src/t_string.c

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