Merge branch 'develop' of https://github.com/nlohmann/json into develop

.gitignore

 json_unit
 json_benchmarks
+json_benchmarks_simple
 fuzz-testing
 
 *.dSYM

benchmarks/Makefile

-all: json_benchmarks
-	./json_benchmarks
 
-json_benchmarks: src/benchmarks.cpp ../src/json.hpp number_jsons
+#
+# Build/run json.hpp benchmarks, eg. CXX=g++-7 make
+# 
+# The existing json_benchmarks did not allow optimization under some compilers
+# 
+all: json_benchmarks json_benchmarks_simple number_jsons
+	bash -c 'time ./json_benchmarks'
+	bash -c 'time ./json_benchmarks_simple'
+
+json_benchmarks: src/benchmarks.cpp ../src/json.hpp
 	$(CXX) -std=c++11 -pthread $(CXXFLAGS) -DNDEBUG -O3 -flto -I thirdparty/benchpress -I thirdparty/cxxopts -I../src src/benchmarks.cpp $(LDFLAGS) -o $@
 
+json_benchmarks_simple: src/benchmarks_simple.cpp ../src/json.hpp
+	$(CXX) -std=c++11 $(CXXFLAGS) -DNDEBUG -O3 -flto -I../src $(<) $(LDFLAGS) -o $@
+
 number_jsons:
 	(test -e files/numbers/floats.json -a -e files/numbers/signed_ints.json -a -e files/numbers/unsigned_ints.json) || (cd files/numbers ; python generate.py)
 
 clean:
-	rm -f json_benchmarks files/numbers/*.json
+	rm -f json_benchmarks json_benchmarks_simple files/numbers/*.json

benchmarks/src/benchmarks.cpp

@@ -34,6 +34,19 @@ static void bench(benchpress::context& ctx,
 {
     // using string streams for benchmarking to factor-out cold-cache disk
     // access.
+#if defined( FROMFILE )
+    std::ifstream istr;
+    {
+        istr.open( in_path, std::ifstream::in );
+
+        // read the stream once
+        json j;
+        istr >> j;
+        // clear flags and rewind
+        istr.clear();
+        istr.seekg(0);
+    }
+#else
     std::stringstream istr;
     {
         // read file into string stream
@@ -43,11 +56,12 @@ static void bench(benchpress::context& ctx,
 
         // read the stream once
         json j;
-        j << istr;
+        istr >> j;
         // clear flags and rewind
         istr.clear();
         istr.seekg(0);
     }
+#endif
 
     switch (mode)
     {
@@ -62,7 +76,7 @@ static void bench(benchpress::context& ctx,
                 istr.clear();
                 istr.seekg(0);
                 json j;
-                j << istr;
+                istr >> j;
             }
 
             break;
@@ -74,7 +88,7 @@ static void bench(benchpress::context& ctx,
         {
             // create JSON value from input
             json j;
-            j << istr;
+            istr >> j;
             std::stringstream ostr;
 
             ctx.reset_timer();

benchmarks/src/benchmarks_simple.cpp

+// 
+// benchmarks_simple.cpp -- a less complex version of benchmarks.cpp, that better reflects actual performance
+// 
+//     For some reason, the complexity of benchmarks.cpp doesn't allow
+// the compiler to optimize code using json.hpp effectively.  The
+// exact same tests, with the use of benchpress and cxxopts produces
+// much faster code, at least under g++.
+// 
+#include <fstream>
+#include <iostream>
+#include <chrono>
+#include <list>
+#include <tuple>
+
+#include <json.hpp>
+
+using json = nlohmann::json;
+
+enum class EMode { input, output, indent };
+
+static double bench(const EMode mode, size_t iters, const std::string& in_path )
+{
+    // using string streams for benchmarking to factor-out cold-cache disk
+    // access.  Define FROMFILE to use file I/O instead.
+#if defined( FROMFILE )
+    std::ifstream istr;
+    {
+        istr.open( in_path, std::ifstream::in );
+
+        // read the stream once
+        json j;
+        istr >> j;
+        // clear flags and rewind
+        istr.clear();
+        istr.seekg(0);
+    }
+#else
+    std::stringstream istr;
+    {
+        // read file into string stream
+        std::ifstream input_file(in_path);
+        istr << input_file.rdbuf();
+        input_file.close();
+
+        // read the stream once
+        json j;
+        istr >> j;
+        // clear flags and rewind
+        istr.clear();
+        istr.seekg(0);
+    }
+#endif
+    double tps = 0;
+    switch (mode)
+    {
+        // benchmarking input
+        case EMode::input:
+        {
+	    auto start = std::chrono::system_clock::now();
+            for (size_t i = 0; i < iters; ++i)
+            {
+                // clear flags and rewind
+                istr.clear();
+                istr.seekg(0);
+                json j;
+                istr >> j;
+            }
+	    auto ended = std::chrono::system_clock::now();
+	    tps = 1.0 / std::chrono::duration<double>( ended - start ).count();
+            break;
+        }
+
+        // benchmarking output
+        case EMode::output:
+        case EMode::indent:
+        {
+            // create JSON value from input
+            json j;
+            istr >> j;
+            std::stringstream ostr;
+
+	    auto start = std::chrono::system_clock::now();
+            for (size_t i = 0; i < iters; ++i)
+            {
+                if (mode == EMode::indent)
+                {
+                    ostr << j;
+                }
+                else
+                {
+                    ostr << std::setw(4) << j;
+                }
+
+                // reset data
+                ostr.str(std::string());
+            }
+	    auto ended = std::chrono::system_clock::now();
+	    tps = 1.0 / std::chrono::duration<double>( ended - start ).count();
+
+            break;
+        }
+    }
+    return tps;
+}
+
+template <typename T>
+struct average {
+    T _sum { 0 };
+    size_t _count { 0 };
+    T operator+=( const T &val_ ) { _sum += val_; +_count++; return val_; }
+    operator T() { return _sum / _count; }
+};
+
+// Execute each test approximately enough times to get near 1
+// transaction per second, and compute the average; a single aggregate
+// number that gives a performance metric representing both parsing
+// and output.
+
+int main( int, char ** )
+{
+    std::list<std::tuple<std::string, EMode, size_t, std::string>> tests {
+	{ "parse jeopardy.json",	EMode::input,   2, "files/jeopardy/jeopardy.json" },
+	{ "parse canada.json",		EMode::input,  30, "files/nativejson-benchmark/canada.json" },
+	{ "parse citm_catalog.json",	EMode::input, 120, "files/nativejson-benchmark/citm_catalog.json" },
+	{ "parse twitter.json",		EMode::input, 225, "files/nativejson-benchmark/twitter.json" },
+	{ "parse floats.json",		EMode::input,   5, "files/numbers/floats.json" },
+	{ "parse signed_ints.json",	EMode::input,   6, "files/numbers/signed_ints.json" },
+	{ "parse unsigned_ints.json",	EMode::input,   6, "files/numbers/unsigned_ints.json" },
+	{ "dump jeopardy.json",		EMode::output,  5, "files/jeopardy/jeopardy.json" },
+	{ "dump jeopardy.json w/ind.",	EMode::indent,  5, "files/jeopardy/jeopardy.json" },
+	{ "dump floats.json",		EMode::output,  2, "files/numbers/floats.json" },
+	{ "dump signed_ints.json",	EMode::output, 20, "files/numbers/signed_ints.json" },
+    };
+    
+    average<double> avg;
+    for ( auto t : tests ) {
+	std::string name, path;
+	EMode mode;
+	size_t iters;
+	std::tie(name, mode, iters, path) = t;
+	auto tps = bench( mode, iters, path );
+	avg += tps;
+	std::cout
+	    << std::left 
+	    << std::setw( 30 ) << name
+	    << std::right	    
+	    << " x " 	<< std::setw(  3 ) << iters
+	    << std::left
+	    << " == " 	<< std::setw( 10 ) << tps
+	    << std::right
+	    << " TPS, "	<< std::setw(  8 ) << std::round( tps * 1e6 / iters )
+	    << " ms/op"
+	    << std::endl;
+    }
+    std::cout << std::setw( 40 ) << "" << std::string( 10, '-' ) << std::endl;
+    std::cout << std::setw( 40 ) << "" << std::setw( 10 ) << std::left << avg << " TPS Average" << std::endl;
+    return 0;
+}

test/CMakeLists.txt

@@ -66,6 +66,22 @@ set_target_properties(catch_main PROPERTIES
 )
 target_include_directories(catch_main PRIVATE "thirdparty/catch")
 
+# https://stackoverflow.com/questions/2368811/how-to-set-warning-level-in-cmake
+if(MSVC)
+    # Force to always compile with W4
+    if(CMAKE_CXX_FLAGS MATCHES "/W[0-4]")
+        string(REGEX REPLACE "/W[0-4]" "/W4" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
+    else()
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W4")
+    endif()
+
+    # Disable warning C4389: '==': signed/unsigned mismatch
+	# Disable warning C4309: 'static_cast': truncation of constant value
+	# Disable warning C4566: character represented by universal-character-name '\uFF01' cannot be represented in the current code page (1252)
+	# Disable warning C4996: 'nlohmann::basic_json<std::map,std::vector,std::string,bool,int64_t,uint64_t,double,std::allocator,nlohmann::adl_serializer>::operator <<': was declared deprecated
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /wd4389 /wd4309 /wd4566 /wd4996")
+endif()
+
 #############################################################################
 # one executable for each unit test file
 #############################################################################

test/src/unit-class_parser.cpp

@@ -215,7 +215,7 @@ TEST_CASE("parser class")
                     std::string s = "\"1\"";
                     s[1] = '\0';
                     CHECK_THROWS_AS(json::parse(s.begin(), s.end()), json::parse_error&);
-                    CHECK_THROWS_WITH(json::parse(s.begin(), s.end()), "[json.exception.parse_error.101] parse error at 2: syntax error - invalid string: control character must be escaped; last read: '\"'");
+                    CHECK_THROWS_WITH(json::parse(s.begin(), s.end()), "[json.exception.parse_error.101] parse error at 2: syntax error - invalid string: control character must be escaped; last read: '\"<U+0000>'");
                 }
             }
 

test/src/unit-constructor1.cpp

@@ -247,7 +247,7 @@ TEST_CASE("constructors")
 
         SECTION("std::pair")
         {
-            std::pair<float, std::string> p{1.0, "string"};
+            std::pair<float, std::string> p{1.0f, "string"};
             json j(p);
 
             CHECK(j.type() == json::value_t::array);

test/src/unit-readme.cpp

@@ -38,6 +38,11 @@ using nlohmann::json;
 #include <unordered_set>
 #include <iostream>
 
+#if defined(_MSC_VER)
+#pragma warning (push)
+#pragma warning (disable : 4189) // local variable is initialized but not referenced
+#endif
+
 TEST_CASE("README", "[hide]")
 {
     {
@@ -298,3 +303,7 @@ TEST_CASE("README", "[hide]")
         std::cout.rdbuf(old_cout_buffer);
     }
 }
+
+#if defined(_MSC_VER)
+#pragma warning (pop)
+#endif

test/src/unit-regression.cpp

@@ -1233,4 +1233,24 @@ TEST_CASE("regression tests")
                               "[json.exception.type_error.302] type must be array, but is null");
         }
     }
+
+    SECTION("issue #367 - Behavior of operator>> should more closely resemble that of built-in overloads.")
+    {
+	SECTION("example 1")
+	{
+	    std::istringstream i1_2_3( "{\"first\": \"one\" }{\"second\": \"two\"}3" );
+	    json j1, j2, j3;
+	    i1_2_3 >> j1;
+	    i1_2_3 >> j2;
+	    i1_2_3 >> j3;
+
+	    std::map<std::string,std::string> m1 = j1;
+	    std::map<std::string,std::string> m2 = j2;
+	    int i3 = j3;
+
+	    CHECK( m1 == ( std::map<std::string,std::string> {{ "first",  "one" }} ));
+	    CHECK( m2 == ( std::map<std::string,std::string> {{ "second", "two" }} ));
+	    CHECK( i3 == 3 );
+	}
+    }
 }

test/src/unit-udt.cpp

@@ -201,7 +201,7 @@ void from_json(const BasicJsonType& j, country& c)
     {
         {u8"中华人民共和国", country::china},
         {"France", country::france},
-        {"Российская Федерация", country::russia}
+        {u8"Российская Федерация", country::russia}
     };
 
     const auto it = m.find(str);