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Bit-related string operations moved to bitop.c

All the general string operations are implemented in t_string.c, however
the bit operations, while targeting the string type, are better served
in a specific file where we have the implementations of the following
four commands and helper functions:

    GETBIT
    SETBIT
    BITOP
    BITCOUNT

In the future this file will probably contain more code related to
making the BITOP and BITCOUNT operations faster.
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1 parent a3f2b48 commit 760e7765263ff4b6d5176830c9e8e8d733744996 @antirez antirez committed May 19, 2012
Showing with 260 additions and 249 deletions.
  1. +1 −1 src/Makefile
  2. +259 −0 src/bitop.c
  3. +0 −248 src/t_string.c
View
2 src/Makefile
@@ -96,7 +96,7 @@ QUIET_LINK = @printf ' %b %b\n' $(LINKCOLOR)LINK$(ENDCOLOR) $(BINCOLOR)$@$(EN
endif
REDIS_SERVER_NAME= redis-server
-REDIS_SERVER_OBJ= adlist.o ae.o anet.o dict.o redis.o sds.o zmalloc.o lzf_c.o lzf_d.o pqsort.o zipmap.o sha1.o ziplist.o release.o networking.o util.o object.o db.o replication.o rdb.o t_string.o t_list.o t_set.o t_zset.o t_hash.o config.o aof.o pubsub.o multi.o debug.o sort.o intset.o syncio.o cluster.o crc16.o endianconv.o slowlog.o scripting.o bio.o rio.o rand.o memtest.o crc64.o
+REDIS_SERVER_OBJ= adlist.o ae.o anet.o dict.o redis.o sds.o zmalloc.o lzf_c.o lzf_d.o pqsort.o zipmap.o sha1.o ziplist.o release.o networking.o util.o object.o db.o replication.o rdb.o t_string.o t_list.o t_set.o t_zset.o t_hash.o config.o aof.o pubsub.o multi.o debug.o sort.o intset.o syncio.o cluster.o crc16.o endianconv.o slowlog.o scripting.o bio.o rio.o rand.o memtest.o crc64.o bitop.o
REDIS_CLI_NAME= redis-cli
REDIS_CLI_OBJ= anet.o sds.o adlist.o redis-cli.o zmalloc.o release.o anet.o ae.o
REDIS_BENCHMARK_NAME= redis-benchmark
View
259 src/bitop.c
@@ -0,0 +1,259 @@
+#include "redis.h"
+
+/* -----------------------------------------------------------------------------
+ * Bits related string commands: GETBIT, SETBIT, BITCOUNT, BITOP.
+ * -------------------------------------------------------------------------- */
+
+#define BITOP_AND 0
+#define BITOP_OR 1
+#define BITOP_XOR 2
+#define BITOP_NOT 3
+
+/* This helper function used by GETBIT / SETBIT parses the bit offset arguemnt
+ * making sure an error is returned if it is negative or if it overflows
+ * Redis 512 MB limit for the string value. */
+static int getBitOffsetFromArgument(redisClient *c, robj *o, size_t *offset) {
+ long long loffset;
+ char *err = "bit offset is not an integer or out of range";
+
+ if (getLongLongFromObjectOrReply(c,o,&loffset,err) != REDIS_OK)
+ return REDIS_ERR;
+
+ /* Limit offset to 512MB in bytes */
+ if ((loffset < 0) || ((unsigned long long)loffset >> 3) >= (512*1024*1024))
+ {
+ addReplyError(c,err);
+ return REDIS_ERR;
+ }
+
+ *offset = (size_t)loffset;
+ return REDIS_OK;
+}
+
+/* SETBIT key offset bitvalue */
+void setbitCommand(redisClient *c) {
+ robj *o;
+ char *err = "bit is not an integer or out of range";
+ size_t bitoffset;
+ int byte, bit;
+ int byteval, bitval;
+ long on;
+
+ if (getBitOffsetFromArgument(c,c->argv[2],&bitoffset) != REDIS_OK)
+ return;
+
+ if (getLongFromObjectOrReply(c,c->argv[3],&on,err) != REDIS_OK)
+ return;
+
+ /* Bits can only be set or cleared... */
+ if (on & ~1) {
+ addReplyError(c,err);
+ return;
+ }
+
+ o = lookupKeyWrite(c->db,c->argv[1]);
+ if (o == NULL) {
+ o = createObject(REDIS_STRING,sdsempty());
+ dbAdd(c->db,c->argv[1],o);
+ } else {
+ if (checkType(c,o,REDIS_STRING)) return;
+
+ /* Create a copy when the object is shared or encoded. */
+ if (o->refcount != 1 || o->encoding != REDIS_ENCODING_RAW) {
+ robj *decoded = getDecodedObject(o);
+ o = createStringObject(decoded->ptr, sdslen(decoded->ptr));
+ decrRefCount(decoded);
+ dbOverwrite(c->db,c->argv[1],o);
+ }
+ }
+
+ /* Grow sds value to the right length if necessary */
+ byte = bitoffset >> 3;
+ o->ptr = sdsgrowzero(o->ptr,byte+1);
+
+ /* 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;
+ signalModifiedKey(c->db,c->argv[1]);
+ server.dirty++;
+ addReply(c, bitval ? shared.cone : shared.czero);
+}
+
+/* GETBIT key offset */
+void getbitCommand(redisClient *c) {
+ robj *o;
+ char llbuf[32];
+ size_t bitoffset;
+ size_t byte, bit;
+ size_t bitval = 0;
+
+ if (getBitOffsetFromArgument(c,c->argv[2],&bitoffset) != REDIS_OK)
+ return;
+
+ if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
+ checkType(c,o,REDIS_STRING)) return;
+
+ byte = bitoffset >> 3;
+ bit = 7 - (bitoffset & 0x7);
+ if (o->encoding != REDIS_ENCODING_RAW) {
+ if (byte < (size_t)ll2string(llbuf,sizeof(llbuf),(long)o->ptr))
+ bitval = llbuf[byte] & (1 << bit);
+ } else {
+ if (byte < sdslen(o->ptr))
+ bitval = ((char*)o->ptr)[byte] & (1 << bit);
+ }
+
+ addReply(c, bitval ? shared.cone : shared.czero);
+}
+
+/* BITOP op_name target_key src_key1 src_key2 src_key3 ... src_keyN */
+void bitopCommand(redisClient *c) {
+ char *opname = c->argv[1]->ptr;
+ robj *o, *targetkey = c->argv[2];
+ long op, j, numkeys;
+ unsigned char **src; /* Array of source strings pointers. */
+ long *len, maxlen = 0; /* Array of length of src strings, and max len. */
+ unsigned char *res = NULL; /* Resulting string. */
+
+ /* Parse the operation name. */
+ if ((opname[0] == 'a' || opname[0] == 'A') && !strcasecmp(opname,"and"))
+ op = BITOP_AND;
+ else if((opname[0] == 'o' || opname[0] == 'O') && !strcasecmp(opname,"or"))
+ op = BITOP_OR;
+ else if((opname[0] == 'x' || opname[0] == 'X') && !strcasecmp(opname,"xor"))
+ op = BITOP_XOR;
+ else if((opname[0] == 'n' || opname[0] == 'N') && !strcasecmp(opname,"not"))
+ op = BITOP_NOT;
+ else {
+ addReply(c,shared.syntaxerr);
+ return;
+ }
+
+ /* Sanity check: NOT accepts only a single key argument. */
+ if (op == BITOP_NOT && c->argc != 4) {
+ addReplyError(c,"BITOP NOT must be called with a single source key.");
+ return;
+ }
+
+ /* Lookup keys, and store pointers to the string objects into an array. */
+ numkeys = c->argc - 3;
+ src = zmalloc(sizeof(unsigned char*) * numkeys);
+ len = zmalloc(sizeof(long) * numkeys);
+ for (j = 0; j < numkeys; j++) {
+ o = lookupKeyRead(c->db,c->argv[j+3]);
+ /* Handle non-existing keys as empty strings. */
+ if (o == NULL) {
+ src[j] = NULL;
+ len[j] = 0;
+ continue;
+ }
+ /* Return an error if one of the keys is not a string. */
+ if (checkType(c,o,REDIS_STRING)) {
+ zfree(src);
+ zfree(len);
+ return;
+ }
+ src[j] = o->ptr;
+ len[j] = sdslen(o->ptr);
+ if (len[j] > maxlen) maxlen = len[j];
+ }
+
+ /* Compute the bit operation, if at least one string is not empty. */
+ if (maxlen) {
+ res = (unsigned char*) sdsnewlen(NULL,maxlen);
+ unsigned char output, byte;
+ long i;
+
+ for (j = 0; j < maxlen; j++) {
+ output = (len[0] <= j) ? 0 : src[0][j];
+ if (op == BITOP_NOT) output = ~output;
+ for (i = 1; i < numkeys; i++) {
+ byte = (len[i] <= j) ? 0 : src[i][j];
+ switch(op) {
+ case BITOP_AND: output &= byte; break;
+ case BITOP_OR: output |= byte; break;
+ case BITOP_XOR: output ^= byte; break;
+ }
+ }
+ res[j] = output;
+ }
+ }
+ zfree(src);
+ zfree(len);
+
+ /* Store the computed value into the target key */
+ if (maxlen) {
+ o = createObject(REDIS_STRING,res);
+ setKey(c->db,targetkey,o);
+ decrRefCount(o);
+ } else if (dbDelete(c->db,targetkey)) {
+ signalModifiedKey(c->db,targetkey);
+ }
+ server.dirty++;
+ addReplyLongLong(c,maxlen); /* Return the output string length in bytes. */
+}
+
+/* BITCOUNT key [start end] */
+void bitcountCommand(redisClient *c) {
+ static const unsigned char bitsinbyte[256] = {0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8};
+ robj *o;
+ long start, end;
+ unsigned char *p;
+ char llbuf[32];
+ size_t strlen;
+
+ /* Lookup, check for type, and return 0 for non existing keys. */
+ if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
+ checkType(c,o,REDIS_STRING)) return;
+
+ /* Set the 'p' pointer to the string, that can be just a stack allocated
+ * array if our string was integer encoded. */
+ if (o->encoding == REDIS_ENCODING_INT) {
+ p = (unsigned char*) llbuf;
+ strlen = ll2string(llbuf,sizeof(llbuf),(long)o->ptr);
+ } else {
+ p = (unsigned char*) o->ptr;
+ strlen = sdslen(o->ptr);
+ }
+
+ /* Parse start/end range if any. */
+ if (c->argc == 4) {
+ if (getLongFromObjectOrReply(c,c->argv[2],&start,NULL) != REDIS_OK)
+ return;
+ if (getLongFromObjectOrReply(c,c->argv[3],&end,NULL) != REDIS_OK)
+ return;
+ /* Convert negative indexes */
+ if (start < 0) start = strlen+start;
+ if (end < 0) end = strlen+end;
+ if (start < 0) start = 0;
+ if (end < 0) end = 0;
+ if ((unsigned)end >= strlen) end = strlen-1;
+ } else if (c->argc == 2) {
+ /* The whole string. */
+ start = 0;
+ end = strlen-1;
+ } else {
+ /* Syntax error. */
+ addReply(c,shared.syntaxerr);
+ return;
+ }
+
+ /* Precondition: end >= 0 && end < strlen, so the only condition where
+ * zero can be returned is: start > end. */
+ if (start > end) {
+ addReply(c,shared.czero);
+ } else {
+ long bits = 0, bytes = end-start+1;
+
+ /* We can finally count bits. */
+ p += start;
+ while(bytes--) bits += bitsinbyte[*p++];
+ addReplyLongLong(c,bits);
+ }
+}
View
248 src/t_string.c
@@ -82,104 +82,6 @@ void getsetCommand(redisClient *c) {
server.dirty++;
}
-static int getBitOffsetFromArgument(redisClient *c, robj *o, size_t *offset) {
- long long loffset;
- char *err = "bit offset is not an integer or out of range";
-
- if (getLongLongFromObjectOrReply(c,o,&loffset,err) != REDIS_OK)
- return REDIS_ERR;
-
- /* Limit offset to 512MB in bytes */
- if ((loffset < 0) || ((unsigned long long)loffset >> 3) >= (512*1024*1024))
- {
- addReplyError(c,err);
- return REDIS_ERR;
- }
-
- *offset = (size_t)loffset;
- return REDIS_OK;
-}
-
-void setbitCommand(redisClient *c) {
- robj *o;
- char *err = "bit is not an integer or out of range";
- size_t bitoffset;
- int byte, bit;
- int byteval, bitval;
- long on;
-
- if (getBitOffsetFromArgument(c,c->argv[2],&bitoffset) != REDIS_OK)
- return;
-
- if (getLongFromObjectOrReply(c,c->argv[3],&on,err) != REDIS_OK)
- return;
-
- /* Bits can only be set or cleared... */
- if (on & ~1) {
- addReplyError(c,err);
- return;
- }
-
- o = lookupKeyWrite(c->db,c->argv[1]);
- if (o == NULL) {
- o = createObject(REDIS_STRING,sdsempty());
- dbAdd(c->db,c->argv[1],o);
- } else {
- if (checkType(c,o,REDIS_STRING)) return;
-
- /* Create a copy when the object is shared or encoded. */
- if (o->refcount != 1 || o->encoding != REDIS_ENCODING_RAW) {
- robj *decoded = getDecodedObject(o);
- o = createStringObject(decoded->ptr, sdslen(decoded->ptr));
- decrRefCount(decoded);
- dbOverwrite(c->db,c->argv[1],o);
- }
- }
-
- /* Grow sds value to the right length if necessary */
- byte = bitoffset >> 3;
- o->ptr = sdsgrowzero(o->ptr,byte+1);
-
- /* 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;
- signalModifiedKey(c->db,c->argv[1]);
- server.dirty++;
- addReply(c, bitval ? shared.cone : shared.czero);
-}
-
-void getbitCommand(redisClient *c) {
- robj *o;
- char llbuf[32];
- size_t bitoffset;
- size_t byte, bit;
- size_t bitval = 0;
-
- if (getBitOffsetFromArgument(c,c->argv[2],&bitoffset) != REDIS_OK)
- return;
-
- if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
- checkType(c,o,REDIS_STRING)) return;
-
- byte = bitoffset >> 3;
- bit = 7 - (bitoffset & 0x7);
- if (o->encoding != REDIS_ENCODING_RAW) {
- if (byte < (size_t)ll2string(llbuf,sizeof(llbuf),(long)o->ptr))
- bitval = llbuf[byte] & (1 << bit);
- } else {
- if (byte < sdslen(o->ptr))
- bitval = ((char*)o->ptr)[byte] & (1 << bit);
- }
-
- addReply(c, bitval ? shared.cone : shared.czero);
-}
-
void setrangeCommand(redisClient *c) {
robj *o;
long offset;
@@ -462,153 +364,3 @@ void strlenCommand(redisClient *c) {
checkType(c,o,REDIS_STRING)) return;
addReplyLongLong(c,stringObjectLen(o));
}
-
-#define BITOP_AND 0
-#define BITOP_OR 1
-#define BITOP_XOR 2
-#define BITOP_NOT 3
-/* BITOP op_name target_key src_key1 src_key2 src_key3 ... src_keyN */
-void bitopCommand(redisClient *c) {
- char *opname = c->argv[1]->ptr;
- robj *o, *targetkey = c->argv[2];
- long op, j, numkeys;
- unsigned char **src; /* Array of source strings pointers. */
- long *len, maxlen = 0; /* Array of length of src strings, and max len. */
- unsigned char *res = NULL; /* Resulting string. */
-
- /* Parse the operation name. */
- if ((opname[0] == 'a' || opname[0] == 'A') && !strcasecmp(opname,"and"))
- op = BITOP_AND;
- else if((opname[0] == 'o' || opname[0] == 'O') && !strcasecmp(opname,"or"))
- op = BITOP_OR;
- else if((opname[0] == 'x' || opname[0] == 'X') && !strcasecmp(opname,"xor"))
- op = BITOP_XOR;
- else if((opname[0] == 'n' || opname[0] == 'N') && !strcasecmp(opname,"not"))
- op = BITOP_NOT;
- else {
- addReply(c,shared.syntaxerr);
- return;
- }
-
- /* Sanity check: NOT accepts only a single key argument. */
- if (op == BITOP_NOT && c->argc != 4) {
- addReplyError(c,"BITOP NOT must be called with a single source key.");
- return;
- }
-
- /* Lookup keys, and store pointers to the string objects into an array. */
- numkeys = c->argc - 3;
- src = zmalloc(sizeof(unsigned char*) * numkeys);
- len = zmalloc(sizeof(long) * numkeys);
- for (j = 0; j < numkeys; j++) {
- o = lookupKeyRead(c->db,c->argv[j+3]);
- /* Handle non-existing keys as empty strings. */
- if (o == NULL) {
- src[j] = NULL;
- len[j] = 0;
- continue;
- }
- /* Return an error if one of the keys is not a string. */
- if (checkType(c,o,REDIS_STRING)) {
- zfree(src);
- zfree(len);
- return;
- }
- src[j] = o->ptr;
- len[j] = sdslen(o->ptr);
- if (len[j] > maxlen) maxlen = len[j];
- }
-
- /* Compute the bit operation, if at least one string is not empty. */
- if (maxlen) {
- res = (unsigned char*) sdsnewlen(NULL,maxlen);
- unsigned char output, byte;
- long i;
-
- for (j = 0; j < maxlen; j++) {
- output = (len[0] <= j) ? 0 : src[0][j];
- if (op == BITOP_NOT) output = ~output;
- for (i = 1; i < numkeys; i++) {
- byte = (len[i] <= j) ? 0 : src[i][j];
- switch(op) {
- case BITOP_AND: output &= byte; break;
- case BITOP_OR: output |= byte; break;
- case BITOP_XOR: output ^= byte; break;
- }
- }
- res[j] = output;
- }
- }
- zfree(src);
- zfree(len);
-
- /* Store the computed value into the target key */
- if (maxlen) {
- o = createObject(REDIS_STRING,res);
- setKey(c->db,targetkey,o);
- decrRefCount(o);
- } else if (dbDelete(c->db,targetkey)) {
- signalModifiedKey(c->db,targetkey);
- }
- server.dirty++;
- addReplyLongLong(c,maxlen); /* Return the output string length in bytes. */
-}
-
-/* BITCOUNT key [start end] */
-void bitcountCommand(redisClient *c) {
- static const unsigned char bitsinbyte[256] = {0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8};
- robj *o;
- long start, end;
- unsigned char *p;
- char llbuf[32];
- size_t strlen;
-
- /* Lookup, check for type, and return 0 for non existing keys. */
- if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
- checkType(c,o,REDIS_STRING)) return;
-
- /* Set the 'p' pointer to the string, that can be just a stack allocated
- * array if our string was integer encoded. */
- if (o->encoding == REDIS_ENCODING_INT) {
- p = (unsigned char*) llbuf;
- strlen = ll2string(llbuf,sizeof(llbuf),(long)o->ptr);
- } else {
- p = (unsigned char*) o->ptr;
- strlen = sdslen(o->ptr);
- }
-
- /* Parse start/end range if any. */
- if (c->argc == 4) {
- if (getLongFromObjectOrReply(c,c->argv[2],&start,NULL) != REDIS_OK)
- return;
- if (getLongFromObjectOrReply(c,c->argv[3],&end,NULL) != REDIS_OK)
- return;
- /* Convert negative indexes */
- if (start < 0) start = strlen+start;
- if (end < 0) end = strlen+end;
- if (start < 0) start = 0;
- if (end < 0) end = 0;
- if ((unsigned)end >= strlen) end = strlen-1;
- } else if (c->argc == 2) {
- /* The whole string. */
- start = 0;
- end = strlen-1;
- } else {
- /* Syntax error. */
- addReply(c,shared.syntaxerr);
- return;
- }
-
- /* Precondition: end >= 0 && end < strlen, so the only condition where
- * zero can be returned is: start > end. */
- if (start > end) {
- addReply(c,shared.czero);
- } else {
- long bits = 0, bytes = end-start+1;
-
- /* We can finally count bits. */
- p += start;
- while(bytes--) bits += bitsinbyte[*p++];
- addReplyLongLong(c,bits);
- }
-}

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