compressing streams

src/main/kotlin/de/gmuth/ipp/attributes/Compression.kt

@@ -8,8 +8,14 @@ import de.gmuth.ipp.core.IppAttribute
 import de.gmuth.ipp.core.IppAttributeBuilder
 import de.gmuth.ipp.core.IppAttributesGroup
 import de.gmuth.ipp.core.IppTag.Keyword
+import java.io.InputStream
+import java.io.OutputStream
+import java.util.zip.DeflaterInputStream
+import java.util.zip.DeflaterOutputStream
+import java.util.zip.GZIPInputStream
+import java.util.zip.GZIPOutputStream
 
-enum class Compression(private val keyword: String) : IppAttributeBuilder {
+enum class Compression(val keyword: String) : IppAttributeBuilder {
 
     COMPRESS("compress"), // RFC 1977
     DEFLATE("deflate"), // RFC 1951
@@ -23,4 +29,19 @@ enum class Compression(private val keyword: String) : IppAttributeBuilder {
         fun fromString(string: String) =
             Compression.values().single { it.keyword == string }
     }
+
+    fun getCompressingOutputStream(outputStream: OutputStream) = when (this) {
+        NONE -> outputStream
+        GZIP -> GZIPOutputStream(outputStream)
+        DEFLATE -> DeflaterOutputStream(outputStream)
+        else -> throw NotImplementedError("compression '$this'")
+    }
+
+    fun getUncompressingInputStream(inputStream: InputStream) = when (this) {
+        NONE -> inputStream
+        GZIP -> GZIPInputStream(inputStream)
+        DEFLATE -> DeflaterInputStream(inputStream)
+        else -> throw NotImplementedError("compression '$this'")
+        // Apache ZCompressorInputStream?
+    }
 }