Added support for binary logging using to_hex(..)

bench/bench.cpp

@@ -32,7 +32,7 @@ void bench_mt(int howmany, std::shared_ptr<spdlog::logger> log, int thread_count
 int main(int argc, char *argv[])
 {
 
-    int howmany = 1000000;
+    int howmany = 100000;
     int queue_size = howmany + 2;
     int threads = 10;
     size_t file_size = 30 * 1024 * 1024;
@@ -54,12 +54,20 @@ int main(int argc, char *argv[])
         cout << "******************************************************************"
                 "*************\n";
 
-        auto basic_st = spdlog::basic_logger_st("basic_st", "logs/basic_st.log", true);
-        bench(howmany, basic_st);
+
+         bench(howmany, spdlog::create<null_sink_st>("null_st"));
+         return 0;
 
         auto rotating_st = spdlog::rotating_logger_st("rotating_st", "logs/rotating_st.log", file_size, rotating_files);
         bench(howmany, rotating_st);
 
+         return 0;
+        auto basic_st = spdlog::basic_logger_st("basic_st", "logs/basic_st.log", true);
+        bench(howmany, basic_st);
+
+        //auto rotating_st = spdlog::rotating_logger_st("rotating_st", "logs/rotating_st.log", file_size, rotating_files);
+        //bench(howmany, rotating_st);
+
         auto daily_st = spdlog::daily_logger_st("daily_st", "logs/daily_st.log");
         bench(howmany, daily_st);
 
@@ -103,15 +111,17 @@ int main(int argc, char *argv[])
     }
     return EXIT_SUCCESS;
 }
+#include "spdlog/extra/to_hex.h"
 
 void bench(int howmany, std::shared_ptr<spdlog::logger> log)
 {
     using std::chrono::high_resolution_clock;
     cout << log->name() << "...\t\t" << flush;
+    char buf[1024];
     auto start = high_resolution_clock::now();
     for (auto i = 0; i < howmany; ++i)
     {
-        log->info("Hello logger: msg number {}", i);
+        log->info("Hello logger: msg number {}", spdlog::to_hex(buf));
     }
 
     auto delta = high_resolution_clock::now() - start;

example/example.cpp

@@ -14,6 +14,7 @@ void basic_example();
 void rotating_example();
 void daily_example();
 void async_example();
+void binary_example();
 void multi_sink_example();
 void user_defined_example();
 void err_handler_example();
@@ -40,6 +41,9 @@ int main(int, char *[])
         // async logging using a backing thread pool
         async_example();
 
+        // log binary data
+        binary_example();
+        
         // a logger can have multiple targets with different formats
         multi_sink_example();
 
@@ -97,6 +101,7 @@ void stdout_example()
     // Customize msg format for all loggers
     spdlog::set_pattern("[%H:%M:%S %z] [%n] [%^---%L---%$] [thread %t] %v");
     console->info("This an info message with custom format");
+    spdlog::set_pattern("%+"); // back to default format
 
     // Compile time log levels
     // define SPDLOG_DEBUG_ON or SPDLOG_TRACE_ON
@@ -148,6 +153,30 @@ void async_example()
     }
 }
 
+// log binary data as hex.
+// many types of std::container<char> types can be used.
+// ranges are supported too.
+// format flags:
+// {:X} - print in uppercase.
+// {:s} - don't separate each byte with space.
+// {:p} - don't print the position on each line start.
+// {:n} - don't split the output to lines.
+
+#include "spdlog/fmt/bin_to_hex.h"
+
+void binary_example()
+{
+    auto console = spdlog::get("console");
+    std::array<char, 80> buf;
+    console->info("Binary example: {}", spdlog::to_hex(buf));
+    console->info("Another binary example:{:n}", spdlog::to_hex(std::begin(buf), std::begin(buf)+10));
+    // more examples:
+    // logger->info("uppercase: {:X}", spdlog::to_hex(buf));
+    // logger->info("uppercase, no delimiters: {:Xs}", spdlog::to_hex(buf));
+    // logger->info("uppercase, no delimiters, no position info: {:Xsp}", spdlog::to_hex(buf));
+
+}
+
 // create logger with 2 targets with different log levels and formats
 // the console will show only warnings or errors, while the file will log all
 

include/spdlog/fmt/bin_to_hex.h

@@ -0,0 +1,167 @@
+//
+// Copyright(c) 2015 Gabi Melman.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+//
+
+#pragma once
+
+//
+// Support for logging binary data as hex
+// format flags:
+// {:X} - print in uppercase.
+// {:s} - don't separate each byte with space.
+// {:p} - don't print the position on each line start.
+// {:n} - don't split the output to lines.
+
+//
+// Examples:
+//
+// std::vector<char> v(200, 0x0b);
+// logger->info("Some buffer {}", spdlog::to_hex(v));
+// char buf[128];
+// logger->info("Some buffer {:X}", spdlog::to_hex(std::begin(buf), std::end(buf)));
+
+
+namespace spdlog {
+namespace details {
+
+template<typename It>
+class bytes_range
+{
+public:
+    bytes_range(It range_begin, It range_end)
+      : begin_(range_begin), end_(range_end)
+    {}
+
+    It begin() const {return begin_;}
+    It end() const {return end_;}
+
+private:
+    It begin_, end_;
+
+};
+} // namespace details
+
+// create a bytes_range that wraps the given container
+template <typename Container>
+inline details::bytes_range<typename Container::const_iterator> to_hex(const Container &container)
+{
+    static_assert(sizeof(typename Container::value_type) == 1, "sizeof(Container::value_type) != 1");
+    using Iter = typename Container::const_iterator;
+    return details::bytes_range<Iter>(std::begin(container), std::end(container));
+}
+
+// create bytes_range from ranges
+template<typename It>
+inline details::bytes_range<It> to_hex(const It range_begin, const It range_end)
+{
+    return details::bytes_range<It>(range_begin, range_end);
+}
+
+
+} // namespace spdlog
+
+namespace fmt {
+
+template<typename T>
+struct formatter<spdlog::details::bytes_range<T>>
+{
+    const std::size_t line_size = 100;
+    const char delimiter = ' ';
+
+    bool put_newlines = true;
+    bool put_delimiters = true;
+    bool use_uppercase = false;
+    bool put_positions = true; // position on start of each line
+
+    // parse the format string flags
+    template<typename ParseContext>
+    auto parse(ParseContext &ctx) -> decltype(ctx.begin())
+    {
+        auto it = ctx.begin();
+        while (*it && *it != '}')
+        {
+            switch (*it)
+            {
+                case 'X':
+                    use_uppercase = true;
+                    break;
+                case 's':
+                    put_delimiters = false;
+                    break;
+                case 'p':
+                    put_positions = false;
+                    break;
+                case 'n':
+                    put_newlines = false;
+                    break;
+            }
+
+            ++it;
+        }
+        return it;
+    }
+
+    // format the given bytes range as hex
+    template<typename FormatContext, typename Container>
+    auto format(const spdlog::details::bytes_range<Container> &the_range, FormatContext &ctx) -> decltype(ctx.out())
+    {
+        const char *hex_upper = "0123456789ABCDEF";
+        const char *hex_lower = "0123456789abcdef";
+        const char *hex_chars = use_uppercase ? hex_upper : hex_lower;
+
+        std::size_t pos = 0;
+        std::size_t column = line_size;
+        auto inserter = ctx.begin();
+
+        for (auto &item:the_range)
+        {
+            auto ch = static_cast<unsigned char>(item);
+            pos++;
+
+            if (put_newlines && column >= line_size)
+            {
+                column = put_newline(inserter, pos);
+
+                // put first byte without delimiter in front of it
+                *inserter++ = hex_chars[(ch >> 4) & 0x0f];
+                *inserter++ = hex_chars[ch & 0x0f];
+                column+= 2;
+                continue;
+            }
+
+            if (put_delimiters)
+            {
+                *inserter++ = delimiter;
+                ++column;
+            }
+
+            *inserter++ = hex_chars[(ch >> 4) & 0x0f];
+            *inserter++ = hex_chars[ch & 0x0f];
+            column+= 2;
+        }
+        return inserter;
+    }
+
+    // put newline(and position header)
+    // return the next column
+    template<typename It>
+    std::size_t put_newline(It inserter, std::size_t pos)
+    {
+#ifdef _WIN32
+        *inserter++ = '\r';
+#endif
+        *inserter++ = '\n';
+
+        if (put_positions)
+        {
+            fmt::format_to(inserter, "{:<04X}: ", pos-1);
+            return 7;
+        }
+        else
+        {
+            return 1;
+        }
+    }
+};
+} // namespace fmt

tests/test_misc.cpp

@@ -134,3 +134,46 @@ TEST_CASE("clone async", "[clone]")
 
     spdlog::drop_all();
 }
+
+
+
+#include "spdlog/fmt/bin_to_hex.h"
+
+TEST_CASE("to_hex", "[to_hex]")
+{
+    std::ostringstream oss;
+    auto oss_sink = std::make_shared<spdlog::sinks::ostream_sink_mt>(oss);
+    spdlog::logger oss_logger("oss", oss_sink);
+
+    std::vector<unsigned char> v {9, 0xa, 0xb, 0xc, 0xff, 0xff};
+    oss_logger.info("{}", spdlog::to_hex(v));
+
+    auto output = oss.str();
+    REQUIRE(ends_with(output, "0000: 09 0a 0b 0c ff ff" + std::string(spdlog::details::os::default_eol)));
+}
+
+TEST_CASE("to_hex_upper", "[to_hex]")
+{
+    std::ostringstream oss;
+    auto oss_sink = std::make_shared<spdlog::sinks::ostream_sink_mt>(oss);
+    spdlog::logger oss_logger("oss", oss_sink);
+
+    std::vector<unsigned char> v {9, 0xa, 0xb, 0xc, 0xff, 0xff};
+    oss_logger.info("{:X}", spdlog::to_hex(v));
+
+    auto output = oss.str();
+    REQUIRE(ends_with(output, "0000: 09 0A 0B 0C FF FF" + std::string(spdlog::details::os::default_eol)));
+}
+
+TEST_CASE("to_hex_no_delimiter", "[to_hex]")
+{
+    std::ostringstream oss;
+    auto oss_sink = std::make_shared<spdlog::sinks::ostream_sink_mt>(oss);
+    spdlog::logger oss_logger("oss", oss_sink);
+
+    std::vector<unsigned char> v {9, 0xa, 0xb, 0xc, 0xff, 0xff};
+    oss_logger.info("{:sX}", spdlog::to_hex(v));
+
+    auto output = oss.str();
+    REQUIRE(ends_with(output, "0000: 090A0B0CFFFF" + std::string(spdlog::details::os::default_eol)));
+}