remove usage of SmallHashMap (#584)

Phase out usage of SmallHashMap type. Would like to
remove this from Atlas to simplify code base.

atlas-aggregator/src/main/scala/com/netflix/atlas/aggregator/PayloadDecoder.scala

@@ -20,7 +20,7 @@ import com.fasterxml.jackson.core.JsonToken
 import com.github.benmanes.caffeine.cache.Caffeine
 import com.netflix.atlas.core.model.TagKey
 import com.netflix.atlas.core.util.IdMap
-import com.netflix.atlas.core.util.SmallHashMap
+import com.netflix.atlas.core.util.SortedTagMap
 import com.netflix.atlas.core.validation.CompositeTagRule
 import com.netflix.atlas.core.validation.Rule
 import com.netflix.atlas.core.validation.TagRule
@@ -191,7 +191,7 @@ class PayloadDecoder(
 
     if (name == null) {
       // This should never happen if clients are working properly
-      val builder = new SmallHashMap.Builder[String, String](n + 1)
+      val builder = new SortedTagMap.Builder(n + 1)
       var i = 0
       while (i < pos) {
         builder.add(tags(i), tags(i + 1))

atlas-aggregator/src/test/scala/com/netflix/atlas/aggregator/UpdateApiSuite.scala

@@ -22,7 +22,7 @@ import org.apache.pekko.http.scaladsl.model.StatusCodes
 import com.fasterxml.jackson.core.JsonFactory
 import com.netflix.atlas.pekko.ByteStringInputStream
 import com.netflix.atlas.core.util.RefIntHashMap
-import com.netflix.atlas.core.util.SmallHashMap
+import com.netflix.atlas.core.util.SortedTagMap
 import com.netflix.atlas.core.util.Strings
 import com.netflix.atlas.json.Json
 import com.netflix.spectator.api.Clock
@@ -181,7 +181,7 @@ class UpdateApiSuite extends FunSuite {
     assertEquals(service.lookup(id).counter(id).actualCount(), 42.0)
   }
 
-  private def createPayload(ts: List[TagMap], op: Int, value: Double): String = {
+  private def createPayload(ts: List[SortedTagMap], op: Int, value: Double): String = {
     val stringTable = new RefIntHashMap[String]()
     ts.foreach { tags =>
       tags.foreachEntry { (k, v) =>
@@ -218,11 +218,11 @@ class UpdateApiSuite extends FunSuite {
     Json.encode(data)
   }
 
-  private def validationTest(tags: TagMap, expectedStatus: StatusCode): FailureMessage = {
+  private def validationTest(tags: SortedTagMap, expectedStatus: StatusCode): FailureMessage = {
     validationTest(List(tags), expectedStatus)
   }
 
-  private def validationTest(ts: List[TagMap], expectedStatus: StatusCode): FailureMessage = {
+  private def validationTest(ts: List[SortedTagMap], expectedStatus: StatusCode): FailureMessage = {
     val clock = new ManualClock()
     val service = createAggrService(clock)
     val parser = factory.createParser(createPayload(ts, 0, 1.0))
@@ -234,23 +234,23 @@ class UpdateApiSuite extends FunSuite {
   }
 
   test("validation: ok") {
-    val tags = SmallHashMap("name" -> "foo")
+    val tags = SortedTagMap("name" -> "foo")
     validationTest(tags, StatusCodes.OK)
   }
 
   test("validation: missing name") {
-    val tags = SmallHashMap("foo" -> "bar")
+    val tags = SortedTagMap("foo" -> "bar")
     val msg = validationTest(tags, StatusCodes.BadRequest)
     assertEquals(msg.errorCount, 1)
     assertEquals(
       msg.message,
-      List("missing key 'name' (tags={\"foo\":\"bar\",\"atlas.dstype\":\"sum\"})")
+      List("missing key 'name' (tags={\"atlas.dstype\":\"sum\",\"foo\":\"bar\"})")
     )
   }
 
   test("validation: name too long") {
     val name = "a" * 300
-    val tags = SmallHashMap("name" -> name)
+    val tags = SortedTagMap("name" -> name)
     val msg = validationTest(tags, StatusCodes.BadRequest)
     assertEquals(msg.errorCount, 1)
     assertEquals(
@@ -265,7 +265,7 @@ class UpdateApiSuite extends FunSuite {
     val tags = Map("name" -> "foo") ++ (0 until 20)
       .map(v => Strings.zeroPad(v, 5))
       .map(v => v -> v)
-    val msg = validationTest(SmallHashMap(tags), StatusCodes.BadRequest)
+    val msg = validationTest(SortedTagMap(tags), StatusCodes.BadRequest)
     assertEquals(msg.errorCount, 1)
     assert(msg.message.head.startsWith("too many user tags: 21 > 20 (tags={"))
   }
@@ -274,12 +274,12 @@ class UpdateApiSuite extends FunSuite {
     val tags = Map("name" -> "foo", "nf.app" -> "www") ++ (0 until 19)
       .map(v => Strings.zeroPad(v, 5))
       .map(v => v -> v)
-    val msg = validationTest(SmallHashMap(tags), StatusCodes.OK)
+    val msg = validationTest(SortedTagMap(tags), StatusCodes.OK)
     assertEquals(msg.errorCount, 0)
   }
 
   test("validation: tag rule") {
-    val tags = SmallHashMap("name" -> "test", "nf.foo" -> "bar")
+    val tags = SortedTagMap("name" -> "test", "nf.foo" -> "bar")
     val msg = validationTest(tags, StatusCodes.BadRequest)
     assertEquals(msg.errorCount, 1)
     assertEquals(
@@ -292,8 +292,8 @@ class UpdateApiSuite extends FunSuite {
 
   test("validation: partial failure") {
     val ts = List(
-      SmallHashMap("name" -> "test", "nf.foo" -> "bar"),
-      SmallHashMap("name" -> "test", "nf.app" -> "bar")
+      SortedTagMap("name" -> "test", "nf.foo" -> "bar"),
+      SortedTagMap("name" -> "test", "nf.app" -> "bar")
     )
     val msg = validationTest(ts, StatusCodes.Accepted)
     assertEquals(msg.errorCount, 1)
@@ -307,7 +307,7 @@ class UpdateApiSuite extends FunSuite {
 
   test("validation: truncate if there are too many errors") {
     val ts = (0 until 20).toList.map { i =>
-      SmallHashMap("name" -> i.toString, "nf.foo" -> "bar")
+      SortedTagMap("name" -> i.toString, "nf.foo" -> "bar")
     }
     val msg = validationTest(ts, StatusCodes.BadRequest)
     assertEquals(msg.errorCount, 20)

atlas-cloudwatch/src/main/scala/com/netflix/atlas/cloudwatch/CloudWatchMetricsProcessor.scala

@@ -22,7 +22,7 @@ import com.netflix.atlas.cloudwatch.CloudWatchMetricsProcessor.normalize
 import com.netflix.atlas.cloudwatch.CloudWatchMetricsProcessor.toAWSDatapoint
 import com.netflix.atlas.cloudwatch.CloudWatchMetricsProcessor.toAWSDimensions
 import com.netflix.atlas.cloudwatch.CloudWatchMetricsProcessor.toTagMap
-import com.netflix.atlas.core.util.SmallHashMap
+import com.netflix.atlas.core.util.SortedTagMap
 import com.netflix.spectator.api.Registry
 import com.typesafe.config.Config
 import com.typesafe.scalalogging.StrictLogging
@@ -1035,8 +1035,7 @@ object CloudWatchMetricsProcessor {
     *     A non-null map with at least the `name` and `aws.namespace` tags.
     */
   private[cloudwatch] def toTagMap(entry: CloudWatchCacheEntry): Map[String, String] = {
-    SmallHashMap(
-      entry.getDimensionsCount + 2,
+    SortedTagMap(
       entry.getDimensionsList.asScala
         .map(d => d.getName -> d.getValue)
         .append("name" -> entry.getMetric)
@@ -1050,14 +1049,13 @@ object CloudWatchMetricsProcessor {
     * Query filter from a [MetricCategory] config. Note that the `name` and `aws.namespace` tags are populated per
     * Atlas standards.
     *
-    * @param entry
-    * The non-null entry to encode.
+    * @param datapoint
+    *     The non-null datapoint to encode.
     * @return
-    * A non-null map with at least the `name` and `aws.namespace` tags.
+    *     A non-null map with at least the `name` and `aws.namespace` tags.
     */
   private[cloudwatch] def toTagMap(datapoint: FirehoseMetric): Map[String, String] = {
-    SmallHashMap(
-      datapoint.dimensions.size + 2,
+    SortedTagMap(
       datapoint.dimensions
         .map(d => d.name() -> d.value())
         .appended("name" -> datapoint.metricName)
@@ -1077,8 +1075,7 @@ object CloudWatchMetricsProcessor {
     *     A non-null map with at least the `name` and `aws.namespace` tags.
     */
   private[cloudwatch] def toTagMap(metric: Metric): Map[String, String] = {
-    SmallHashMap(
-      metric.dimensions().size() + 2,
+    SortedTagMap(
       metric
         .dimensions()
         .asScala

atlas-persistence/src/main/scala/com/netflix/atlas/persistence/RollingFileWriter.scala

@@ -190,7 +190,7 @@ class RollingFileWriter(
   }
 
   private def toAvro(dp: Datapoint): GenericRecord = {
-    // Use custom wrapper for SmallHashMap if possible as it avoids allocations when
+    // Use custom wrapper for scala Map if possible as it avoids allocations when
     // iterating across the entries.
     val tags = toCompressedJavaMap(dp.tags)
     val record = new GenericData.Record(RollingFileWriter.AvroSchema)