Package org.apache.beam.sdk.metrics

Class MetricFiltering

  • public class MetricFiltering
extends java.lang.Object
    Implements matching for metrics filters. Specifically, matching for metric name, namespace, and step name.

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static boolean matches​(MetricsFilter filter, MetricKey key)
      Matching logic is implemented here rather than in MetricsFilter because we would like MetricsFilter to act as a "dumb" value-object, with the possibility of replacing it with a Proto/JSON/etc.
      static boolean matchesScope​(java.lang.String actualScope, java.util.Set<java.lang.String> scopes)
      matchesScope(actualScope, scopes) returns true if the scope of a metric is matched by any of the filters in scopes.
      static boolean subPathMatches​(java.lang.String haystack, java.lang.String needle)
      subPathMatches(haystack, needle) returns true if needle represents a path within haystack.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Method Detail

      • matches

        public static boolean matches​(MetricsFilter filter,
                              MetricKey key)
        Matching logic is implemented here rather than in MetricsFilter because we would like MetricsFilter to act as a "dumb" value-object, with the possibility of replacing it with a Proto/JSON/etc. schema object.
        Parameters:
        filter - MetricsFilter with the matching information of an actual metric
        key - MetricKey with the information of a metric
        Returns:
        whether the filter matches the key or not

      • subPathMatches

        public static boolean subPathMatches​(java.lang.String haystack,
                                     java.lang.String needle)
        subPathMatches(haystack, needle) returns true if needle represents a path within haystack. For example, "foo/bar" is in "a/foo/bar/b", but not "a/fool/bar/b" or "a/foo/bart/b".

      • matchesScope

        public static boolean matchesScope​(java.lang.String actualScope,
                                   java.util.Set<java.lang.String> scopes)
        matchesScope(actualScope, scopes) returns true if the scope of a metric is matched by any of the filters in scopes. A metric scope is a path of type "A/B/D". A path is matched by a filter if the filter is equal to the path (e.g. "A/B/D", or if it represents a subpath within it (e.g. "A/B" or "B/D", but not "A/D").

        Per https://docs.oracle.com/en/java/javase/14/docs/api/java.base/java/util/Set.html "sets contain ... at most one null element" / "Some set implementations have restrictions on the elements that they may contain. For example, some implementations prohibit null elements". Since sets cannot in general contain null it is not safe to check for membership of null, so the caller must determine what to do with a null actualScope.