1// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
2// Distributed under the MIT License (http://opensource.org/licenses/MIT)
3
4#pragma once
5
6#include <map>
7#include <string>
8
9#include <spdlog/common.h>
10
11// MDC is a simple map of key->string values stored in thread local storage whose content will be printed by the loggers.
12// Note: Not supported in async mode (thread local storage - so the async thread pool have different copy).
13//
14// Usage example:
15// spdlog::mdc::put("mdc_key_1", "mdc_value_1");
16// spdlog::info("Hello, {}", "World!"); // => [2024-04-26 02:08:05.040] [info] [mdc_key_1:mdc_value_1] Hello, World!
17
18namespace spdlog {
19class SPDLOG_API mdc {
20public:
21 using mdc_map_t = std::map<std::string, std::string>;
22
23 static void put(const std::string &key, const std::string &value) {
24 get_context()[key] = value;
25 }
26
27 static std::string get(const std::string &key) {
28 auto &context = get_context();
29 auto it = context.find(x: key);
30 if (it != context.end()) {
31 return it->second;
32 }
33 return "";
34 }
35
36 static void remove(const std::string &key) { get_context().erase(x: key); }
37
38 static void clear() { get_context().clear(); }
39
40 static mdc_map_t &get_context() {
41 static thread_local mdc_map_t context;
42 return context;
43 }
44};
45
46} // namespace spdlog
47