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// Copyright (c) 2017-2022 Cloudflare, Inc.
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// Licensed under the Apache 2.0 license found in the LICENSE file or at:
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//     https://opensource.org/licenses/Apache-2.0
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#pragma once
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#include <kj/exception.h>
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#include <kj/function.h>
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#include <kj/main.h>
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#include <kj/string.h>
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namespace workerd::server {
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class JsonLogger: public kj::ExceptionCallback {
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 public:
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  void logMessage(kj::LogSeverity severity,
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      const char* file,
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      int line,
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      int contextDepth,
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      kj::String&& text) override;
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  kj::Function<void(kj::Function<void()>)> getThreadInitializer() override;
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  StackTraceMode stackTraceMode() override {
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    return StackTraceMode::ADDRESS_ONLY;
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  }
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 private:
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  bool loggingInProgress = false;
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};
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class StructuredLoggingProcessContext final: public kj::ProcessContext {
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  // A ProcessContext implementation that supports both plain text and structured JSON logging.
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  // This context wraps TopLevelProcessContext and adds the ability to emit log messages in
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  // JSON format when structured logging is enabled.
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 public:
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  explicit StructuredLoggingProcessContext(kj::StringPtr programName);
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  // Enable structured JSON logging. This can only be called once and cannot be reversed.
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  // When enabled: Log messages are formatted as JSON and sent to stdout or stderr
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  //               This also enables an ExceptionCallback to replace KJ_LOGs with structured logs.
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  //               To reduce code duplication from TopLevelProcessContext, while JsonLogger sends
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  //               all logs to stdout, StructuredLoggingProcessContext sends all to the fd that
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  //               TopLevelProcessContext would have sent to.
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  // When disabled: Log messages are sent as plain text to stdout or stderr (like
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  //                TopLevelProcessContext)
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  void enableStructuredLogging();
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  kj::StringPtr getProgramName() override;
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  KJ_NORETURN(void exit() override);
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  void warning(kj::StringPtr message) const override;
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  void error(kj::StringPtr message) const override;
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  KJ_NORETURN(void exitError(kj::StringPtr message) override);
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  KJ_NORETURN(void exitInfo(kj::StringPtr message) override);
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  void increaseLoggingVerbosity() override;
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 private:
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  kj::TopLevelProcessContext topLevelContext;
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  kj::Maybe<JsonLogger> jsonLogger;
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  bool useStructuredLogging = false;
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};
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}  // namespace workerd::server