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Reduce size of ClassInfoCache by 32 bytes per cache entry #56

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Merged
mcculls merged 1 commit into from
Mar 9, 2026
Merged

Reduce size of ClassInfoCache by 32 bytes per cache entry #56

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10 changes: 5 additions & 5 deletions utils/src/main/java/datadog/instrument/utils/ClassInfoCache.java
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Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@
package datadog.instrument.utils;

import java.util.Arrays;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.AtomicInteger;

/**
* Shares class information from multiple classloaders in a single cache.
Expand All @@ -28,7 +28,7 @@ public final class ClassInfoCache<T> {
private static final int ALL_CLASS_LOADERS = -1;

// global monotonic counter; cheap way to track aging as info is shared
static final AtomicLong TICKS = new AtomicLong();
static final AtomicInteger TICKS = new AtomicInteger(Integer.MIN_VALUE);

// fixed-size hashtable of shared information, indexed by class-name
private final SharedInfo[] shared;
Expand Down Expand Up @@ -190,7 +190,7 @@ public void share(String className, T info, int classLoaderKeyId) {
// always wrap info in a new wrapper to avoid consistency issues
final SharedInfo update = new SharedInfo(className, info, classLoaderKeyId);

long oldestTick = Long.MAX_VALUE;
int oldestTick = Integer.MAX_VALUE;
int oldestSlot = -1;

// search by repeated hashing; stop when we find an empty slot,
Expand All @@ -200,7 +200,7 @@ public void share(String className, T info, int classLoaderKeyId) {
SharedInfo existing = shared[slot];
if (existing != null && !existing.equals(update)) {
// slot already used by a different class
long tick = existing.accessed;
int tick = existing.accessed;
if (i < MAX_HASH_ATTEMPTS) {
// still more slots to search
if (tick < oldestTick) {
Expand Down Expand Up @@ -246,7 +246,7 @@ static final class SharedInfo {
// optional class-loader key
final int classLoaderKeyId;

long accessed;
int accessed;

SharedInfo(String className, Object classInfo, int classLoaderKeyId) {
this.className = className;
Expand Down
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