groovy

@EqualsAndHashCode should allow caching of hashCode values

Details

  • Type: Improvement Improvement
  • Status: Closed Closed
  • Priority: Major Major
  • Resolution: Fixed
  • Affects Version/s: 1.8-rc-1
  • Fix Version/s: 2.1.0-rc-2, 2.1.0
  • Component/s: None
  • Labels:
    None
  • Number of attachments :
    0

Description

NOTE: @ToString moved to linked issue

For an immutable object, a hashcode value & toString value only need to be computed once and cached. Then the hashcode and toString methods can just return the cached values.

The @ToString and @EqualsAndHashCode ast transformation should have options to allow for caching. For example:

@ToString(cache=true)
@EqualsAndHashCode(cache=true)

Also, the @Immutable annotation should use the @ToString and @EqualsAndHashCode transformation with this caching capability enabled.

Issue Links

relates to

Improvement - An improvement or enhancement to an existing feature or task. GROOVY-5928 @ToString should allow caching of toString values

  • Major - Major loss of function.
  • Closed - The issue is considered finished, the resolution is correct. Issues which are not closed can be reopened.

Activity

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Travis added a comment -

btw. See Effective Java 2nd ed. page 49 for details on caching of hashCodes. Josh Bloch talks about either calculating the hashcode on construction or lazily the first time it's requested.

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Travis added a comment - btw. See Effective Java 2nd ed. page 49 for details on caching of hashCodes. Josh Bloch talks about either calculating the hashcode on construction or lazily the first time it's requested.
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Travis added a comment -

The following method already exists on the transformation class that is used by the @EqualsAndHashCode method. The caching functionality is just not exposed in the annotation.

EqualsAndHashCodeASTTransformation.createHashCode(ClassNode cNode, boolean cacheResult, boolean includeFields, boolean callSuper, List<String> excludes)
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Travis added a comment - The following method already exists on the transformation class that is used by the @EqualsAndHashCode method. The caching functionality is just not exposed in the annotation. EqualsAndHashCodeASTTransformation.createHashCode(ClassNode cNode, boolean cacheResult, boolean includeFields, boolean callSuper, List< String > excludes)
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Paul King added a comment -

At the moment, caching is always turned on for @Immutable objects and left off for other objects. You are asking for control when not using @Immutable?

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Paul King added a comment - At the moment, caching is always turned on for @Immutable objects and left off for other objects. You are asking for control when not using @Immutable ?
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Travis added a comment -

That is correct. We are creating immutable classes without using @Immutable and we would like to use these transformations with their caching behavior.

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Travis added a comment - That is correct. We are creating immutable classes without using @Immutable and we would like to use these transformations with their caching behavior.
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Cedric Champeau added a comment -

As an improvement, moved to 2.1.0.

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Cedric Champeau added a comment - As an improvement, moved to 2.1.0.
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Paul King added a comment -

Clone - split @ToString and @EqualsAndHashCode requests into two parts

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Paul King added a comment - Clone - split @ToString and @EqualsAndHashCode requests into two parts
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Paul King added a comment -

the capability for caching is now exposed for hashCode generation

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Paul King added a comment - the capability for caching is now exposed for hashCode generation

People

  • Assignee:
    Paul King
    Reporter:
    Travis
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Dates

  • Created:
    Updated:
    Resolved: