![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2026\/09\/20260905175659-6a9c57eb87b2b.png\")
<\/p>\n\u672c\u7bc7\u6587\u7ae0\u4f7f\u7528c++20\u6807\u51c6\u5b9e\u73b0\u7684\u4e00\u4e2a\u81ea\u5b9a\u4e49\u7684\u65e5\u5fd7\u7f13\u51b2\u533a\u3002\u6253\u5370\u65e5\u5fd7\u5bf9\u4e8e\u6bcf\u4e00\u4e2a\u9879\u76ee\u6765\u8bf4\u90fd\u662f\u5fc5\u4e0d\u53ef\u5c11\u7684，\u5728muduo\u5e93\u91cc\u9762\u6211\u4eec\u4e5f\u7b80\u5355\u7684\u5b9e\u73b0\u4e86\u4e00\u4e2a\u65e5\u5fd7\u7684\u6253\u5370，\u5927\u5bb6\u5982\u679c\u6709\u5174\u8da3\u53ef\u4ee5\u770b\u4e00\u770b\u6211\u4e4b\u524d\u7684\u8fd9\u4e2a\u535a\u5ba2\u5199\u6587\u7ae0-CSDN\u521b\u4f5c\u4e2d\u5fc3\u3002\u4e0d\u8fc7\u90a3\u4e2a\u662f\u6bd4\u8f83\u7b80\u6613\u7684，\u800c\u672c\u7bc7\u6587\u7ae0\u7684\u4e0a\u4e0b\u7bc7\u5c06\u5b8c\u6210\u4e00\u4e2a\u590d\u6742，\u9ad8\u6027\u80fd\u7684\u6253\u5370\u65e5\u5fd7\u5668\u3002<\/p>\n
\u6253\u5370\u65e5\u5fd7\u662f\u4e3a\u4e86\u53ef\u4ee5\u66f4\u5feb\u7684\u53d1\u73b0\u9519\u8bef，\u800c\u6211\u4eec\u7684\u9519\u8bef\u662f\u5206\u7b49\u7ea7\u7684，\u6709\u7684\u9519\u8bef\u65e0\u4f24\u5927\u96c5，\u800c\u6709\u7684\u9519\u8bef\u4e00\u65e6\u53d1\u751f\u5c31\u4f1a\u9020\u6210\u635f\u5931，\u6240\u4ee5\u6211\u4eec\u9700\u8981\u7ed9\u65e5\u5fd7\u5206\u51e0\u4e2a\u7ea7\u522b\u3001<\/p>\n
\u7136\u540e\u5bf9\u4e8e\u65e5\u5fd7\u6240\u5bf9\u5916\u63d0\u4f9b\u7684\u51fd\u6570，\u4e00\u5171\u5c31\u4e24\u4e2a，\u4e00\u4e2a\u662f\u628aLevel\u8f6c\u5316\u6210string\u7684\u7c7b\u578b，\u56e0\u4e3a\u6211\u4eec\u7684enum\u5e95\u5c42\u8fd8\u662fuint8\u7c7b\u578b，\u6211\u4eec\u4e3a\u4e86\u53ef\u4ee5\u66f4\u597d\u7684\u770b\u51fa\u5230\u5e95\u662f\u4ec0\u4e48\u7c7b\u578b\u7684\u9519\u8bef，\u9700\u8981\u8f6c\u5316\u6210\u5b57\u7b26\u4e32\u3002<\/p>\n
\u8fd8\u6709\u4e00\u4e2a\u662f\u628a\u4e00\u4e2a\u5b57\u7b26\u4e32\u5f62\u5f0f\u7684\u65e5\u5fd7\u7ea7\u522b，\u8f6c\u6362\u6210 LogLevel::Level \u679a\u4e3e\u503c，\u4e00\u822c\u7684\u7528\u6cd5\u5982\u4e0b：<\/p>\n
auto level = LogLevel::FromString("debug");
\nclass PANS_API LogLevel final
\n{
\npublic:
\n enum class Level : std::uint8_t
\n {
\n LOG_DEBUG, \/\/ \u8c03\u8bd5\u7ec6\u8282
\n LOG_INFO, \/\/ \u8bb0\u5f55\u6b63\u5e38\u8fd0\u884c\u7684\u4fe1\u606f
\n LOG_WARN, \/\/ \u53ef\u80fd\u5b58\u5728\u7684\u95ee\u9898
\n LOG_ERROR, \/\/ \u64cd\u4f5c\u5931\u8d25，\u9700\u8981\u68c0\u67e5
\n LOG_FATAL, \/\/ \u7a0b\u5e8f\u5982\u679c\u7ee7\u7eed\u8fd0\u884c\u4f1a\u9020\u6210\u635f\u5931
\n LOG_OFF, \/\/ \u5173\u95ed\u65e5\u5fd7
\n };<\/p>\n
[[nodiscard]] static std::string_view ToString(Level level) noexcept;
\n [[nodiscard]] static LogLevel::Level FromString(std::string_view value) noexcept;
\n}; <\/p>\n
\u6211\u4eec\u8fd9\u91cc\u7528\u5b8f\u6765\u7b80\u5316\u4ee3\u7801\u7684\u4e66\u5199，\u5e76\u4e14\u56e0\u4e3a\u8fd9\u4e2a\u5b8f\u662f\u5b9a\u4e49\u5728\u51fd\u6570\u7684\u5185\u90e8，\u6240\u4ee5\u5f53\u6211\u4eec\u7528\u5b8c\u8fd9\u4e2a\u5b8f\u4e4b\u540e，\u6211\u4eec\u9700\u8981\u53ca\u65f6\u7684\u91ca\u653e\u6389\u3002FromString\u8fd9\u4e2a\u51fd\u6570\u7684\u601d\u8def\u5c31\u662f\u521b\u5efa\u4e00\u4e2a\u6570\u7ec4\u6765\u5b58\u50a8\u5927\u5199\u7684value，\u7136\u540e\u8fd4\u56de\u8fd9\u4e2a，\u6240\u4ee5\u4e3b\u8981\u7684\u4f5c\u7528\u5c31\u662f\u8f6c\u5316\u4e3a\u5927\u5199，\u56e0\u4e3a\u5916\u90e8\u53ef\u80fd\u4f1a\u4f20\u9012\u5c0f\u5199\u7684，\u7c7b\u4f3c\u4e8edebug\u4e4b\u7c7b\u7684\u3002<\/p>\n
std::string_view LogLevel::ToString(Level level) noexcept
\n{
\n switch (level)
\n {
\n#define XX(name) case Level::LOG_##name : return #name;
\n XX(DEBUG)
\n XX(INFO)
\n XX(WARN)
\n XX(ERROR)
\n XX(FATAL)
\n XX(OFF)
\n }
\n#undef XX
\n return "UNKNOWN";
\n}<\/p>\n
\/\/ \u628a\u4e00\u4e2a\u5b57\u7b26\u4e32\u5f62\u5f0f\u7684\u65e5\u5fd7\u7ea7\u522b，\u8f6c\u6362\u6210 LogLevel::Level \u679a\u4e3e\u503c
\nLogLevel::Level LogLevel::FromString(std::string_view value) noexcept
\n{
\n std::array<char, 6> normalized{};
\n std::transform(value.begin(), value.end(), normalized.begin(), [](unsigned char character){
\n return static_cast<char>(std::toupper(character));
\n });
\n const std::string_view upper_value(normalized.data(), value.size());
\n#define XX(name) if(upper_value == #name) return Level::LOG_##name;
\n XX(DEBUG)
\n XX(INFO)
\n XX(WARN)
\n XX(FATAL)
\n XX(OFF)
\n XX(ERROR)
\n#undef XX
\n return Level::LOG_OFF;
\n} <\/p>\n
\u63a5\u4e0b\u6765\u5c31\u662f\u6bd4\u8f83\u5173\u952e\u7684\u7f13\u51b2\u533a，\u5176\u5b9e\u5927\u90e8\u5206\u7684\u9879\u76ee\u91cc\u9762\u6253\u5370\u7684\u65e5\u5fd7\u90fd\u662f\u5728\u5806\u4e0a\u6253\u5370\u7684，\u5806\u4e0a\u5199\u5b8c\u5373\u91ca\u653e，\u91cc\u9762\u6bd4\u8f83\u5178\u578b\u7684\u5c31\u662fsylar\u7684\u670d\u52a1\u5668\u67b6\u6784，\u5c31\u662f\u7528std::stringstream，\u8fd9\u4e2a\u7684\u4f18\u70b9\u5c31\u662f\u6bd4\u8f83\u7684\u7b80\u5355\u5bb9\u6613\u5b9e\u73b0\u3002\u4f46\u662f\u7f3a\u70b9\u4e5f\u6bd4\u8f83\u660e\u663e，\u6211\u4eec\u62ff\u5230\u6570\u636e\u7684\u65f6\u5019\u9700\u8981\u7528std::string\u6765\u63a5\u53d7，\u591a\u4e86\u4e00\u6b21\u62f7\u8d1d，\u800c\u81ea\u5b9a\u4e49\u7684\u7f13\u51b2\u533a\u6211\u4eec\u53ef\u4ee5\u5f00\u7a97\u53e3，\u7528string_view\u6765\u76f4\u63a5\u62ff\u6570\u636e\u3002<\/p>\n
\u56e0\u4e3a\u4e00\u822c\u7684\u65e5\u5fd7\u90fd\u662f\u5c11\u4e8e200\u5b57\u7684，\u6808\u7684\u7a7a\u95f4\u5b8c\u5168\u8db3\u591f，\u4f46\u662f\u4e5f\u4e0d\u6392\u9664\u4e00\u4e9b\u6bd4\u8f83\u957f\u7684\u65e5\u5fd7\u4fe1\u606f，\u8fd9\u4e2a\u65f6\u5019\u6211\u4eec\u5c31\u9700\u8981\u628a\u65e5\u5fd7\u7684\u5185\u5bb9\u653e\u5728\u5806\u4e0a，\u65b9\u4fbf\u6269\u5bb9\u5904\u7406\u3002\u6240\u4ee5\u6211\u4eec\u7684\u76ee\u7684\u5c31\u662f\u5982\u679c\u65e5\u5fd7\u4fe1\u606f\u6bd4\u8f83\u5c11\u5c31\u5728\u6808\u4e0a，\u65e5\u5fd7\u6bd4\u8f83\u957f\u5c31\u5728\u5806\u4e0a\u3002\u90a3\u4e48\u6211\u4eec\u5f88\u5bb9\u6613\u60f3\u5230\u7684\u67b6\u6784\u5c31\u662farray\u548cvector<\/p>\n
\u8fd9\u91cc\u89e3\u91ca\u4e00\u4e0b，\u6211\u4eec\u5728\u7f13\u51b2\u533a\u5bf9\u8c61\u91cc\u9762\u7684\u6210\u5458array\u548c\u6210\u5458\u4e00\u8d77\u88ab\u653e\u5728\u4e86\u6808\u4e0a，\u968f\u7740\u7f13\u51b2\u533a\u4e00\u8d77\u88ab\u9500\u6bc1，\u800cvector\u7684\u4e00\u4e9b\u5c5e\u6027，\u6bd4\u5982size，type\u653e\u5728\u4e86\u6808\u4e0a，\u5176\u6570\u636e\u662f\u653e\u5728\u4e86\u5806\u4e0a，\u65b9\u4fbf\u6269\u5bb9\u3002<\/p>\n
\u6211\u4eec\u8fd9\u91cc\u8fd8\u662f\u7528\u7684\u7c7b\u6a21\u677f，\u56e0\u4e3a\u6211\u4eec\u7684\u5185\u8054\u7f13\u51b2\u533a\u7684\u5927\u5c0f\u8fd8\u662f\u4e0d\u786e\u5b9a\u7684，\u5176\u4e2d\u5bf9\u5916\u63d0\u4f9b\u7684API\u4e3b\u8981\u5c31\u662fappend，\u5176\u4e2d\u7684\u903b\u8f91\u662f\u5982\u679c\u5806\u4e0a\u6ca1\u6709\u5185\u5bb9\u5e76\u4e14\u8981\u5199\u7684\u5185\u5bb9\u6ca1\u6709\u8d85\u8fc7\u9650\u5236，\u90a3\u4e48\u5c31\u5199\u5165inline<\/p>\n
\u5982\u679c\u8d85\u51fa\u4e86，\u5e76\u4e14overflow\u662f\u7a7a\u7684，\u90a3\u4e48\u6211\u4eec\u5148\u628a\u4e4b\u524d\u5728inline\u7684\u6570\u636e\u901a\u8fc7insert\u62f7\u8d1d\u5230overflow\u91cc\u9762，\u518d\u628a\u5f53\u524d\u7684\u6570\u636einsert\u5230end（）\u540e\u9762\u3002<\/p>\n
\u8fd9\u91cc\u8981\u8bf4\u660e\u4e00\u4e0b\u5b50std::string_view，\u8fd9\u4e2a\u6027\u80fd\u5f88\u9ad8，\u56e0\u4e3a\u5176\u4e0d\u9700\u8981\u62f7\u8d1d\u5230string，\u91cc\u9762\u7ba1\u7406\u4e86\u4e00\u4e2a\u6307\u9488ptr\u548cstring\u7684\u5927\u5c0fsize，\u6240\u4ee5\u6211\u4eec<\/p>\n
\/\/ \u81ea\u5b9a\u4e49\u4e00\u4e2a\u65e5\u5fd7\u7f13\u51b2\u533a，\u9488\u5bf9\u9ad8\u9891，\u5c0f\u6570\u636e\u91cf\u7684\u65e5\u5fd7\u573a\u666f，\u5728\u6808\u4e0a\u5206\u914d\u65e5\u5fd7\u7f13\u51b2\u533a，\u4e0e\u8d85\u957f\u65e5\u5fd7，\u518d\u5728\u5806\u4e0a\u5206\u914d\u5185\u5b58
\ntemplate <std::size_t INLINE_CAPACITY>
\nclass InlineBuffer
\n{
\npublic:
\n void append(const char* data, std::size_t size)
\n {
\n if (size == 0)
\n {
\n return;
\n }
\n if (overflow_.empty() && size + size_ <= INLINE_CAPACITY)
\n {
\n std::memcpy(inline_.data() + size_, data, size);
\n size_ += size;
\n return;
\n }<\/p>\n
if (overflow_.empty())
\n {
\n const std::size_t required_capacity = size_ + size;
\n overflow_.reserve(std::max(required_capacity, 2 * INLINE_CAPACITY));
\n overflow_.insert(overflow_.end(), inline_.data(), inline_.data() + size_);
\n }
\n overflow_.insert(overflow_.end(), data, data + size);
\n size_ += size;
\n }<\/p>\n
void append(std::string_view value)
\n {
\n append(value.data(), value.size());
\n }<\/p>\n
void append(char value)
\n {
\n append(&value, 1);
\n }<\/p>\n
[[nodiscard]] const char* data() const noexcept
\n {
\n return overflow_.empty() ? inline_.data() : overflow_.data();
\n }<\/p>\n
[[nodiscard]] std::size_t size() const noexcept
\n {
\n return size_;
\n }<\/p>\n
[[nodiscard]] std::string_view view() const noexcept
\n {
\n return {data(), size()};
\n }<\/p>\n
private:
\n std::array<char, INLINE_CAPACITY> inline_{};
\n std::vector<char> overflow_;
\n std::size_t size_;
\n}; <\/p>\n
\u4e3a\u4e86\u7ee7\u7eed\u53ef\u4ee5\u4f7f\u7528\u6d41\u5f0f\u8f93\u5165\u7684\u63a5\u53e3，\u6211\u4eec\u91cd\u65b0\u5b9e\u73b0\u4e86\u4e00\u4e2astreambuf，\u7136\u540e\u91cd\u5199\u5bf9\u5e94\u7684\u63a5\u53e3\u3002<\/p>\n
\u8fd9\u4e2a\u662f\u6211\u4eec\u7684\u76ee\u6807，\u4f46\u662f\u4e0e\u7cfb\u7edf\u63d0\u4f9bput_area\u4e0d\u540c\u7684\u662f，\u6211\u4eec\u6709\u81ea\u5df1\u7684\u7f13\u51b2\u533a\u4e86，\u7cfb\u7edf\u7684put_area\u4f1a\u7ef4\u62a4\u4e24\u4e2a\u6307\u9488pptr\u548cepptr，\u800c\u6211\u4eec\u56e0\u4e3a\u6ca1\u6709\u63d0\u4f9b\u8fd9\u4e2aput_area\u6240\u4ee5\u4e0d\u4f1a\u8fdb\u5165if（）\u91cc\u9762，\u800c\u662f\u76f4\u63a5return，\u6267\u884coverflow\u51fd\u6570（\u6211\u4eec\u9700\u8981\u91cd\u5199）<\/p>\n
<\/p>\n
std::ostream \u8d1f\u8d23\u683c\u5f0f\u5316\u8f93\u51fa，std::streambuf \u8d1f\u8d23\u628a\u6570\u636e\u4ea4\u7ed9\u5b9e\u9645\u7684\u5b58\u50a8\u5bf9\u8c61\u3002<\/p>\n
streambuf \u9ed8\u8ba4\u6ca1\u6709\u81ea\u5df1\u7684\u8f93\u51fa\u7f13\u51b2\u533a，pbase\/pptr\/epptr \u90fd\u4e3a\u7a7a；<\/p>\n
\u5982\u679c\u901a\u8fc7 setp() \u8bbe\u7f6e\u7f13\u51b2\u533a，sputc() \u4f1a\u5148\u5224\u65ad pptr() < epptr()， \u6709\u7a7a\u95f4\u5c31\u76f4\u63a5\u5199\u5165，\u6ca1\u6709\u7a7a\u95f4\u624d\u8c03\u7528 overflow()\u3002<\/p>\n
\u591a\u4e2a\u5b57\u7b26\u901a\u8fc7 sputn() \u8fdb\u5165\u865a\u51fd\u6570 xsputn()\u3002 \u672c\u7c7b\u6ca1\u6709\u8c03\u7528 setp()，\u56e0\u6b64\u4e0d\u4f7f\u7528 streambuf \u81ea\u5df1\u7684\u7f13\u51b2\u533a：<\/p>\n
\u5355\u5b57\u7b26 -> sputc() -> \u65e0\u53ef\u7528\u7a7a\u95f4 -> overflow() -> InlineBuffer<\/p>\n
\u591a\u5b57\u7b26 -> sputn() -> xsputn() -> InlineBuffer<\/p>\n
\u6240\u4ee5 SmallStreamBuffer \u7684\u4f5c\u7528\u5c31\u662f： \u628a std::ostream \u7684\u8f93\u51fa\u63a5\u53e3\u76f4\u63a5\u8f6c\u63a5\u5230\u81ea\u5df1\u7684 InlineBuffer\u3002<\/p>\n
\/\/ \u7ee7\u627fstd::streambuf\u662f\u4e3a\u4e86\u80fd\u591f\u80fd\u591f\u7ee7\u7eed\u4f7f\u7528\u6d41\u5f0f\u8f93\u5165\u63a5\u53e3，\u517c\u5bb9ostream\u751f\u6001
\ntemplate <std::size_t INLINE_CAPACITY>
\nclass SmallStreamBuffer : public std::streambuf
\n{
\npublic:
\n explicit SmallStreamBuffer(InlineBuffer<INLINE_CAPACITY>& buffer) noexcept
\n : buffer_(buffer)
\n {}<\/p>\n
protected:
\n std::streamsize xsputn(const char* data, std::streamsize size) override
\n {
\n if (size <= 0)
\n {
\n return 0;
\n }<\/p>\n
buffer_.append(data, static_cast<std::size_t>(size));
\n return size;
\n }<\/p>\n
int_type overflow(int_type character) override
\n {
\n \/\/ overflow，\u9664\u4e86\u53ef\u4ee5\u63a5\u53d7\u4e00\u822c\u5b57\u7b26，\u8fd8\u53ef\u80fd\u4f1a\u63a5\u6536\u6d41\u7ec8\u6b62\u7b26EOF
\n \/\/ \u5982\u679c\u6211\u4eec\u9047\u5230\u4e86EOF, \u628a\u5b83\u8f6c\u6210\u975eEOF\u503c\u5411\u4e0a\u62a5\u544a\u5199\u5165\u6210\u529f，\u5b9e\u9645\u4e0a\u4e0d\u5411Buffer\u91cc\u5199\u5165\u4efb\u4f55\u503c\u3002
\n if (traits_type::eq_int_type(character, traits_type::eof()))
\n {
\n return traits_type::not_eof(character);
\n }
\n buffer_.append(traits_type::to_char_type(character));
\n return character;
\n }<\/p>\n
private:
\n InlineBuffer<INLINE_CAPACITY>& buffer_;
\n}; <\/p>\n
\u672c\u7bc7\u6587\u7ae0\u5230\u8fd9\u91cc\u5c31\u7ed3\u675f\u4e86！！！！\u5e0c\u671b\u53ef\u4ee5\u5e2e\u52a9\u5927\u5bb6\u7406\u89e3~~~<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5f15\u8a00
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