intset encoding for sets, refactored set tests to test both encodings

Makefile

@@ -15,7 +15,7 @@ endif
 CCOPT= $(CFLAGS) $(CCLINK) $(ARCH) $(PROF)
 DEBUG?= -g -rdynamic -ggdb 
 
-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
+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 intset.o
 BENCHOBJ = ae.o anet.o redis-benchmark.o sds.o adlist.o zmalloc.o
 CLIOBJ = anet.o sds.o adlist.o redis-cli.o zmalloc.o linenoise.o
 CHECKDUMPOBJ = redis-check-dump.o lzf_c.o lzf_d.o
@@ -54,6 +54,7 @@ redis.o: redis.c fmacros.h config.h redis.h ae.h sds.h anet.h dict.h \
 sds.o: sds.c sds.h zmalloc.h
 zipmap.o: zipmap.c zmalloc.h
 ziplist.o: ziplist.c zmalloc.h
+intset.o: intset.c zmalloc.h
 zmalloc.o: zmalloc.c config.h
 
 redis-server: $(OBJ)

intset.c

@@ -60,8 +60,8 @@ static intset *intsetUpgrade(intset *is, uint8_t newenc, uint8_t extra, uint8_t
  * 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 = is->length-1, mid;
-    int64_t cur;
+    int min = 0, max = is->length-1, mid = -1;
+    int64_t cur = -1;
 
     /* The value can never be found when the set is empty */
     if (is->length == 0) {
@@ -179,6 +179,21 @@ int64_t intsetRandom(intset *is) {
     return INTSET_GET(is,rand()%is->length);
 }
 
+/* Sets the value to 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 < is->length) {
+        *value = INTSET_GET(is,pos);
+        return 1;
+    }
+    return 0;
+}
+
+/* Return intset length */
+uint32_t intsetLen(intset *is) {
+    return is->length;
+}
+
 #ifdef INTSET_TEST_MAIN
 #include <sys/time.h>
 

intset.h

@@ -13,5 +13,7 @@ intset *intsetAdd(intset *is, int64_t value, uint8_t *success);
 intset *intsetRemove(intset *is, int64_t value, uint8_t *success);
 uint8_t intsetFind(intset *is, int64_t value);
 int64_t intsetRandom(intset *is);
+uint8_t intsetGet(intset *is, uint32_t pos, int64_t *value);
+uint32_t intsetLen(intset *is);
 
 #endif // __INTSET_H

redis.c

@@ -76,6 +76,7 @@
 #include "pqsort.h" /* Partial qsort for SORT+LIMIT */
 #include "zipmap.h" /* Compact dictionary-alike data structure */
 #include "ziplist.h" /* Compact list data structure */
+#include "intset.h" /* Compact integer set structure */
 #include "sha1.h"   /* SHA1 is used for DEBUG DIGEST */
 #include "release.h" /* Release and/or git repository information */
 
@@ -132,9 +133,10 @@
 #define REDIS_ENCODING_ZIPMAP 3  /* Encoded as zipmap */
 #define REDIS_ENCODING_LIST 4    /* Encoded as zipmap */
 #define REDIS_ENCODING_ZIPLIST 5 /* Encoded as ziplist */
+#define REDIS_ENCODING_INTSET 6  /* Encoded as intset */
 
 static char* strencoding[] = {
-    "raw", "int", "hashtable", "zipmap", "list", "ziplist"
+    "raw", "int", "hashtable", "zipmap", "list", "ziplist", "intset"
 };
 
 /* Object types only used for dumping to disk */
@@ -651,6 +653,7 @@ static void call(redisClient *c, struct redisCommand *cmd);
 static void resetClient(redisClient *c);
 static void convertToRealHash(robj *o);
 static void listTypeConvert(robj *o, int enc);
+static void setTypeConvert(robj *o, int enc);
 static int pubsubUnsubscribeAllChannels(redisClient *c, int notify);
 static int pubsubUnsubscribeAllPatterns(redisClient *c, int notify);
 static void freePubsubPattern(void *p);
@@ -3069,6 +3072,13 @@ static robj *createSetObject(void) {
     return o;
 }
 
+static robj *createIntsetObject(void) {
+    intset *is = intsetNew();
+    robj *o = createObject(REDIS_SET,is);
+    o->encoding = REDIS_ENCODING_INTSET;
+    return o;
+}
+
 static robj *createHashObject(void) {
     /* All the Hashes start as zipmaps. Will be automatically converted
      * into hash tables if there are enough elements or big elements
@@ -3107,7 +3117,16 @@ static void freeListObject(robj *o) {
 }
 
 static void freeSetObject(robj *o) {
-    dictRelease((dict*) o->ptr);
+    switch (o->encoding) {
+    case REDIS_ENCODING_HT:
+        dictRelease((dict*) o->ptr);
+        break;
+    case REDIS_ENCODING_INTSET:
+        zfree(o->ptr);
+        break;
+    default:
+        redisPanic("Unknown set encoding type");
+    }
 }
 
 static void freeZsetObject(robj *o) {
@@ -3371,7 +3390,7 @@ static int getLongLongFromObject(robj *o, long long *target) {
         }
     }
 
-    *target = value;
+    if (target) *target = value;
     return REDIS_OK;
 }
 
@@ -3789,17 +3808,29 @@ static int rdbSaveObject(FILE *fp, robj *o) {
         }
     } else if (o->type == REDIS_SET) {
         /* Save a set value */
-        dict *set = o->ptr;
-        dictIterator *di = dictGetIterator(set);
-        dictEntry *de;
-
-        if (rdbSaveLen(fp,dictSize(set)) == -1) return -1;
-        while((de = dictNext(di)) != NULL) {
-            robj *eleobj = dictGetEntryKey(de);
+        if (o->encoding == REDIS_ENCODING_HT) {
+            dict *set = o->ptr;
+            dictIterator *di = dictGetIterator(set);
+            dictEntry *de;
 
-            if (rdbSaveStringObject(fp,eleobj) == -1) return -1;
+            if (rdbSaveLen(fp,dictSize(set)) == -1) return -1;
+            while((de = dictNext(di)) != NULL) {
+                robj *eleobj = dictGetEntryKey(de);
+                if (rdbSaveStringObject(fp,eleobj) == -1) return -1;
+            }
+            dictReleaseIterator(di);
+        } else if (o->encoding == REDIS_ENCODING_INTSET) {
+            intset *is = o->ptr;
+            long long llval;
+            int i = 0;
+
+            if (rdbSaveLen(fp,intsetLen(is)) == -1) return -1;
+            while(intsetGet(is,i++,&llval)) {
+                if (rdbSaveLongLongAsStringObject(fp,llval) == -1) return -1;
+            }
+        } else {
+            redisPanic("Unknown set encoding");
         }
-        dictReleaseIterator(di);
     } else if (o->type == REDIS_ZSET) {
         /* Save a set value */
         zset *zs = o->ptr;
@@ -5459,12 +5490,37 @@ static void rpoplpushcommand(redisClient *c) {
 
 /* ==================================== Sets ================================ */
 
+/* Factory method to return a set that *can* hold "value". When the object has
+ * an integer-encodable value, an intset will be returned. Otherwise a regular
+ * hash table. */
+static robj *setTypeCreate(robj *value) {
+    if (getLongLongFromObject(value,NULL) == REDIS_OK)
+        return createIntsetObject();
+    return createSetObject();
+}
+
 static int setTypeAdd(robj *subject, robj *value) {
+    long long llval;
     if (subject->encoding == REDIS_ENCODING_HT) {
         if (dictAdd(subject->ptr,value,NULL) == DICT_OK) {
             incrRefCount(value);
             return 1;
         }
+    } else if (subject->encoding == REDIS_ENCODING_INTSET) {
+        if (getLongLongFromObject(value,&llval) == REDIS_OK) {
+            uint8_t success;
+            subject->ptr = intsetAdd(subject->ptr,llval,&success);
+            if (success) return 1;
+        } else {
+            /* Failed to get integer from object, convert to regular set. */
+            setTypeConvert(subject,REDIS_ENCODING_HT);
+
+            /* The set *was* an intset and this value is not integer
+             * encodable, so dictAdd should always work. */
+            redisAssert(dictAdd(subject->ptr,value,NULL) == DICT_OK);
+            incrRefCount(value);
+            return 1;
+        }
     } else {
         redisPanic("Unknown set encoding");
     }
@@ -5472,11 +5528,18 @@ static int setTypeAdd(robj *subject, robj *value) {
 }
 
 static int setTypeRemove(robj *subject, robj *value) {
+    long long llval;
     if (subject->encoding == REDIS_ENCODING_HT) {
         if (dictDelete(subject->ptr,value) == DICT_OK) {
             if (htNeedsResize(subject->ptr)) dictResize(subject->ptr);
             return 1;
         }
+    } else if (subject->encoding == REDIS_ENCODING_INTSET) {
+        if (getLongLongFromObject(value,&llval) == REDIS_OK) {
+            uint8_t success;
+            subject->ptr = intsetRemove(subject->ptr,llval,&success);
+            if (success) return 1;
+        }
     } else {
         redisPanic("Unknown set encoding");
     }
@@ -5484,24 +5547,35 @@ static int setTypeRemove(robj *subject, robj *value) {
 }
 
 static int setTypeIsMember(robj *subject, robj *value) {
+    long long llval;
     if (subject->encoding == REDIS_ENCODING_HT) {
         return dictFind((dict*)subject->ptr,value) != NULL;
+    } else if (subject->encoding == REDIS_ENCODING_INTSET) {
+        if (getLongLongFromObject(value,&llval) == REDIS_OK) {
+            return intsetFind((intset*)subject->ptr,llval);
+        }
     } else {
         redisPanic("Unknown set encoding");
     }
+    return 0;
 }
 
 /* Structure to hold set iteration abstraction. */
 typedef struct {
+    robj *subject;
     int encoding;
+    int ii; /* intset iterator */
     dictIterator *di;
 } setIterator;
 
 static setIterator *setTypeInitIterator(robj *subject) {
     setIterator *si = zmalloc(sizeof(setIterator));
+    si->subject = subject;
     si->encoding = subject->encoding;
     if (si->encoding == REDIS_ENCODING_HT) {
         si->di = dictGetIterator(subject->ptr);
+    } else if (si->encoding == REDIS_ENCODING_INTSET) {
+        si->ii = 0;
     } else {
         redisPanic("Unknown set encoding");
     }
@@ -5525,6 +5599,10 @@ static robj *setTypeNext(setIterator *si) {
             ret = dictGetEntryKey(de);
             incrRefCount(ret);
         }
+    } else if (si->encoding == REDIS_ENCODING_INTSET) {
+        long long llval;
+        if (intsetGet(si->subject->ptr,si->ii++,&llval))
+            ret = createStringObjectFromLongLong(llval);
     }
     return ret;
 }
@@ -5538,6 +5616,9 @@ robj *setTypeRandomElement(robj *subject) {
         dictEntry *de = dictGetRandomKey(subject->ptr);
         ret = dictGetEntryKey(de);
         incrRefCount(ret);
+    } else if (subject->encoding == REDIS_ENCODING_INTSET) {
+        long long llval = intsetRandom(subject->ptr);
+        ret = createStringObjectFromLongLong(llval);
     } else {
         redisPanic("Unknown set encoding");
     }
@@ -5547,17 +5628,41 @@ robj *setTypeRandomElement(robj *subject) {
 static unsigned long setTypeSize(robj *subject) {
     if (subject->encoding == REDIS_ENCODING_HT) {
         return dictSize((dict*)subject->ptr);
+    } else if (subject->encoding == REDIS_ENCODING_INTSET) {
+        return intsetLen((intset*)subject->ptr);
     } else {
         redisPanic("Unknown set encoding");
     }
 }
 
+static void setTypeConvert(robj *subject, int enc) {
+    setIterator *si;
+    robj *element;
+    redisAssert(subject->type == REDIS_SET);
+
+    if (enc == REDIS_ENCODING_HT) {
+        dict *d = dictCreate(&setDictType,NULL);
+
+        /* setTypeGet returns a robj with incremented refcount */
+        si = setTypeInitIterator(subject);
+        while ((element = setTypeNext(si)) != NULL)
+            redisAssert(dictAdd(d,element,NULL) == DICT_OK);
+        setTypeReleaseIterator(si);
+
+        subject->encoding = REDIS_ENCODING_HT;
+        zfree(subject->ptr);
+        subject->ptr = d;
+    } else {
+        redisPanic("Unsupported set conversion");
+    }
+}
+
 static void saddCommand(redisClient *c) {
     robj *set;
 
     set = lookupKeyWrite(c->db,c->argv[1]);
     if (set == NULL) {
-        set = createSetObject();
+        set = setTypeCreate(c->argv[2]);
         dbAdd(c->db,c->argv[1],set);
     } else {
         if (set->type != REDIS_SET) {
@@ -5616,7 +5721,7 @@ static void smoveCommand(redisClient *c) {
     server.dirty++;
     /* Add the element to the destination set */
     if (!dstset) {
-        dstset = createSetObject();
+        dstset = setTypeCreate(c->argv[3]);
         dbAdd(c->db,c->argv[2],dstset);
     }
     setTypeAdd(dstset,c->argv[3]);
@@ -5724,7 +5829,7 @@ static void sinterGenericCommand(redisClient *c, robj **setkeys, unsigned long s
     } else {
         /* If we have a target key where to store the resulting set
          * create this key with an empty set inside */
-        dstset = createSetObject();
+        dstset = createIntsetObject();
     }
 
     /* Iterate all the elements of the first (smallest) set, and test
@@ -5802,7 +5907,7 @@ static void sunionDiffGenericCommand(redisClient *c, robj **setkeys, int setnum,
     /* We need a temp set object to store our union. If the dstkey
      * is not NULL (that is, we are inside an SUNIONSTORE operation) then
      * this set object will be the resulting object to set into the target key*/
-    dstset = createSetObject();
+    dstset = createIntsetObject();
 
     /* Iterate all the elements of all the sets, add every element a single
      * time to the result set */

tests/unit/type/set.tcl

 start_server {tags {"set"}} {
-    test {SADD, SCARD, SISMEMBER, SMEMBERS basics} {
-        r sadd myset foo
-        r sadd myset bar
-        list [r scard myset] [r sismember myset foo] \
-            [r sismember myset bar] [r sismember myset bla] \
-            [lsort [r smembers myset]]
-    } {2 1 1 0 {bar foo}}
-
-    test {SADD adding the same element multiple times} {
-        r sadd myset foo
-        r sadd myset foo
-        r sadd myset foo
-        r scard myset
-    } {2}
+    proc create_set {key entries} {
+        r del $key
+        foreach entry $entries { r sadd $key $entry }
+    }
+
+    test {SADD, SCARD, SISMEMBER, SMEMBERS basics - regular set} {
+        create_set myset {foo}
+        assert_encoding hashtable myset
+        assert_equal 1 [r sadd myset bar]
+        assert_equal 0 [r sadd myset bar]
+        assert_equal 2 [r scard myset]
+        assert_equal 1 [r sismember myset foo]
+        assert_equal 1 [r sismember myset bar]
+        assert_equal 0 [r sismember myset bla]
+        assert_equal {bar foo} [lsort [r smembers myset]]
+    }
+
+    test {SADD, SCARD, SISMEMBER, SMEMBERS basics - intset} {
+        create_set myset {17}
+        assert_encoding intset myset
+        assert_equal 1 [r sadd myset 16]
+        assert_equal 0 [r sadd myset 16]
+        assert_equal 2 [r scard myset]
+        assert_equal 1 [r sismember myset 16]
+        assert_equal 1 [r sismember myset 17]
+        assert_equal 0 [r sismember myset 18]
+        assert_equal {16 17} [lsort [r smembers myset]]
+    }
 
     test {SADD against non set} {
         r lpush mylist foo
-        catch {r sadd mylist bar} err
-        format $err
-    } {ERR*kind*}
-
-    test {SREM basics} {
-        r sadd myset ciao
-        r srem myset foo
-        lsort [r smembers myset]
-    } {bar ciao}
-
-    test {Mass SADD and SINTER with two sets} {
+        assert_error ERR*kind* {r sadd mylist bar}
+    }
+
+    test {SREM basics - regular set} {
+        create_set myset {foo bar ciao}
+        assert_encoding hashtable myset
+        assert_equal 0 [r srem myset qux]
+        assert_equal 1 [r srem myset foo]
+        assert_equal {bar ciao} [lsort [r smembers myset]]
+    }
+
+    test {SREM basics - intset} {
+        create_set myset {3 4 5}
+        assert_encoding intset myset
+        assert_equal 0 [r srem myset 6]
+        assert_equal 1 [r srem myset 4]
+        assert_equal {3 5} [lsort [r smembers myset]]
+    }
+
+    foreach {type} {hashtable intset} {
+        for {set i 1} {$i <= 5} {incr i} {
+            r del [format "set%d" $i]
+        }
         for {set i 0} {$i < 1000} {incr i} {
             r sadd set1 $i
             r sadd set2 [expr $i+995]
         }
-        lsort [r sinter set1 set2]
-    } {995 996 997 998 999}
+        foreach i {999 995 1000 2000} {
+            r sadd set3 $i
+        }
+        for {set i 5} {$i < 1000} {incr i} {
+            r sadd set4 $i
+        }
+        r sadd set5 0
+
+        # it is possible that a hashtable encoded only contains integers,
+        # because it is converted from an intset to a hashtable when a
+        # non-integer element is added and then removed.
+        if {$type eq "hashtable"} {
+            for {set i 1} {$i <= 5} {incr i} {
+                r sadd [format "set%d" $i] foo
+                r srem [format "set%d" $i] foo
+            }
+        }
+
+        test "Generated sets must be encoded as $type" {
+            for {set i 1} {$i <= 5} {incr i} {
+                assert_encoding $type [format "set%d" $i]
+            }
+        }
+
+        test "SINTER with two sets - $type" {
+            assert_equal {995 996 997 998 999} [lsort [r sinter set1 set2]]
+        }
+
+        test "SINTERSTORE with two sets - $type" {
+            r sinterstore setres set1 set2
+            assert_encoding intset setres
+            assert_equal {995 996 997 998 999} [lsort [r smembers setres]]
+        }
+
+        test "SINTERSTORE with two sets, after a DEBUG RELOAD - $type" {
+            r debug reload
+            r sinterstore setres set1 set2
+            assert_encoding intset setres
+            assert_equal {995 996 997 998 999} [lsort [r smembers setres]]
+        }
+
+        test "SUNION with two sets - $type" {
+            set expected [lsort -uniq "[r smembers set1] [r smembers set2]"]
+            assert_equal $expected [lsort [r sunion set1 set2]]
+        }
+
+        test "SUNIONSTORE with two sets - $type" {
+            r sunionstore setres set1 set2
+            assert_encoding intset setres
+            set expected [lsort -uniq "[r smembers set1] [r smembers set2]"]
+            assert_equal $expected [lsort [r smembers setres]]
+        }
+
+        test "SINTER against three sets - $type" {
+            assert_equal {995 999} [lsort [r sinter set1 set2 set3]]
+        }
+
+        test "SINTERSTORE with three sets - $type" {
+            r sinterstore setres set1 set2 set3
+            assert_equal {995 999} [r smembers setres]
+        }
+
+        test "SUNION with non existing keys - $type" {
+            set expected [lsort -uniq "[r smembers set1] [r smembers set2]"]
+            assert_equal $expected [lsort [r sunion nokey1 set1 set2 nokey2]]
+        }
+
+        test "SDIFF with two sets - $type" {
+            assert_equal {0 1 2 3 4} [lsort [r sdiff set1 set4]]
+        }
 
-    test {SUNION with two sets} {
-        lsort [r sunion set1 set2]
-    } [lsort -uniq "[r smembers set1] [r smembers set2]"]
+        test "SDIFF with three sets - $type" {
+            assert_equal {1 2 3 4} [lsort [r sdiff set1 set4 set5]]
+        }
 
-    test {SINTERSTORE with two sets} {
-        r sinterstore setres set1 set2
-        lsort [r smembers setres]
-    } {995 996 997 998 999}
+        test "SDIFFSTORE with three sets - $type" {
+            r sdiffstore setres set1 set4 set5
+            assert_encoding intset setres
+            assert_equal {1 2 3 4} [lsort [r smembers setres]]
+        }
+    }
 
-    test {SINTERSTORE with two sets, after a DEBUG RELOAD} {
-        r debug reload
-        r sinterstore setres set1 set2
-        lsort [r smembers setres]
-    } {995 996 997 998 999}
+    test "SINTER against non-set should throw error" {
+        r set key1 x
+        assert_error "ERR*wrong kind*" {r sinter key1 noset}
+    }
 
-    test {SUNIONSTORE with two sets} {
-        r sunionstore setres set1 set2
-        lsort [r smembers setres]
-    } [lsort -uniq "[r smembers set1] [r smembers set2]"]
+    test "SUNION against non-set should throw error" {
+        r set key1 x
+        assert_error "ERR*wrong kind*" {r sunion key1 noset}
+    }
 
-    test {SUNIONSTORE against non existing keys} {
+    test "SINTERSTORE against non existing keys should delete dstkey" {
         r set setres xxx
-        list [r sunionstore setres foo111 bar222] [r exists xxx]
-    } {0 0}
-
-    test {SINTER against three sets} {
-        r sadd set3 999
-        r sadd set3 995
-        r sadd set3 1000
-        r sadd set3 2000
-        lsort [r sinter set1 set2 set3]
-    } {995 999}
-
-    test {SINTERSTORE with three sets} {
-        r sinterstore setres set1 set2 set3
-        lsort [r smembers setres]
-    } {995 999}
-
-    test {SUNION with non existing keys} {
-        lsort [r sunion nokey1 set1 set2 nokey2]
-    } [lsort -uniq "[r smembers set1] [r smembers set2]"]
-
-    test {SDIFF with two sets} {
-        for {set i 5} {$i < 1000} {incr i} {
-            r sadd set4 $i
+        assert_equal 0 [r sinterstore setres foo111 bar222]
+        assert_equal 0 [r exists setres]
+    }
+
+    test "SUNIONSTORE against non existing keys should delete dstkey" {
+        r set setres xxx
+        assert_equal 0 [r sunionstore setres foo111 bar222]
+        assert_equal 0 [r exists setres]
+    }
+
+    foreach {type contents} {hashtable {a b c} intset {1 2 3}} {
+        test "SPOP basics - $type" {
+            create_set myset $contents
+            assert_encoding $type myset
+            assert_equal $contents [lsort [list [r spop myset] [r spop myset] [r spop myset]]]
+            assert_equal 0 [r scard myset]
         }
-        lsort [r sdiff set1 set4]
-    } {0 1 2 3 4}
 
-    test {SDIFF with three sets} {
-        r sadd set5 0
-        lsort [r sdiff set1 set4 set5]
-    } {1 2 3 4}
-
-    test {SDIFFSTORE with three sets} {
-        r sdiffstore sres set1 set4 set5
-        lsort [r smembers sres]
-    } {1 2 3 4}
-
-    test {SPOP basics} {
-        r del myset
-        r sadd myset 1
-        r sadd myset 2
-        r sadd myset 3
-        list [lsort [list [r spop myset] [r spop myset] [r spop myset]]] [r scard myset]
-    } {{1 2 3} 0}
-    
-    test {SRANDMEMBER} {
-        r del myset
-        r sadd myset a
-        r sadd myset b
-        r sadd myset c
-        unset -nocomplain myset
-        array set myset {}
-        for {set i 0} {$i < 100} {incr i} {
-            set myset([r srandmember myset]) 1
-        }
-        lsort [array names myset]
-    } {a b c}
-    
+        test "SRANDMEMBER - $type" {
+            create_set myset $contents
+            unset -nocomplain myset
+            array set myset {}
+            for {set i 0} {$i < 100} {incr i} {
+                set myset([r srandmember myset]) 1
+            }
+            assert_equal $contents [lsort [array names myset]]
+        }
+    }
+
     test {SMOVE basics} {
         r sadd myset1 a
         r sadd myset1 b