kcenon::logger::log_writer_interface Interface Reference

Base interface for all log writers and decorators. More...

#include <log_writer_interface.h>

Inheritance diagram for kcenon::logger::log_writer_interface:

Collaboration diagram for kcenon::logger::log_writer_interface:

Public Member Functions
virtual	~log_writer_interface ()=default
virtual common::VoidResult	write (const log_entry &entry)=0
	Write a log entry.
virtual common::VoidResult	flush ()=0
	Flush any buffered data.
virtual common::VoidResult	close ()
	Close the writer and release resources.
virtual auto	is_open () const -> bool
	Check if writer is open and ready.
virtual std::string	get_name () const =0
virtual bool	is_healthy () const =0
	Check if the writer is healthy.

Detailed Description

Base interface for all log writers and decorators.

This interface defines the contract for all log writers. It serves as the foundation for the Decorator pattern, enabling composable log writer pipelines where writers can be wrapped with additional functionality (e.g., buffering, encryption, async processing).

Follows the Single Responsibility Principle - only responsible for writing logs. All methods use Result-based error handling for consistent error propagation.

Note

Implementations should be thread-safe when used in concurrent contexts.

Example: Implementations must override write(), flush(), close(), is_open(), get_name(), and is_healthy() methods. See file_writer or console_writer for concrete examples.

Decorator pattern usage: Writers can be composed by wrapping a base writer with decorators (e.g., buffered_writer wraps base writer, async_writer wraps buffered_writer) to create composable log processing pipelines.

Since

1.0.0

4.0.0 Added close() and is_open() for Decorator pattern support

Definition at line 50 of file log_writer_interface.h.

Constructor & Destructor Documentation

~log_writer_interface()

virtual kcenon::logger::log_writer_interface::~log_writer_interface ( )

virtualdefault

Member Function Documentation

close()

virtual common::VoidResult kcenon::logger::log_writer_interface::close ( )

inlinevirtual

Close the writer and release resources.

Returns

common::VoidResult indicating success or failure

Closes the writer, flushing any remaining buffered data and releasing all associated resources (file handles, network connections, etc.). After calling close(), the writer should not be used for further operations.

Note

Implementations should be idempotent - calling close() multiple times should not cause errors. Subsequent write() calls after close() may fail.

Default implementation calls flush() and returns success. Subclasses with resources (file handles, connections) should override to release them.

Since

4.0.0

Implemented in kcenon::logger::file_writer.

Definition at line 97 of file log_writer_interface.h.

                                     {
        return flush();
    }

References flush().

Referenced by kcenon::logger::network_writer::connect(), and kcenon::logger::network_writer::disconnect().

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flush()

virtual common::VoidResult kcenon::logger::log_writer_interface::flush ( )

pure virtual

Flush any buffered data.

Returns

common::VoidResult indicating success or failure

Forces any buffered log entries to be written to the underlying output destination immediately. This method should be called before program termination or when immediate persistence is required.

Note

Some writers may perform synchronous I/O in this method, which could block for an extended period.

Implemented in kcenon::logger::async::high_performance_async_writer, kcenon::logger::async_writer, kcenon::logger::base_writer, kcenon::logger::batch_writer, kcenon::logger::buffered_writer, kcenon::logger::composite_writer, kcenon::logger::console_writer, kcenon::logger::critical_writer, kcenon::logger::decorator_writer_base, kcenon::logger::file_writer, kcenon::logger::hybrid_writer, kcenon::logger::network_writer, kcenon::logger::otlp_writer, and kcenon::logger::thread_safe_writer.

Referenced by close(), kcenon::logger::async_writer::flush(), kcenon::logger::batch_writer::flush_batch_unsafe(), kcenon::logger::buffered_writer::flush_buffer_unsafe(), and kcenon::logger::async_writer::flush_remaining().

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get_name()

virtual std::string kcenon::logger::log_writer_interface::get_name ( ) const

pure virtual

Implemented in counted_console_writer, kcenon::logger::async::high_performance_async_writer, kcenon::logger::async_writer, kcenon::logger::base_writer, kcenon::logger::batch_writer, kcenon::logger::composite_writer, kcenon::logger::console_writer, kcenon::logger::critical_writer, kcenon::logger::decorator_writer_base, kcenon::logger::file_writer, kcenon::logger::filtered_writer, kcenon::logger::formatted_writer, kcenon::logger::hybrid_writer, kcenon::logger::network_writer, kcenon::logger::otlp_writer, kcenon::logger::rotating_file_writer, and memory_writer.

Referenced by kcenon::logger::async_writer::get_name(), kcenon::logger::batch_writer::get_name(), kcenon::logger::filtered_writer::get_name(), and kcenon::logger::formatted_writer::get_name().

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is_healthy()

virtual bool kcenon::logger::log_writer_interface::is_healthy ( ) const

pure virtual

Check if the writer is healthy.

Returns

true if the writer is operational

Returns whether the writer is functioning correctly. Unlike is_open(), this method may perform additional health checks such as verifying disk space, network connectivity, or buffer status.

Note

This method may be slower than is_open() due to additional checks.

Implemented in kcenon::logger::async::high_performance_async_writer, kcenon::logger::async_writer, kcenon::logger::base_writer, kcenon::logger::batch_writer, kcenon::logger::composite_writer, kcenon::logger::console_writer, kcenon::logger::critical_writer, kcenon::logger::decorator_writer_base, kcenon::logger::file_writer, kcenon::logger::hybrid_writer, kcenon::logger::otlp_writer, kcenon::logger::queued_writer_base< Container >, kcenon::logger::queued_writer_base< std::queue< log_entry > >, and kcenon::logger::queued_writer_base< std::vector< log_entry > >.

Referenced by kcenon::logger::async_writer::is_healthy(), kcenon::logger::batch_writer::is_healthy(), and kcenon::logger::queued_writer_base< Container >::is_healthy().

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is_open()

virtual auto kcenon::logger::log_writer_interface::is_open ( ) const -> bool

inlinenodiscardvirtual

Check if writer is open and ready.

Returns

true if the writer is open and ready to accept writes

Returns whether the writer is in an operational state. A writer is considered open if:

• Resources have been successfully initialized
• close() has not been called
• No fatal errors have occurred

Note

This method should be fast and non-blocking.

Default implementation returns true (assumes always open). Subclasses with closeable resources should override to check actual state.

Since

4.0.0

Implemented in kcenon::logger::file_writer.

Definition at line 118 of file log_writer_interface.h.

                                                       {
        return true;
    }

write()

virtual common::VoidResult kcenon::logger::log_writer_interface::write ( const log_entry & entry )

pure virtual

Write a log entry.

Parameters

entry

The log entry to write

Returns

common::VoidResult indicating success or failure

This method should write the provided log entry to the underlying output destination (file, console, network, etc.). The implementation may buffer the data and defer actual I/O until flush() is called.

Note

Thread-safety is implementation-dependent. Consult specific writer documentation for thread-safety guarantees.

Implemented in kcenon::logger::async::high_performance_async_writer, kcenon::logger::async_writer, kcenon::logger::base_writer, kcenon::logger::batch_writer, kcenon::logger::buffered_writer, kcenon::logger::composite_writer, kcenon::logger::console_writer, kcenon::logger::critical_writer, kcenon::logger::decorator_writer_base, kcenon::logger::encrypted_writer, kcenon::logger::file_writer, kcenon::logger::filtered_writer, kcenon::logger::formatted_writer, kcenon::logger::hybrid_writer, kcenon::logger::network_writer, kcenon::logger::otlp_writer, kcenon::logger::rotating_file_writer, and kcenon::logger::thread_safe_writer.

Referenced by kcenon::logger::batch_writer::flush_batch_unsafe(), kcenon::logger::buffered_writer::flush_buffer_unsafe(), kcenon::logger::async_writer::flush_remaining(), kcenon::logger::async_writer::process_messages(), kcenon::logger::async_writer::write(), kcenon::logger::filtered_writer::write(), and kcenon::logger::formatted_writer::write().

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The documentation for this interface was generated from the following file:

• include/kcenon/logger/interfaces/log_writer_interface.h