Added AvroBinaryWriter

centurion-avro/src/main/kotlin/com/sksamuel/centurion/avro/io/AvroWriter.kt

@@ -0,0 +1,55 @@
+package com.sksamuel.centurion.avro.io
+
+import org.apache.avro.Schema
+import org.apache.avro.generic.GenericDatumWriter
+import org.apache.avro.generic.GenericRecord
+import org.apache.avro.io.DatumWriter
+import org.apache.avro.io.EncoderFactory
+import java.io.OutputStream
+
+///**
+// * An [AvroWriter] will write [GenericRecord]s to an output stream.
+// *
+// * There are three implementations of this stream
+// *  - a Data stream,
+// *  - a Binary stream
+// *  - a Json stream
+// *
+// * See the methods on the companion object to create instances of each
+// * of these types of stream.
+// */
+
+/**
+ * Creates an [AvroBinaryWriterFactory] for a given schema which can then be used
+ * to create [AvroBinaryWriter]s. These writers share a thread safe [DatumWriter].
+ */
+class AvroBinaryWriterFactory(schema: Schema, private val factory: EncoderFactory) {
+   constructor(schema: Schema) : this(schema, EncoderFactory.get())
+
+   private val datumWriter = GenericDatumWriter<GenericRecord>(schema)
+   fun writer(output: OutputStream): AvroBinaryWriter {
+      return AvroBinaryWriter(datumWriter, output, factory)
+   }
+}
+
+class AvroBinaryWriter(
+   private val datumWriter: DatumWriter<GenericRecord>,
+   private val output: OutputStream,
+   private val factory: EncoderFactory,
+) : AutoCloseable {
+
+   private val encoder = factory.binaryEncoder(output, null)
+
+   fun write(record: GenericRecord) {
+      datumWriter.write(record, encoder)
+   }
+
+   fun flush() {
+      encoder.flush()
+   }
+
+   override fun close() {
+      flush()
+      output.close()
+   }
+}