Add options to use system abseil, lz4 and cityhash

This change solves #86, #99.

Furthermore, it eases Conan packaging, as Conan already provides
abseil, lz4 and cityhash.

Signed-off-by: David Keller <david@woorton.com>

Author: DavidWoorton

.github/workflows/linux.yml

@@ -14,8 +14,9 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        compiler: [clang-6, gcc-7, gcc-8, gcc-9]
-        ssl: [ssl_ON, ssl_OFF]
+        compiler: []
+        ssl: []
+        dependencies: []
         include:
         - compiler: clang-6
           INSTALL: clang-6.0
@@ -39,10 +40,16 @@ jobs:
 
         - ssl: ssl_ON
           INSTALL_SSL: libssl-dev
-          EXTRA_CMAKE_FLAGS: -DWITH_OPENSSL=ON
+          OPENSSL_CMAKE_OPTION: -DWITH_OPENSSL=ON
 
         - ssl: ssl_OFF
-          EXTRA_CMAKE_FLAGS: -DWITH_OPENSSL=OFF
+          OPENSSL_CMAKE_OPTION: -DWITH_OPENSSL=OFF
+
+        - dependencies: dependencies_SYSTEM
+          DEPENDENCIES_CMAKE_OPTIONS: -DWITH_SYSTEM_ABSEIL=ON -DWITH_SYSTEM_LZ4=ON -DWITH_SYSTEM_CITYHASH=ON
+
+        - dependencies: dependencies_BUILT_IN
+          DEPENDENCIES_CMAKE_OPTIONS: -DWITH_SYSTEM_ABSEIL=OFF -DWITH_SYSTEM_LZ4=OFF -DWITH_SYSTEM_CITYHASH=OFF
 
     steps:
     - uses: actions/checkout@v2
@@ -57,7 +64,8 @@ jobs:
           -DCMAKE_CXX_COMPILER=${{ matrix.CXX_COMPILER}} \
           -B ${{github.workspace}}/build \
           -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}} -DBUILD_TESTS=ON \
-          ${{ matrix.EXTRA_CMAKE_FLAGS }}
+          ${{ matrix.OPENSSL_CMAKE_OPTION}} \
+          ${{ matrix.DEPENDENCIES_CMAKE_OPTIONS }}
 
     - name: Build
       run: cmake --build ${{github.workspace}}/build --config ${{env.BUILD_TYPE}} --target all

CMakeLists.txt

@@ -7,6 +7,9 @@ INCLUDE (cmake/openssl.cmake)
 OPTION (BUILD_BENCHMARK "Build benchmark" OFF)
 OPTION (BUILD_TESTS "Build tests" OFF)
 OPTION (WITH_OPENSSL "Use OpenSSL for TLS connections" OFF)
+OPTION (USE_SYSTEM_ABSEIL "Use system ABSEIL" OFF)
+OPTION (USE_SYSTEM_LZ4 "Use system LZ4" OFF)
+OPTION (USE_SYSTEM_CITYHASH "Use system cityhash" OFF)
 
 PROJECT (CLICKHOUSE-CLIENT)
 
@@ -27,13 +30,30 @@ PROJECT (CLICKHOUSE-CLIENT)
     ENDIF ()
 
     INCLUDE_DIRECTORIES (.)
-    INCLUDE_DIRECTORIES (contrib)
+
+    IF (USE_SYSTEM_ABSEIL)
+        FIND_PACKAGE(absl REQUIRED)
+    ELSE ()
+        INCLUDE_DIRECTORIES (contrib/absl)
+        SUBDIRS (contrib/absl/absl)
+    ENDIF ()
+
+    IF (USE_SYSTEM_LZ4)
+        FIND_PACKAGE(lz4 REQUIRED)
+    ELSE ()
+        INCLUDE_DIRECTORIES (contrib/lz4/lz4)
+        SUBDIRS (contrib/lz4/lz4)
+    ENDIF ()
+
+    IF (USE_SYSTEM_CITYHASH)
+        FIND_PACKAGE(cityhash REQUIRED)
+    ELSE ()
+        INCLUDE_DIRECTORIES (contrib/cityhash/cityhash)
+        SUBDIRS (contrib/cityhash/cityhash)
+    ENDIF ()
 
     SUBDIRS (
         clickhouse
-        contrib/absl
-        contrib/cityhash
-        contrib/lz4
     )
 
     IF (BUILD_BENCHMARK)

clickhouse/CMakeLists.txt

@@ -38,16 +38,16 @@ ENDIF ()
 ADD_LIBRARY (clickhouse-cpp-lib SHARED ${clickhouse-cpp-lib-src})
 SET_TARGET_PROPERTIES(clickhouse-cpp-lib PROPERTIES LINKER_LANGUAGE CXX)
 TARGET_LINK_LIBRARIES (clickhouse-cpp-lib
-    absl-lib
-    cityhash-lib
-    lz4-lib
+    absl::absl
+    cityhash::cityhash
+    lz4::lz4
 )
 
 ADD_LIBRARY (clickhouse-cpp-lib-static STATIC ${clickhouse-cpp-lib-src})
 TARGET_LINK_LIBRARIES (clickhouse-cpp-lib-static
-    absl-lib
-    cityhash-lib
-    lz4-lib
+    absl::absl
+    cityhash::cityhash
+    lz4::lz4
 )
 
 IF (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")

clickhouse/base/compressed.cpp

@@ -2,8 +2,8 @@
 #include "wire_format.h"
 #include "output.h"
 
-#include <cityhash/city.h>
-#include <lz4/lz4.h>
+#include <city.h>
+#include <lz4.h>
 #include <stdexcept>
 #include <system_error>
 

clickhouse/columns/lowcardinality.cpp

@@ -4,7 +4,7 @@
 #include "nullable.h"
 #include "../base/wire_format.h"
 
-#include <cityhash/city.h>
+#include <city.h>
 
 #include <functional>
 #include <string_view>

clickhouse/types/types.cpp

@@ -1,6 +1,6 @@
 #include "types.h"
 
-#include <cityhash/city.h>
+#include <city.h>
 
 #include <stdexcept>
 

contrib/absl/CMakeLists.txt

@@ -0,0 +1,5 @@
+ADD_LIBRARY (absl STATIC
+    numeric/int128.cc
+)
+
+ADD_LIBRARY (absl::absl ALIAS absl)

contrib/absl/absl/CMakeLists.txt

@@ -0,0 +1,7 @@
+ADD_LIBRARY (cityhash STATIC
+    city.cc
+)
+
+set_property(TARGET cityhash PROPERTY POSITION_INDEPENDENT_CODE ON)
+
+ADD_LIBRARY (cityhash::cityhash ALIAS cityhash)

contrib/absl/base/attributes.h renamed to contrib/absl/absl/base/attributes.h

@@ -0,0 +1,8 @@
+ADD_LIBRARY (lz4 STATIC
+    lz4.c
+    lz4hc.c
+)
+
+set_property(TARGET lz4 PROPERTY POSITION_INDEPENDENT_CODE ON)
+
+ADD_LIBRARY(lz4::lz4 ALIAS lz4)