finagle-mysql: Make it easier to use a ctu.Time with PreparedStatements

Problem

To use a ctu.Time with a PreparedStatement, the Time must be converted to a
java.sql.Timestamp.

Solution

Add an implicit so one does not need to explicitly do the conversion.

JIRA Issues: CSL-6011

Differential Revision: https://phabricator.twitter.biz/D182973

Author: Stefan Lance

CHANGES

@@ -10,6 +10,10 @@ Unreleased
 New Features
 ~~~~~~~~~~~~
 
+  * finagle-mysql: `com.twitter.util.Time` can now be used with
+    `PreparedStatement`s without converting the `ctu.Time` to a `java.sql.Timestamp`.
+    ``PHAB_ID=D182973``
+
   * finagle-stats: Adds a lint rule to detect when metrics with colliding names are used.
     ``PHAB_ID=D183494``
 

finagle-mysql/src/main/scala/com/twitter/finagle/mysql/CanBeParameter.scala

@@ -300,6 +300,18 @@ object CanBeParameter {
     }
   }
 
+  // Note that Timestamp is UTC only and includes both Date and Time parts.
+  // See https://dev.mysql.com/doc/refman/8.0/en/datetime.html.
+  implicit val ctuTimeCanBeParameter: CanBeParameter[com.twitter.util.Time] = {
+    new CanBeParameter[com.twitter.util.Time] {
+      def sizeOf(param: com.twitter.util.Time): Int = 12
+      def typeCode(param: com.twitter.util.Time): Short = Type.Timestamp
+      def write(writer: MysqlBufWriter, param: com.twitter.util.Time): Unit = {
+        valueCanBeParameter.write(writer, TimestampValue(new java.sql.Timestamp(param.inMillis)))
+      }
+    }
+  }
+
   implicit val nullCanBeParameter: CanBeParameter[Null] = {
     new CanBeParameter[Null] {
       def sizeOf(param: Null): Int = 0

finagle-mysql/src/test/scala/com/twitter/finagle/mysql/ParameterTest.scala

@@ -135,6 +135,12 @@ class ParameterTest extends FunSuite {
     assert(param.value == value)
   }
 
+  test("com.twitter.util.Time") {
+    val value = com.twitter.util.Time.fromMilliseconds(3L)
+    val param: Parameter = value
+    assert(param.value == value)
+  }
+
   test("null") {
     val value: String = null
     val param: Parameter = value