           }
 389           printf(";\n");
 390           break;
 391         }
 392         case SQLITE_INSERT: {
 393           int i;
 394           printf("/* %d */ INSERT INTO %s VALUES", cnt, zSQLTabName);
 395           for(i=0; i<nCol; i++){
 396             sqlite3_value *pVal;
 397             printf("%c", i==0 ? '(' : ',');
 398             sqlite3changeset_new(pIter, i, &pVal);
 399             renderValue(pVal);
 400           }
 401           printf(");\n");
 402           break;
 403         }
 404       }
 405     }
 406     printf("COMMIT;\n");
 407     sqlite3changeset_finalize(pIter);
 408     sqlite3_free(zPrevTab);
 409     sqlite3_free(zSQLTabName);
 410   }else
 411
 412   /* If nothing else matches, show the usage comment */
 413   usage(argv[0]);
 414   sqlite3_free(pBuf);
 415   return 0;
 416 }