Adds a pool for PresenceBitmap instances. #1044
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tgregg
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ion-11-encoding-optimize-initial-expression-array-size-session-pools-merge-presencebitmap-pool
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tgregg
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Jan 30, 2025
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| val nonRequiredParametersCount = signature.count { it.cardinality != ParameterCardinality.ExactlyOne } | ||
| val usePresenceBits = nonRequiredParametersCount > PRESENCE_BITS_SIZE_THRESHOLD || signature.any { it.type.taglessEncodingKind != null } | ||
| var nonRequiredParametersCount = 0 | ||
| var usePresenceBits = false | ||
| for (i in signature.indices) { | ||
| val parameter = signature[i] | ||
| if (parameter.cardinality != ParameterCardinality.ExactlyOne) { | ||
| nonRequiredParametersCount++ | ||
| } | ||
| usePresenceBits = usePresenceBits or (parameter.type.taglessEncodingKind != null) | ||
| } | ||
| usePresenceBits = usePresenceBits or (nonRequiredParametersCount > PRESENCE_BITS_SIZE_THRESHOLD) |
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The result is the same, but the new (uglier) version achieves two things:
- It eliminates
ArrayList$Itrallocations that are implicit to Kotlin'sList.countandList.anymethods. These were showing up prominently in memory profiles. This change alone lowered allocation rate from 147 KB/op to 139 KB/op. - It only loops through the signature once, instead of (worst case) two full times.
jobarr-amzn
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Feb 11, 2025
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| usePresenceBits = usePresenceBits or (parameter.type.taglessEncodingKind != null) | ||
| } | ||
| usePresenceBits = usePresenceBits or (nonRequiredParametersCount > PRESENCE_BITS_SIZE_THRESHOLD) |
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or spelled out does not short-circuit, is there a reason to use it?
Suggested change
| usePresenceBits = usePresenceBits or (parameter.type.taglessEncodingKind != null) | |
| } | |
| usePresenceBits = usePresenceBits or (nonRequiredParametersCount > PRESENCE_BITS_SIZE_THRESHOLD) | |
| usePresenceBits = usePresenceBits || (parameter.type.taglessEncodingKind != null) | |
| } | |
| usePresenceBits = usePresenceBits || (nonRequiredParametersCount > PRESENCE_BITS_SIZE_THRESHOLD) |
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Description of changes:
This just adds a pool to the existing abstraction. We may still choose to overhaul the abstraction on the read side, as suggested here: #1032 (review)
This has a minimal effect on speed, but a fairly significant effect on allocation rate.
Speed: 245 ms/op -> 244 ms /op (~0%)
Allocation rate: 157 KB/op -> 139 KB/op (-11.5%)
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.