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-rw-r--r--src/intset.c560
1 files changed, 560 insertions, 0 deletions
diff --git a/src/intset.c b/src/intset.c
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+++ b/src/intset.c
@@ -0,0 +1,560 @@
+/*
+ * Copyright (c) 2009-2012, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ * Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of Redis nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "intset.h"
+#include "zmalloc.h"
+#include "endianconv.h"
+#include "redisassert.h"
+
+/* Note that these encodings are ordered, so:
+ * INTSET_ENC_INT16 < INTSET_ENC_INT32 < INTSET_ENC_INT64. */
+#define INTSET_ENC_INT16 (sizeof(int16_t))
+#define INTSET_ENC_INT32 (sizeof(int32_t))
+#define INTSET_ENC_INT64 (sizeof(int64_t))
+
+/* Return the required encoding for the provided value. */
+static uint8_t _intsetValueEncoding(int64_t v) {
+ if (v < INT32_MIN || v > INT32_MAX)
+ return INTSET_ENC_INT64;
+ else if (v < INT16_MIN || v > INT16_MAX)
+ return INTSET_ENC_INT32;
+ else
+ return INTSET_ENC_INT16;
+}
+
+/* Return the value at pos, given an encoding. */
+static int64_t _intsetGetEncoded(intset *is, int pos, uint8_t enc) {
+ int64_t v64;
+ int32_t v32;
+ int16_t v16;
+
+ if (enc == INTSET_ENC_INT64) {
+ memcpy(&v64,((int64_t*)is->contents)+pos,sizeof(v64));
+ memrev64ifbe(&v64);
+ return v64;
+ } else if (enc == INTSET_ENC_INT32) {
+ memcpy(&v32,((int32_t*)is->contents)+pos,sizeof(v32));
+ memrev32ifbe(&v32);
+ return v32;
+ } else {
+ memcpy(&v16,((int16_t*)is->contents)+pos,sizeof(v16));
+ memrev16ifbe(&v16);
+ return v16;
+ }
+}
+
+/* Return the value at pos, using the configured encoding. */
+static int64_t _intsetGet(intset *is, int pos) {
+ return _intsetGetEncoded(is,pos,intrev32ifbe(is->encoding));
+}
+
+/* Set the value at pos, using the configured encoding. */
+static void _intsetSet(intset *is, int pos, int64_t value) {
+ uint32_t encoding = intrev32ifbe(is->encoding);
+
+ if (encoding == INTSET_ENC_INT64) {
+ ((int64_t*)is->contents)[pos] = value;
+ memrev64ifbe(((int64_t*)is->contents)+pos);
+ } else if (encoding == INTSET_ENC_INT32) {
+ ((int32_t*)is->contents)[pos] = value;
+ memrev32ifbe(((int32_t*)is->contents)+pos);
+ } else {
+ ((int16_t*)is->contents)[pos] = value;
+ memrev16ifbe(((int16_t*)is->contents)+pos);
+ }
+}
+
+/* Create an empty intset. */
+intset *intsetNew(void) {
+ intset *is = zmalloc(sizeof(intset));
+ is->encoding = intrev32ifbe(INTSET_ENC_INT16);
+ is->length = 0;
+ return is;
+}
+
+/* Resize the intset */
+static intset *intsetResize(intset *is, uint32_t len) {
+ uint64_t size = (uint64_t)len*intrev32ifbe(is->encoding);
+ assert(size <= SIZE_MAX - sizeof(intset));
+ is = zrealloc(is,sizeof(intset)+size);
+ return is;
+}
+
+/* Search for the position of "value". Return 1 when the value was found and
+ * sets "pos" to the position of the value within the intset. Return 0 when
+ * the value is not present in the intset and sets "pos" to the position
+ * where "value" can be inserted. */
+static uint8_t intsetSearch(intset *is, int64_t value, uint32_t *pos) {
+ int min = 0, max = intrev32ifbe(is->length)-1, mid = -1;
+ int64_t cur = -1;
+
+ /* The value can never be found when the set is empty */
+ if (intrev32ifbe(is->length) == 0) {
+ if (pos) *pos = 0;
+ return 0;
+ } else {
+ /* Check for the case where we know we cannot find the value,
+ * but do know the insert position. */
+ if (value > _intsetGet(is,max)) {
+ if (pos) *pos = intrev32ifbe(is->length);
+ return 0;
+ } else if (value < _intsetGet(is,0)) {
+ if (pos) *pos = 0;
+ return 0;
+ }
+ }
+
+ while(max >= min) {
+ mid = ((unsigned int)min + (unsigned int)max) >> 1;
+ cur = _intsetGet(is,mid);
+ if (value > cur) {
+ min = mid+1;
+ } else if (value < cur) {
+ max = mid-1;
+ } else {
+ break;
+ }
+ }
+
+ if (value == cur) {
+ if (pos) *pos = mid;
+ return 1;
+ } else {
+ if (pos) *pos = min;
+ return 0;
+ }
+}
+
+/* Upgrades the intset to a larger encoding and inserts the given integer. */
+static intset *intsetUpgradeAndAdd(intset *is, int64_t value) {
+ uint8_t curenc = intrev32ifbe(is->encoding);
+ uint8_t newenc = _intsetValueEncoding(value);
+ int length = intrev32ifbe(is->length);
+ int prepend = value < 0 ? 1 : 0;
+
+ /* First set new encoding and resize */
+ is->encoding = intrev32ifbe(newenc);
+ is = intsetResize(is,intrev32ifbe(is->length)+1);
+
+ /* Upgrade back-to-front so we don't overwrite values.
+ * Note that the "prepend" variable is used to make sure we have an empty
+ * space at either the beginning or the end of the intset. */
+ while(length--)
+ _intsetSet(is,length+prepend,_intsetGetEncoded(is,length,curenc));
+
+ /* Set the value at the beginning or the end. */
+ if (prepend)
+ _intsetSet(is,0,value);
+ else
+ _intsetSet(is,intrev32ifbe(is->length),value);
+ is->length = intrev32ifbe(intrev32ifbe(is->length)+1);
+ return is;
+}
+
+static void intsetMoveTail(intset *is, uint32_t from, uint32_t to) {
+ void *src, *dst;
+ uint32_t bytes = intrev32ifbe(is->length)-from;
+ uint32_t encoding = intrev32ifbe(is->encoding);
+
+ if (encoding == INTSET_ENC_INT64) {
+ src = (int64_t*)is->contents+from;
+ dst = (int64_t*)is->contents+to;
+ bytes *= sizeof(int64_t);
+ } else if (encoding == INTSET_ENC_INT32) {
+ src = (int32_t*)is->contents+from;
+ dst = (int32_t*)is->contents+to;
+ bytes *= sizeof(int32_t);
+ } else {
+ src = (int16_t*)is->contents+from;
+ dst = (int16_t*)is->contents+to;
+ bytes *= sizeof(int16_t);
+ }
+ memmove(dst,src,bytes);
+}
+
+/* Insert an integer in the intset */
+intset *intsetAdd(intset *is, int64_t value, uint8_t *success) {
+ uint8_t valenc = _intsetValueEncoding(value);
+ uint32_t pos;
+ if (success) *success = 1;
+
+ /* Upgrade encoding if necessary. If we need to upgrade, we know that
+ * this value should be either appended (if > 0) or prepended (if < 0),
+ * because it lies outside the range of existing values. */
+ if (valenc > intrev32ifbe(is->encoding)) {
+ /* This always succeeds, so we don't need to curry *success. */
+ return intsetUpgradeAndAdd(is,value);
+ } else {
+ /* Abort if the value is already present in the set.
+ * This call will populate "pos" with the right position to insert
+ * the value when it cannot be found. */
+ if (intsetSearch(is,value,&pos)) {
+ if (success) *success = 0;
+ return is;
+ }
+
+ is = intsetResize(is,intrev32ifbe(is->length)+1);
+ if (pos < intrev32ifbe(is->length)) intsetMoveTail(is,pos,pos+1);
+ }
+
+ _intsetSet(is,pos,value);
+ is->length = intrev32ifbe(intrev32ifbe(is->length)+1);
+ return is;
+}
+
+/* Delete integer from intset */
+intset *intsetRemove(intset *is, int64_t value, int *success) {
+ uint8_t valenc = _intsetValueEncoding(value);
+ uint32_t pos;
+ if (success) *success = 0;
+
+ if (valenc <= intrev32ifbe(is->encoding) && intsetSearch(is,value,&pos)) {
+ uint32_t len = intrev32ifbe(is->length);
+
+ /* We know we can delete */
+ if (success) *success = 1;
+
+ /* Overwrite value with tail and update length */
+ if (pos < (len-1)) intsetMoveTail(is,pos+1,pos);
+ is = intsetResize(is,len-1);
+ is->length = intrev32ifbe(len-1);
+ }
+ return is;
+}
+
+/* Determine whether a value belongs to this set */
+uint8_t intsetFind(intset *is, int64_t value) {
+ uint8_t valenc = _intsetValueEncoding(value);
+ return valenc <= intrev32ifbe(is->encoding) && intsetSearch(is,value,NULL);
+}
+
+/* Return random member */
+int64_t intsetRandom(intset *is) {
+ uint32_t len = intrev32ifbe(is->length);
+ assert(len); /* avoid division by zero on corrupt intset payload. */
+ return _intsetGet(is,rand()%len);
+}
+
+/* Return the largest member. */
+int64_t intsetMax(intset *is) {
+ uint32_t len = intrev32ifbe(is->length);
+ return _intsetGet(is, len - 1);
+}
+
+/* Return the smallest member. */
+int64_t intsetMin(intset *is) {
+ return _intsetGet(is, 0);
+}
+
+/* Get the value at the given position. When this position is
+ * out of range the function returns 0, when in range it returns 1. */
+uint8_t intsetGet(intset *is, uint32_t pos, int64_t *value) {
+ if (pos < intrev32ifbe(is->length)) {
+ *value = _intsetGet(is,pos);
+ return 1;
+ }
+ return 0;
+}
+
+/* Return intset length */
+uint32_t intsetLen(const intset *is) {
+ return intrev32ifbe(is->length);
+}
+
+/* Return intset blob size in bytes. */
+size_t intsetBlobLen(intset *is) {
+ return sizeof(intset)+(size_t)intrev32ifbe(is->length)*intrev32ifbe(is->encoding);
+}
+
+/* Validate the integrity of the data structure.
+ * when `deep` is 0, only the integrity of the header is validated.
+ * when `deep` is 1, we make sure there are no duplicate or out of order records. */
+int intsetValidateIntegrity(const unsigned char *p, size_t size, int deep) {
+ intset *is = (intset *)p;
+ /* check that we can actually read the header. */
+ if (size < sizeof(*is))
+ return 0;
+
+ uint32_t encoding = intrev32ifbe(is->encoding);
+
+ size_t record_size;
+ if (encoding == INTSET_ENC_INT64) {
+ record_size = INTSET_ENC_INT64;
+ } else if (encoding == INTSET_ENC_INT32) {
+ record_size = INTSET_ENC_INT32;
+ } else if (encoding == INTSET_ENC_INT16){
+ record_size = INTSET_ENC_INT16;
+ } else {
+ return 0;
+ }
+
+ /* check that the size matches (all records are inside the buffer). */
+ uint32_t count = intrev32ifbe(is->length);
+ if (sizeof(*is) + count*record_size != size)
+ return 0;
+
+ /* check that the set is not empty. */
+ if (count==0)
+ return 0;
+
+ if (!deep)
+ return 1;
+
+ /* check that there are no dup or out of order records. */
+ int64_t prev = _intsetGet(is,0);
+ for (uint32_t i=1; i<count; i++) {
+ int64_t cur = _intsetGet(is,i);
+ if (cur <= prev)
+ return 0;
+ prev = cur;
+ }
+
+ return 1;
+}
+
+#ifdef REDIS_TEST
+#include <sys/time.h>
+#include <time.h>
+
+#if 0
+static void intsetRepr(intset *is) {
+ for (uint32_t i = 0; i < intrev32ifbe(is->length); i++) {
+ printf("%lld\n", (uint64_t)_intsetGet(is,i));
+ }
+ printf("\n");
+}
+
+static void error(char *err) {
+ printf("%s\n", err);
+ exit(1);
+}
+#endif
+
+static void ok(void) {
+ printf("OK\n");
+}
+
+static long long usec(void) {
+ struct timeval tv;
+ gettimeofday(&tv,NULL);
+ return (((long long)tv.tv_sec)*1000000)+tv.tv_usec;
+}
+
+static intset *createSet(int bits, int size) {
+ uint64_t mask = (1<<bits)-1;
+ uint64_t value;
+ intset *is = intsetNew();
+
+ for (int i = 0; i < size; i++) {
+ if (bits > 32) {
+ value = (rand()*rand()) & mask;
+ } else {
+ value = rand() & mask;
+ }
+ is = intsetAdd(is,value,NULL);
+ }
+ return is;
+}
+
+static void checkConsistency(intset *is) {
+ for (uint32_t i = 0; i < (intrev32ifbe(is->length)-1); i++) {
+ uint32_t encoding = intrev32ifbe(is->encoding);
+
+ if (encoding == INTSET_ENC_INT16) {
+ int16_t *i16 = (int16_t*)is->contents;
+ assert(i16[i] < i16[i+1]);
+ } else if (encoding == INTSET_ENC_INT32) {
+ int32_t *i32 = (int32_t*)is->contents;
+ assert(i32[i] < i32[i+1]);
+ } else {
+ int64_t *i64 = (int64_t*)is->contents;
+ assert(i64[i] < i64[i+1]);
+ }
+ }
+}
+
+#define UNUSED(x) (void)(x)
+int intsetTest(int argc, char **argv, int flags) {
+ uint8_t success;
+ int i;
+ intset *is;
+ srand(time(NULL));
+
+ UNUSED(argc);
+ UNUSED(argv);
+ UNUSED(flags);
+
+ printf("Value encodings: "); {
+ assert(_intsetValueEncoding(-32768) == INTSET_ENC_INT16);
+ assert(_intsetValueEncoding(+32767) == INTSET_ENC_INT16);
+ assert(_intsetValueEncoding(-32769) == INTSET_ENC_INT32);
+ assert(_intsetValueEncoding(+32768) == INTSET_ENC_INT32);
+ assert(_intsetValueEncoding(-2147483648) == INTSET_ENC_INT32);
+ assert(_intsetValueEncoding(+2147483647) == INTSET_ENC_INT32);
+ assert(_intsetValueEncoding(-2147483649) == INTSET_ENC_INT64);
+ assert(_intsetValueEncoding(+2147483648) == INTSET_ENC_INT64);
+ assert(_intsetValueEncoding(-9223372036854775808ull) ==
+ INTSET_ENC_INT64);
+ assert(_intsetValueEncoding(+9223372036854775807ull) ==
+ INTSET_ENC_INT64);
+ ok();
+ }
+
+ printf("Basic adding: "); {
+ is = intsetNew();
+ is = intsetAdd(is,5,&success); assert(success);
+ is = intsetAdd(is,6,&success); assert(success);
+ is = intsetAdd(is,4,&success); assert(success);
+ is = intsetAdd(is,4,&success); assert(!success);
+ assert(6 == intsetMax(is));
+ assert(4 == intsetMin(is));
+ ok();
+ zfree(is);
+ }
+
+ printf("Large number of random adds: "); {
+ uint32_t inserts = 0;
+ is = intsetNew();
+ for (i = 0; i < 1024; i++) {
+ is = intsetAdd(is,rand()%0x800,&success);
+ if (success) inserts++;
+ }
+ assert(intrev32ifbe(is->length) == inserts);
+ checkConsistency(is);
+ ok();
+ zfree(is);
+ }
+
+ printf("Upgrade from int16 to int32: "); {
+ is = intsetNew();
+ is = intsetAdd(is,32,NULL);
+ assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT16);
+ is = intsetAdd(is,65535,NULL);
+ assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT32);
+ assert(intsetFind(is,32));
+ assert(intsetFind(is,65535));
+ checkConsistency(is);
+ zfree(is);
+
+ is = intsetNew();
+ is = intsetAdd(is,32,NULL);
+ assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT16);
+ is = intsetAdd(is,-65535,NULL);
+ assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT32);
+ assert(intsetFind(is,32));
+ assert(intsetFind(is,-65535));
+ checkConsistency(is);
+ ok();
+ zfree(is);
+ }
+
+ printf("Upgrade from int16 to int64: "); {
+ is = intsetNew();
+ is = intsetAdd(is,32,NULL);
+ assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT16);
+ is = intsetAdd(is,4294967295,NULL);
+ assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT64);
+ assert(intsetFind(is,32));
+ assert(intsetFind(is,4294967295));
+ checkConsistency(is);
+ zfree(is);
+
+ is = intsetNew();
+ is = intsetAdd(is,32,NULL);
+ assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT16);
+ is = intsetAdd(is,-4294967295,NULL);
+ assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT64);
+ assert(intsetFind(is,32));
+ assert(intsetFind(is,-4294967295));
+ checkConsistency(is);
+ ok();
+ zfree(is);
+ }
+
+ printf("Upgrade from int32 to int64: "); {
+ is = intsetNew();
+ is = intsetAdd(is,65535,NULL);
+ assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT32);
+ is = intsetAdd(is,4294967295,NULL);
+ assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT64);
+ assert(intsetFind(is,65535));
+ assert(intsetFind(is,4294967295));
+ checkConsistency(is);
+ zfree(is);
+
+ is = intsetNew();
+ is = intsetAdd(is,65535,NULL);
+ assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT32);
+ is = intsetAdd(is,-4294967295,NULL);
+ assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT64);
+ assert(intsetFind(is,65535));
+ assert(intsetFind(is,-4294967295));
+ checkConsistency(is);
+ ok();
+ zfree(is);
+ }
+
+ printf("Stress lookups: "); {
+ long num = 100000, size = 10000;
+ int i, bits = 20;
+ long long start;
+ is = createSet(bits,size);
+ checkConsistency(is);
+
+ start = usec();
+ for (i = 0; i < num; i++) intsetSearch(is,rand() % ((1<<bits)-1),NULL);
+ printf("%ld lookups, %ld element set, %lldusec\n",
+ num,size,usec()-start);
+ zfree(is);
+ }
+
+ printf("Stress add+delete: "); {
+ int i, v1, v2;
+ is = intsetNew();
+ for (i = 0; i < 0xffff; i++) {
+ v1 = rand() % 0xfff;
+ is = intsetAdd(is,v1,NULL);
+ assert(intsetFind(is,v1));
+
+ v2 = rand() % 0xfff;
+ is = intsetRemove(is,v2,NULL);
+ assert(!intsetFind(is,v2));
+ }
+ checkConsistency(is);
+ ok();
+ zfree(is);
+ }
+
+ return 0;
+}
+#endif
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