src/t_string.c

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