fix buffer length bug

src/de/mod.rs

@@ -1,4 +1,3 @@
-use std::cmp;
 use std::io::Read;
 use std::marker::PhantomData;
 
@@ -12,8 +11,6 @@ use self::read::BincodeRead;
 
 pub mod read;
 
-const BLOCK_SIZE: usize = 65536;
-
 /// A Deserializer that reads bytes from a buffer.
 ///
 /// This struct should rarely be used.
@@ -53,22 +50,9 @@ impl<'de, R: BincodeRead<'de>, E: ByteOrder, S: SizeLimit> Deserializer<R, S, E>
     }
 
     fn read_vec(&mut self) -> Result<Vec<u8>> {
-        let mut len: usize = try!(serde::Deserialize::deserialize(&mut *self));
-
-        let mut result = Vec::new();
-        let mut off = 0;
-        while len > 0 {
-            let reserve = cmp::min(len, BLOCK_SIZE);
-            try!(self.read_bytes(reserve as u64));
-            unsafe {
-                result.reserve(reserve);
-                result.set_len(off + reserve);
-            }
-            try!(self.reader.read_exact(&mut result[off..]));
-            len -= reserve;
-            off += reserve;
-        }
-        Ok(result)
+        let len: usize = try!(serde::Deserialize::deserialize(&mut *self));
+        self.read_bytes(len as u64)?;
+        self.reader.get_byte_buffer(len)
     }
 
     fn read_string(&mut self) -> Result<String> {

src/de/read.rs

@@ -9,6 +9,9 @@ pub trait BincodeRead<'storage>: IoRead {
     fn forward_read_str<V>(&mut self, length: usize, visitor: V) ->  Result<V::Value>
     where V: serde::de::Visitor<'storage>;
 
+    #[doc(hidden)]
+    fn get_byte_buffer(&mut self, length: usize) -> Result<Vec<u8>>;
+
     #[doc(hidden)]
     fn forward_read_bytes<V: serde::de::Visitor<'storage>>(&mut self, length: usize, visitor: V) ->  Result<V::Value>
     where V: serde::de::Visitor<'storage>;
@@ -74,6 +77,21 @@ impl <'storage> BincodeRead<'storage> for SliceReader<'storage> {
         self.slice = &self.slice[length..];
         r
     }
+
+    fn get_byte_buffer(&mut self, length: usize) -> Result<Vec<u8>> {
+        use ::ErrorKind;
+        if length > self.slice.len() {
+            return Err(Box::new(ErrorKind::InvalidEncoding {
+                            desc: "string was not valid utf8",
+                            detail: None,
+                        }));
+        }
+
+        let r = &self.slice[..length];
+        self.slice = &self.slice[length..];
+        Ok(r.to_vec())
+    }
+
     fn forward_read_bytes<V: serde::de::Visitor<'storage>>(&mut self, length: usize, visitor: V) ->  Result<V::Value> {
         use ::ErrorKind;
         if length > self.slice.len() {
@@ -106,10 +124,24 @@ impl <R> BincodeRead<'static> for IoReadReader<R> where R: IoRead {
         let r = visitor.visit_str(string);
         r
     }
+
+    fn get_byte_buffer(&mut self, length: usize) -> Result<Vec<u8>> {
+        let current_length = self.temp_buffer.len();
+        if length > current_length{
+            self.temp_buffer.reserve_exact(length - current_length);
+            unsafe { self.temp_buffer.set_len(length); }
+        }
+
+        self.reader.read_exact(&mut self.temp_buffer[..length])?;
+
+        Ok(self.temp_buffer[..length].to_vec())
+    }
+
     fn forward_read_bytes<V: serde::de::Visitor<'static>>(&mut self, length: usize, visitor: V) ->  Result<V::Value> {
         let current_length = self.temp_buffer.len();
         if length > current_length{
             self.temp_buffer.reserve_exact(length - current_length);
+            unsafe { self.temp_buffer.set_len(length); }
         }
 
         self.reader.read_exact(&mut self.temp_buffer[..length])?;