DragonBox integration

.gitmodules

@@ -209,3 +209,6 @@
 	path = contrib/abseil-cpp
 	url = https://github.com/ClickHouse-Extras/abseil-cpp.git
 	branch = lts_2020_02_25
+[submodule "contrib/dragonbox"]
+	path = contrib/dragonbox
+	url = https://github.com/kitaisreal/dragonbox.git

contrib/CMakeLists.txt

@@ -322,3 +322,5 @@ endif()
 if (USE_INTERNAL_ROCKSDB_LIBRARY)
     add_subdirectory(rocksdb-cmake)
 endif()
+
+add_subdirectory(dragonbox)

contrib/dragonbox

@@ -0,0 +1 @@
+Subproject commit 17d07b00f9c70d61c60c3bd1046c2ef6814d14c6

docker/test/fasttest/run.sh

@@ -155,6 +155,7 @@ function clone_submodules
             contrib/croaring
             contrib/miniselect
             contrib/xz
+            contrib/dragonbox
         )
 
         git submodule sync

src/CMakeLists.txt

@@ -243,6 +243,7 @@ target_link_libraries (clickhouse_common_io
             common
             ${DOUBLE_CONVERSION_LIBRARIES}
             ryu
+            dragonbox_to_chars
 )
 
 if(RE2_LIBRARY)

src/IO/WriteHelpers.h

@@ -29,7 +29,7 @@
 #include <IO/DoubleConverter.h>
 #include <IO/WriteBufferFromString.h>
 
-#include <ryu/ryu.h>
+#include <dragonbox/dragonbox_to_chars.h>
 
 #include <Formats/FormatSettings.h>
 
@@ -228,14 +228,14 @@ inline size_t writeFloatTextFastPath(T x, char * buffer)
         if (DecomposedFloat64(x).is_inside_int64())
             result = itoa(Int64(x), buffer) - buffer;
         else
-            result = d2s_buffered_n(x, buffer);
+            result = jkj::dragonbox::to_chars_n(x, buffer) - buffer;
     }
     else
     {
         if (DecomposedFloat32(x).is_inside_int32())
             result = itoa(Int32(x), buffer) - buffer;
         else
-            result = f2s_buffered_n(x, buffer);
+            result = jkj::dragonbox::to_chars_n(x, buffer) - buffer;
     }
 
     if (result <= 0)

src/IO/tests/CMakeLists.txt

@@ -82,6 +82,7 @@ target_link_libraries (zlib_ng_bug PRIVATE ${ZLIB_LIBRARIES})
 
 add_executable (ryu_test ryu_test.cpp)
 target_link_libraries (ryu_test PRIVATE ryu)
+target_link_libraries (ryu_test PRIVATE dragonbox_to_chars)
 
 add_executable (zstd_buffers zstd_buffers.cpp)
 target_link_libraries (zstd_buffers PRIVATE clickhouse_common_io)

src/IO/tests/ryu_test.cpp

@@ -2,7 +2,7 @@
 #include <iostream>
 #include <cstring>
 #include <ryu/ryu.h>
-
+#include <dragonbox/dragonbox_to_chars.h>
 
 struct DecomposedFloat64
 {
@@ -84,9 +84,14 @@ int main(int argc, char ** argv)
     double x = argc > 1 ? std::stod(argv[1]) : 0;
     char buf[32];
 
+    std::cout << "ryu output" << std::endl;
     d2s_buffered(x, buf);
     std::cout << buf << "\n";
 
+    std::cout << "dragonbox output" << std::endl;
+    jkj::dragonbox::to_chars(x, buf);
+    std::cout << buf << "\n";
+
     std::cout << DecomposedFloat64(x).isInsideInt64() << "\n";
 
     return 0;