# FixedWindowRollingPolicy Class Reference

Inherits RollingPolicyBase.

List of all members.

## Detailed Description

When rolling over, `FixedWindowRollingPolicy` renames files according to a fixed window algorithm as described below.

The ActiveFileName property, which is required, represents the name of the file where current logging output will be written. The FileNamePattern option represents the file name pattern for the archived (rolled over) log files. If present, the FileNamePattern option must include an integer token, that is the string "%i" somwhere within the pattern.

Let max and min represent the values of respectively the MaxIndex and MinIndex options. Let "foo.log" be the value of the ActiveFile option and "foo.%i.log" the value of FileNamePattern. Then, when rolling over, the file `foo.max.log` will be deleted, the file `foo.max-1.log` will be renamed as `foo.max.log`, the file `foo.max-2.log` renamed as `foo.max-1.log`, and so on, the file `foo.min+1.log` renamed as `foo.min+2.log`. Lastly, the active file `foo.log` will be renamed as `foo.min.log` and a new active file name `foo.log` will be created.

Given that this rollover algorithm requires as many file renaming operations as the window size, large window sizes are discouraged. The current implementation will automatically reduce the window size to 12 when larger values are specified by the user.

## Public Member Functions

| FixedWindowRollingPolicy ()
void | activateOptions (log4cxx::helpers::Pool &p)
| Activate the options that were previously set with calls to option setters.
void | setOption (const LogString &option, const LogString &value)
| Set `option` to `value`.
void | rollover ()
int | getMaxIndex () const
int | getMinIndex () const
void | setMaxIndex (int newVal)
void | setMinIndex (int newVal)
virtual RolloverDescriptionPtr | initialize (const LogString &file, const bool append, log4cxx::helpers::Pool &p)
| Initialize the policy and return any initial actions for rolling file appender.
virtual RolloverDescriptionPtr | rollover (const LogString &activeFile, log4cxx::helpers::Pool &p)
| Prepare for a rollover.

## Protected Member Functions

log4cxx::pattern::PatternMap | getFormatSpecifiers () const

## Constructor & Destructor Documentation

FixedWindowRollingPolicy | ( |  | ) |

## Member Function Documentation

void activateOptions | ( | log4cxx::helpers::Pool & | p | ) | `[virtual]`

Activate the options that were previously set with calls to option setters.

This allows to defer activiation of the options until all options have been set. This is required for components which have related options that remain ambigous until all are set.

For example, the FileAppender has the File and Append options both of which are ambigous until the other is also set.

Implements RollingPolicyBase.

log4cxx::pattern::PatternMap getFormatSpecifiers | ( |  | ) | const`[protected, virtual]`

| Implements RollingPolicyBase.

int getMaxIndex | ( |  | ) | const

int getMinIndex | ( |  | ) | const

virtual RolloverDescriptionPtr initialize | ( | const LogString & | file,
|  | const bool | append,
|  | log4cxx::helpers::Pool & | p
| ) | `[virtual]`

Initialize the policy and return any initial actions for rolling file appender.

Parameters:

  | file | current value of RollingFileAppender::getFile().
  | append | current value of RollingFileAppender::getAppend().
  | p | pool used for any required memory allocations.

Returns:
  Description of the initialization, may be null to indicate no initialization needed.

Exceptions:

  | SecurityException | if denied access to log files.

Implements RollingPolicy.

virtual RolloverDescriptionPtr rollover | ( | const LogString & | activeFile,
|  | log4cxx::helpers::Pool & | p
| ) | `[virtual]`

Prepare for a rollover.

This method is called prior to closing the active log file, performs any necessary preliminary actions and describes actions needed after close of current log file.

Parameters:

  | activeFile | file name for current active log file.
  | p | pool used for any required memory allocations.

Returns:
  Description of pending rollover, may be null to indicate no rollover at this time.

Exceptions:

  | SecurityException | if denied access to log files.

Implements RollingPolicy.

void rollover | ( |  | ) |

void setMaxIndex | ( | int | newVal | ) |

void setMinIndex | ( | int | newVal | ) |

void setOption | ( | const LogString & | option,
|  | const LogString & | value
| ) | `[virtual]`

| Set `option` to `value`. The handling of each option depends on the OptionHandler instance. Some options may become active immediately whereas other may be activated only when activateOptions is called. Reimplemented from RollingPolicyBase.

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

- fixedwindowrollingpolicy.h