Class AdaptingCircularBufferCounter

java.lang.Object
io.opentelemetry.sdk.metrics.internal.aggregator.AdaptingCircularBufferCounter
final class AdaptingCircularBufferCounter extends Object
A circle-buffer-backed exponential counter.

The first recorded value becomes the 'baseIndex'. Going backwards leads to start/stop index

This expand start/End index as it sees values.

This class is NOT thread-safe. It is expected to be behind a synchronized incrementer.

  • Field Details

    • NULL_INDEX

      private static final int NULL_INDEX
      See Also:

    • endIndex

      private int endIndex

    • startIndex

      private int startIndex

    • baseIndex

      private int baseIndex

    • backing

      private final AdaptingIntegerArray backing

  • Constructor Details

    • AdaptingCircularBufferCounter

      AdaptingCircularBufferCounter(int maxSize)
      Constructs a circular buffer that will hold at most maxSize buckets.

    • AdaptingCircularBufferCounter

      AdaptingCircularBufferCounter(AdaptingCircularBufferCounter toCopy)
      (Deep)-Copies the values from another exponential counter.

  • Method Details

    • getIndexStart

      int getIndexStart()
      The first index with a recording. May be negative.

      Note: the returned value is not meaningful when isEmpty returns true.

      Returns:
      the first index with a recording.

    • getIndexEnd

      int getIndexEnd()
      The last index with a recording. May be negative.

      Note: the returned value is not meaningful when isEmpty returns true.

      Returns:
      The last index with a recording.

    • increment

      boolean increment(int index, long delta)
      Persist new data at index, incrementing by delta amount.
      Parameters:
      index - The index of where to perform the incrementation.
      delta - How much to increment the index by.
      Returns:
      success status.

    • get

      long get(int index)
      Get the number of recordings for the given index.
      Returns:
      the number of recordings for the index, or 0 if the index is out of bounds.

    • isEmpty

      boolean isEmpty()
      Boolean denoting if the backing structure has recordings or not.
      Returns:
      true if no recordings, false if at least one recording.

    • getMaxSize

      int getMaxSize()
      Returns the maximum number of buckets allowed in this counter.

    • clear

      void clear()
      Resets all bucket counts to zero and resets index start/end tracking.

    • toBufferIndex

      private int toBufferIndex(int index)

    • toString

      public String toString()
      Overrides:
      toString in class Object