Adds resource name matching to the trace sampling rules

dd-trace-core/src/main/java/datadog/trace/common/sampling/RuleBasedTraceSampler.java

@@ -67,6 +67,7 @@ public static RuleBasedTraceSampler build(
             new TraceSamplingRule(
                 rule.getService(),
                 rule.getName(),
+                rule.getResource(),
                 new DeterministicSampler.TraceSampler(rule.getSampleRate()));
         samplingRules.add(samplingRule);
       }

dd-trace-core/src/main/java/datadog/trace/common/sampling/SamplingRule.java

@@ -1,7 +1,8 @@
 package datadog.trace.common.sampling;
 
 import datadog.trace.core.CoreSpan;
-import datadog.trace.core.util.GlobPattern;
+import datadog.trace.core.util.Matcher;
+import datadog.trace.core.util.Matchers;
 import datadog.trace.core.util.SimpleRateLimiter;
 import java.util.regex.Pattern;
 
@@ -74,28 +75,32 @@ protected <T extends CoreSpan<T>> CharSequence getRelevantString(final T span) {
   }
 
   public static final class TraceSamplingRule extends SamplingRule {
-    private final String serviceName;
-    private final String operationName;
+    private final Matcher serviceMatcher;
+    private final Matcher operationMatcher;
+    private final Matcher resourceMatcher;
 
     public TraceSamplingRule(
-        final String exactServiceName, final String exactOperationName, final RateSampler sampler) {
+        final String serviceGlob,
+        final String operationGlob,
+        final String resourceGlob,
+        final RateSampler sampler) {
       super(sampler);
-      this.serviceName = exactServiceName;
-      this.operationName = exactOperationName;
+      serviceMatcher = Matchers.compileGlob(serviceGlob);
+      operationMatcher = Matchers.compileGlob(operationGlob);
+      resourceMatcher = Matchers.compileGlob(resourceGlob);
     }
 
     @Override
     public <T extends CoreSpan<T>> boolean matches(T span) {
-      return (serviceName == null || serviceName.equals(span.getServiceName()))
-          && (operationName == null || operationName.contentEquals(span.getOperationName()));
+      return Matchers.matches(serviceMatcher, span.getServiceName())
+          && Matchers.matches(operationMatcher, span.getOperationName())
+          && Matchers.matches(resourceMatcher, span.getResourceName());
     }
   }
 
   public static final class SpanSamplingRule extends SamplingRule {
-    private final String serviceExactName;
-    private final Pattern servicePattern;
-    private final String operationExactName;
-    private final Pattern operationPattern;
+    private final Matcher serviceMatcher;
+    private final Matcher operationMatcher;
 
     private final SimpleRateLimiter rateLimiter;
 
@@ -106,43 +111,16 @@ public SpanSamplingRule(
         final SimpleRateLimiter rateLimiter) {
       super(sampler);
 
-      if (serviceName == null || "*".equals(serviceName)) {
-        this.serviceExactName = null;
-        this.servicePattern = null;
-      } else if (isExactMatcher(serviceName)) {
-        this.serviceExactName = serviceName;
-        this.servicePattern = null;
-      } else {
-        this.serviceExactName = null;
-        this.servicePattern = GlobPattern.globToRegexPattern(serviceName);
-      }
-
-      if (operationName == null || "*".equals(operationName)) {
-        this.operationExactName = null;
-        this.operationPattern = null;
-      } else if (isExactMatcher(operationName)) {
-        this.operationExactName = operationName;
-        this.operationPattern = null;
-      } else {
-        this.operationExactName = null;
-        this.operationPattern = GlobPattern.globToRegexPattern(operationName);
-      }
+      serviceMatcher = Matchers.compileGlob(serviceName);
+      operationMatcher = Matchers.compileGlob(operationName);
 
       this.rateLimiter = rateLimiter;
     }
 
-    private boolean isExactMatcher(String serviceNameGlob) {
-      return !serviceNameGlob.contains("*") && !serviceNameGlob.contains("?");
-    }
-
     @Override
     public <T extends CoreSpan<T>> boolean matches(T span) {
-      return (serviceExactName == null || serviceExactName.equals(span.getServiceName()))
-          && (servicePattern == null || servicePattern.matcher(span.getServiceName()).matches())
-          && (operationExactName == null
-              || operationExactName.contentEquals(span.getOperationName()))
-          && (operationPattern == null
-              || operationPattern.matcher(span.getOperationName()).matches());
+      return Matchers.matches(serviceMatcher, span.getServiceName())
+          && Matchers.matches(operationMatcher, span.getOperationName());
     }
 
     @Override

dd-trace-core/src/main/java/datadog/trace/common/sampling/TraceSamplingRules.java

@@ -17,49 +17,62 @@ public class TraceSamplingRules {
   private static final Logger log = LoggerFactory.getLogger(TraceSamplingRules.class);
 
   public static final class Rule {
-    public static Rule create(String service, String name, double sampleRate) {
+    public static Rule create(String service, String name, String resource, double sampleRate) {
       if (sampleRate < 0 || sampleRate > 1.0) {
         logError(
-            service, name, Double.toString(sampleRate), "sample_rate must be between 0.0 and 1.0");
+            service,
+            name,
+            resource,
+            Double.toString(sampleRate),
+            "sample_rate must be between 0.0 and 1.0");
         return null;
       }
-      return new Rule(service, name, sampleRate);
+      return new Rule(service, name, resource, sampleRate);
     }
 
-    public static Rule create(String service, String name, String sample_rate) {
+    public static Rule create(String service, String name, String resource, String sample_rate) {
       if (sample_rate == null) {
-        logError(service, name, null, "missing mandatory sample_rate");
+        logError(service, name, resource, null, "missing mandatory sample_rate");
         return null;
       }
       try {
-        return create(service, name, Double.parseDouble(sample_rate));
+        return create(service, name, resource, Double.parseDouble(sample_rate));
       } catch (NumberFormatException ex) {
-        logError(service, name, sample_rate, "sample_rate must be a number between 0.0 and 1.0");
+        logError(
+            service,
+            name,
+            resource,
+            sample_rate,
+            "sample_rate must be a number between 0.0 and 1.0");
         return null;
       }
     }
 
-    private static void logError(String service, String name, String sample_rate, String error) {
+    private static void logError(
+        String service, String name, String resource, String sample_rate, String error) {
       log.error(
           "Skipping invalid Trace Sampling Rule: { \"service\": \""
               + service
               + "\", \"name\": \""
               + name
+              + "\", \"resource\": \""
+              + resource
               + "\", \"sample_rate\": "
               + sample_rate
               + " } - "
               + error);
     }
 
     private final String service;
-
     private final String name;
+    private final String resource;
 
     private final double sampleRate;
 
-    private Rule(String service, String name, double sampleRate) {
+    private Rule(String service, String name, String resource, double sampleRate) {
       this.service = service;
       this.name = name;
+      this.resource = resource;
       this.sampleRate = sampleRate;
     }
 
@@ -71,6 +84,10 @@ public String getName() {
       return name;
     }
 
+    public String getResource() {
+      return resource;
+    }
+
     public double getSampleRate() {
       return sampleRate;
     }
@@ -88,10 +105,11 @@ public static TraceSamplingRules deserialize(String json) {
   private static final class JsonRule {
     String service;
     String name;
+    String resource;
     String sample_rate;
 
     private Rule toRule() {
-      return Rule.create(service, name, sample_rate);
+      return Rule.create(service, name, resource, sample_rate);
     }
   }
 

dd-trace-core/src/main/java/datadog/trace/core/util/GlobPattern.java

@@ -5,20 +5,11 @@
 public final class GlobPattern {
 
   public static Pattern globToRegexPattern(String globPattern) {
-    if (globPattern == null) {
-      return null;
-    }
     String regex = globToRegex(globPattern);
-    if (regex == null) {
-      return null;
-    }
     return Pattern.compile(regex);
   }
 
   private static String globToRegex(String globPattern) {
-    if ("*".equals(globPattern)) {
-      return null;
-    }
     StringBuilder sb = new StringBuilder(64);
     sb.append('^');
     for (int i = 0; i < globPattern.length(); i++) {

dd-trace-core/src/main/java/datadog/trace/core/util/Matcher.java

@@ -0,0 +1,7 @@
+package datadog.trace.core.util;
+
+public interface Matcher {
+  public boolean matches(String str);
+
+  public boolean matches(CharSequence charSeq);
+}

dd-trace-core/src/main/java/datadog/trace/core/util/Matchers.java

@@ -0,0 +1,69 @@
+package datadog.trace.core.util;
+
+import java.util.regex.Pattern;
+
+public final class Matchers {
+  private Matchers() {}
+
+  public static final Matcher compileGlob(String glob) {
+    if (glob == null || glob.equals("*")) {
+      // DQH - Decided not to an anyMatcher because that's likely to
+      // cause our call site to go megamorphic
+      return null;
+    } else if (isExact(glob)) {
+      return new ExactMatcher(glob);
+    } else {
+      // DQH - not sure about the error handling here
+      Pattern pattern = GlobPattern.globToRegexPattern(glob);
+      return pattern == null ? null : new PatternMatcher(pattern);
+    }
+  }
+
+  public static boolean matches(Matcher matcher, String str) {
+    return (matcher == null) || matcher.matches(str);
+  }
+
+  public static boolean matches(Matcher matcher, CharSequence charSeq) {
+    return (matcher == null) || matcher.matches(charSeq);
+  }
+
+  static boolean isExact(String glob) {
+    return (glob.indexOf('*') == -1) && (glob.indexOf('?') == -1);
+  }
+
+  static final class ExactMatcher implements Matcher {
+    private final String exact;
+
+    ExactMatcher(String exact) {
+      this.exact = exact;
+    }
+
+    @Override
+    public boolean matches(String str) {
+      return exact.equals(str);
+    }
+
+    @Override
+    public boolean matches(CharSequence charSeq) {
+      return exact.contentEquals(charSeq);
+    }
+  }
+
+  static final class PatternMatcher implements Matcher {
+    private final Pattern pattern;
+
+    PatternMatcher(Pattern pattern) {
+      this.pattern = pattern;
+    }
+
+    @Override
+    public boolean matches(CharSequence charSeq) {
+      return pattern.matcher(charSeq).matches();
+    }
+
+    @Override
+    public boolean matches(String str) {
+      return pattern.matcher(str).matches();
+    }
+  }
+}

dd-trace-core/src/test/groovy/datadog/trace/common/sampling/RuleBasedSamplingTest.groovy

@@ -159,7 +159,9 @@ class RuleBasedSamplingTest extends DDCoreSpecification {
     DDSpan span = tracer.buildSpan("operation")
       .withServiceName("service")
       .withTag("env", "bar")
-      .ignoreActiveSpan().start()
+      .withResourceName("resource")
+      .ignoreActiveSpan()
+      .start()
     ((PrioritySampler) sampler).setSamplingPriority(span)
 
     then:
@@ -214,6 +216,20 @@ class RuleBasedSamplingTest extends DDCoreSpecification {
     "[{\"name\": \"xxx\", \"sample_rate\": 0}, {\"name\": \"operation\", \"sample_rate\": 1}]"                                                           | null        | 1.0              | 50                | null              | USER_KEEP
     "[{\"name\": \"xxx\", \"sample_rate\": 1}, {\"name\": \"operation\", \"sample_rate\": 0}]"                                                           | null        | 0                | null              | null              | USER_DROP
 
+    // Matching resource : keep
+    "[{\"resource\": \"resource\", \"sample_rate\": 1}]"                                                                                                 | null        | 1.0              | 50                | null              | USER_KEEP
+
+    // Matching operation: drop
+    "[{\"resource\": \"resource\", \"sample_rate\": 0}]"                                                                                                 | null        | 0                | null              | null              | USER_DROP
+
+    // Matching operation overrides default rate
+    "[{\"resource\": \"resource\", \"sample_rate\": 1}]"                                                                                                 | "0"         | 1.0              | 50                | null              | USER_KEEP
+    "[{\"resource\": \"resource\", \"sample_rate\": 0}]"                                                                                                 | "1"         | 0                | null              | null              | USER_DROP
+
+    // multiple operation combinations
+    "[{\"resource\": \"xxx\", \"sample_rate\": 0}, {\"resource\": \"resource\", \"sample_rate\": 1}]"                                                    | null        | 1.0              | 50                | null              | USER_KEEP
+    "[{\"resource\": \"xxx\", \"sample_rate\": 1}, {\"resource\": \"resource\", \"sample_rate\": 0}]"                                                    | null        | 0                | null              | null              | USER_DROP
+
     // Service and operation name rules
     "[{\"service\": \"service\", \"sample_rate\": 1}, {\"name\": \"operation\", \"sample_rate\": 0}]"                                                    | null        | 1.0              | 50                | null              | USER_KEEP
     "[{\"service\": \"service\", \"sample_rate\": 1}, {\"name\": \"xxx\", \"sample_rate\": 0}]"                                                          | null        | 1.0              | 50                | null              | USER_KEEP
@@ -227,6 +243,7 @@ class RuleBasedSamplingTest extends DDCoreSpecification {
     "[{\"service\": \"service\", \"name\": \"xxx\", \"sample_rate\": 0}, {\"service\": \"service\", \"name\": \"operation\", \"sample_rate\": 1}]"       | null        | 1.0              | 50                | null              | USER_KEEP
     "[{\"service\": \"service\", \"name\": \"xxx\", \"sample_rate\": 0}, {\"service\": \"service\", \"sample_rate\": 1}]"                                | null        | 1.0              | 50                | null              | USER_KEEP
     "[{\"service\": \"service\", \"name\": \"xxx\", \"sample_rate\": 0}, {\"name\": \"operation\", \"sample_rate\": 1}]"                                 | null        | 1.0              | 50                | null              | USER_KEEP
+    "[{\"service\": \"service\", \"resource\": \"xxx\", \"sample_rate\": 0}, {\"resource\": \"resource\", \"sample_rate\": 1}]"                          | null        | 1.0              | 50                | null              | USER_KEEP
     "[{\"service\": \"service\", \"name\": \"operation\", \"sample_rate\": 0}, {\"service\": \"service\", \"name\": \"operation\", \"sample_rate\": 1}]" | null        | 0                | null              | null              | USER_DROP
     "[{\"service\": \"service\", \"name\": \"operation\", \"sample_rate\": 0}]"                                                                          | null        | 0                | null              | null              | USER_DROP
   }

dd-trace-core/src/test/groovy/datadog/trace/common/sampling/TraceSamplingRulesTest.groovy

@@ -18,27 +18,37 @@ class TraceSamplingRulesTest extends DDCoreSpecification {
       {\"service\": \"usersvc\", \"name\": \"healthcheck\", \"sample_rate\": 0.0}, 
       {\"service\": \"service-name\", \"sample_rate\": 0.5}, 
       {\"name\": \"operation-name\", \"sample_rate\": 0.75}, 
+      {\"resource\": \"resource-name\", \"sample_rate\": 1},
       {\"sample_rate\": 0.25}
     ]""")
 
     then:
-    rules.rules.size() == 4
+    rules.rules.size() == 5
 
     rules.rules[0].service == "usersvc"
     rules.rules[0].name == "healthcheck"
+    rules.rules[0].resource == null
     rules.rules[0].sampleRate == 0.0d
 
     rules.rules[1].service == "service-name"
     rules.rules[1].name == null
+    rules.rules[1].resource == null
     rules.rules[1].sampleRate == 0.5d
 
     rules.rules[2].service == null
     rules.rules[2].name == "operation-name"
+    rules.rules[2].resource == null
     rules.rules[2].sampleRate == 0.75d
 
     rules.rules[3].service == null
     rules.rules[3].name == null
-    rules.rules[3].sampleRate == 0.25d
+    rules.rules[3].resource == "resource-name"
+    rules.rules[3].sampleRate == 1d
+
+    rules.rules[4].service == null
+    rules.rules[4].name == null
+    rules.rules[4].resource == null
+    rules.rules[4].sampleRate == 0.25d
   }
 
   def "Skip Trace Sampling Rules with invalid rate values"() {