Merge pull request #29 from petrosagg/reuse-allocation

postgres-replication: reuse underlying allocation for tuple data

Author: petrosagg

postgres-replication/src/protocol.rs

@@ -442,9 +442,8 @@ impl TupleData {
             TUPLE_DATA_TOAST_TAG => TupleData::UnchangedToast,
             TUPLE_DATA_TEXT_TAG => {
                 let len = buf.read_i32::<BigEndian>()?;
-                let mut data = vec![0; len as usize];
-                buf.read_exact(&mut data)?;
-                TupleData::Text(data.into())
+                let data = buf.read_buf(len as usize)?;
+                TupleData::Text(data)
             }
             TUPLE_DATA_BINARY_TAG => {
                 let len = buf.read_i32::<BigEndian>()?;
@@ -778,6 +777,20 @@ impl Buffer {
         self.idx = self.bytes.len();
         buf
     }
+
+    #[inline]
+    fn read_buf(&mut self, len: usize) -> io::Result<Bytes> {
+        if self.idx + len <= self.bytes.len() {
+            let buf = self.bytes.slice(self.idx..(self.idx + len));
+            self.idx += len;
+            Ok(buf)
+        } else {
+            Err(io::Error::new(
+                io::ErrorKind::UnexpectedEof,
+                "unexpected EOF",
+            ))
+        }
+    }
 }
 
 impl Read for Buffer {