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   sqlite3_int64 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 = ftell(f);
  54   rewind(f);
  55   pBuf = sqlite3_malloc64( sz ? sz : 1 );
  56   if( pBuf==0 ){
  57     fprintf(stderr, "cannot allocate %d to hold content of \"%s\"\n",
  58             (int)sz, zFilename);
  59     exit(1);
  60   }
  61   if( sz>0 ){
  62     if( fread(pBuf, (size_t)sz, 1, f)!=1 ){
  63       fprintf(stderr, "cannot read all %d bytes of \"%s\"\n",
  64               (int)sz, zFilename);
  65       exit(1);
  66     }
  67     fclose(f);
  68   }
  69   *pSz = (int)sz;
  70   *ppBuf = pBuf;
  71 }
  72
  73 /* Array for converting from half-bytes (nybbles) into ASCII hex
  74 ** digits. */
  75 static const char hexdigits[] = {
  76   '0', '1', '2', '3', '4', '5', '6', '7',
  77   '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
  78 };
  79
  80 /*
  81 ** Render an sqlite3_value as an SQL string.
  82 */
  83 static void renderValue(sqlite3_value *pVal){
  84   switch( sqlite3_value_type(pVal) ){
  85     case SQLITE_FLOAT: {
  86       double r1;
  87       char zBuf[50];
  88       r1 = sqlite3_value_double(pVal);
  89       sqlite3_snprintf(sizeof(zBuf), zBuf, "%!.15g", r1);
  90       printf("%s", zBuf);
  91       break;
  92     }
  93     case SQLITE_INTEGER: {
  94       printf("%lld", sqlite3_value_int64(pVal));
  95       break;
  96     }
  97     case SQLITE_BLOB: {
  98       char const *zBlob = sqlite3_value_blob(pVal);
  99       int nBlob = sqlite3_value_bytes(pVal);
 100       int i;
 101       printf("x'");
 102       for(i=0; i<nBlob; i++){
 103         putchar(hexdigits[(zBlob[i]>>4)&0x0F]);
 104         putchar(hexdigits[(zBlob[i])&0x0F]);
 105       }
 106       putchar('\'');
 107       break;
 108     }
 109     case SQLITE_TEXT: {
 110       const unsigned char *zArg = sqlite3_value_text(pVal);
 111       putchar('\'');
 112       while( zArg[0] ){
 113         putchar(zArg[0]);
 114         if( zArg[0]=='\'' ) putchar(zArg[0]);
 115         zArg++;
 116       }
 117       putchar('\'');
 118       break;
 119     }
 120     default: {
 121       assert( sqlite3_value_type(pVal)==SQLITE_NULL );
 122       printf("NULL");
 123       break;
 124     }
 125   }
 126 }
 127
 128 /*
 129 ** Number of conflicts seen
 130 */
 131 static int nConflict = 0;
 132
 133 /*
 134 ** The conflict callback
 135 */
 136 static int conflictCallback(
 137   void *pCtx,
 138   int eConflict,
 139   sqlite3_changeset_iter *pIter
 140 ){
 141   int op, bIndirect, nCol, i;
 142   const char *zTab;
 143   unsigned char *abPK;
 144   const char *zType = "";
 145   const char *zOp = "";
 146   const char *zSep = " ";
 147
 148   nConflict++;
 149   sqlite3changeset_op(pIter, &zTab, &nCol, &op, &bIndirect);
 150   sqlite3changeset_pk(pIter, &abPK, 0);
 151   switch( eConflict ){
 152     case SQLITE_CHANGESET_DATA:         zType = "DATA";         break;
 153     case SQLITE_CHANGESET_NOTFOUND:     zType = "NOTFOUND";     break;
 154     case SQLITE_CHANGESET_CONFLICT:     zType = "PRIMARY KEY";  break;
 155     case SQLITE_CHANGESET_FOREIGN_KEY:  zType = "FOREIGN KEY";  break;
 156     case SQLITE_CHANGESET_CONSTRAINT:   zType = "CONSTRAINT";   break;
 157   }
 158   switch( op ){
 159     case SQLITE_UPDATE:     zOp = "UPDATE of";     break;
 160     case SQLITE_INSERT:     zOp = "INSERT into";   break;
 161     case SQLITE_DELETE:     zOp = "DELETE from";   break;
 162   }
 163   printf("%s conflict on %s table %s with primary key", zType, zOp, zTab);
 164   for(i=0; i<nCol; i++){
 165     sqlite3_value *pVal;
 166     if( abPK[i]==0 ) continue;
 167     printf("%s", zSep);
 168     if( op==SQLITE_INSERT ){
 169       sqlite3changeset_new(pIter, i, &pVal);
 170     }else{
 171       sqlite3changeset_old(pIter, i, &pVal);
 172     }
 173     renderValue(pVal);
 174     zSep = ",";
 175   }
 176   printf("\n");
 177   return SQLITE_CHANGESET_OMIT;
 178 }
 179
 180 int main(int argc, char **argv){
 181   int sz, rc;
 182   void *pBuf = 0;
 183   if( argc<3 ) usage(argv[0]);
 184   readFile(argv[1], &sz, &pBuf);
 185
 186   /* changeset FILENAME apply DB
 187   ** Apply the changeset in FILENAME to the database file DB
 188   */
 189   if( strcmp(argv[2],"apply")==0 ){
 190     sqlite3 *db;
 191     if( argc!=4 ) usage(argv[0]);
 192     rc = sqlite3_open(argv[3], &db);
 193     if( rc!=SQLITE_OK ){
 194       fprintf(stderr, "unable to open database file \"%s\": %s\n",
 195               argv[3], sqlite3_errmsg(db));
 196       sqlite3_close(db);
 197       exit(1);
 198     }
 199     sqlite3_exec(db, "BEGIN", 0, 0, 0);
 200     nConflict = 0;
 201     rc = sqlite3changeset_apply(db, sz, pBuf, 0, conflictCallback, 0);
 202     if( rc ){
 203       fprintf(stderr, "sqlite3changeset_apply() returned %d\n", rc);
 204     }
 205     if( nConflict ){
 206       fprintf(stderr, "%d conflicts - no changes applied\n", nConflict);
 207       sqlite3_exec(db, "ROLLBACK", 0, 0, 0);
 208     }else if( rc ){
 209       fprintf(stderr, "sqlite3changeset_apply() returns %d "
 210                       "- no changes applied\n", rc);
 211       sqlite3_exec(db, "ROLLBACK", 0, 0, 0);
 212     }else{
 213       sqlite3_exec(db, "COMMIT", 0, 0, 0);
 214     }
 215     sqlite3_close(db);
 216   }else
 217
 218   /* changeset FILENAME concat FILE2 OUT
 219   ** Add changeset FILE2 onto the end of the changeset in FILENAME
 220   ** and write the result into OUT.
 221   */
 222   if( strcmp(argv[2],"concat")==0 ){
 223     int szB;
 224     void *pB;
 225     int szOut;
 226     void *pOutBuf;
 227     FILE *out;
 228     const char *zOut = argv[4];
 229     if( argc!=5 ) usage(argv[0]);
 230     out = fopen(zOut, "wb");
 231     if( out==0 ){
 232       fprintf(stderr, "cannot open \"%s\" for writing\n", zOut);
 233       exit(1);
 234     }
 235     readFile(argv[3], &szB, &pB);
 236     rc = sqlite3changeset_concat(sz, pBuf, szB, pB, &szOut, &pOutBuf);
 237     if( rc!=SQLITE_OK ){
 238       fprintf(stderr, "sqlite3changeset_concat() returns %d\n", rc);
 239     }else if( szOut>0 && fwrite(pOutBuf, szOut, 1, out)!=1 ){
 240       fprintf(stderr, "unable to write all %d bytes of output to \"%s\"\n",
 241               szOut, zOut);
 242     }
 243     fclose(out);
 244     sqlite3_free(pOutBuf);
 245     sqlite3_free(pB);
 246   }else
 247
 248   /* changeset FILENAME dump
 249   ** Show the complete content of the changeset in FILENAME
 250   */
 251   if( strcmp(argv[2],"dump")==0 ){
 252     int cnt = 0;
 253     int i;
 254     sqlite3_changeset_iter *pIter;
 255     rc = sqlite3changeset_start(&pIter, sz, pBuf);
 256     if( rc!=SQLITE_OK ){
 257       fprintf(stderr, "sqlite3changeset_start() returns %d\n", rc);
 258       exit(1);
 259     }
 260     while( sqlite3changeset_next(pIter)==SQLITE_ROW ){
 261       int op, bIndirect, nCol;
 262       const char *zTab;
 263       unsigned char *abPK;
 264       sqlite3changeset_op(pIter, &zTab, &nCol, &op, &bIndirect);
 265       cnt++;
 266       printf("%d: %s table=[%s] indirect=%d nColumn=%d\n",
 267              cnt, op==SQLITE_INSERT ? "INSERT" :
 268                        op==SQLITE_UPDATE ? "UPDATE" : "DELETE",
 269              zTab, bIndirect, nCol);
 270       sqlite3changeset_pk(pIter, &abPK, 0);
 271       for(i=0; i<nCol; i++){
 272         sqlite3_value *pVal;
 273         pVal = 0;
 274         sqlite3changeset_old(pIter, i, &pVal);
 275         if( pVal ){
 276           printf("    old[%d]%s = ", i, abPK[i] ? "pk" : "  ");
 277           renderValue(pVal);
 278           printf("\n");
 279         }
 280         pVal = 0;
 281         sqlite3changeset_new(pIter, i, &pVal);
 282         if( pVal ){
 283           printf("    new[%d]%s = ", i, abPK[i] ? "pk" : "  ");
 284           renderValue(pVal);
 285           printf("\n");
 286         }
 287       }
 288     }
 289     sqlite3changeset_finalize(pIter);
 290   }else
 291
 292   /* changeset FILENAME invert OUT
 293   ** Invert the changes in FILENAME and writes the result on OUT
 294   */
 295   if( strcmp(argv[2],"invert")==0 ){
 296     FILE *out;
 297     int szOut = 0;
 298     void *pOutBuf = 0;
 299     const char *zOut = argv[3];
 300     if( argc!=4 ) usage(argv[0]);
 301     out = fopen(zOut, "wb");
 302     if( out==0 ){
 303       fprintf(stderr, "cannot open \"%s\" for writing\n", zOut);
 304       exit(1);
 305     }
 306     rc = sqlite3changeset_invert(sz, pBuf, &szOut, &pOutBuf);
 307     if( rc!=SQLITE_OK ){
 308       fprintf(stderr, "sqlite3changeset_invert() returns %d\n", rc);
 309     }else if( szOut>0 && fwrite(pOutBuf, szOut, 1, out)!=1 ){
 310       fprintf(stderr, "unable to write all %d bytes of output to \"%s\"\n",
 311               szOut, zOut);
 312     }
 313     fclose(out);
 314     sqlite3_free(pOutBuf);
 315   }else
 316
 317   /* changeset FILE sql
 318   ** Show the content of the changeset as pseudo-SQL
 319   */
 320   if( strcmp(argv[2],"sql")==0 ){
 321     int cnt = 0;
 322     char *zPrevTab = 0;
 323     char *zSQLTabName = 0;
 324     sqlite3_changeset_iter *pIter = 0;
 325     rc = sqlite3changeset_start(&pIter, sz, pBuf);
 326     if( rc!=SQLITE_OK ){
 327       fprintf(stderr, "sqlite3changeset_start() returns %d\n", rc);
 328       exit(1);
 329     }
 330     printf("BEGIN;\n");
 331     while( sqlite3changeset_next(pIter)==SQLITE_ROW ){
 332       int op, bIndirect, nCol;
 333       const char *zTab;
 334       sqlite3changeset_op(pIter, &zTab, &nCol, &op, &bIndirect);
 335       cnt++;
 336       if( zPrevTab==0 || strcmp(zPrevTab,zTab)!=0 ){
 337         sqlite3_free(zPrevTab);
 338         sqlite3_free(zSQLTabName);
 339         zPrevTab = sqlite3_mprintf("%s", zTab);
 340         if( !isalnum(zTab[0]) || sqlite3_strglob("*[^a-zA-Z0-9]*",zTab)==0 ){
 341           zSQLTabName = sqlite3_mprintf("\"%w\"", zTab);
 342         }else{
 343           zSQLTabName = sqlite3_mprintf("%s", zTab);
 344         }
 345         printf("/****** Changes for table %s ***************/\n", zSQLTabName);
 346       }
 347       switch( op ){
 348         case SQLITE_DELETE: {
 349           unsigned char *abPK;
 350           int i;
 351           const char *zSep = " ";
 352           sqlite3changeset_pk(pIter, &abPK, 0);
 353           printf("/* %d */ DELETE FROM %s WHERE", cnt, zSQLTabName);
 354           for(i=0; i<nCol; i++){
 355             sqlite3_value *pVal;
 356             if( abPK[i]==0 ) continue;
 357             printf("%sc%d=", zSep, i+1);
 358             zSep = " AND ";
 359             sqlite3changeset_old(pIter, i, &pVal);
 360             renderValue(pVal);
 361           }
 362           printf(";\n");
 363           break;
 364         }
 365         case SQLITE_UPDATE: {
 366           unsigned char *abPK;
 367           int i;
 368           const char *zSep = " ";
 369           sqlite3changeset_pk(pIter, &abPK, 0);
 370           printf("/* %d */ UPDATE %s SET", cnt, zSQLTabName);
 371           for(i=0; i<nCol; i++){
 372             sqlite3_value *pVal = 0;
 373             sqlite3changeset_new(pIter, i, &pVal);
 374             if( pVal ){
 375               printf("%sc%d=", zSep, i+1);
 376               zSep = ", ";
 377               renderValue(pVal);
 378             }
 379           }
 380           printf(" WHERE");
 381           zSep = " ";
 382           for(i=0; i<nCol; i++){
 383             sqlite3_value *pVal;
 384             if( abPK[i]==0 ) continue;
 385             printf("%sc%d=", zSep, i+1);
 386             zSep = " AND ";
 387             sqlite3changeset_old(pIter, i, &pVal);
 388             renderValue(pVal);
 389           }
 390           printf(";\n");
 391           break;
 392         }
 393         case SQLITE_INSERT: {
 394           int i;
 395           printf("/* %d */ INSERT INTO %s VALUES", cnt, zSQLTabName);
 396           for(i=0; i<nCol; i++){
 397             sqlite3_value *pVal;
 398             printf("%c", i==0 ? '(' : ',');
 399             sqlite3changeset_new(pIter, i, &pVal);
 400             renderValue(pVal);
 401           }
 402           printf(");\n");
 403           break;
 404         }
 405       }
 406     }
 407     printf("COMMIT;\n");
 408     sqlite3changeset_finalize(pIter);
 409     sqlite3_free(zPrevTab);
 410     sqlite3_free(zSQLTabName);
 411   }else
 412
 413   /* If nothing else matches, show the usage comment */
 414   usage(argv[0]);
 415   sqlite3_free(pBuf);
 416   return 0;
 417 }