add deserialize_in_place

Cargo.toml

@@ -18,9 +18,9 @@ description = "A binary serialization / deserialization strategy that uses Serde
 
 [dependencies]
 byteorder = "1.2.0"
-serde = "1.0.16"
+serde = "1.0.27"
 
 [dev-dependencies]
-serde_bytes = "0.10.*"
-serde_derive = "1.0.16"
+serde_bytes = "0.10.3"
+serde_derive = "1.0.27"
 

src/config.rs

@@ -255,6 +255,13 @@ impl Config {
         config_map!(self, opts => ::internal::deserialize(bytes, opts))
     }
 
+    /// TODO: document
+    #[doc(hidden)]
+    #[inline(always)]
+    pub fn deserialize_in_place<'a, T: serde::de::Deserialize<'a>>(&self, reader: &'a [u8], place: &mut T) -> Result<()> {
+        config_map!(self, opts => ::internal::deserialize_in_place(reader, opts, place))
+    }
+
     /// Deserializes an object directly from a `Read`er using this configuration
     ///
     /// If this returns an `Error`, `reader` may be in an invalid state.

src/internal.rs

@@ -93,6 +93,21 @@ where
     serde::Deserialize::deserialize(&mut deserializer)
 }
 
+pub(crate) fn deserialize_in_place<'a, T, O>(
+    bytes: &'a [u8],
+    options: O,
+    place: &mut T,
+) -> Result<()>
+where
+    T: serde::de::Deserialize<'a>,
+    O: Options,
+{
+    let reader = ::de::read::SliceReader::new(bytes);
+    let options = ::config::WithOtherLimit::new(options, Infinite);
+    let mut deserializer = ::de::Deserializer::<_, _>::new(reader, options);
+    serde::Deserialize::deserialize_in_place(&mut deserializer, place)
+}
+
 pub(crate) fn deserialize<'a, T, O>(bytes: &'a [u8], options: O) -> Result<T>
 where
     T: serde::de::Deserialize<'a>,

src/lib.rs

@@ -112,6 +112,15 @@ where
     config().deserialize_from_custom(reader)
 }
 
+/// TODO: document
+#[doc(hidden)]
+pub fn deserialize_in_place<'a, T>(bytes: &'a[u8], place: &mut T) -> Result<()>
+where
+    T: serde::de::Deserialize<'a>,
+{
+    config().deserialize_in_place(bytes, place)
+}
+
 /// Deserializes a slice of bytes into an instance of `T` using the default configuration.
 pub fn deserialize<'a, T>(bytes: &'a [u8]) -> Result<T>
 where

tests/test.rs

@@ -10,7 +10,8 @@ use std::fmt::Debug;
 use std::collections::HashMap;
 use std::borrow::Cow;
 
-use bincode::{config, deserialize, deserialize_from, serialize, serialized_size, ErrorKind, Result};
+use bincode::{config, deserialize, deserialize_from, deserialize_in_place, serialize,
+              serialized_size, ErrorKind, Result};
 
 fn the_same<V>(element: V)
 where
@@ -315,7 +316,9 @@ fn test_serialized_size_bounded() {
     assert!(
         config()
             .limit(8 + 3 * 4 - 1)
-            .serialized_size(&vec![0u32, 1u32, 2u32]).is_err());
+            .serialized_size(&vec![0u32, 1u32, 2u32])
+            .is_err()
+    );
 }
 
 #[test]
@@ -461,11 +464,38 @@ fn test_zero_copy_parse() {
     }
 }
 
+#[test]
+fn test_zero_copy_parse_deserialize_into() {
+    #[derive(Serialize, Deserialize, Eq, PartialEq, Debug)]
+    struct Foo<'a> {
+        borrowed_str: &'a str,
+        borrowed_bytes: &'a [u8],
+    }
+
+    let f = Foo {
+        borrowed_str: "hi",
+        borrowed_bytes: &[0, 1, 2, 3],
+    };
+
+    {
+        let encoded = serialize(&f).unwrap();
+        let mut target = Foo {
+            borrowed_str: "hello",
+            borrowed_bytes: &[10, 11, 12, 13],
+        };
+        deserialize_in_place(&encoded[..], &mut target).unwrap();
+        assert_eq!(target, f);
+    }
+}
+
 #[test]
 fn not_human_readable() {
     use std::net::Ipv4Addr;
     let ip = Ipv4Addr::new(1, 2, 3, 4);
     the_same(ip);
     assert_eq!(&ip.octets()[..], &serialize(&ip).unwrap()[..]);
-    assert_eq!(::std::mem::size_of::<Ipv4Addr>() as u64, serialized_size(&ip).unwrap());
+    assert_eq!(
+        ::std::mem::size_of::<Ipv4Addr>() as u64,
+        serialized_size(&ip).unwrap()
+    );
 }