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

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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.function.Predicate;
import java.util.regex.Pattern;
import javax.annotation.Nullable;
import wavefront.report.Annotation;
import wavefront.report.Span;

/**
 * Force lowercase transformer. Converts a specified component of a point (metric name, source name
 * or a point tag value, depending on "scope" parameter) to lower case to enforce consistency.
 *
 * @author [email protected]
 */
public class SpanForceLowercaseTransformer implements Function {

  private final String scope;
  @Nullable private final Pattern compiledMatchPattern;
  private final boolean firstMatchOnly;
  private final PreprocessorRuleMetrics ruleMetrics;
  private final Predicate v2Predicate;

  public SpanForceLowercaseTransformer(
      final String scope,
      @Nullable final String patternMatch,
      final boolean firstMatchOnly,
      @Nullable final Predicate v2Predicate,
      final PreprocessorRuleMetrics ruleMetrics) {
    this.scope = Preconditions.checkNotNull(scope, "[scope] can't be null");
    Preconditions.checkArgument(!scope.isEmpty(), "[scope] can't be blank");
    this.compiledMatchPattern = patternMatch != null ? Pattern.compile(patternMatch) : null;
    this.firstMatchOnly = firstMatchOnly;
    Preconditions.checkNotNull(ruleMetrics, "PreprocessorRuleMetrics can't be null");
    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;

      switch (scope) {
        case "spanName":
          if (compiledMatchPattern != null
              && !compiledMatchPattern.matcher(span.getName()).matches()) {
            break;
          }
          span.setName(span.getName().toLowerCase());
          ruleMetrics.incrementRuleAppliedCounter();
          break;
        case "sourceName": // source name is not case sensitive in Wavefront, but we'll do
          // it anyway
          if (compiledMatchPattern != null
              && !compiledMatchPattern.matcher(span.getSource()).matches()) {
            break;
          }
          span.setSource(span.getSource().toLowerCase());
          ruleMetrics.incrementRuleAppliedCounter();
          break;
        default:
          for (Annotation x : span.getAnnotations()) {
            if (x.getKey().equals(scope)
                && (compiledMatchPattern == null
                    || compiledMatchPattern.matcher(x.getValue()).matches())) {
              x.setValue(x.getValue().toLowerCase());
              ruleMetrics.incrementRuleAppliedCounter();
              if (firstMatchOnly) {
                break;
              }
            }
          }
      }
      return span;
    } finally {
      ruleMetrics.ruleEnd(startNanos);
    }
  }
}