feat: add PARSE_TIME and FORMAT_TIME functions

docs/developer-guide/ksqldb-reference/scalar-functions.md

@@ -1199,6 +1199,33 @@ TIMEZONE is an optional parameter and it is a `java.util.TimeZone` ID format, fo
 "America/Los_Angeles", "PDT", "Europe/London". For more information on timestamp formats, see
 [DateTimeFormatter](https://cnfl.io/java-dtf).
 
+### `FORMAT_TIME`
+
+Since: 0.20
+
+```sql
+FORMAT_TIME(time, 'HH:mm:ss.SSS')
+```
+
+Converts a TIME value into the string representation of the time in the given format.
+Single quotes in the time format can be escaped with two successive single quotes, `''`, for
+example: `'''T''HH:mm:ssX'`.
+
+For more information on time formats, see [DateTimeFormatter](https://cnfl.io/java-dtf).
+
+### `PARSE_TIME`
+
+Since: 0.20
+
+```sql
+PARSE_TIME(col1, 'HH:mm:ss.SSS')
+```
+
+Converts a string value in the given format into a TIME value. Single quotes in the time
+format can be escaped with two successive single quotes, `''`, for example: `'''T''HH:mm:ssX'`.
+
+For more information on time formats, see [DateTimeFormatter](https://cnfl.io/java-dtf).
+
 ### `CONVERT_TZ`
 
 ```sql

ksqldb-common/src/main/java/io/confluent/ksql/function/types/ParamTypes.java

@@ -156,6 +156,8 @@ private static boolean isPrimitiveMatch(
         || base == SqlBaseType.BOOLEAN  && declared instanceof BooleanType
         || base == SqlBaseType.DOUBLE   && declared instanceof DoubleType
         || base == SqlBaseType.DECIMAL  && declared instanceof DecimalType
+        || base == SqlBaseType.TIME  && declared instanceof TimeType
+        || base == SqlBaseType.DATE  && declared instanceof DateType
         || base == SqlBaseType.TIMESTAMP  && declared instanceof TimestampType
         || allowCast && base.canImplicitlyCast(functionToSqlBaseConverter().toBaseType(declared));
     // CHECKSTYLE_RULES.ON: BooleanExpressionComplexity

ksqldb-engine/src/main/java/io/confluent/ksql/function/UdafTypes.java

@@ -30,6 +30,7 @@
 import java.lang.reflect.Type;
 import java.lang.reflect.TypeVariable;
 import java.math.BigDecimal;
+import java.sql.Time;
 import java.sql.Timestamp;
 import java.util.List;
 import java.util.Map;
@@ -56,6 +57,7 @@ class UdafTypes {
       .add(Struct.class)
       .add(List.class)
       .add(Map.class)
+      .add(Time.class)
       .add(Timestamp.class)
       .add(TimeUnit.class)
       .add(Function.class)

ksqldb-engine/src/main/java/io/confluent/ksql/function/udf/datetime/FormatTime.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2021 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.datetime;
+
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
+import io.confluent.ksql.function.FunctionCategory;
+import io.confluent.ksql.function.KsqlFunctionException;
+import io.confluent.ksql.function.udf.Udf;
+import io.confluent.ksql.function.udf.UdfDescription;
+import io.confluent.ksql.function.udf.UdfParameter;
+import io.confluent.ksql.util.KsqlConstants;
+import java.sql.Time;
+import java.time.LocalTime;
+import java.time.format.DateTimeFormatter;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+
+@UdfDescription(
+    name = "format_time",
+    category = FunctionCategory.DATE_TIME,
+    author = KsqlConstants.CONFLUENT_AUTHOR,
+    description = "Converts a TIME value into the string representation of the time"
+        + " in the given format."
+)
+public class FormatTime {
+
+  private final LoadingCache<String, DateTimeFormatter> formatters =
+      CacheBuilder.newBuilder()
+          .maximumSize(1000)
+          .build(CacheLoader.from(DateTimeFormatter::ofPattern));
+
+  @Udf(description = "Converts a TIME value into the"
+      + " string representation of the time in the given format."
+      + " The format pattern should be in the format expected"
+      + " by java.time.format.DateTimeFormatter")
+  public String formatTime(
+      @UdfParameter(
+          description = "TIME value.") final Time time,
+      @UdfParameter(
+          description = "The format pattern should be in the format expected by"
+              + " java.time.format.DateTimeFormatter.") final String formatPattern) {
+    if (time == null) {
+      return null;
+    }
+    try {
+      final DateTimeFormatter formatter = formatters.get(formatPattern);
+      return LocalTime.ofNanoOfDay(TimeUnit.MILLISECONDS.toNanos(time.getTime())).format(formatter);
+    } catch (ExecutionException | RuntimeException e) {
+      throw new KsqlFunctionException("Failed to format time "
+          + LocalTime.ofNanoOfDay(time.getTime() * 1000000)
+          + " with formatter '" + formatPattern
+          + "': " + e.getMessage(), e);
+    }
+  }
+}

ksqldb-engine/src/main/java/io/confluent/ksql/function/udf/datetime/ParseTime.java

@@ -0,0 +1,77 @@
+/*
+ * 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.datetime;
+
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
+import io.confluent.ksql.function.FunctionCategory;
+import io.confluent.ksql.function.KsqlFunctionException;
+import io.confluent.ksql.function.udf.Udf;
+import io.confluent.ksql.function.udf.UdfDescription;
+import io.confluent.ksql.function.udf.UdfParameter;
+import io.confluent.ksql.util.KsqlConstants;
+import java.sql.Time;
+import java.time.LocalTime;
+import java.time.format.DateTimeFormatter;
+import java.time.temporal.ChronoField;
+import java.time.temporal.TemporalAccessor;
+import java.util.Arrays;
+import java.util.Optional;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+
+@UdfDescription(
+    name = "parse_time",
+    category = FunctionCategory.DATE_TIME,
+    author = KsqlConstants.CONFLUENT_AUTHOR,
+    description = "Converts a string representation of a time in the given format"
+        + " into a TIME value."
+)
+public class ParseTime {
+
+  private final LoadingCache<String, DateTimeFormatter> formatters =
+      CacheBuilder.newBuilder()
+          .maximumSize(1000)
+          .build(CacheLoader.from(DateTimeFormatter::ofPattern));
+
+  @Udf(description = "Converts a string representation of a time in the given format"
+      + " into the TIME value.")
+  public Time parseTime(
+      @UdfParameter(
+          description = "The string representation of a time.") final String formattedTime,
+      @UdfParameter(
+          description = "The format pattern should be in the format expected by"
+              + " java.time.format.DateTimeFormatter.") final String formatPattern) {
+    try {
+      final TemporalAccessor ta = formatters.get(formatPattern).parse(formattedTime);
+      final Optional<ChronoField> dateField = Arrays.stream(ChronoField.values())
+          .filter(field -> field.isDateBased())
+          .filter(field -> ta.isSupported(field))
+          .findFirst();
+
+      if (dateField.isPresent()) {
+        throw new KsqlFunctionException("Time format contains date field.");
+      }
+
+      return new Time(TimeUnit.NANOSECONDS.toMillis(LocalTime.from(ta).toNanoOfDay()));
+    } catch (ExecutionException | RuntimeException e) {
+      throw new KsqlFunctionException("Failed to parse time '" + formattedTime
+          + "' with formatter '" + formatPattern
+          + "': " + e.getMessage(), e);
+    }
+  }
+}

ksqldb-engine/src/test/java/io/confluent/ksql/function/udf/datetime/FormatTimeTest.java

@@ -0,0 +1,104 @@
+/*
+ * Copyright 2021 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.datetime;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.containsString;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertThrows;
+import static org.junit.Assert.fail;
+
+import io.confluent.ksql.function.KsqlFunctionException;
+import java.sql.Time;
+import java.util.stream.IntStream;
+import org.junit.Before;
+import org.junit.Test;
+
+public class FormatTimeTest {
+
+  private FormatTime udf;
+
+  @Before
+  public void setUp() {
+    udf = new FormatTime();
+  }
+
+  @Test
+  public void shouldConvertTimeToString() {
+    // When:
+    final String result = udf.formatTime(new Time(65000), "HHmmss");
+
+    // Then:
+    assertThat(result, is("000105"));
+  }
+
+  @Test
+  public void shouldRejectUnsupportedFields() {
+    // When:
+    final Exception e = assertThrows(
+        KsqlFunctionException.class,
+        () -> udf.formatTime(new Time(65000), "yyyy HHmmss"));
+
+    // Then:
+    assertThat(e.getMessage(), is("Failed to format time 00:01:05 with formatter 'yyyy HHmmss': Unsupported field: YearOfEra"));
+  }
+
+  @Test
+  public void shouldSupportEmbeddedChars() {
+    // When:
+    final Object result = udf.formatTime(new Time(65000), "HH:mm:ss.SSS'Fred'");
+
+    // Then:
+    assertThat(result, is("00:01:05.000Fred"));
+  }
+
+  @Test
+  public void shouldThrowIfFormatInvalid() {
+    // When:
+    final Exception e = assertThrows(
+        KsqlFunctionException.class,
+        () -> udf.formatTime(new Time(65000), "invalid")
+    );
+
+    // Then:
+    assertThat(e.getMessage(), containsString("Failed to format time 00:01:05 with formatter 'invalid'"));
+  }
+
+  @Test
+  public void shouldByThreadSafeAndWorkWithManyDifferentFormatters() {
+    IntStream.range(0, 10_000)
+        .parallel()
+        .forEach(idx -> {
+          try {
+            final String pattern = "HH:mm:ss'X" + idx + "'";
+            final String result = udf.formatTime(new Time(65000), pattern);
+            assertThat(result, is("00:01:05X" + idx));
+          } catch (final Exception e) {
+            fail(e.getMessage());
+          }
+        });
+  }
+
+  @Test
+  public void shoudlReturnNull() {
+    // When:
+    final Object result = udf.formatTime(null, "HH:mm:ss.SSS");
+
+    // Then:
+    assertNull(result);
+  }
+}