com.wavefront.agent.preprocessor.SpanDropAnnotationTransformer Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of proxy Show documentation

Service for batching and relaying metric traffic to Wavefront

There is a newer version: 4.36

package com.wavefront.agent.preprocessor;

import com.google.common.base.Function;
import com.google.common.base.Preconditions;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.function.Predicate;
import java.util.regex.Pattern;
import javax.annotation.Nullable;
import wavefront.report.Annotation;
import wavefront.report.Span;

/**
 * Removes a span annotation with a specific key if its value matches an optional regex pattern
 * (always remove if null)
 *
 * @author [email protected]
 */
public class SpanDropAnnotationTransformer implements Function {

  private final Pattern compiledKeyPattern;
  @Nullable private final Pattern compiledValuePattern;
  private final boolean firstMatchOnly;
  private final PreprocessorRuleMetrics ruleMetrics;
  private final Predicate v2Predicate;

  public SpanDropAnnotationTransformer(
      final String key,
      @Nullable final String patternMatch,
      final boolean firstMatchOnly,
      @Nullable final Predicate v2Predicate,
      final PreprocessorRuleMetrics ruleMetrics) {
    this.compiledKeyPattern =
        Pattern.compile(Preconditions.checkNotNull(key, "[key] can't be null"));
    Preconditions.checkArgument(!key.isEmpty(), "[key] can't be blank");
    this.compiledValuePattern = patternMatch != null ? Pattern.compile(patternMatch) : null;
    Preconditions.checkNotNull(ruleMetrics, "PreprocessorRuleMetrics can't be null");
    this.firstMatchOnly = firstMatchOnly;
    this.ruleMetrics = ruleMetrics;
    this.v2Predicate = v2Predicate != null ? v2Predicate : x -> true;
  }

  @Nullable
  @Override
  public Span apply(@Nullable Span span) {
    if (span == null) return null;
    long startNanos = ruleMetrics.ruleStart();
    try {
      if (!v2Predicate.test(span)) return span;

      List annotations = new ArrayList<>(span.getAnnotations());
      Iterator iterator = annotations.iterator();
      boolean changed = false;
      while (iterator.hasNext()) {
        Annotation entry = iterator.next();
        if (compiledKeyPattern.matcher(entry.getKey()).matches()
            && (compiledValuePattern == null
                || compiledValuePattern.matcher(entry.getValue()).matches())) {
          changed = true;
          iterator.remove();
          ruleMetrics.incrementRuleAppliedCounter();
          if (firstMatchOnly) {
            break;
          }
        }
      }
      if (changed) {
        span.setAnnotations(annotations);
      }
      return span;
    } finally {
      ruleMetrics.ruleEnd(startNanos);
    }
  }
}