Disable negative offsets for SETRANGE

[redis.git] / src / t_string.c

diff --git a/src/t_string.c b/src/t_string.c
index b71bfe99b793a3e456de02032ac5570e09fd7c36..324e01ab4f3b4f1384c13157aae850ce5a648e6d 100644 (file)
--- a/src/t_string.c
+++ b/src/t_string.c
@@ -96,10 +96,8 @@ static int getBitOffsetFromArgument(redisClient *c, robj *o, size_t *offset) {
     if (getLongLongFromObjectOrReply(c,o,&loffset,err) != REDIS_OK)
         return REDIS_ERR;
 
-    /* Limit offset to SIZE_T_MAX or 512MB in bytes */
-    if ((loffset < 0) ||
-        ((unsigned long long)loffset >= (unsigned)SIZE_T_MAX) ||
-        ((unsigned long long)loffset >> 3) >= (512*1024*1024))
+    /* Limit offset to 512MB in bytes */
+    if ((loffset < 0) || ((unsigned long long)loffset >> 3) >= (512*1024*1024))
     {
         addReplyError(c,err);
         return REDIS_ERR;
@@ -113,17 +111,18 @@ void setbitCommand(redisClient *c) {
     robj *o;
     char *err = "bit is not an integer or out of range";
     size_t bitoffset;
-    long long bitvalue;
-    int byte, bit, on;
+    int byte, bit;
+    int byteval, bitval;
+    long on;
 
     if (getBitOffsetFromArgument(c,c->argv[2],&bitoffset) != REDIS_OK)
         return;
 
-    if (getLongLongFromObjectOrReply(c,c->argv[3],&bitvalue,err) != REDIS_OK)
+    if (getLongFromObjectOrReply(c,c->argv[3],&on,err) != REDIS_OK)
         return;
 
-    /* A bit can only be set to be on or off... */
-    if (bitvalue & ~1) {
+    /* Bits can only be set or cleared... */
+    if (on & ~1) {
         addReplyError(c,err);
         return;
     }
@@ -144,23 +143,30 @@ void setbitCommand(redisClient *c) {
         }
     }
 
+    /* Grow sds value to the right length if necessary */
     byte = bitoffset >> 3;
-    bit = 7 - (bitoffset & 0x7);
-    on = bitvalue & 0x1;
     o->ptr = sdsgrowzero(o->ptr,byte+1);
-    ((char*)o->ptr)[byte] |= on << bit;
-    ((char*)o->ptr)[byte] &= ~((!on) << bit);
 
+    /* Get current values */
+    byteval = ((char*)o->ptr)[byte];
+    bit = 7 - (bitoffset & 0x7);
+    bitval = byteval & (1 << bit);
+
+    /* Update byte with new bit value and return original value */
+    byteval &= ~(1 << bit);
+    byteval |= ((on & 0x1) << bit);
+    ((char*)o->ptr)[byte] = byteval;
     touchWatchedKey(c->db,c->argv[1]);
     server.dirty++;
-    addReply(c,shared.cone);
+    addReply(c, bitval ? shared.cone : shared.czero);
 }
 
 void getbitCommand(redisClient *c) {
     robj *o;
-    size_t bitoffset, byte, bitmask;
-    int on = 0;
     char llbuf[32];
+    size_t bitoffset;
+    size_t byte, bit;
+    size_t bitval = 0;
 
     if (getBitOffsetFromArgument(c,c->argv[2],&bitoffset) != REDIS_OK)
         return;
@@ -169,15 +175,16 @@ void getbitCommand(redisClient *c) {
         checkType(c,o,REDIS_STRING)) return;
 
     byte = bitoffset >> 3;
-    bitmask = 1 << (7 - (bitoffset & 0x7));
+    bit = 7 - (bitoffset & 0x7);
     if (o->encoding != REDIS_ENCODING_RAW) {
         if (byte < (size_t)ll2string(llbuf,sizeof(llbuf),(long)o->ptr))
-            on = llbuf[byte] & bitmask;
+            bitval = llbuf[byte] & (1 << bit);
     } else {
         if (byte < sdslen(o->ptr))
-            on = ((sds)o->ptr)[byte] & bitmask;
+            bitval = ((char*)o->ptr)[byte] & (1 << bit);
     }
-    addReply(c, on ? shared.cone : shared.czero);
+
+    addReply(c, bitval ? shared.cone : shared.czero);
 }
 
 void setrangeCommand(redisClient *c) {
@@ -188,11 +195,13 @@ void setrangeCommand(redisClient *c) {
     if (getLongFromObjectOrReply(c,c->argv[2],&offset,NULL) != REDIS_OK)
         return;
 
+    if (offset < 0) {
+        addReplyError(c,"offset is out of range");
+        return;
+    }
+
     o = lookupKeyWrite(c->db,c->argv[1]);
     if (o == NULL) {
-        /* Negative offset is always 0 for non-existing keys */
-        if (offset < 0) offset = 0;
-
         /* Return 0 when setting nothing on a non-existing string */
         if (sdslen(value) == 0) {
             addReply(c,shared.czero);
@@ -226,15 +235,6 @@ void setrangeCommand(redisClient *c) {
             return;
         }
 
-        /* Convert negative indexes. Note that for SETRANGE, the meaning of a
-         * negative index is a little different than for other commands.
-         * Here, an offset of -1 points to the trailing NULL byte of the
-         * string instead of the last character. */
-        if (offset < 0) {
-            offset = olen+1+offset;
-            if (offset < 0) offset = 0;
-        }
-
         /* Return when the resulting string exceeds allowed size */
         if (checkStringLength(c,offset+sdslen(value)) != REDIS_OK)
             return;