Adding xxHash64 and xxHash32 functions

dbms/src/Functions/CMakeLists.txt

@@ -12,7 +12,7 @@ add_library(clickhouse_functions ${LINK_MODE} ${clickhouse_functions_sources})
 
 target_link_libraries(clickhouse_functions
     PUBLIC
-        dbms 
+        dbms
     PRIVATE
         clickhouse_dictionaries
         ${CONSISTENT_HASHING_LIBRARY}
@@ -21,7 +21,8 @@ target_link_libraries(clickhouse_functions
         ${METROHASH_LIBRARIES}
         murmurhash
         ${BASE64_LIBRARY}
-        ${OPENSSL_CRYPTO_LIBRARY})
+        ${OPENSSL_CRYPTO_LIBRARY}
+        ${LZ4_LIBRARY})
 
 target_include_directories (clickhouse_functions SYSTEM BEFORE PUBLIC ${DIVIDE_INCLUDE_DIR})
 

dbms/src/Functions/FunctionsHashing.cpp

@@ -27,5 +27,7 @@ void registerFunctionsHashing(FunctionFactory & factory)
     factory.registerFunction<FunctionMurmurHash3_32>();
     factory.registerFunction<FunctionMurmurHash3_64>();
     factory.registerFunction<FunctionMurmurHash3_128>();
+    factory.registerFunction<FunctionXxHash32>();
+    factory.registerFunction<FunctionXxHash64>();
 }
 }

dbms/src/Functions/FunctionsHashing.h

@@ -7,6 +7,7 @@
 #include <metrohash.h>
 #include <murmurhash2.h>
 #include <murmurhash3.h>
+#include <xxhash.h>
 
 #include <Poco/ByteOrder.h>
 
@@ -117,6 +118,7 @@ struct HalfMD5Impl
 
     /// If true, it will use intHash32 or intHash64 to hash POD types. This behaviour is intended for better performance of some functions.
     /// Otherwise it will hash bytes in memory as a string using corresponding hash function.
+
     static constexpr bool use_int_hash_for_pods = false;
 };
 
@@ -401,6 +403,44 @@ struct ImplMetroHash64
     static constexpr bool use_int_hash_for_pods = true;
 };
 
+struct ImplXxHash32
+{
+    static constexpr auto name = "xxHash32";
+    using ReturnType = UInt32;
+
+    static auto apply(const char * s, const size_t len) { return XXH32(s, len, 0); }
+    /**
+      *  With current implementation with more than 1 arguments it will give the results
+      *  non-reproducable from outside of CH.
+      *
+      *  Proper way of combining several input is to use streaming mode of hash function
+      *  https://github.com/Cyan4973/xxHash/issues/114#issuecomment-334908566
+      *
+      *  In common case doable by init_state / update_state / finalize_state
+      */
+    static auto combineHashes(UInt32 h1, UInt32 h2) { return IntHash32Impl::apply(h1) ^ h2; }
+
+    static constexpr bool use_int_hash_for_pods = false;
+};
+
+
+struct ImplXxHash64
+{
+    static constexpr auto name = "xxHash64";
+    using ReturnType = UInt64;
+    using uint128_t = CityHash_v1_0_2::uint128;
+
+    static auto apply(const char * s, const size_t len) { return XXH64(s, len, 0); }
+
+    /*
+       With current implementation with more than 1 arguments it will give the results
+       non-reproducable from outside of CH. (see comment on ImplXxHash32).
+     */
+    static auto combineHashes(UInt64 h1, UInt64 h2) { return CityHash_v1_0_2::Hash128to64(uint128_t(h1, h2)); }
+
+    static constexpr bool use_int_hash_for_pods = false;
+};
+
 
 template <typename Impl>
 class FunctionStringHashFixedString : public IFunction
@@ -1024,6 +1064,8 @@ using FunctionMurmurHash2_64 = FunctionAnyHash<MurmurHash2Impl64>;
 using FunctionMurmurHash3_32 = FunctionAnyHash<MurmurHash3Impl32>;
 using FunctionMurmurHash3_64 = FunctionAnyHash<MurmurHash3Impl64>;
 using FunctionMurmurHash3_128 = FunctionStringHashFixedString<MurmurHash3Impl128>;
+using FunctionXxHash32 = FunctionAnyHash<ImplXxHash32>;
+using FunctionXxHash64 = FunctionAnyHash<ImplXxHash64>;
 using FunctionJavaHash = FunctionAnyHash<JavaHashImpl>;
 using FunctionHiveHash = FunctionAnyHash<HiveHashImpl>;
 

dbms/tests/queries/0_stateless/00803_xxhash.reference

@@ -0,0 +1,54 @@
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
+1
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+1
+1
+1
+1
+1
+1
+1
+1
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+1
+1
+1
+1
+1
+1
+1
+1

dbms/tests/queries/0_stateless/00803_xxhash.sql

@@ -0,0 +1,77 @@
+SELECT hex(xxHash64('')) = upper('ef46db3751d8e999');
+SELECT hex(xxHash32('')) = upper('02cc5d05');
+
+SELECT hex(xxHash64('ABC')) = upper('e66ae7354fcfee98');
+SELECT hex(xxHash32('ABC')) = upper('80712ed5');
+
+SELECT hex(xxHash64('xxhash')) = upper('32dd38952c4bc720');
+
+--
+
+SELECT xxHash64(NULL) is NULL;
+SELECT xxHash64()       = toUInt64(16324913028386710556);
+
+SELECT xxHash64(0)      = toUInt64(16804241149081757544);
+SELECT xxHash64(123456) = toUInt64(9049736899514479480);
+
+select xxHash64(toUInt8(0))  = xxHash64('\0');
+select xxHash64(toUInt16(0)) = xxHash64('\0\0');
+select xxHash64(toUInt32(0)) = xxHash64('\0\0\0\0');
+select xxHash64(toUInt64(0)) = xxHash64('\0\0\0\0\0\0\0\0');
+
+SELECT xxHash64(CAST(3 AS UInt8))        = toUInt64(2244420788148980662);
+SELECT xxHash64(CAST(1.2684 AS Float32)) = toUInt64(6662491266811474554);
+SELECT xxHash64(CAST(-154477 AS Int64))  = toUInt64(1162348840373071858);
+
+SELECT xxHash64('')    = toUInt64(17241709254077376921);
+SELECT xxHash64('foo') = toUInt64(3728699739546630719);
+SELECT xxHash64(CAST('foo' AS FixedString(3))) = xxHash64('foo');
+SELECT xxHash64(CAST('bar' AS FixedString(3))) = toUInt64(5234164152756840025);
+SELECT xxHash64(x) = toUInt64(9962287286179718960) FROM (SELECT CAST(1 AS Enum8('a' = 1, 'b' = 2)) as x);
+
+SELECT xxHash64('\x01') = toUInt64(9962287286179718960);
+SELECT xxHash64('\x02\0') = toUInt64(6482051057365497128);
+SELECT xxHash64('\x03\0\0\0') = toUInt64(13361037350151369407);
+
+SELECT xxHash64(1) = toUInt64(9962287286179718960);
+SELECT xxHash64(toUInt16(2)) = toUInt64(6482051057365497128);
+SELECT xxHash64(toUInt32(3)) = toUInt64(13361037350151369407);
+
+SELECT xxHash64(1, 2, 3) = toUInt64(13728743482242651702);
+SELECT xxHash64(1, 3, 2) = toUInt64(10226792638577471533);
+SELECT xxHash64(('a', [1, 2, 3], 4, (4, ['foo', 'bar'], 1, (1, 2)))) = toUInt64(3521288460171939489);
+
+--
+
+SELECT xxHash32(NULL) is NULL;
+SELECT xxHash32()       = toUInt32(4263699484);
+
+SELECT xxHash32(0)      = toUInt32(3479547966);
+SELECT xxHash32(123456) = toUInt32(1434661961);
+
+select xxHash32(toUInt8(0))  = xxHash32('\0');
+select xxHash32(toUInt16(0)) = xxHash32('\0\0');
+select xxHash32(toUInt32(0)) = xxHash32('\0\0\0\0');
+
+SELECT xxHash32(CAST(3 AS UInt8))        = toUInt32(565077562);
+SELECT xxHash32(CAST(1.2684 AS Float32)) = toUInt32(3120514536);
+SELECT xxHash32(CAST(-154477 AS Int32))  = toUInt32(3279223048);
+
+SELECT xxHash32('')    = toUInt32(46947589);
+SELECT xxHash32('foo') = toUInt32(3792637401);
+SELECT xxHash32(CAST('foo' AS FixedString(3))) = xxHash32('foo');
+SELECT xxHash32(CAST('bar' AS FixedString(3))) = toUInt32(1101146924);
+SELECT xxHash32(x) = toUInt32(949155633) FROM (SELECT CAST(1 AS Enum8('a' = 1, 'b' = 2)) as x);
+
+SELECT xxHash32('\x01') = toUInt32(949155633);
+SELECT xxHash32('\x02\0') = toUInt32(332955956);
+SELECT xxHash32('\x03\0\0\0') = toUInt32(2158931063);
+
+SELECT xxHash32(1) = toUInt32(949155633);
+SELECT xxHash32(toUInt16(2)) = toUInt32(332955956);
+SELECT xxHash32(toUInt32(3)) = toUInt32(2158931063);
+
+SELECT xxHash32(1, 2, 3) = toUInt32(441104368);
+SELECT xxHash32(1, 3, 2) = toUInt32(912264289);
+SELECT xxHash32(('a', [1, 2, 3], 4, (4, ['foo', 'bar'], 1, (1, 2)))) = toUInt32(1930126291);
+