Merge pull request #211 from knight42/copy_to

Add Response::copy_to

.travis.yml

@@ -32,4 +32,4 @@ cache:
 
 script:
   - cargo build $FEATURES
-  - cargo test $FEATURES
+  - cargo test -v $FEATURES

src/response.rs

@@ -165,6 +165,32 @@ impl Response {
         serde_json::from_reader(self).map_err(::error::from)
     }
 
+    /// Copy the response body into a writer.
+    ///
+    /// This function internally uses [`std::io::copy`] and hence will continuously read data from
+    /// the body and then write it into writer in a streaming fashion until EOF is met.
+    ///
+    /// On success, the total number of bytes that were copied to `writer` is returned.
+    /// [`std::io::copy`]: https://doc.rust-lang.org/std/io/fn.copy.html
+    ///
+    /// # Example
+    ///
+    /// ```rust
+    /// # fn run() -> Result<(), Box<::std::error::Error>> {
+    /// let mut resp = reqwest::get("http://httpbin.org/range/5")?;
+    /// let mut buf: Vec<u8> = vec![];
+    /// resp.copy_to(&mut buf)?;
+    /// assert_eq!(b"abcde", buf.as_slice());
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline]
+    pub fn copy_to<W: ?Sized>(&mut self, w: &mut W) -> io::Result<u64>
+        where W: io::Write
+    {
+        io::copy(self, w)
+    }
+
     /// Turn a response into an error if the server returned an error.
     ///
     /// # Example

tests/client.rs

@@ -5,6 +5,40 @@ mod support;
 
 use std::io::Read;
 
+#[test]
+fn test_response_copy_to() {
+    let server = server! {
+        request: b"\
+            GET /1 HTTP/1.1\r\n\
+            Host: $HOST\r\n\
+            User-Agent: $USERAGENT\r\n\
+            Accept: */*\r\n\
+            Accept-Encoding: gzip\r\n\
+            \r\n\
+            ",
+        response: b"\
+            HTTP/1.1 200 OK\r\n\
+            Server: test\r\n\
+            Content-Length: 5\r\n\
+            \r\n\
+            Hello\
+            "
+    };
+
+    let url = format!("http://{}/1", server.addr());
+    let mut res = reqwest::get(&url).unwrap();
+    assert_eq!(res.url().as_str(), &url);
+    assert_eq!(res.status(), reqwest::StatusCode::Ok);
+    assert_eq!(res.headers().get(),
+               Some(&reqwest::header::Server::new("test".to_string())));
+    assert_eq!(res.headers().get(),
+               Some(&reqwest::header::ContentLength(5)));
+
+    let mut buf: Vec<u8> = vec![];
+    res.copy_to(&mut buf).unwrap();
+    assert_eq!(b"Hello", buf.as_slice());
+}
+
 #[test]
 fn test_get() {
     let server = server! {