src/t_string.c

   1 #include "redis.h"
   2 #include <math.h> /* isnan(), isinf() */
   3
   4 /*-----------------------------------------------------------------------------
   5  * String Commands
   6  *----------------------------------------------------------------------------*/
   7
   8 static int checkStringLength(redisClient *c, long long size) {
   9     if (size > 512*1024*1024) {
  10         addReplyError(c,"string exceeds maximum allowed size (512MB)");
  11         return REDIS_ERR;
  12     }
  13     return REDIS_OK;
  14 }
  15
  16 void setGenericCommand(redisClient *c, int nx, robj *key, robj *val, robj *expire, int unit) {
  17     long long milliseconds = 0; /* initialized to avoid an harmness warning */
  18
  19     if (expire) {
  20         if (getLongLongFromObjectOrReply(c, expire, &milliseconds, NULL) != REDIS_OK)
  21             return;
  22         if (milliseconds <= 0) {
  23             addReplyError(c,"invalid expire time in SETEX");
  24             return;
  25         }
  26         if (unit == UNIT_SECONDS) milliseconds *= 1000;
  27     }
  28
  29     if (lookupKeyWrite(c->db,key) != NULL && nx) {
  30         addReply(c,shared.czero);
  31         return;
  32     }
  33     setKey(c->db,key,val);
  34     server.dirty++;
  35     if (expire) setExpire(c->db,key,mstime()+milliseconds);
  36     addReply(c, nx ? shared.cone : shared.ok);
  37 }
  38
  39 void setCommand(redisClient *c) {
  40     c->argv[2] = tryObjectEncoding(c->argv[2]);
  41     setGenericCommand(c,0,c->argv[1],c->argv[2],NULL,0);
  42 }
  43
  44 void setnxCommand(redisClient *c) {
  45     c->argv[2] = tryObjectEncoding(c->argv[2]);
  46     setGenericCommand(c,1,c->argv[1],c->argv[2],NULL,0);
  47 }
  48
  49 void setexCommand(redisClient *c) {
  50     c->argv[3] = tryObjectEncoding(c->argv[3]);
  51     setGenericCommand(c,0,c->argv[1],c->argv[3],c->argv[2],UNIT_SECONDS);
  52 }
  53
  54 void psetexCommand(redisClient *c) {
  55     c->argv[3] = tryObjectEncoding(c->argv[3]);
  56     setGenericCommand(c,0,c->argv[1],c->argv[3],c->argv[2],UNIT_MILLISECONDS);
  57 }
  58
  59 int getGenericCommand(redisClient *c) {
  60     robj *o;
  61
  62     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL)
  63         return REDIS_OK;
  64
  65     if (o->type != REDIS_STRING) {
  66         addReply(c,shared.wrongtypeerr);
  67         return REDIS_ERR;
  68     } else {
  69         addReplyBulk(c,o);
  70         return REDIS_OK;
  71     }
  72 }
  73
  74 void getCommand(redisClient *c) {
  75     getGenericCommand(c);
  76 }
  77
  78 void getsetCommand(redisClient *c) {
  79     if (getGenericCommand(c) == REDIS_ERR) return;
  80     c->argv[2] = tryObjectEncoding(c->argv[2]);
  81     setKey(c->db,c->argv[1],c->argv[2]);
  82     server.dirty++;
  83 }
  84
  85 static int getBitOffsetFromArgument(redisClient *c, robj *o, size_t *offset) {
  86     long long loffset;
  87     char *err = "bit offset is not an integer or out of range";
  88
  89     if (getLongLongFromObjectOrReply(c,o,&loffset,err) != REDIS_OK)
  90         return REDIS_ERR;
  91
  92     /* Limit offset to 512MB in bytes */
  93     if ((loffset < 0) || ((unsigned long long)loffset >> 3) >= (512*1024*1024))
  94     {
  95         addReplyError(c,err);
  96         return REDIS_ERR;
  97     }
  98
  99     *offset = (size_t)loffset;
 100     return REDIS_OK;
 101 }
 102
 103 void setbitCommand(redisClient *c) {
 104     robj *o;
 105     char *err = "bit is not an integer or out of range";
 106     size_t bitoffset;
 107     int byte, bit;
 108     int byteval, bitval;
 109     long on;
 110
 111     if (getBitOffsetFromArgument(c,c->argv[2],&bitoffset) != REDIS_OK)
 112         return;
 113
 114     if (getLongFromObjectOrReply(c,c->argv[3],&on,err) != REDIS_OK)
 115         return;
 116
 117     /* Bits can only be set or cleared... */
 118     if (on & ~1) {
 119         addReplyError(c,err);
 120         return;
 121     }
 122
 123     o = lookupKeyWrite(c->db,c->argv[1]);
 124     if (o == NULL) {
 125         o = createObject(REDIS_STRING,sdsempty());
 126         dbAdd(c->db,c->argv[1],o);
 127     } else {
 128         if (checkType(c,o,REDIS_STRING)) return;
 129
 130         /* Create a copy when the object is shared or encoded. */
 131         if (o->refcount != 1 || o->encoding != REDIS_ENCODING_RAW) {
 132             robj *decoded = getDecodedObject(o);
 133             o = createStringObject(decoded->ptr, sdslen(decoded->ptr));
 134             decrRefCount(decoded);
 135             dbOverwrite(c->db,c->argv[1],o);
 136         }
 137     }
 138
 139     /* Grow sds value to the right length if necessary */
 140     byte = bitoffset >> 3;
 141     o->ptr = sdsgrowzero(o->ptr,byte+1);
 142
 143     /* Get current values */
 144     byteval = ((char*)o->ptr)[byte];
 145     bit = 7 - (bitoffset & 0x7);
 146     bitval = byteval & (1 << bit);
 147
 148     /* Update byte with new bit value and return original value */
 149     byteval &= ~(1 << bit);
 150     byteval |= ((on & 0x1) << bit);
 151     ((char*)o->ptr)[byte] = byteval;
 152     signalModifiedKey(c->db,c->argv[1]);
 153     server.dirty++;
 154     addReply(c, bitval ? shared.cone : shared.czero);
 155 }
 156
 157 void getbitCommand(redisClient *c) {
 158     robj *o;
 159     char llbuf[32];
 160     size_t bitoffset;
 161     size_t byte, bit;
 162     size_t bitval = 0;
 163
 164     if (getBitOffsetFromArgument(c,c->argv[2],&bitoffset) != REDIS_OK)
 165         return;
 166
 167     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
 168         checkType(c,o,REDIS_STRING)) return;
 169
 170     byte = bitoffset >> 3;
 171     bit = 7 - (bitoffset & 0x7);
 172     if (o->encoding != REDIS_ENCODING_RAW) {
 173         if (byte < (size_t)ll2string(llbuf,sizeof(llbuf),(long)o->ptr))
 174             bitval = llbuf[byte] & (1 << bit);
 175     } else {
 176         if (byte < sdslen(o->ptr))
 177             bitval = ((char*)o->ptr)[byte] & (1 << bit);
 178     }
 179
 180     addReply(c, bitval ? shared.cone : shared.czero);
 181 }
 182
 183 void setrangeCommand(redisClient *c) {
 184     robj *o;
 185     long offset;
 186     sds value = c->argv[3]->ptr;
 187
 188     if (getLongFromObjectOrReply(c,c->argv[2],&offset,NULL) != REDIS_OK)
 189         return;
 190
 191     if (offset < 0) {
 192         addReplyError(c,"offset is out of range");
 193         return;
 194     }
 195
 196     o = lookupKeyWrite(c->db,c->argv[1]);
 197     if (o == NULL) {
 198         /* Return 0 when setting nothing on a non-existing string */
 199         if (sdslen(value) == 0) {
 200             addReply(c,shared.czero);
 201             return;
 202         }
 203
 204         /* Return when the resulting string exceeds allowed size */
 205         if (checkStringLength(c,offset+sdslen(value)) != REDIS_OK)
 206             return;
 207
 208         o = createObject(REDIS_STRING,sdsempty());
 209         dbAdd(c->db,c->argv[1],o);
 210     } else {
 211         size_t olen;
 212
 213         /* Key exists, check type */
 214         if (checkType(c,o,REDIS_STRING))
 215             return;
 216
 217         /* Return existing string length when setting nothing */
 218         olen = stringObjectLen(o);
 219         if (sdslen(value) == 0) {
 220             addReplyLongLong(c,olen);
 221             return;
 222         }
 223
 224         /* Return when the resulting string exceeds allowed size */
 225         if (checkStringLength(c,offset+sdslen(value)) != REDIS_OK)
 226             return;
 227
 228         /* Create a copy when the object is shared or encoded. */
 229         if (o->refcount != 1 || o->encoding != REDIS_ENCODING_RAW) {
 230             robj *decoded = getDecodedObject(o);
 231             o = createStringObject(decoded->ptr, sdslen(decoded->ptr));
 232             decrRefCount(decoded);
 233             dbOverwrite(c->db,c->argv[1],o);
 234         }
 235     }
 236
 237     if (sdslen(value) > 0) {
 238         o->ptr = sdsgrowzero(o->ptr,offset+sdslen(value));
 239         memcpy((char*)o->ptr+offset,value,sdslen(value));
 240         signalModifiedKey(c->db,c->argv[1]);
 241         server.dirty++;
 242     }
 243     addReplyLongLong(c,sdslen(o->ptr));
 244 }
 245
 246 void getrangeCommand(redisClient *c) {
 247     robj *o;
 248     long start, end;
 249     char *str, llbuf[32];
 250     size_t strlen;
 251
 252     if (getLongFromObjectOrReply(c,c->argv[2],&start,NULL) != REDIS_OK)
 253         return;
 254     if (getLongFromObjectOrReply(c,c->argv[3],&end,NULL) != REDIS_OK)
 255         return;
 256     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptybulk)) == NULL ||
 257         checkType(c,o,REDIS_STRING)) return;
 258
 259     if (o->encoding == REDIS_ENCODING_INT) {
 260         str = llbuf;
 261         strlen = ll2string(llbuf,sizeof(llbuf),(long)o->ptr);
 262     } else {
 263         str = o->ptr;
 264         strlen = sdslen(str);
 265     }
 266
 267     /* Convert negative indexes */
 268     if (start < 0) start = strlen+start;
 269     if (end < 0) end = strlen+end;
 270     if (start < 0) start = 0;
 271     if (end < 0) end = 0;
 272     if ((unsigned)end >= strlen) end = strlen-1;
 273
 274     /* Precondition: end >= 0 && end < strlen, so the only condition where
 275      * nothing can be returned is: start > end. */
 276     if (start > end) {
 277         addReply(c,shared.emptybulk);
 278     } else {
 279         addReplyBulkCBuffer(c,(char*)str+start,end-start+1);
 280     }
 281 }
 282
 283 void mgetCommand(redisClient *c) {
 284     int j;
 285
 286     addReplyMultiBulkLen(c,c->argc-1);
 287     for (j = 1; j < c->argc; j++) {
 288         robj *o = lookupKeyRead(c->db,c->argv[j]);
 289         if (o == NULL) {
 290             addReply(c,shared.nullbulk);
 291         } else {
 292             if (o->type != REDIS_STRING) {
 293                 addReply(c,shared.nullbulk);
 294             } else {
 295                 addReplyBulk(c,o);
 296             }
 297         }
 298     }
 299 }
 300
 301 void msetGenericCommand(redisClient *c, int nx) {
 302     int j, busykeys = 0;
 303
 304     if ((c->argc % 2) == 0) {
 305         addReplyError(c,"wrong number of arguments for MSET");
 306         return;
 307     }
 308     /* Handle the NX flag. The MSETNX semantic is to return zero and don't
 309      * set nothing at all if at least one already key exists. */
 310     if (nx) {
 311         for (j = 1; j < c->argc; j += 2) {
 312             if (lookupKeyWrite(c->db,c->argv[j]) != NULL) {
 313                 busykeys++;
 314             }
 315         }
 316         if (busykeys) {
 317             addReply(c, shared.czero);
 318             return;
 319         }
 320     }
 321
 322     for (j = 1; j < c->argc; j += 2) {
 323         c->argv[j+1] = tryObjectEncoding(c->argv[j+1]);
 324         setKey(c->db,c->argv[j],c->argv[j+1]);
 325     }
 326     server.dirty += (c->argc-1)/2;
 327     addReply(c, nx ? shared.cone : shared.ok);
 328 }
 329
 330 void msetCommand(redisClient *c) {
 331     msetGenericCommand(c,0);
 332 }
 333
 334 void msetnxCommand(redisClient *c) {
 335     msetGenericCommand(c,1);
 336 }
 337
 338 void incrDecrCommand(redisClient *c, long long incr) {
 339     long long value, oldvalue;
 340     robj *o, *new;
 341
 342     o = lookupKeyWrite(c->db,c->argv[1]);
 343     if (o != NULL && checkType(c,o,REDIS_STRING)) return;
 344     if (getLongLongFromObjectOrReply(c,o,&value,NULL) != REDIS_OK) return;
 345
 346     oldvalue = value;
 347     value += incr;
 348     if ((incr < 0 && value > oldvalue) || (incr > 0 && value < oldvalue)) {
 349         addReplyError(c,"increment or decrement would overflow");
 350         return;
 351     }
 352     new = createStringObjectFromLongLong(value);
 353     if (o)
 354         dbOverwrite(c->db,c->argv[1],new);
 355     else
 356         dbAdd(c->db,c->argv[1],new);
 357     signalModifiedKey(c->db,c->argv[1]);
 358     server.dirty++;
 359     addReply(c,shared.colon);
 360     addReply(c,new);
 361     addReply(c,shared.crlf);
 362 }
 363
 364 void incrCommand(redisClient *c) {
 365     incrDecrCommand(c,1);
 366 }
 367
 368 void decrCommand(redisClient *c) {
 369     incrDecrCommand(c,-1);
 370 }
 371
 372 void incrbyCommand(redisClient *c) {
 373     long long incr;
 374
 375     if (getLongLongFromObjectOrReply(c, c->argv[2], &incr, NULL) != REDIS_OK) return;
 376     incrDecrCommand(c,incr);
 377 }
 378
 379 void decrbyCommand(redisClient *c) {
 380     long long incr;
 381
 382     if (getLongLongFromObjectOrReply(c, c->argv[2], &incr, NULL) != REDIS_OK) return;
 383     incrDecrCommand(c,-incr);
 384 }
 385
 386 void incrbyfloatCommand(redisClient *c) {
 387     long double incr, value;
 388     robj *o, *new, *aux;
 389
 390     o = lookupKeyWrite(c->db,c->argv[1]);
 391     if (o != NULL && checkType(c,o,REDIS_STRING)) return;
 392     if (getLongDoubleFromObjectOrReply(c,o,&value,NULL) != REDIS_OK ||
 393         getLongDoubleFromObjectOrReply(c,c->argv[2],&incr,NULL) != REDIS_OK)
 394         return;
 395
 396     value += incr;
 397     if (isnan(value) || isinf(value)) {
 398         addReplyError(c,"increment would produce NaN or Infinity");
 399         return;
 400     }
 401     new = createStringObjectFromLongDouble(value);
 402     if (o)
 403         dbOverwrite(c->db,c->argv[1],new);
 404     else
 405         dbAdd(c->db,c->argv[1],new);
 406     signalModifiedKey(c->db,c->argv[1]);
 407     server.dirty++;
 408     addReplyBulk(c,new);
 409
 410     /* Always replicate INCRBYFLOAT as a SET command with the final value
 411      * in order to make sure that differences in float pricision or formatting
 412      * will not create differences in replicas or after an AOF restart. */
 413     aux = createStringObject("SET",3);
 414     rewriteClientCommandArgument(c,0,aux);
 415     decrRefCount(aux);
 416     rewriteClientCommandArgument(c,2,new);
 417 }
 418
 419 void appendCommand(redisClient *c) {
 420     size_t totlen;
 421     robj *o, *append;
 422
 423     o = lookupKeyWrite(c->db,c->argv[1]);
 424     if (o == NULL) {
 425         /* Create the key */
 426         c->argv[2] = tryObjectEncoding(c->argv[2]);
 427         dbAdd(c->db,c->argv[1],c->argv[2]);
 428         incrRefCount(c->argv[2]);
 429         totlen = stringObjectLen(c->argv[2]);
 430     } else {
 431         /* Key exists, check type */
 432         if (checkType(c,o,REDIS_STRING))
 433             return;
 434
 435         /* "append" is an argument, so always an sds */
 436         append = c->argv[2];
 437         totlen = stringObjectLen(o)+sdslen(append->ptr);
 438         if (checkStringLength(c,totlen) != REDIS_OK)
 439             return;
 440
 441         /* If the object is shared or encoded, we have to make a copy */
 442         if (o->refcount != 1 || o->encoding != REDIS_ENCODING_RAW) {
 443             robj *decoded = getDecodedObject(o);
 444             o = createStringObject(decoded->ptr, sdslen(decoded->ptr));
 445             decrRefCount(decoded);
 446             dbOverwrite(c->db,c->argv[1],o);
 447         }
 448
 449         /* Append the value */
 450         o->ptr = sdscatlen(o->ptr,append->ptr,sdslen(append->ptr));
 451         totlen = sdslen(o->ptr);
 452     }
 453     signalModifiedKey(c->db,c->argv[1]);
 454     server.dirty++;
 455     addReplyLongLong(c,totlen);
 456 }
 457
 458 void strlenCommand(redisClient *c) {
 459     robj *o;
 460     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
 461         checkType(c,o,REDIS_STRING)) return;
 462     addReplyLongLong(c,stringObjectLen(o));
 463 }
 464