feat: add ARRAY_LENGTH UDF

ksql-engine/src/main/java/io/confluent/ksql/function/udf/array/ArrayLength.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2020 Confluent Inc.
+ *
+ * Licensed under the Confluent Community License (the "License"; you may not use
+ * this file except in compliance with the License. You may obtain a copy of the
+ * License at
+ *
+ * http://www.confluent.io/confluent-community-license
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OF ANY KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+
+package io.confluent.ksql.function.udf.array;
+
+import io.confluent.ksql.function.udf.Udf;
+import io.confluent.ksql.function.udf.UdfDescription;
+import io.confluent.ksql.function.udf.UdfParameter;
+import java.util.List;
+
+/**
+ * Returns the length of an array
+ */
+@SuppressWarnings("MethodMayBeStatic") // UDF methods can not be static.
+@UdfDescription(name = "ARRAY_LENGTH", description = "Returns the length on an array")
+public class ArrayLength {
+
+  @Udf
+  public <T> int calcArrayLength(
+      @UdfParameter(description = "The array") final List<T> array
+  ) {
+    return array == null
+        ? 0
+        : array.size();
+  }
+}

ksql-engine/src/test/java/io/confluent/ksql/function/udf/array/ArrayLengthTest.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2020 Confluent Inc.
+ *
+ * Licensed under the Confluent Community License (the "License"); you may not use
+ * this file except in compliance with the License.  You may obtain a copy of the
+ * License at
+ *
+ * http://www.confluent.io/confluent-community-license
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OF ANY KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+
+package io.confluent.ksql.function.udf.array;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+
+import com.google.common.collect.ImmutableList;
+import org.junit.Before;
+import org.junit.Test;
+
+public class ArrayLengthTest {
+
+  private ArrayLength udf;
+
+  @Before
+  public void setUp() {
+    udf = new ArrayLength();
+  }
+
+  @Test
+  public void shouldReturnZeroForNullArray() {
+    assertThat(udf.calcArrayLength(null), is(0));
+  }
+
+  @Test
+  public void shouldReturnArraySize() {
+    assertThat(udf.calcArrayLength(ImmutableList.of()), is(0));
+    assertThat(udf.calcArrayLength(ImmutableList.of(1)), is(1));
+    assertThat(udf.calcArrayLength(ImmutableList.of("one", "two")), is(2));
+  }
+}

ksql-functional-tests/src/test/resources/historical_plans/array_-_array_length_-_primitives/6.0.0_1583509764019/plan.json

@@ -0,0 +1,146 @@
+{
+  "plan" : [ {
+    "@type" : "ksqlPlanV1",
+    "statementText" : "CREATE STREAM INPUT (BOOLEAN_ARRAY ARRAY<BOOLEAN>, INT_ARRAY ARRAY<INTEGER>, BIGINT_ARRAY ARRAY<BIGINT>, DOUBLE_ARRAY ARRAY<DOUBLE>, STRING_ARRAY ARRAY<STRING>, DECIMAL_ARRAY ARRAY<DECIMAL(2, 1)>) WITH (KAFKA_TOPIC='test_topic', VALUE_FORMAT='JSON');",
+    "ddlCommand" : {
+      "@type" : "createStreamV1",
+      "sourceName" : "INPUT",
+      "schema" : "`ROWKEY` STRING KEY, `BOOLEAN_ARRAY` ARRAY<BOOLEAN>, `INT_ARRAY` ARRAY<INTEGER>, `BIGINT_ARRAY` ARRAY<BIGINT>, `DOUBLE_ARRAY` ARRAY<DOUBLE>, `STRING_ARRAY` ARRAY<STRING>, `DECIMAL_ARRAY` ARRAY<DECIMAL(2, 1)>",
+      "keyField" : null,
+      "timestampColumn" : null,
+      "topicName" : "test_topic",
+      "formats" : {
+        "keyFormat" : {
+          "format" : "KAFKA",
+          "properties" : { }
+        },
+        "valueFormat" : {
+          "format" : "JSON",
+          "properties" : { }
+        },
+        "options" : [ ]
+      },
+      "windowInfo" : null
+    },
+    "queryPlan" : null
+  }, {
+    "@type" : "ksqlPlanV1",
+    "statementText" : "CREATE STREAM OUTPUT AS SELECT\n  ARRAY_LENGTH(INPUT.BOOLEAN_ARRAY) BOOLEAN_LEN,\n  ARRAY_LENGTH(INPUT.INT_ARRAY) INT_LEN,\n  ARRAY_LENGTH(INPUT.BIGINT_ARRAY) BIGINT_LEN,\n  ARRAY_LENGTH(INPUT.DOUBLE_ARRAY) DOUBLE_LEN,\n  ARRAY_LENGTH(INPUT.STRING_ARRAY) STRING_LEN,\n  ARRAY_LENGTH(INPUT.DECIMAL_ARRAY) DECIMAL_LEN\nFROM INPUT INPUT\nEMIT CHANGES",
+    "ddlCommand" : {
+      "@type" : "createStreamV1",
+      "sourceName" : "OUTPUT",
+      "schema" : "`ROWKEY` STRING KEY, `BOOLEAN_LEN` INTEGER, `INT_LEN` INTEGER, `BIGINT_LEN` INTEGER, `DOUBLE_LEN` INTEGER, `STRING_LEN` INTEGER, `DECIMAL_LEN` INTEGER",
+      "keyField" : null,
+      "timestampColumn" : null,
+      "topicName" : "OUTPUT",
+      "formats" : {
+        "keyFormat" : {
+          "format" : "KAFKA",
+          "properties" : { }
+        },
+        "valueFormat" : {
+          "format" : "JSON",
+          "properties" : { }
+        },
+        "options" : [ ]
+      },
+      "windowInfo" : null
+    },
+    "queryPlan" : {
+      "sources" : [ "INPUT" ],
+      "sink" : "OUTPUT",
+      "physicalPlan" : {
+        "@type" : "streamSinkV1",
+        "properties" : {
+          "queryContext" : "OUTPUT"
+        },
+        "source" : {
+          "@type" : "streamSelectV1",
+          "properties" : {
+            "queryContext" : "Project"
+          },
+          "source" : {
+            "@type" : "streamSourceV1",
+            "properties" : {
+              "queryContext" : "KsqlTopic/Source"
+            },
+            "topicName" : "test_topic",
+            "formats" : {
+              "keyFormat" : {
+                "format" : "KAFKA",
+                "properties" : { }
+              },
+              "valueFormat" : {
+                "format" : "JSON",
+                "properties" : { }
+              },
+              "options" : [ ]
+            },
+            "timestampColumn" : null,
+            "sourceSchema" : "`ROWKEY` STRING KEY, `BOOLEAN_ARRAY` ARRAY<BOOLEAN>, `INT_ARRAY` ARRAY<INTEGER>, `BIGINT_ARRAY` ARRAY<BIGINT>, `DOUBLE_ARRAY` ARRAY<DOUBLE>, `STRING_ARRAY` ARRAY<STRING>, `DECIMAL_ARRAY` ARRAY<DECIMAL(2, 1)>"
+          },
+          "selectExpressions" : [ "ARRAY_LENGTH(BOOLEAN_ARRAY) AS BOOLEAN_LEN", "ARRAY_LENGTH(INT_ARRAY) AS INT_LEN", "ARRAY_LENGTH(BIGINT_ARRAY) AS BIGINT_LEN", "ARRAY_LENGTH(DOUBLE_ARRAY) AS DOUBLE_LEN", "ARRAY_LENGTH(STRING_ARRAY) AS STRING_LEN", "ARRAY_LENGTH(DECIMAL_ARRAY) AS DECIMAL_LEN" ]
+        },
+        "formats" : {
+          "keyFormat" : {
+            "format" : "KAFKA",
+            "properties" : { }
+          },
+          "valueFormat" : {
+            "format" : "JSON",
+            "properties" : { }
+          },
+          "options" : [ ]
+        },
+        "topicName" : "OUTPUT",
+        "timestampColumn" : null
+      },
+      "queryId" : "CSAS_OUTPUT_0"
+    }
+  } ],
+  "configs" : {
+    "ksql.extension.dir" : "ext",
+    "ksql.streams.cache.max.bytes.buffering" : "0",
+    "ksql.security.extension.class" : null,
+    "ksql.transient.prefix" : "transient_",
+    "ksql.persistence.wrap.single.values" : "true",
+    "ksql.authorization.cache.expiry.time.secs" : "30",
+    "ksql.schema.registry.url" : "",
+    "ksql.streams.default.deserialization.exception.handler" : "io.confluent.ksql.errors.LogMetricAndContinueExceptionHandler",
+    "ksql.output.topic.name.prefix" : "",
+    "ksql.streams.auto.offset.reset" : "earliest",
+    "ksql.query.pull.enable.standby.reads" : "false",
+    "ksql.connect.url" : "http://localhost:8083",
+    "ksql.service.id" : "some.ksql.service.id",
+    "ksql.internal.topic.min.insync.replicas" : "1",
+    "ksql.streams.shutdown.timeout.ms" : "300000",
+    "ksql.streams.state.dir" : "/var/folders/2d/3pt97ylj3zngd51bwl91bl3r0000gp/T/confluent6704432109653647691",
+    "ksql.internal.topic.replicas" : "1",
+    "ksql.insert.into.values.enabled" : "true",
+    "ksql.query.pull.max.allowed.offset.lag" : "9223372036854775807",
+    "ksql.streams.default.production.exception.handler" : "io.confluent.ksql.errors.ProductionExceptionHandlerUtil$LogAndFailProductionExceptionHandler",
+    "ksql.access.validator.enable" : "auto",
+    "ksql.streams.bootstrap.servers" : "localhost:0",
+    "ksql.streams.commit.interval.ms" : "2000",
+    "ksql.metric.reporters" : "",
+    "ksql.streams.auto.commit.interval.ms" : "0",
+    "ksql.metrics.extension" : null,
+    "ksql.streams.topology.optimization" : "all",
+    "ksql.query.pull.streamsstore.rebalancing.timeout.ms" : "10000",
+    "ksql.hidden.topics" : "_confluent.*,__confluent.*,_schemas,__consumer_offsets,__transaction_state,connect-configs,connect-offsets,connect-status,connect-statuses",
+    "ksql.streams.num.stream.threads" : "4",
+    "ksql.timestamp.throw.on.invalid" : "false",
+    "ksql.authorization.cache.max.entries" : "10000",
+    "ksql.metrics.tags.custom" : "",
+    "ksql.pull.queries.enable" : "true",
+    "ksql.udfs.enabled" : "true",
+    "ksql.udf.enable.security.manager" : "true",
+    "ksql.connect.worker.config" : "",
+    "ksql.any.key.name.enabled" : "false",
+    "ksql.sink.window.change.log.additional.retention" : "1000000",
+    "ksql.readonly.topics" : "_confluent.*,__confluent.*,_schemas,__consumer_offsets,__transaction_state,connect-configs,connect-offsets,connect-status,connect-statuses",
+    "ksql.udf.collect.metrics" : "false",
+    "ksql.persistent.prefix" : "query_",
+    "ksql.query.persistent.active.limit" : "2147483647"
+  }
+}

ksql-functional-tests/src/test/resources/historical_plans/array_-_array_length_-_primitives/6.0.0_1583509764019/spec.json

@@ -0,0 +1,47 @@
+{
+  "version" : "6.0.0",
+  "timestamp" : 1583509764019,
+  "schemas" : {
+    "CSAS_OUTPUT_0.KsqlTopic.Source" : "STRUCT<BOOLEAN_ARRAY ARRAY<BOOLEAN>, INT_ARRAY ARRAY<INT>, BIGINT_ARRAY ARRAY<BIGINT>, DOUBLE_ARRAY ARRAY<DOUBLE>, STRING_ARRAY ARRAY<VARCHAR>, DECIMAL_ARRAY ARRAY<DECIMAL(2, 1)>> NOT NULL",
+    "CSAS_OUTPUT_0.OUTPUT" : "STRUCT<BOOLEAN_LEN INT, INT_LEN INT, BIGINT_LEN INT, DOUBLE_LEN INT, STRING_LEN INT, DECIMAL_LEN INT> NOT NULL"
+  },
+  "inputs" : [ {
+    "topic" : "test_topic",
+    "key" : "",
+    "value" : {
+      "boolean_array" : [ true ],
+      "int_array" : [ -1, 0 ],
+      "bigint_array" : [ -1, 0, 1 ],
+      "double_array" : [ 0.0, 0.1, 0.2, 0.3 ],
+      "string_array" : [ "a", "b", "c", "d", "e" ],
+      "decimal_array" : [ 1.0, 1.1, 1.2, 1.3, 1.4, 1.5 ]
+    }
+  }, {
+    "topic" : "test_topic",
+    "key" : "",
+    "value" : { }
+  } ],
+  "outputs" : [ {
+    "topic" : "OUTPUT",
+    "key" : "",
+    "value" : {
+      "BOOLEAN_LEN" : 1,
+      "INT_LEN" : 2,
+      "BIGINT_LEN" : 3,
+      "DOUBLE_LEN" : 4,
+      "STRING_LEN" : 5,
+      "DECIMAL_LEN" : 6
+    }
+  }, {
+    "topic" : "OUTPUT",
+    "key" : "",
+    "value" : {
+      "BOOLEAN_LEN" : 0,
+      "INT_LEN" : 0,
+      "BIGINT_LEN" : 0,
+      "DOUBLE_LEN" : 0,
+      "STRING_LEN" : 0,
+      "DECIMAL_LEN" : 0
+    }
+  } ]
+}

ksql-functional-tests/src/test/resources/historical_plans/array_-_array_length_-_primitives/6.0.0_1583509764019/topology

@@ -0,0 +1,13 @@
+Topologies:
+   Sub-topology: 0
+    Source: KSTREAM-SOURCE-0000000000 (topics: [test_topic])
+      --> KSTREAM-TRANSFORMVALUES-0000000001
+    Processor: KSTREAM-TRANSFORMVALUES-0000000001 (stores: [])
+      --> Project
+      <-- KSTREAM-SOURCE-0000000000
+    Processor: Project (stores: [])
+      --> KSTREAM-SINK-0000000003
+      <-- KSTREAM-TRANSFORMVALUES-0000000001
+    Sink: KSTREAM-SINK-0000000003 (topic: OUTPUT)
+      <-- Project
+