move payload futures from actix-http

Cargo.toml

@@ -81,7 +81,7 @@ mime = "0.3"
 net2 = "0.2.33"
 parking_lot = "0.7"
 regex = "1.0"
-serde = "1.0"
+serde = { version = "1.0", features=["derive"] }
 serde_json = "1.0"
 serde_urlencoded = "^0.5.3"
 time = "0.1"

src/error.rs

@@ -3,8 +3,12 @@ use std::fmt;
 
 pub use actix_http::error::*;
 use derive_more::{Display, From};
+use serde_json::error::Error as JsonError;
 use url::ParseError as UrlParseError;
 
+use crate::http::StatusCode;
+use crate::HttpResponse;
+
 /// Errors which can occur when attempting to generate resource uri.
 #[derive(Debug, PartialEq, Display, From)]
 pub enum UrlGenerationError {
@@ -41,3 +45,100 @@ impl<E: fmt::Debug> From<actix_rt::blocking::BlockingError<E>> for BlockingError
         }
     }
 }
+
+/// A set of errors that can occur during parsing urlencoded payloads
+#[derive(Debug, Display, From)]
+pub enum UrlencodedError {
+    /// Can not decode chunked transfer encoding
+    #[display(fmt = "Can not decode chunked transfer encoding")]
+    Chunked,
+    /// Payload size is bigger than allowed. (default: 256kB)
+    #[display(fmt = "Urlencoded payload size is bigger than allowed. (default: 256kB)")]
+    Overflow,
+    /// Payload size is now known
+    #[display(fmt = "Payload size is now known")]
+    UnknownLength,
+    /// Content type error
+    #[display(fmt = "Content type error")]
+    ContentType,
+    /// Parse error
+    #[display(fmt = "Parse error")]
+    Parse,
+    /// Payload error
+    #[display(fmt = "Error that occur during reading payload: {}", _0)]
+    Payload(PayloadError),
+}
+
+/// Return `BadRequest` for `UrlencodedError`
+impl ResponseError for UrlencodedError {
+    fn error_response(&self) -> HttpResponse {
+        match *self {
+            UrlencodedError::Overflow => {
+                HttpResponse::new(StatusCode::PAYLOAD_TOO_LARGE)
+            }
+            UrlencodedError::UnknownLength => {
+                HttpResponse::new(StatusCode::LENGTH_REQUIRED)
+            }
+            _ => HttpResponse::new(StatusCode::BAD_REQUEST),
+        }
+    }
+}
+
+/// A set of errors that can occur during parsing json payloads
+#[derive(Debug, Display, From)]
+pub enum JsonPayloadError {
+    /// Payload size is bigger than allowed. (default: 256kB)
+    #[display(fmt = "Json payload size is bigger than allowed. (default: 256kB)")]
+    Overflow,
+    /// Content type error
+    #[display(fmt = "Content type error")]
+    ContentType,
+    /// Deserialize error
+    #[display(fmt = "Json deserialize error: {}", _0)]
+    Deserialize(JsonError),
+    /// Payload error
+    #[display(fmt = "Error that occur during reading payload: {}", _0)]
+    Payload(PayloadError),
+}
+
+/// Return `BadRequest` for `UrlencodedError`
+impl ResponseError for JsonPayloadError {
+    fn error_response(&self) -> HttpResponse {
+        match *self {
+            JsonPayloadError::Overflow => {
+                HttpResponse::new(StatusCode::PAYLOAD_TOO_LARGE)
+            }
+            _ => HttpResponse::new(StatusCode::BAD_REQUEST),
+        }
+    }
+}
+
+/// Error type returned when reading body as lines.
+#[derive(From, Display, Debug)]
+pub enum ReadlinesError {
+    /// Error when decoding a line.
+    #[display(fmt = "Encoding error")]
+    /// Payload size is bigger than allowed. (default: 256kB)
+    EncodingError,
+    /// Payload error.
+    #[display(fmt = "Error that occur during reading payload: {}", _0)]
+    Payload(PayloadError),
+    /// Line limit exceeded.
+    #[display(fmt = "Line limit exceeded")]
+    LimitOverflow,
+    /// ContentType error.
+    #[display(fmt = "Content-type error")]
+    ContentTypeError(ContentTypeError),
+}
+
+/// Return `BadRequest` for `ReadlinesError`
+impl ResponseError for ReadlinesError {
+    fn error_response(&self) -> HttpResponse {
+        match *self {
+            ReadlinesError::LimitOverflow => {
+                HttpResponse::new(StatusCode::PAYLOAD_TOO_LARGE)
+            }
+            _ => HttpResponse::new(StatusCode::BAD_REQUEST),
+        }
+    }
+}

src/lib.rs

@@ -58,7 +58,10 @@ pub mod dev {
     pub use crate::service::{
         HttpServiceFactory, ServiceFromRequest, ServiceRequest, ServiceResponse,
     };
+    pub use crate::types::form::UrlEncoded;
     pub use crate::types::json::JsonBody;
+    pub use crate::types::payload::HttpMessageBody;
+    pub use crate::types::readlines::Readlines;
 
     pub use actix_http::body::{Body, BodyLength, MessageBody, ResponseBody};
     pub use actix_http::dev::ResponseBuilder as HttpResponseBuilder;

src/types/form.rs

@@ -3,13 +3,17 @@
 use std::rc::Rc;
 use std::{fmt, ops};
 
-use actix_http::dev::UrlEncoded;
+use actix_http::error::{Error, PayloadError, UrlencodedError};
-use actix_http::error::{Error, UrlencodedError};
+use actix_http::{HttpMessage, Payload};
-use bytes::Bytes;
+use bytes::{Bytes, BytesMut};
-use futures::{Future, Stream};
+use encoding::all::UTF_8;
+use encoding::types::{DecoderTrap, Encoding};
+use encoding::EncodingRef;
+use futures::{Future, Poll, Stream};
 use serde::de::DeserializeOwned;
 
 use crate::extract::FromRequest;
+use crate::http::header::CONTENT_LENGTH;
 use crate::request::HttpRequest;
 use crate::service::ServiceFromRequest;
 
@@ -167,13 +171,145 @@ impl Default for FormConfig {
     }
 }
 
+/// Future that resolves to a parsed urlencoded values.
+///
+/// Parse `application/x-www-form-urlencoded` encoded request's body.
+/// Return `UrlEncoded` future. Form can be deserialized to any type that
+/// implements `Deserialize` trait from *serde*.
+///
+/// Returns error:
+///
+/// * content type is not `application/x-www-form-urlencoded`
+/// * content-length is greater than 32k
+///
+pub struct UrlEncoded<T: HttpMessage, U> {
+    stream: Payload<T::Stream>,
+    limit: usize,
+    length: Option<usize>,
+    encoding: EncodingRef,
+    err: Option<UrlencodedError>,
+    fut: Option<Box<Future<Item = U, Error = UrlencodedError>>>,
+}
+
+impl<T, U> UrlEncoded<T, U>
+where
+    T: HttpMessage,
+    T::Stream: Stream<Item = Bytes, Error = PayloadError>,
+{
+    /// Create a new future to URL encode a request
+    pub fn new(req: &mut T) -> UrlEncoded<T, U> {
+        // check content type
+        if req.content_type().to_lowercase() != "application/x-www-form-urlencoded" {
+            return Self::err(UrlencodedError::ContentType);
+        }
+        let encoding = match req.encoding() {
+            Ok(enc) => enc,
+            Err(_) => return Self::err(UrlencodedError::ContentType),
+        };
+
+        let mut len = None;
+        if let Some(l) = req.headers().get(CONTENT_LENGTH) {
+            if let Ok(s) = l.to_str() {
+                if let Ok(l) = s.parse::<usize>() {
+                    len = Some(l)
+                } else {
+                    return Self::err(UrlencodedError::UnknownLength);
+                }
+            } else {
+                return Self::err(UrlencodedError::UnknownLength);
+            }
+        };
+
+        UrlEncoded {
+            encoding,
+            stream: req.take_payload(),
+            limit: 32_768,
+            length: len,
+            fut: None,
+            err: None,
+        }
+    }
+
+    fn err(e: UrlencodedError) -> Self {
+        UrlEncoded {
+            stream: Payload::None,
+            limit: 32_768,
+            fut: None,
+            err: Some(e),
+            length: None,
+            encoding: UTF_8,
+        }
+    }
+
+    /// Change max size of payload. By default max size is 256Kb
+    pub fn limit(mut self, limit: usize) -> Self {
+        self.limit = limit;
+        self
+    }
+}
+
+impl<T, U> Future for UrlEncoded<T, U>
+where
+    T: HttpMessage,
+    T::Stream: Stream<Item = Bytes, Error = PayloadError> + 'static,
+    U: DeserializeOwned + 'static,
+{
+    type Item = U;
+    type Error = UrlencodedError;
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+        if let Some(ref mut fut) = self.fut {
+            return fut.poll();
+        }
+
+        if let Some(err) = self.err.take() {
+            return Err(err);
+        }
+
+        // payload size
+        let limit = self.limit;
+        if let Some(len) = self.length.take() {
+            if len > limit {
+                return Err(UrlencodedError::Overflow);
+            }
+        }
+
+        // future
+        let encoding = self.encoding;
+        let fut = std::mem::replace(&mut self.stream, Payload::None)
+            .from_err()
+            .fold(BytesMut::with_capacity(8192), move |mut body, chunk| {
+                if (body.len() + chunk.len()) > limit {
+                    Err(UrlencodedError::Overflow)
+                } else {
+                    body.extend_from_slice(&chunk);
+                    Ok(body)
+                }
+            })
+            .and_then(move |body| {
+                if (encoding as *const Encoding) == UTF_8 {
+                    serde_urlencoded::from_bytes::<U>(&body)
+                        .map_err(|_| UrlencodedError::Parse)
+                } else {
+                    let body = encoding
+                        .decode(&body, DecoderTrap::Strict)
+                        .map_err(|_| UrlencodedError::Parse)?;
+                    serde_urlencoded::from_str::<U>(&body)
+                        .map_err(|_| UrlencodedError::Parse)
+                }
+            });
+        self.fut = Some(Box::new(fut));
+        self.poll()
+    }
+}
+
 #[cfg(test)]
 mod tests {
-    use actix_http::http::header;
     use bytes::Bytes;
-    use serde_derive::Deserialize;
+    use serde::Deserialize;
 
     use super::*;
+    use crate::http::header::CONTENT_TYPE;
     use crate::test::{block_on, TestRequest};
 
     #[derive(Deserialize, Debug, PartialEq)]
@@ -183,15 +319,91 @@ mod tests {
 
     #[test]
     fn test_form() {
-        let mut req = TestRequest::with_header(
+        let mut req =
-            header::CONTENT_TYPE,
+            TestRequest::with_header(CONTENT_TYPE, "application/x-www-form-urlencoded")
-            "application/x-www-form-urlencoded",
+                .header(CONTENT_LENGTH, "11")
-        )
-        .header(header::CONTENT_LENGTH, "11")
                 .set_payload(Bytes::from_static(b"hello=world"))
                 .to_from();
 
         let s = block_on(Form::<Info>::from_request(&mut req)).unwrap();
         assert_eq!(s.hello, "world");
     }
+
+    fn eq(err: UrlencodedError, other: UrlencodedError) -> bool {
+        match err {
+            UrlencodedError::Chunked => match other {
+                UrlencodedError::Chunked => true,
+                _ => false,
+            },
+            UrlencodedError::Overflow => match other {
+                UrlencodedError::Overflow => true,
+                _ => false,
+            },
+            UrlencodedError::UnknownLength => match other {
+                UrlencodedError::UnknownLength => true,
+                _ => false,
+            },
+            UrlencodedError::ContentType => match other {
+                UrlencodedError::ContentType => true,
+                _ => false,
+            },
+            _ => false,
+        }
+    }
+
+    #[test]
+    fn test_urlencoded_error() {
+        let mut req =
+            TestRequest::with_header(CONTENT_TYPE, "application/x-www-form-urlencoded")
+                .header(CONTENT_LENGTH, "xxxx")
+                .to_request();
+        let info = block_on(UrlEncoded::<_, Info>::new(&mut req));
+        assert!(eq(info.err().unwrap(), UrlencodedError::UnknownLength));
+
+        let mut req =
+            TestRequest::with_header(CONTENT_TYPE, "application/x-www-form-urlencoded")
+                .header(CONTENT_LENGTH, "1000000")
+                .to_request();
+        let info = block_on(UrlEncoded::<_, Info>::new(&mut req));
+        assert!(eq(info.err().unwrap(), UrlencodedError::Overflow));
+
+        let mut req = TestRequest::with_header(CONTENT_TYPE, "text/plain")
+            .header(CONTENT_LENGTH, "10")
+            .to_request();
+        let info = block_on(UrlEncoded::<_, Info>::new(&mut req));
+        assert!(eq(info.err().unwrap(), UrlencodedError::ContentType));
+    }
+
+    #[test]
+    fn test_urlencoded() {
+        let mut req =
+            TestRequest::with_header(CONTENT_TYPE, "application/x-www-form-urlencoded")
+                .header(CONTENT_LENGTH, "11")
+                .set_payload(Bytes::from_static(b"hello=world"))
+                .to_request();
+
+        let info = block_on(UrlEncoded::<_, Info>::new(&mut req)).unwrap();
+        assert_eq!(
+            info,
+            Info {
+                hello: "world".to_owned()
+            }
+        );
+
+        let mut req = TestRequest::with_header(
+            CONTENT_TYPE,
+            "application/x-www-form-urlencoded; charset=utf-8",
+        )
+        .header(CONTENT_LENGTH, "11")
+        .set_payload(Bytes::from_static(b"hello=world"))
+        .to_request();
+
+        let info = block_on(UrlEncoded::<_, Info>::new(&mut req)).unwrap();
+        assert_eq!(
+            info,
+            Info {
+                hello: "world".to_owned()
+            }
+        );
+    }
 }

src/types/json.rs

@@ -393,7 +393,7 @@ mod tests {
     #[test]
     fn test_json_body() {
         let mut req = TestRequest::default().to_request();
-        let json = block_on(req.json::<MyObject>());
+        let json = block_on(JsonBody::<_, MyObject>::new(&mut req));
         assert!(json_eq(json.err().unwrap(), JsonPayloadError::ContentType));
 
         let mut req = TestRequest::default()
@@ -402,7 +402,7 @@ mod tests {
                 header::HeaderValue::from_static("application/text"),
             )
             .to_request();
-        let json = block_on(req.json::<MyObject>());
+        let json = block_on(JsonBody::<_, MyObject>::new(&mut req));
         assert!(json_eq(json.err().unwrap(), JsonPayloadError::ContentType));
 
         let mut req = TestRequest::default()
@@ -416,7 +416,7 @@ mod tests {
             )
             .to_request();
 
-        let json = block_on(req.json::<MyObject>().limit(100));
+        let json = block_on(JsonBody::<_, MyObject>::new(&mut req).limit(100));
         assert!(json_eq(json.err().unwrap(), JsonPayloadError::Overflow));
 
         let mut req = TestRequest::default()
@@ -431,7 +431,7 @@ mod tests {
             .set_payload(Bytes::from_static(b"{\"name\": \"test\"}"))
             .to_request();
 
-        let json = block_on(req.json::<MyObject>());
+        let json = block_on(JsonBody::<_, MyObject>::new(&mut req));
         assert_eq!(
             json.ok().unwrap(),
             MyObject {

src/types/mod.rs

@@ -1,10 +1,11 @@
 //! Helper types
 
-mod form;
+pub(crate) mod form;
 pub(crate) mod json;
 mod path;
-mod payload;
+pub(crate) mod payload;
 mod query;
+pub(crate) mod readlines;
 
 pub use self::form::{Form, FormConfig};
 pub use self::json::{Json, JsonConfig};

src/types/payload.rs

@@ -1,10 +1,9 @@
 //! Payload/Bytes/String extractors
 use std::str;
 
-use actix_http::dev::MessageBody;
 use actix_http::error::{Error, ErrorBadRequest, PayloadError};
 use actix_http::HttpMessage;
-use bytes::Bytes;
+use bytes::{Bytes, BytesMut};
 use encoding::all::UTF_8;
 use encoding::types::{DecoderTrap, Encoding};
 use futures::future::{err, Either, FutureResult};
@@ -12,6 +11,7 @@ use futures::{Future, Poll, Stream};
 use mime::Mime;
 
 use crate::extract::FromRequest;
+use crate::http::header;
 use crate::service::ServiceFromRequest;
 
 /// Payload extractor returns request 's payload stream.
@@ -152,7 +152,7 @@ where
         }
 
         let limit = cfg.limit;
-        Either::A(Box::new(MessageBody::new(req).limit(limit).from_err()))
+        Either::A(Box::new(HttpMessageBody::new(req).limit(limit).from_err()))
     }
 }
 
@@ -213,7 +213,7 @@ where
         let limit = cfg.limit;
 
         Either::A(Box::new(
-            MessageBody::new(req)
+            HttpMessageBody::new(req)
                 .limit(limit)
                 .from_err()
                 .and_then(move |body| {
@@ -287,6 +287,109 @@ impl Default for PayloadConfig {
     }
 }
 
+/// Future that resolves to a complete http message body.
+///
+/// Load http message body.
+///
+/// By default only 256Kb payload reads to a memory, then
+/// `PayloadError::Overflow` get returned. Use `MessageBody::limit()`
+/// method to change upper limit.
+pub struct HttpMessageBody<T: HttpMessage> {
+    limit: usize,
+    length: Option<usize>,
+    stream: actix_http::Payload<T::Stream>,
+    err: Option<PayloadError>,
+    fut: Option<Box<Future<Item = Bytes, Error = PayloadError>>>,
+}
+
+impl<T> HttpMessageBody<T>
+where
+    T: HttpMessage,
+    T::Stream: Stream<Item = Bytes, Error = PayloadError>,
+{
+    /// Create `MessageBody` for request.
+    pub fn new(req: &mut T) -> HttpMessageBody<T> {
+        let mut len = None;
+        if let Some(l) = req.headers().get(header::CONTENT_LENGTH) {
+            if let Ok(s) = l.to_str() {
+                if let Ok(l) = s.parse::<usize>() {
+                    len = Some(l)
+                } else {
+                    return Self::err(PayloadError::UnknownLength);
+                }
+            } else {
+                return Self::err(PayloadError::UnknownLength);
+            }
+        }
+
+        HttpMessageBody {
+            stream: req.take_payload(),
+            limit: 262_144,
+            length: len,
+            fut: None,
+            err: None,
+        }
+    }
+
+    /// Change max size of payload. By default max size is 256Kb
+    pub fn limit(mut self, limit: usize) -> Self {
+        self.limit = limit;
+        self
+    }
+
+    fn err(e: PayloadError) -> Self {
+        HttpMessageBody {
+            stream: actix_http::Payload::None,
+            limit: 262_144,
+            fut: None,
+            err: Some(e),
+            length: None,
+        }
+    }
+}
+
+impl<T> Future for HttpMessageBody<T>
+where
+    T: HttpMessage,
+    T::Stream: Stream<Item = Bytes, Error = PayloadError> + 'static,
+{
+    type Item = Bytes;
+    type Error = PayloadError;
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+        if let Some(ref mut fut) = self.fut {
+            return fut.poll();
+        }
+
+        if let Some(err) = self.err.take() {
+            return Err(err);
+        }
+
+        if let Some(len) = self.length.take() {
+            if len > self.limit {
+                return Err(PayloadError::Overflow);
+            }
+        }
+
+        // future
+        let limit = self.limit;
+        self.fut = Some(Box::new(
+            std::mem::replace(&mut self.stream, actix_http::Payload::None)
+                .from_err()
+                .fold(BytesMut::with_capacity(8192), move |mut body, chunk| {
+                    if (body.len() + chunk.len()) > limit {
+                        Err(PayloadError::Overflow)
+                    } else {
+                        body.extend_from_slice(&chunk);
+                        Ok(body)
+                    }
+                })
+                .map(|body| body.freeze()),
+        ));
+        self.poll()
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use bytes::Bytes;
@@ -332,4 +435,38 @@ mod tests {
         let s = block_on(String::from_request(&mut req)).unwrap();
         assert_eq!(s, "hello=world");
     }
+
+    #[test]
+    fn test_message_body() {
+        let mut req =
+            TestRequest::with_header(header::CONTENT_LENGTH, "xxxx").to_request();
+        let res = block_on(HttpMessageBody::new(&mut req));
+        match res.err().unwrap() {
+            PayloadError::UnknownLength => (),
+            _ => unreachable!("error"),
+        }
+
+        let mut req =
+            TestRequest::with_header(header::CONTENT_LENGTH, "1000000").to_request();
+        let res = block_on(HttpMessageBody::new(&mut req));
+        match res.err().unwrap() {
+            PayloadError::Overflow => (),
+            _ => unreachable!("error"),
+        }
+
+        let mut req = TestRequest::default()
+            .set_payload(Bytes::from_static(b"test"))
+            .to_request();
+        let res = block_on(HttpMessageBody::new(&mut req));
+        assert_eq!(res.ok().unwrap(), Bytes::from_static(b"test"));
+
+        let mut req = TestRequest::default()
+            .set_payload(Bytes::from_static(b"11111111111111"))
+            .to_request();
+        let res = block_on(HttpMessageBody::new(&mut req).limit(5));
+        match res.err().unwrap() {
+            PayloadError::Overflow => (),
+            _ => unreachable!("error"),
+        }
+    }
 }

src/types/readlines.rs

@@ -0,0 +1,210 @@
+use std::str;
+
+use bytes::{Bytes, BytesMut};
+use encoding::all::UTF_8;
+use encoding::types::{DecoderTrap, Encoding};
+use encoding::EncodingRef;
+use futures::{Async, Poll, Stream};
+
+use crate::dev::Payload;
+use crate::error::{PayloadError, ReadlinesError};
+use crate::HttpMessage;
+
+/// Stream to read request line by line.
+pub struct Readlines<T: HttpMessage> {
+    stream: Payload<T::Stream>,
+    buff: BytesMut,
+    limit: usize,
+    checked_buff: bool,
+    encoding: EncodingRef,
+    err: Option<ReadlinesError>,
+}
+
+impl<T> Readlines<T>
+where
+    T: HttpMessage,
+    T::Stream: Stream<Item = Bytes, Error = PayloadError>,
+{
+    /// Create a new stream to read request line by line.
+    pub fn new(req: &mut T) -> Self {
+        let encoding = match req.encoding() {
+            Ok(enc) => enc,
+            Err(err) => return Self::err(err.into()),
+        };
+
+        Readlines {
+            stream: req.take_payload(),
+            buff: BytesMut::with_capacity(262_144),
+            limit: 262_144,
+            checked_buff: true,
+            err: None,
+            encoding,
+        }
+    }
+
+    /// Change max line size. By default max size is 256Kb
+    pub fn limit(mut self, limit: usize) -> Self {
+        self.limit = limit;
+        self
+    }
+
+    fn err(err: ReadlinesError) -> Self {
+        Readlines {
+            stream: Payload::None,
+            buff: BytesMut::new(),
+            limit: 262_144,
+            checked_buff: true,
+            encoding: UTF_8,
+            err: Some(err),
+        }
+    }
+}
+
+impl<T> Stream for Readlines<T>
+where
+    T: HttpMessage,
+    T::Stream: Stream<Item = Bytes, Error = PayloadError>,
+{
+    type Item = String;
+    type Error = ReadlinesError;
+
+    fn poll(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
+        if let Some(err) = self.err.take() {
+            return Err(err);
+        }
+
+        // check if there is a newline in the buffer
+        if !self.checked_buff {
+            let mut found: Option<usize> = None;
+            for (ind, b) in self.buff.iter().enumerate() {
+                if *b == b'\n' {
+                    found = Some(ind);
+                    break;
+                }
+            }
+            if let Some(ind) = found {
+                // check if line is longer than limit
+                if ind + 1 > self.limit {
+                    return Err(ReadlinesError::LimitOverflow);
+                }
+                let enc: *const Encoding = self.encoding as *const Encoding;
+                let line = if enc == UTF_8 {
+                    str::from_utf8(&self.buff.split_to(ind + 1))
+                        .map_err(|_| ReadlinesError::EncodingError)?
+                        .to_owned()
+                } else {
+                    self.encoding
+                        .decode(&self.buff.split_to(ind + 1), DecoderTrap::Strict)
+                        .map_err(|_| ReadlinesError::EncodingError)?
+                };
+                return Ok(Async::Ready(Some(line)));
+            }
+            self.checked_buff = true;
+        }
+        // poll req for more bytes
+        match self.stream.poll() {
+            Ok(Async::Ready(Some(mut bytes))) => {
+                // check if there is a newline in bytes
+                let mut found: Option<usize> = None;
+                for (ind, b) in bytes.iter().enumerate() {
+                    if *b == b'\n' {
+                        found = Some(ind);
+                        break;
+                    }
+                }
+                if let Some(ind) = found {
+                    // check if line is longer than limit
+                    if ind + 1 > self.limit {
+                        return Err(ReadlinesError::LimitOverflow);
+                    }
+                    let enc: *const Encoding = self.encoding as *const Encoding;
+                    let line = if enc == UTF_8 {
+                        str::from_utf8(&bytes.split_to(ind + 1))
+                            .map_err(|_| ReadlinesError::EncodingError)?
+                            .to_owned()
+                    } else {
+                        self.encoding
+                            .decode(&bytes.split_to(ind + 1), DecoderTrap::Strict)
+                            .map_err(|_| ReadlinesError::EncodingError)?
+                    };
+                    // extend buffer with rest of the bytes;
+                    self.buff.extend_from_slice(&bytes);
+                    self.checked_buff = false;
+                    return Ok(Async::Ready(Some(line)));
+                }
+                self.buff.extend_from_slice(&bytes);
+                Ok(Async::NotReady)
+            }
+            Ok(Async::NotReady) => Ok(Async::NotReady),
+            Ok(Async::Ready(None)) => {
+                if self.buff.is_empty() {
+                    return Ok(Async::Ready(None));
+                }
+                if self.buff.len() > self.limit {
+                    return Err(ReadlinesError::LimitOverflow);
+                }
+                let enc: *const Encoding = self.encoding as *const Encoding;
+                let line = if enc == UTF_8 {
+                    str::from_utf8(&self.buff)
+                        .map_err(|_| ReadlinesError::EncodingError)?
+                        .to_owned()
+                } else {
+                    self.encoding
+                        .decode(&self.buff, DecoderTrap::Strict)
+                        .map_err(|_| ReadlinesError::EncodingError)?
+                };
+                self.buff.clear();
+                Ok(Async::Ready(Some(line)))
+            }
+            Err(e) => Err(ReadlinesError::from(e)),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::test::{block_on, TestRequest};
+
+    #[test]
+    fn test_readlines() {
+        let mut req = TestRequest::default()
+            .set_payload(Bytes::from_static(
+                b"Lorem Ipsum is simply dummy text of the printing and typesetting\n\
+                  industry. Lorem Ipsum has been the industry's standard dummy\n\
+                  Contrary to popular belief, Lorem Ipsum is not simply random text.",
+            ))
+            .to_request();
+        let stream = match block_on(Readlines::new(&mut req).into_future()) {
+            Ok((Some(s), stream)) => {
+                assert_eq!(
+                    s,
+                    "Lorem Ipsum is simply dummy text of the printing and typesetting\n"
+                );
+                stream
+            }
+            _ => unreachable!("error"),
+        };
+
+        let stream = match block_on(stream.into_future()) {
+            Ok((Some(s), stream)) => {
+                assert_eq!(
+                    s,
+                    "industry. Lorem Ipsum has been the industry's standard dummy\n"
+                );
+                stream
+            }
+            _ => unreachable!("error"),
+        };
+
+        match block_on(stream.into_future()) {
+            Ok((Some(s), stream)) => {
+                assert_eq!(
+                    s,
+                    "Contrary to popular belief, Lorem Ipsum is not simply random text."
+                );
+            }
+            _ => unreachable!("error"),
+        }
+    }
+}