kcenon::logger::thread_safe_writer Class Reference

Base class providing automatic thread-safety for writer implementations. More...

#include <thread_safe_writer.h>

Inheritance diagram for kcenon::logger::thread_safe_writer:

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Public Member Functions
	thread_safe_writer (std::unique_ptr< log_formatter_interface > formatter=nullptr)
	Constructor with optional formatter.
	~thread_safe_writer () override=default
	Virtual destructor.
	thread_safe_writer (const thread_safe_writer &)=delete
thread_safe_writer &	operator= (const thread_safe_writer &)=delete
	thread_safe_writer (thread_safe_writer &&)=delete
thread_safe_writer &	operator= (thread_safe_writer &&)=delete
common::VoidResult	write (const log_entry &entry) final
	Thread-safe write operation for structured log entries.
common::VoidResult	flush () final
	Thread-safe flush operation.
Public Member Functions inherited from kcenon::logger::base_writer
	base_writer (std::unique_ptr< log_formatter_interface > formatter=nullptr)
	Constructor with optional formatter.
virtual	~base_writer ()=default
virtual void	set_use_color (bool use_color)
	Set whether to use color output (if supported)
bool	use_color () const
	Get current color output setting.
virtual std::string	get_name () const override=0
virtual bool	is_healthy () const override
	Check if the writer is healthy and operational.
log_formatter_interface *	get_formatter () const
	Get the current formatter.
Public Member Functions inherited from kcenon::logger::log_writer_interface
virtual	~log_writer_interface ()=default
virtual common::VoidResult	close ()
	Close the writer and release resources.
virtual auto	is_open () const -> bool
	Check if writer is open and ready.

Protected Member Functions
virtual common::VoidResult	write_entry_impl (const log_entry &entry)=0
	Implementation of structured write operation (override in derived classes)
virtual common::VoidResult	flush_impl ()=0
	Implementation of flush operation (override in derived classes)
std::mutex &	get_mutex () const
	Access the writer mutex for extended operations.
Protected Member Functions inherited from kcenon::logger::base_writer
std::string	format_log_entry (const log_entry &entry) const
	Format a log entry using the current formatter.

Private Attributes
std::mutex	write_mutex_

Detailed Description

Base class providing automatic thread-safety for writer implementations.

This class uses the Template Method pattern to provide automatic mutex-based synchronization. Public methods acquire a lock and delegate to protected virtual *_impl methods that derived classes override.

Benefits:

• Eliminates mutex boilerplate from derived classes
• Consistent locking strategy across all writers
• Derived classes focus only on output-specific logic
• Thread-safety cannot be accidentally omitted

Thread-safety guarantees:

• All public write/flush operations are serialized
• Derived class *_impl methods are called while holding the lock
• The mutex is always released, even on exceptions (RAII)

Note

Non-copyable and non-movable (contains std::mutex)

For high-performance scenarios requiring lock-free operation, use high_performance_async_writer instead.

Since

1.3.0

Examples

custom_writer_example.cpp.

Definition at line 81 of file thread_safe_writer.h.

Constructor & Destructor Documentation

thread_safe_writer() [1/3]

kcenon::logger::thread_safe_writer::thread_safe_writer ( std::unique_ptr< log_formatter_interface > formatter = nullptr )

explicit

Constructor with optional formatter.

Parameters

formatter

Custom formatter (default: timestamp_formatter)

Since

1.3.0

Definition at line 10 of file thread_safe_writer.cpp.

    : base_writer(std::move(formatter)) {
}

~thread_safe_writer()

kcenon::logger::thread_safe_writer::~thread_safe_writer ( )

overridedefault

Virtual destructor.

thread_safe_writer() [2/3]

kcenon::logger::thread_safe_writer::thread_safe_writer ( const thread_safe_writer & )

delete

thread_safe_writer() [3/3]

kcenon::logger::thread_safe_writer::thread_safe_writer ( thread_safe_writer && )

delete

Member Function Documentation

flush()

common::VoidResult kcenon::logger::thread_safe_writer::flush ( )

finalvirtual

Thread-safe flush operation.

Returns

common::VoidResult Success or error code

Acquires the mutex and delegates to flush_impl(). This method is final to ensure thread-safety is not bypassed.

Since

1.3.0

Implements kcenon::logger::base_writer.

Definition at line 19 of file thread_safe_writer.cpp.

                                           {
    std::lock_guard<std::mutex> lock(write_mutex_);
    return flush_impl();
}

References flush_impl(), and write_mutex_.

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flush_impl()

virtual common::VoidResult kcenon::logger::thread_safe_writer::flush_impl ( )

protectedpure virtual

Implementation of flush operation (override in derived classes)

Returns

common::VoidResult Success or error code

Called by flush() while holding the mutex. Derived classes implement their output-specific flush logic here.

Note

The mutex is held when this method is called.

Do not call public methods on 'this' (would cause deadlock).

Since

1.3.0

Implemented in counted_console_writer, and memory_writer.

Referenced by flush().

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get_mutex()

std::mutex & kcenon::logger::thread_safe_writer::get_mutex ( ) const

inlineprotected

Access the writer mutex for extended operations.

Returns

Reference to the internal mutex

Allows derived classes to use the same mutex for additional thread-safe operations beyond write/flush. Use with caution to avoid deadlocks.

Warning

Only use for operations that cannot be performed within write_impl() or flush_impl().

Since

1.3.0

Examples

custom_writer_example.cpp.

Definition at line 174 of file thread_safe_writer.h.

{ return write_mutex_; }

Referenced by memory_writer::clear(), counted_console_writer::get_count(), memory_writer::get_entries(), counted_console_writer::print_stats(), memory_writer::size(), and counted_console_writer::total_count().

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operator=() [1/2]

thread_safe_writer & kcenon::logger::thread_safe_writer::operator= ( const thread_safe_writer & )

delete

operator=() [2/2]

thread_safe_writer & kcenon::logger::thread_safe_writer::operator= ( thread_safe_writer && )

delete

write()

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

finalvirtual

Thread-safe write operation for structured log entries.

Parameters

entry

The log entry to write (includes structured fields)

Returns

common::VoidResult Success or error code

Acquires the mutex and delegates to write_entry_impl(). This method preserves all log entry data including structured fields, OpenTelemetry context, and category information.

Note

This is the primary method for writing logs. It preserves all structured logging information.

Since

3.4.0

3.5.0 This is now the only write method (legacy API removed)

Implements kcenon::logger::base_writer.

Definition at line 14 of file thread_safe_writer.cpp.

                                                                 {
    std::lock_guard<std::mutex> lock(write_mutex_);
    return write_entry_impl(entry);
}

References write_entry_impl(), and write_mutex_.

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write_entry_impl()

virtual common::VoidResult kcenon::logger::thread_safe_writer::write_entry_impl ( const log_entry & entry )

protectedpure virtual

Implementation of structured write operation (override in derived classes)

Parameters

entry

The log entry to write (includes structured fields)

Returns

common::VoidResult Success or error code

Called by write(const log_entry&) while holding the mutex. Derived classes must override this method to implement their output logic.

Note

The mutex is held when this method is called.

Do not call public methods on 'this' (would cause deadlock).

Since

3.4.0

3.5.0 Now pure virtual - implementations must override this

Implemented in counted_console_writer, and memory_writer.

Referenced by write().

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Member Data Documentation

write_mutex_

std::mutex kcenon::logger::thread_safe_writer::write_mutex_

mutableprivate

Mutex for thread-safe write/flush operations

Definition at line 178 of file thread_safe_writer.h.

Referenced by flush(), and write().

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The documentation for this class was generated from the following files:

• include/kcenon/logger/writers/thread_safe_writer.h
• src/impl/writers/thread_safe_writer.cpp