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 void setrangeCommand(redisClient *c) {
  86     robj *o;
  87     long offset;
  88     sds value = c->argv[3]->ptr;
  89
  90     if (getLongFromObjectOrReply(c,c->argv[2],&offset,NULL) != REDIS_OK)
  91         return;
  92
  93     if (offset < 0) {
  94         addReplyError(c,"offset is out of range");
  95         return;
  96     }
  97
  98     o = lookupKeyWrite(c->db,c->argv[1]);
  99     if (o == NULL) {
 100         /* Return 0 when setting nothing on a non-existing string */
 101         if (sdslen(value) == 0) {
 102             addReply(c,shared.czero);
 103             return;
 104         }
 105
 106         /* Return when the resulting string exceeds allowed size */
 107         if (checkStringLength(c,offset+sdslen(value)) != REDIS_OK)
 108             return;
 109
 110         o = createObject(REDIS_STRING,sdsempty());
 111         dbAdd(c->db,c->argv[1],o);
 112     } else {
 113         size_t olen;
 114
 115         /* Key exists, check type */
 116         if (checkType(c,o,REDIS_STRING))
 117             return;
 118
 119         /* Return existing string length when setting nothing */
 120         olen = stringObjectLen(o);
 121         if (sdslen(value) == 0) {
 122             addReplyLongLong(c,olen);
 123             return;
 124         }
 125
 126         /* Return when the resulting string exceeds allowed size */
 127         if (checkStringLength(c,offset+sdslen(value)) != REDIS_OK)
 128             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     if (sdslen(value) > 0) {
 140         o->ptr = sdsgrowzero(o->ptr,offset+sdslen(value));
 141         memcpy((char*)o->ptr+offset,value,sdslen(value));
 142         signalModifiedKey(c->db,c->argv[1]);
 143         server.dirty++;
 144     }
 145     addReplyLongLong(c,sdslen(o->ptr));
 146 }
 147
 148 void getrangeCommand(redisClient *c) {
 149     robj *o;
 150     long start, end;
 151     char *str, llbuf[32];
 152     size_t strlen;
 153
 154     if (getLongFromObjectOrReply(c,c->argv[2],&start,NULL) != REDIS_OK)
 155         return;
 156     if (getLongFromObjectOrReply(c,c->argv[3],&end,NULL) != REDIS_OK)
 157         return;
 158     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptybulk)) == NULL ||
 159         checkType(c,o,REDIS_STRING)) return;
 160
 161     if (o->encoding == REDIS_ENCODING_INT) {
 162         str = llbuf;
 163         strlen = ll2string(llbuf,sizeof(llbuf),(long)o->ptr);
 164     } else {
 165         str = o->ptr;
 166         strlen = sdslen(str);
 167     }
 168
 169     /* Convert negative indexes */
 170     if (start < 0) start = strlen+start;
 171     if (end < 0) end = strlen+end;
 172     if (start < 0) start = 0;
 173     if (end < 0) end = 0;
 174     if ((unsigned)end >= strlen) end = strlen-1;
 175
 176     /* Precondition: end >= 0 && end < strlen, so the only condition where
 177      * nothing can be returned is: start > end. */
 178     if (start > end) {
 179         addReply(c,shared.emptybulk);
 180     } else {
 181         addReplyBulkCBuffer(c,(char*)str+start,end-start+1);
 182     }
 183 }
 184
 185 void mgetCommand(redisClient *c) {
 186     int j;
 187
 188     addReplyMultiBulkLen(c,c->argc-1);
 189     for (j = 1; j < c->argc; j++) {
 190         robj *o = lookupKeyRead(c->db,c->argv[j]);
 191         if (o == NULL) {
 192             addReply(c,shared.nullbulk);
 193         } else {
 194             if (o->type != REDIS_STRING) {
 195                 addReply(c,shared.nullbulk);
 196             } else {
 197                 addReplyBulk(c,o);
 198             }
 199         }
 200     }
 201 }
 202
 203 void msetGenericCommand(redisClient *c, int nx) {
 204     int j, busykeys = 0;
 205
 206     if ((c->argc % 2) == 0) {
 207         addReplyError(c,"wrong number of arguments for MSET");
 208         return;
 209     }
 210     /* Handle the NX flag. The MSETNX semantic is to return zero and don't
 211      * set nothing at all if at least one already key exists. */
 212     if (nx) {
 213         for (j = 1; j < c->argc; j += 2) {
 214             if (lookupKeyWrite(c->db,c->argv[j]) != NULL) {
 215                 busykeys++;
 216             }
 217         }
 218         if (busykeys) {
 219             addReply(c, shared.czero);
 220             return;
 221         }
 222     }
 223
 224     for (j = 1; j < c->argc; j += 2) {
 225         c->argv[j+1] = tryObjectEncoding(c->argv[j+1]);
 226         setKey(c->db,c->argv[j],c->argv[j+1]);
 227     }
 228     server.dirty += (c->argc-1)/2;
 229     addReply(c, nx ? shared.cone : shared.ok);
 230 }
 231
 232 void msetCommand(redisClient *c) {
 233     msetGenericCommand(c,0);
 234 }
 235
 236 void msetnxCommand(redisClient *c) {
 237     msetGenericCommand(c,1);
 238 }
 239
 240 void incrDecrCommand(redisClient *c, long long incr) {
 241     long long value, oldvalue;
 242     robj *o, *new;
 243
 244     o = lookupKeyWrite(c->db,c->argv[1]);
 245     if (o != NULL && checkType(c,o,REDIS_STRING)) return;
 246     if (getLongLongFromObjectOrReply(c,o,&value,NULL) != REDIS_OK) return;
 247
 248     oldvalue = value;
 249     if ((incr < 0 && oldvalue < 0 && incr < (LLONG_MIN-oldvalue)) ||
 250         (incr > 0 && oldvalue > 0 && incr > (LLONG_MAX-oldvalue))) {
 251         addReplyError(c,"increment or decrement would overflow");
 252         return;
 253     }
 254     value += incr;
 255     new = createStringObjectFromLongLong(value);
 256     if (o)
 257         dbOverwrite(c->db,c->argv[1],new);
 258     else
 259         dbAdd(c->db,c->argv[1],new);
 260     signalModifiedKey(c->db,c->argv[1]);
 261     server.dirty++;
 262     addReply(c,shared.colon);
 263     addReply(c,new);
 264     addReply(c,shared.crlf);
 265 }
 266
 267 void incrCommand(redisClient *c) {
 268     incrDecrCommand(c,1);
 269 }
 270
 271 void decrCommand(redisClient *c) {
 272     incrDecrCommand(c,-1);
 273 }
 274
 275 void incrbyCommand(redisClient *c) {
 276     long long incr;
 277
 278     if (getLongLongFromObjectOrReply(c, c->argv[2], &incr, NULL) != REDIS_OK) return;
 279     incrDecrCommand(c,incr);
 280 }
 281
 282 void decrbyCommand(redisClient *c) {
 283     long long incr;
 284
 285     if (getLongLongFromObjectOrReply(c, c->argv[2], &incr, NULL) != REDIS_OK) return;
 286     incrDecrCommand(c,-incr);
 287 }
 288
 289 void incrbyfloatCommand(redisClient *c) {
 290     long double incr, value;
 291     robj *o, *new, *aux;
 292
 293     o = lookupKeyWrite(c->db,c->argv[1]);
 294     if (o != NULL && checkType(c,o,REDIS_STRING)) return;
 295     if (getLongDoubleFromObjectOrReply(c,o,&value,NULL) != REDIS_OK ||
 296         getLongDoubleFromObjectOrReply(c,c->argv[2],&incr,NULL) != REDIS_OK)
 297         return;
 298
 299     value += incr;
 300     if (isnan(value) || isinf(value)) {
 301         addReplyError(c,"increment would produce NaN or Infinity");
 302         return;
 303     }
 304     new = createStringObjectFromLongDouble(value);
 305     if (o)
 306         dbOverwrite(c->db,c->argv[1],new);
 307     else
 308         dbAdd(c->db,c->argv[1],new);
 309     signalModifiedKey(c->db,c->argv[1]);
 310     server.dirty++;
 311     addReplyBulk(c,new);
 312
 313     /* Always replicate INCRBYFLOAT as a SET command with the final value
 314      * in order to make sure that differences in float pricision or formatting
 315      * will not create differences in replicas or after an AOF restart. */
 316     aux = createStringObject("SET",3);
 317     rewriteClientCommandArgument(c,0,aux);
 318     decrRefCount(aux);
 319     rewriteClientCommandArgument(c,2,new);
 320 }
 321
 322 void appendCommand(redisClient *c) {
 323     size_t totlen;
 324     robj *o, *append;
 325
 326     o = lookupKeyWrite(c->db,c->argv[1]);
 327     if (o == NULL) {
 328         /* Create the key */
 329         c->argv[2] = tryObjectEncoding(c->argv[2]);
 330         dbAdd(c->db,c->argv[1],c->argv[2]);
 331         incrRefCount(c->argv[2]);
 332         totlen = stringObjectLen(c->argv[2]);
 333     } else {
 334         /* Key exists, check type */
 335         if (checkType(c,o,REDIS_STRING))
 336             return;
 337
 338         /* "append" is an argument, so always an sds */
 339         append = c->argv[2];
 340         totlen = stringObjectLen(o)+sdslen(append->ptr);
 341         if (checkStringLength(c,totlen) != REDIS_OK)
 342             return;
 343
 344         /* If the object is shared or encoded, we have to make a copy */
 345         if (o->refcount != 1 || o->encoding != REDIS_ENCODING_RAW) {
 346             robj *decoded = getDecodedObject(o);
 347             o = createStringObject(decoded->ptr, sdslen(decoded->ptr));
 348             decrRefCount(decoded);
 349             dbOverwrite(c->db,c->argv[1],o);
 350         }
 351
 352         /* Append the value */
 353         o->ptr = sdscatlen(o->ptr,append->ptr,sdslen(append->ptr));
 354         totlen = sdslen(o->ptr);
 355     }
 356     signalModifiedKey(c->db,c->argv[1]);
 357     server.dirty++;
 358     addReplyLongLong(c,totlen);
 359 }
 360
 361 void strlenCommand(redisClient *c) {
 362     robj *o;
 363     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
 364         checkType(c,o,REDIS_STRING)) return;
 365     addReplyLongLong(c,stringObjectLen(o));
 366 }