Introduce dependency xxhash for bloomfilter (#1694)

CMakeLists.txt

@@ -131,6 +131,7 @@ include(cmake/rocksdb.cmake)
 include(cmake/libevent.cmake)
 include(cmake/fmt.cmake)
 include(cmake/jsoncons.cmake)
+include(cmake/xxhash.cmake)
 
 if (ENABLE_LUAJIT)
 include(cmake/luajit.cmake)
@@ -160,6 +161,7 @@ list(APPEND EXTERNAL_LIBS tbb)
 list(APPEND EXTERNAL_LIBS jsoncons)
 list(APPEND EXTERNAL_LIBS Threads::Threads)
 list(APPEND EXTERNAL_LIBS ${Backtrace_LIBRARY})
+list(APPEND EXTERNAL_LIBS xxhash)
 
 # Add git sha to version.h
 find_package(Git REQUIRED)

cmake/utils.cmake

@@ -27,6 +27,7 @@ endmacro()
 
 function(FetchContent_MakeAvailableWithArgs dep)
   if(NOT ${dep}_POPULATED)
+    message("Fetching ${dep}...")
     FetchContent_Populate(${dep})
 
     foreach(arg IN LISTS ARGN)

cmake/xxhash.cmake

@@ -0,0 +1,35 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+include_guard()
+
+include(cmake/utils.cmake)
+
+FetchContent_DeclareGitHubWithMirror(xxhash
+  Cyan4973/xxHash v0.8.2
+  MD5=4b793d916f9b8e4ceb984a00e356bdb2
+)
+
+FetchContent_GetProperties(xxhash)
+if(NOT xxhash_POPULATED)
+  FetchContent_Populate(xxhash)
+
+  set(BUILD_SHARED_LIBS OFF)
+  set(XXHASH_BUILD_XXHSUM OFF)
+
+  add_subdirectory(${xxhash_SOURCE_DIR}/cmake_unofficial ${xxhash_BUILD_DIR} EXCLUDE_FROM_ALL)
+endif()