Class InstantPatternDynamicFormatter

java.lang.Object

org.apache.logging.log4j.core.util.internal.instant.InstantPatternDynamicFormatter

All Implemented Interfaces:

InstantFormatter, InstantPatternFormatter

final class InstantPatternDynamicFormatter
extends Object
implements InstantPatternFormatter

An InstantPatternFormatter that uses DateTimeFormatter under the hood. The pattern is analyzed and parts that require a precision lower than or equal to are precomputed, cached, and updated once every . The rest is computed dynamically.

For instance, given the pattern yyyy-MM-dd'T'HH:mm:ss.SSSX, the generated formatter will

1. Sequence the pattern and assign a time precision to each part (e.g., MM is of month precision)
2. Precompute and cache the output for parts that are of precision lower than or equal to (i.e., yyyy-MM-dd'T'HH:mm: and X) and cache it
3. Upon a formatting request, combine the cached outputs with the dynamic parts (i.e., ss.SSS)

Since:

2.25.0

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	InstantPatternDynamicFormatter.AbstractFormatter
(package private) static final class	InstantPatternDynamicFormatter.DynamicPatternSequence	Creates formatters that use DateTimeFormatter.
(package private) static class	InstantPatternDynamicFormatter.PatternSequence
(package private) static class	InstantPatternDynamicFormatter.SecondPatternSequence
(package private) static final class	InstantPatternDynamicFormatter.StaticPatternSequence
private static final class	InstantPatternDynamicFormatter.TimestampedFormatter

Nested classes/interfaces inherited from interface InstantPatternFormatter

InstantPatternFormatter.Builder

Field Summary

Fields

Modifier and Type	Field	Description
(package private) static final ChronoUnit	PRECISION_THRESHOLD
private final AtomicReference<InstantPatternDynamicFormatter.TimestampedFormatter>	timestampedFormatterRef

Fields inherited from interface InstantPatternFormatter

LEGACY_FORMATTERS_ENABLED

Constructor Summary

Constructors

Constructor	Description
InstantPatternDynamicFormatter(String pattern, Locale locale, TimeZone timeZone)

Method Summary

Modifier and Type	Method	Description
private static InstantPatternFormatter	createFormatter(String pattern, Locale locale, TimeZone timeZone, ChronoUnit precisionThreshold, Instant creationInstant)
private static InstantPatternDynamicFormatter.TimestampedFormatter	createTimestampedFormatter(String pattern, Locale locale, TimeZone timeZone, @Nullable Instant creationInstant)
void	formatTo(StringBuilder buffer, Instant instant)
private InstantPatternFormatter	getEffectiveFormatter(Instant instant)
Locale	getLocale()
String	getPattern()
ChronoUnit	getPrecision()
private static InstantPatternDynamicFormatter.PatternSequence	getStaticPatternSequence(String pattern, int startIndex, int endIndex)
TimeZone	getTimeZone()
private static boolean	isDynamicPatternLetter(char c)
private static List<InstantPatternDynamicFormatter.PatternSequence>	mergeFactories(List<InstantPatternDynamicFormatter.PatternSequence> sequences, ChronoUnit precisionThreshold)	Merges pattern sequences using InstantPatternDynamicFormatter.PatternSequence.tryMerge(InstantPatternDynamicFormatter.PatternSequence, ChronoUnit).
private static ChronoUnit	min(ChronoUnit left, ChronoUnit right)
private static List<InstantPatternDynamicFormatter.PatternSequence>	sequencePattern(String pattern)
(package private) static List<InstantPatternDynamicFormatter.PatternSequence>	sequencePattern(String pattern, ChronoUnit precisionThreshold)
private static long	toEpochMinutes(Instant instant)
private static TemporalAccessor	toTemporalAccessor(Instant instant)

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface InstantFormatter

format

Field Details

PRECISION_THRESHOLD

static final ChronoUnit PRECISION_THRESHOLD

timestampedFormatterRef

private final AtomicReference<InstantPatternDynamicFormatter.TimestampedFormatter> timestampedFormatterRef

Constructor Details

InstantPatternDynamicFormatter

InstantPatternDynamicFormatter(String pattern,
 Locale locale,
 TimeZone timeZone)

Method Details

getPattern

public String getPattern()

Specified by:

getPattern in interface InstantPatternFormatter

getLocale

public Locale getLocale()

Specified by:

getLocale in interface InstantPatternFormatter

getTimeZone

public TimeZone getTimeZone()

Specified by:

getTimeZone in interface InstantPatternFormatter

getPrecision

public ChronoUnit getPrecision()

Specified by:

getPrecision in interface InstantFormatter

Returns:

the time precision of the formatted output

formatTo

public void formatTo(StringBuilder buffer,
 Instant instant)

Specified by:

formatTo in interface InstantFormatter

getEffectiveFormatter

private InstantPatternFormatter getEffectiveFormatter(Instant instant)

createTimestampedFormatter

private static InstantPatternDynamicFormatter.TimestampedFormatter createTimestampedFormatter(String pattern,
 Locale locale,
 TimeZone timeZone,
 @Nullable Instant creationInstant)

createFormatter

private static InstantPatternFormatter createFormatter(String pattern,
 Locale locale,
 TimeZone timeZone,
 ChronoUnit precisionThreshold,
 Instant creationInstant)

min

private static ChronoUnit min(ChronoUnit left,
 ChronoUnit right)

sequencePattern

static List<InstantPatternDynamicFormatter.PatternSequence> sequencePattern(String pattern,
 ChronoUnit precisionThreshold)

sequencePattern

private static List<InstantPatternDynamicFormatter.PatternSequence> sequencePattern(String pattern)

getStaticPatternSequence

private static InstantPatternDynamicFormatter.PatternSequence getStaticPatternSequence(String pattern,
 int startIndex,
 int endIndex)

isDynamicPatternLetter

private static boolean isDynamicPatternLetter(char c)

mergeFactories

private static List<InstantPatternDynamicFormatter.PatternSequence> mergeFactories(List<InstantPatternDynamicFormatter.PatternSequence> sequences,
 ChronoUnit precisionThreshold)

Merges pattern sequences using InstantPatternDynamicFormatter.PatternSequence.tryMerge(InstantPatternDynamicFormatter.PatternSequence, ChronoUnit).

Example

For example, given the yyyy-MM-dd'T'HH:mm:ss.SSS pattern, a precision threshold of ChronoUnit.MINUTES and the three implementations (InstantPatternDynamicFormatter.DynamicPatternSequence, InstantPatternDynamicFormatter.StaticPatternSequence and InstantPatternDynamicFormatter.SecondPatternSequence) from this class, this method will combine pattern sequences associated with yyyy-MM-dd'T'HH:mm: into a single sequence, since these are consecutive and effectively constant sequences.

[
    dateTimeFormatter(pattern="yyyy", precision=YEARS),
    static(literal="-"),
    dateTimeFormatter(pattern="MM", precision=MONTHS),
    static(literal="-"),
    dateTimeFormatter(pattern="dd", precision=DAYS),
    static(literal="T"),
    dateTimeFormatter(pattern="HH", precision=HOURS),
    static(literal=":"),
    dateTimeFormatter(pattern="mm", precision=MINUTES),
    static(literal=":"),
    second(pattern="ss", precision=SECONDS),
    static(literal="."),
    second(pattern="SSS", precision=MILLISECONDS)
    dateTimeFormatter(pattern="X", precision=HOURS),
]

The above sequencing implies creation of 12 InstantPatternDynamicFormatter.AbstractFormatters. This method transforms it to the following:

[
    dateTimeFormatter(pattern="yyyy-MM-dd'T'HH:mm", precision=MINUTES),
    second(pattern="ss.SSS", precision=MILLISECONDS),
    dateTimeFormatter(pattern="X", precision=MINUTES)
]

The resultant sequencing effectively translates to 3 InstantPatternDynamicFormatter.AbstractFormatters.

Parameters:

sequences - a list of pattern formatter factories

precisionThreshold - a precision threshold to determine effectively constant sequences

Returns:

transformed sequencing, where sequences that are effectively constant or effectively dynamic are merged.

toEpochMinutes

private static long toEpochMinutes(Instant instant)

toTemporalAccessor

private static TemporalAccessor toTemporalAccessor(Instant instant)