Optimize GenericConversionService.findConverterForClassPair [SPR-6749]

[spring-projects-issues]

Oliver Becker opened SPR-6749 and commented

The method findConverterForClassPair in GenericConversionService checks interfaces unnecessarily multiple times. This will lead to a performance penalty if no converter can be found.

The point is that addInterfaceHierarchy() adds the entire interface hierarchy to the classQueue (which was done for fixing #10963). However for every processed interface in the queue its entire hierarchy is appended to queue again. In the end a base interface of a multi-level interface hierarchy will be processed multiple times.

---

Affects: 3.0 GA

This issue is a sub-task of #10963

Issue Links:

• Review Converter resolution algorithm [SPR-6314] #10980 Review Converter resolution algorithm
• Cache results of Converter lookup in GenericConversionService to improve performance [SPR-7110] #11770 Cache results of Converter lookup in GenericConversionService to improve performance

Referenced from: commits ad93d20

1 votes, 3 watchers

[spring-projects-issues]

Keith Donald commented

The overhead of processing the same interfaces multiple times is illustrated by the following trace logging when converting a String[] array to a LinkedList:

GenericConversionService - Converting value array<String>['1', '2', '3'] of [TypeDescriptor java.lang.String[]] to [TypeDescriptor java.util.LinkedList<?>]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [[Ljava.lang.String;]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.LinkedList]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.List]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.Collection]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.Deque]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.Queue]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.Collection]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Cloneable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.AbstractSequentialList]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.Collection]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.Queue]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.Collection]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.Collection]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.AbstractList]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.Collection]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.List]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.Collection]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.AbstractCollection]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.Collection]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.Collection]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Iterable]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [[Ljava.lang.Object;]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.LinkedList]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.List]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.util.Collection]
TRACE: org.springframework.core.convert.support.GenericConversionService - Found matchable converters org.springframework.core.convert.support.ArrayToCollectionConverter@4104c575
TRACE: org.springframework.core.convert.support.GenericConversionService - Matching org.springframework.core.convert.support.ArrayToCollectionConverter@4104c575
DEBUG: org.springframework.core.convert.support.GenericConversionService - Checking if I can convert [TypeDescriptor java.lang.String] to [TypeDescriptor.NULL]
DEBUG: org.springframework.core.convert.support.GenericConversionService - Yes, I can convert
DEBUG: org.springframework.core.convert.support.GenericConversionService - Matched converter org.springframework.core.convert.support.ArrayToCollectionConverter@4104c575
DEBUG: org.springframework.core.convert.support.GenericConversionService - Converting value '1' of [TypeDescriptor java.lang.String] to [TypeDescriptor java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Comparable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.CharSequence]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Comparable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.CharSequence]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [java.lang.Comparable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Comparable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.CharSequence]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [java.lang.CharSequence]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Comparable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.CharSequence]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - Found matchable converters org.springframework.core.convert.support.ObjectToStringConverter@203fa5ac
TRACE: org.springframework.core.convert.support.GenericConversionService - Matching org.springframework.core.convert.support.ObjectToStringConverter@203fa5ac
DEBUG: org.springframework.core.convert.support.GenericConversionService - Matched converter org.springframework.core.convert.support.ObjectToStringConverter@203fa5ac
DEBUG: org.springframework.core.convert.support.GenericConversionService - Converted to '1'
DEBUG: org.springframework.core.convert.support.GenericConversionService - Converting value '2' of [TypeDescriptor java.lang.String] to [TypeDescriptor java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Comparable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.CharSequence]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Comparable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.CharSequence]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [java.lang.Comparable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Comparable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.CharSequence]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [java.lang.CharSequence]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Comparable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.CharSequence]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - Found matchable converters org.springframework.core.convert.support.ObjectToStringConverter@203fa5ac
TRACE: org.springframework.core.convert.support.GenericConversionService - Matching org.springframework.core.convert.support.ObjectToStringConverter@203fa5ac
DEBUG: org.springframework.core.convert.support.GenericConversionService - Matched converter org.springframework.core.convert.support.ObjectToStringConverter@203fa5ac
DEBUG: org.springframework.core.convert.support.GenericConversionService - Converted to '2'
DEBUG: org.springframework.core.convert.support.GenericConversionService - Converting value '3' of [TypeDescriptor java.lang.String] to [TypeDescriptor java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Comparable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.CharSequence]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Comparable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.CharSequence]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [java.lang.Comparable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Comparable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.CharSequence]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [java.lang.CharSequence]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.io.Serializable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Comparable]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.CharSequence]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - Looking for converters indexed by sourceType [java.lang.Object]
TRACE: org.springframework.core.convert.support.GenericConversionService - and indexed by targetType [java.lang.String]
TRACE: org.springframework.core.convert.support.GenericConversionService - Found matchable converters org.springframework.core.convert.support.ObjectToStringConverter@203fa5ac
TRACE: org.springframework.core.convert.support.GenericConversionService - Matching org.springframework.core.convert.support.ObjectToStringConverter@203fa5ac
DEBUG: org.springframework.core.convert.support.GenericConversionService - Matched converter org.springframework.core.convert.support.ObjectToStringConverter@203fa5ac
DEBUG: org.springframework.core.convert.support.GenericConversionService - Converted to '3'
DEBUG: org.springframework.core.convert.support.GenericConversionService - Converted to list['1', '2', '3']

[spring-projects-issues]

Rossen Stoyanchev commented

A second point to be made is that when a superclass is added, its interface hierarchy will likely be a subset (and hence overlap) with the interface hierarchy of the current class.

[spring-projects-issues]

Keith Donald commented

Now in addition to caching converter resolution results we track interfaces we've already attempted so we don't try the same interface again for a given sourceType and sourceType->targetType match.