Allow clients that lack absl to built and use the library

Moved Int128 definition to a separate header
Added few extra methods to ColumnDecimal that do not rely on Int128
Ensured that client programs can be built without absl headers present.

Author: Enmk

.travis.yml

@@ -49,10 +49,14 @@ before_install: |
   fi
 
 # Build steps
-script:
-  - eval "${MATRIX_EVAL}"
-  - mkdir build
-  - cd build
-  - cmake .. -DBUILD_TESTS=ON && make
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then ./ut/clickhouse-cpp-ut ; fi
-  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then ./ut/clickhouse-cpp-ut --gtest_filter=-"Client/*:*Performance*" ; fi
+script: |
+  eval "${MATRIX_EVAL}"
+  mkdir build
+  cd build
+  cmake .. -DBUILD_TESTS=ON && cmake --build . --target all
+  if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then ./ut/clickhouse-cpp-ut ; fi
+  if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then ./ut/clickhouse-cpp-ut --gtest_filter=-"Client/*:*Performance*" ; fi
+  # Test clients that do not have absl in the system still can be built
+  cmake --build . --target install . && cmake --build . --target clean
+  cd ./tests/simple && mkdir build && cd ./build
+  cmake .. -DBUILD_SAMPLE_WITH_INT128=ON -DCMAKE_CXX_STANDARD=17 -DCMAKE_CXX_STANDARD_REQUIRED=ON && cmake --build . --target all

CMakeLists.txt

@@ -10,9 +10,9 @@ PROJECT (CLICKHOUSE-CLIENT)
 
     USE_CXX17()
 
-	IF ("${CMAKE_BUILD_TYPE}" STREQUAL "")
-		set(CMAKE_BUILD_TYPE "Debug")
-	ENDIF()
+    IF ("${CMAKE_BUILD_TYPE}" STREQUAL "")
+        set(CMAKE_BUILD_TYPE "Debug")
+    ENDIF()
 
     IF (UNIX)
         IF (APPLE)
@@ -43,4 +43,4 @@ PROJECT (CLICKHOUSE-CLIENT)
             tests/simple
             ut
         )
-	ENDIF (BUILD_TESTS)
+    ENDIF (BUILD_TESTS)

clickhouse/CMakeLists.txt

@@ -100,3 +100,4 @@ INSTALL(FILES columns/uuid.h DESTINATION include/clickhouse/columns/)
 # types
 INSTALL(FILES types/type_parser.h DESTINATION include/clickhouse/types/)
 INSTALL(FILES types/types.h DESTINATION include/clickhouse/types/)
+INSTALL(FILES types/int128.h DESTINATION include/clickhouse/types/)

clickhouse/columns/date.cpp

@@ -1,5 +1,7 @@
 #include "date.h"
 
+#include "../types/int128.h"
+
 namespace clickhouse {
 
 ColumnDate::ColumnDate()

clickhouse/columns/decimal.cpp

@@ -1,5 +1,7 @@
 #include "decimal.h"
 
+#include "../types/int128.h"
+
 namespace
 {
 using namespace clickhouse;
@@ -117,6 +119,10 @@ ColumnDecimal::ColumnDecimal(TypeRef type, ColumnRef data)
 {
 }
 
+void ColumnDecimal::Append(Int64 value) {
+    Append(static_cast<Int128>(value));
+}
+
 void ColumnDecimal::Append(const Int128& value) {
     if (data_->Type()->GetCode() == Type::Int32) {
         data_->As<ColumnInt32>()->Append(static_cast<ColumnInt32::DataType>(value));
@@ -191,6 +197,10 @@ Int128 ColumnDecimal::At(size_t i) const {
     }
 }
 
+Int64 ColumnDecimal::AtAsInt64(size_t i) const {
+    return static_cast<Int64>(At(i));
+}
+
 void ColumnDecimal::Append(ColumnRef column) {
     if (auto col = column->As<ColumnDecimal>()) {
         data_->Append(col->data_);

clickhouse/columns/decimal.h

@@ -12,10 +12,12 @@ class ColumnDecimal : public Column {
 public:
     ColumnDecimal(size_t precision, size_t scale);
 
+    void Append(Int64 value); /// When Int128 is not supported by\not available to users.
     void Append(const Int128& value);
     void Append(const std::string& value);
 
     Int128 At(size_t i) const;
+    Int64 AtAsInt64(size_t i) const; /// result will overflow if value doesn't fit into Int64.
 
 public:
     void Append(ColumnRef column) override;

clickhouse/columns/factory.cpp

@@ -16,6 +16,7 @@
 #include "uuid.h"
 
 #include "../types/type_parser.h"
+#include "../types/int128.h"
 
 #include <stdexcept>
 

clickhouse/columns/numeric.cpp

@@ -1,6 +1,8 @@
 #include "numeric.h"
 #include "utils.h"
 
+#include "../types/int128.h"
+
 namespace clickhouse {
 
 template <typename T>

clickhouse/columns/numeric.h

@@ -1,7 +1,11 @@
 #pragma once
 
 #include "column.h"
-#include "absl/numeric/int128.h"
+
+namespace absl
+{
+class int128;
+}
 
 namespace clickhouse {
 

clickhouse/types/int128.h

@@ -0,0 +1,9 @@
+#pragma once
+
+/// In a separate header to allow basic non-Int128 functionality on systems that lack absl.
+#include <absl/numeric/int128.h>
+
+namespace clickhouse
+{
+using Int128 = absl::int128;
+}