@@ -27,47 +27,25 @@
 
 type context struct {
 	table [256]byte
 }
 
-// Returns an MTF encoder over the provided io.Writer
-func Encoder(writer io.Writer) io.Writer {
-	var enc encoder
-	enc.table = initial
-	enc.target = writer
-	return &enc
-}
-
-type encoder struct {
-	context
-	target io.Writer
-}
-
-func (c *encoder) Write(data []byte) (int, error) {
-	var (
-		dataLength int    = len(data)
-		buffer     []byte = make([]byte, dataLength)
-	)
-
-	// io.Write must not modify the passed data in any way
-	// TODO - check sync.Pool or a local free-list for amortizing buffers
-	// TODO - use a buffer with a fixed max size to avoid OOM conditions
-
-	// Loop over the input data
+// Encodes data in place
+func (c *context) encode(data []byte) {
 	for index, value := range data {
 
 		// Shortcut for sequential, equal values
 		if c.table[0] == value {
-			buffer[index] = 0
+			data[index] = 0
 			continue
 		}
 
 		// Loop over the MTF table
 		for j := byte(1); j != 0; j++ {
 			if c.table[j] == value {
 				// Output the value
-				buffer[index] = j
+				data[index] = j
 
 				// Shift the table
 				copy(c.table[1:], c.table[:j])
 
 				// Restore the value in front and break
@@ -74,15 +52,54 @@
 				c.table[0] = value
 				break
 			}
 		}
 	}
+}
+
+// Decode data in place
+func (c *context) decode(data []byte) {
+	for index, value := range data {
+		position := value
+
+		// Shortcut for sequential, equal values
+		if position == 0 {
+			data[index] = c.table[0]
+			continue
+		}
+
+		// Output the value
+		data[index] = c.table[position]
+
+		// Shift the table and restore the value in front
+		copy(c.table[1:], c.table[:position])
+		c.table[0] = data[index]
+	}
+}
+
+// Returns an MTF encoder over the provided io.Reader
+func Encoder(reader io.Reader) io.Reader {
+	var enc encoder
+	enc.table = initial
+	enc.source = reader
+	return &enc
+}
+
+type encoder struct {
+	context
+	source io.Reader
+}
+
+// Read and encode data in place
+func (c *encoder) Read(output []byte) (count int, err error) {
+	count, err = c.source.Read(output)
+	c.encode(output[:count])
 
-	return c.target.Write(buffer)
+	return count, err
 }
 
-// Returns an MTF decoder over the provided io.Writer
+// Returns an MTF decoder over the provided io.Reader
 func Decoder(reader io.Reader) io.Reader {
 	var dec decoder
 	dec.table = initial
 	dec.source = reader
 	return &dec
@@ -91,33 +108,12 @@
 type decoder struct {
 	context
 	source io.Reader
 }
 
-func (c *decoder) Read(output []byte) (int, error) {
-	var (
-		count    int
-		err      error
-		position byte
-	)
-
-	// Read from the source and decode in place
+// Read and decode data in place
+func (c *decoder) Read(output []byte) (count int, err error) {
 	count, err = c.source.Read(output)
-	for i := 0; i < count; i++ {
-		position = output[i]
-
-		// Shortcut for sequential, equal values
-		if position == 0 {
-			output[i] = c.table[0]
-			continue
-		}
-
-		// Output the value
-		output[i] = c.table[position]
-
-		// Shift the table and restore the value in front
-		copy(c.table[1:], c.table[:position])
-		c.table[0] = output[i]
-	}
+	c.decode(output[:count])
 
 	return count, err
 }