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mcculls wants to merge 1 commit into from
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WIP: instrumenter index experiment #9031

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9 changes: 2 additions & 7 deletions dd-java-agent/agent-builder/src/main/java/datadog/trace/agent/tooling/AgentInstaller.java
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Original file line number Diff line number Diff line change
Expand Up @@ -178,7 +178,8 @@ public static ClassFileTransformer installBytebuddyAgent(
InstrumenterState.initialize(instrumenterIndex.instrumentationCount());

// combine known modules indexed at build-time with extensions contributed at run-time
Iterable<InstrumenterModule> instrumenterModules = withExtensions(instrumenterIndex.modules());
Iterable<InstrumenterModule> instrumenterModules =
withExtensions(instrumenterIndex.modules(enabledSystems));

// This needs to be a separate loop through all instrumentations before we start adding
// advice so that we can exclude field injection, since that will try to check exclusion
Expand All @@ -200,12 +201,6 @@ public static ClassFileTransformer installBytebuddyAgent(

int installedCount = 0;
for (InstrumenterModule module : instrumenterModules) {
if (!enabledSystems.contains(module.targetSystem())) {
if (DEBUG) {
log.debug("Not applicable - instrumentation.class={}", module.getClass().getName());
}
continue;
}
if (!module.isEnabled(enabledSystems)) {
if (DEBUG) {
log.debug("Not enabled - instrumentation.class={}", module.getClass().getName());
Expand Down
44 changes: 36 additions & 8 deletions dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/InstrumenterIndex.java
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@
import static java.nio.charset.StandardCharsets.UTF_8;
import static java.util.Collections.singletonList;

import datadog.trace.agent.tooling.InstrumenterModule.TargetSystem;
import datadog.trace.agent.tooling.bytebuddy.SharedTypePools;
import datadog.trace.agent.tooling.bytebuddy.matcher.HierarchyMatchers;
import java.io.BufferedInputStream;
Expand Down Expand Up @@ -51,15 +52,18 @@ final class InstrumenterIndex {

private final InstrumenterModule[] modules;

// packed sequence of module type names and their expected member names:
// module1, memberCount, memberA, memberB, module2, memberCount, memberC, ...
// packed sequence of module type names, their target systems, and their expected member names:
// module1, targetSystemId, memberCount, memberA, memberB,
// module2, targetSystemId, memberCount, memberC, ...
// (each string is encoded as its length plus that number of ASCII bytes)
private final byte[] packedNames;
private int nameIndex;

// current module details
private int instrumentationId = -1;
private String moduleName;
private int targetSystemId;

private int memberCount;

// current member details
Expand All @@ -74,20 +78,34 @@ private InstrumenterIndex(int instrumentationCount, int transformationCount, byt
}

public Iterable<InstrumenterModule> modules() {
return ModuleIterator::new;
return () -> new ModuleIterator(-1);
}

public Iterable<InstrumenterModule> modules(Set<TargetSystem> enabledSystems) {
return () -> new ModuleIterator(systemMask(enabledSystems));
}

private int systemMask(Set<TargetSystem> enabledSystems) {
int systemMask = 0;
for (TargetSystem system : enabledSystems) {
systemMask |= (1 << system.ordinal());
}
return systemMask;
}

final class ModuleIterator implements Iterator<InstrumenterModule> {
private int systemMask;
private InstrumenterModule module;

ModuleIterator() {
ModuleIterator(int systemMask) {
this.systemMask = systemMask;
restart();
}

@Override
public boolean hasNext() {
while (null == module && hasNextModule()) {
module = nextModule();
module = nextModule(systemMask);
}
return null != module;
}
Expand Down Expand Up @@ -148,7 +166,7 @@ boolean hasNextModule() {
}

/** Returns the next {@link InstrumenterModule} in the index. */
InstrumenterModule nextModule() {
InstrumenterModule nextModule(int systemMask) {
while (memberCount > 0) {
skipMember(); // skip past unmatched members from previous module
}
Expand All @@ -157,10 +175,14 @@ InstrumenterModule nextModule() {
// use data from previously loaded module
moduleName = module.getClass().getName();
skipName();
skipNumber();
} else {
moduleName = readName();
module = buildNodule();
modules[instrumentationId] = module;
targetSystemId = readNumber();
if ((systemMask & (1 << targetSystemId)) != 0) {
module = buildNodule();
modules[instrumentationId] = module;
}
}
memberCount = readNumber();
if (SELF_MEMBERSHIP == memberCount) {
Expand Down Expand Up @@ -217,6 +239,11 @@ private int readNumber() {
return 0xFF & (int) packedNames[nameIndex++];
}

/** Skips an unsigned byte from the packed name sequence. */
private void skipNumber() {
nameIndex++;
}

public static InstrumenterIndex readIndex() {
URL indexResource = instrumenterClassLoader.getResource(INSTRUMENTER_INDEX_NAME);
if (null != indexResource) {
Expand Down Expand Up @@ -295,6 +322,7 @@ public void buildIndex() {
instrumentationCount++;
out.writeByte(moduleName.length());
out.writeBytes(moduleName);
out.writeByte(module.targetSystem().ordinal());
try {
List<Instrumenter> members = module.typeInstrumentations();
if (members.equals(singletonList(module))) {
Expand Down