# Poco

# class Message

Library: Foundation
Package: Logging
Header: Poco/Message.h

## Description

This class represents a log message that is sent through a chain of log channels.

A Message contains a priority denoting the severity of the message, a source describing its origin, a text describing its meaning, the time of its creation, and an identifier of the process and thread that created the message.

Optionally a Message can also contain the source file path and line number of the statement generating the message.

A Message can also contain any number of named parameters that contain additional information about the event that caused the message.

## Member Summary

Member Functions: get, getAll, getOsTid, getPid, getPriority, getSource, getSourceFile, getSourceLine, getText, getThread, getTid, getTime, has, init, operator =, operator [], set, setPid, setPriority, setSource, setSourceFile, setSourceLine, setText, setThread, setTid, setTime, swap

## Types Aliases

### StringMap

using StringMap = std::map < std::string, std::string >;

## Enumerations

### Priority

PRIO_FATAL = 1

A fatal error. The application will most likely terminate. This is the highest priority.

PRIO_CRITICAL

A critical error. The application might not be able to continue running successfully.

PRIO_ERROR

An error. An operation did not complete successfully, but the application as a whole is not affected.

PRIO_WARNING

A warning. An operation completed with an unexpected result.

PRIO_NOTICE

A notice, which is an information with just a higher priority.

PRIO_INFORMATION

An informational message, usually denoting the successful completion of an operation.

PRIO_DEBUG

A debugging message.

PRIO_TRACE

A tracing message. This is the lowest priority.

## Constructors

### Message

Message();

Creates an empty Message. The thread and process ids are set.

### Message

Message(
const Message & msg
);

Creates a Message by copying another one.

### Message

Message(
Message && msg
) noexcept;

Creates a Message by copying another one.

### Message

Message(
const Message & msg,
const std::string & text
);

Creates a Message by copying all but the text from another message.

### Message

Message(
const std::string & source,
const std::string & text,
Priority prio
);

Creates a Message with the given source, text and priority. The thread and process ids are set.

### Message

Message(
const std::string & source,
std::string && text,
Priority prio
);

Creates a Message with the given source, text and priority. The text is moved into the message. The thread and process ids are set.

### Message

Message(
const std::string & source,
const std::string & text,
Priority prio,
const char * file,
LineNumber line
);

Creates a Message with the given source, text, priority, source file path and line.

The source file path must be a static string with a lifetime that's at least the lifetime of the message object (the string is not copied internally). Usually, this will be the path string obtained from the __FILE__ macro.

The thread and process ids are set.

### Message

Message(
const std::string & source,
std::string && text,
Priority prio,
const char * file,
LineNumber line
);

Creates a Message with the given source, text, priority, source file path and line.

The text is moved into the message.

The source file path must be a static string with a lifetime that's at least the lifetime of the message object (the string is not copied internally). Usually, this will be the path string obtained from the __FILE__ macro.

The thread and process ids are set.

## Destructor

### ~Message

~Message();

Destroys the Message.

## Member Functions

### get

const std::string & get(
const std::string & param
) const;

Returns a const reference to the value of the parameter with the given name. Throws a NotFoundException if the parameter does not exist.

### get

std::string get(
const std::string & param,
const std::string & defaultValue
) const;

Returns the value of the parameter with the given name. If the parameter with the given name does not exist, then defaultValue is returned.

### getAll

const StringMap & getAll() const;

Returns a const reference to all the values

### getOsTid

long getOsTid() const;

Returns the numeric thread identifier for the message.

### getPid

long getPid() const;

Returns the process identifier for the message.

### getPriority

Priority getPriority() const;

Returns the priority of the message.

### getSource

const std::string & getSource() const;

Returns the source of the message.

### getSourceFile

const char * getSourceFile() const;

Returns the source file path of the code creating the message. May be 0 if not set.

### getSourceLine

LineNumber getSourceLine() const;

Returns the source file line of the statement generating the log message. May be 0 if not set.

### getText

const std::string & getText() const;

Returns the text of the message.

### getThread

const std::string & getThread() const;

Returns the thread identifier for the message.

### getTid

long getTid() const;

Returns the numeric thread identifier for the message.

### getTime

const Timestamp & getTime() const;

Returns the time of the message.

### has

bool has(
const std::string & param
) const;

Returns true if a parameter with the given name exists.

### operator =

Message & operator = (
const Message & msg
);

Assignment operator.

### operator =

Message & operator = (
Message && msg
) noexcept;

Assignment operator.

### operator []

const std::string & operator[] (
const std::string & param
) const;

Returns a const reference to the value of the parameter with the given name. Throws a NotFoundException if the parameter does not exist.

### operator []

std::string & operator[] (
const std::string & param
);

Returns a reference to the value of the parameter with the given name. This can be used to set the parameter's value. If the parameter does not exist, it is created with an empty string value.

### set

void set(
const std::string & param,
const std::string & value
);

Sets the value for a parameter. If the parameter does not exist, then it is created.

### setPid

void setPid(
long pid
);

Sets the process identifier for the message.

### setPriority

void setPriority(
Priority prio
);

Sets the priority of the message.

### setSource

void setSource(
const std::string & src
);

Sets the source of the message.

### setSourceFile

void setSourceFile(
const char * file
);

Sets the source file path of the statement generating the log message.

File must be a static string, such as the value of the __FILE__ macro. The string is not copied internally for performance reasons.

### setSourceLine

void setSourceLine(
LineNumber line
);

Sets the source file line of the statement generating the log message.

This is usually the result of the __LINE__ macro.

### setText

void setText(
const std::string & text
);

Sets the text of the message.

### setThread

void setThread(
const std::string & thread
);

Sets the thread identifier for the message.

### setTid

void setTid(
long pid
);

Sets the numeric thread identifier for the message.

### setTime

void setTime(
const Timestamp & time
);

Sets the time of the message.

### swap

void swap(
Message & msg
);

Swaps the message with another one.

### init

void init();