Add dynamic headers support

src/lib.rs

@@ -284,6 +284,105 @@ pub struct Request<'headers, 'buf: 'headers> {
     pub headers: &'headers mut [Header<'buf>]
 }
 
+/// A parsed Request that allocates headers dynamically
+///
+/// The optional values will be `None` if a parse was not complete, and did not
+/// parse the associated property. This allows you to inspect the parts that
+/// could be parsed, before reading more, in case you wish to exit early.
+/// 
+/// The fields of this struct are private. The user need to call
+/// `get_request` to obtain a static snapshot and check the result.
+///
+/// # Example
+///
+/// ```no_run
+/// let buf = b"GET /404 HTTP/1.1\r\nHost:";
+/// let mut req = httparse::DynRequest::new(None);
+/// let res = req.parse(buf).unwrap();
+/// if res.is_partial() {
+///     // get a snapshot with statically allocated headers
+///     let req = req.get_request(buf);
+///     match req.path {
+///         Some(ref path) => {
+///             // check router for path.
+///             // /404 doesn't exist? we could stop parsing
+///         },
+///         None => {
+///             // must read more and parse again
+///         }
+///     }
+/// }
+/// ```
+#[derive(Debug, PartialEq, Clone)]
+#[cfg(feature = "std")]
+pub struct DynRequest<'headers> {
+    method: Option<(usize,usize)>,
+    path: Option<(usize,usize)>,
+    version: Option<u8>,
+    headers: Vec<Header<'headers>>
+}
+
+#[cfg(feature = "std")]
+impl<'headers> DynRequest<'headers> {
+    /// Create a request that will allocate headers dynamically
+    #[inline]    
+    pub fn new(header_capacity: Option<usize>) -> DynRequest<'headers> {
+        DynRequest {
+            method: None,
+            path: None,
+            version: None,
+            headers: if let Some(cap) = header_capacity { Vec::with_capacity(cap) } else { vec![] }
+        }
+    }
+    /// After a call to `parse`, call this method to obtain the result.
+    /// 
+    pub fn get_request<'buf>(&'buf mut self, buf: &'buf [u8]) -> Request<'headers, 'buf> {
+        Request {
+            method: self.method.and_then(|(start, len)|
+                std::str::from_utf8(&buf[start..start+len]).ok()),
+            path: self.path.and_then(|(start, len)| 
+                std::str::from_utf8(&buf[start..start+len]).ok()),
+            version: self.version,
+            headers: &mut self.headers
+        }
+    }
+    /// Try to parse a buffer of bytes into the Request.
+    /// Call `get_request` to check the result.
+    pub fn parse<'buf: 'headers>(&mut self, buf: &'buf [u8]) -> Result<usize>
+    {
+        let orig_len = buf.len();
+        let mut bytes = Bytes::new(buf);
+        let mut pos = 0;
+        complete!(skip_empty_lines(&mut bytes));
+        self.method = match try!(parse_token_offset(&mut bytes)) {
+            Status::Complete((s,l,p)) => {
+                let r =Some((s+pos, l));
+                pos += p;
+                r
+            },
+            Status::Partial => return Ok(Status::Partial)
+        };
+        self.path = match try!(parse_uri_offset(&mut bytes)) {
+            Status::Complete((s,l,_)) => {
+                Some((s+pos, l))
+            },
+            Status::Partial => return Ok(Status::Partial)
+        };
+        self.version = Some(complete!(parse_version(&mut bytes)));
+        newline!(bytes);
+
+        let len = orig_len - bytes.len();
+        let header_cnt = self.headers.len();
+        self.headers.push(EMPTY_HEADER);
+        let mut headers_len = 0;
+        let mut headers_ref = &mut self.headers[header_cnt..];
+        while bytes.pos()<bytes.len() {
+            headers_len += complete!(parse_headers_iter(&mut headers_ref, &mut bytes));
+        }
+        Ok(Status::Complete(len + headers_len))
+    }
+} 
+
 impl<'h, 'b> Request<'h, 'b> {
     /// Creates a new Request, using a slice of headers you allocate.
     #[inline]
@@ -427,6 +526,8 @@ pub struct Header<'a> {
 /// ```
 pub const EMPTY_HEADER: Header<'static> = Header { name: "", value: b"" };
 
+
+
 #[inline]
 fn parse_version(bytes: &mut Bytes) -> Result<u8> {
     if let Some(mut eight) = bytes.next_8() {
@@ -498,6 +599,27 @@ fn parse_reason<'a>(bytes: &mut Bytes<'a>) -> Result<&'a str> {
     }
 }
 
+#[inline]
+#[cfg(feature = "std")]
+fn parse_token_offset<'a>(bytes: &mut Bytes<'a>) -> Result<(usize,usize,usize)> {
+    let start = bytes.pos();
+    loop {
+        let b = next!(bytes);        
+        if b == b' ' {
+            // we need to keep track of the position of the bytes.
+            // after slice_skip the position will be reset so
+            // we have to get it here.
+            let pos = bytes.pos();
+            return Ok(Status::Complete((start, unsafe {
+                // all bytes up till `i` must have been `is_token`.
+                str::from_utf8_unchecked(bytes.slice_skip(1))
+            }.len(), pos)));
+        } else if !is_token(b) {
+            return Err(Error::Token);
+        }
+    }
+}
+
 #[inline]
 fn parse_token<'a>(bytes: &mut Bytes<'a>) -> Result<&'a str> {
     loop {
@@ -513,6 +635,29 @@ fn parse_token<'a>(bytes: &mut Bytes<'a>) -> Result<&'a str> {
     }
 }
 
+#[inline]
+#[cfg(feature = "std")]
+fn parse_uri_offset<'a>(bytes: &mut Bytes<'a>) -> Result<(usize, usize, usize)> {
+    let start = bytes.pos();
+    simd::match_uri_vectored(bytes);
+
+    loop {
+        let b = next!(bytes);
+        if b == b' ' {
+            // we need to keep track of the position of the bytes.
+            // after slice_skip the position will be reset so
+            // we have to get it here.
+            let pos = bytes.pos();
+            return Ok(Status::Complete((start,unsafe {
+                // all bytes up till `i` must have been `is_token`.
+                str::from_utf8_unchecked(bytes.slice_skip(1))
+            }.len(), pos)));
+        } else if !is_uri_token(b) {
+            return Err(Error::Token);
+        }
+    }
+}
+
 #[inline]
 fn parse_uri<'a>(bytes: &mut Bytes<'a>) -> Result<&'a str> {
     simd::match_uri_vectored(bytes);

tests/uri.rs

@@ -2,6 +2,9 @@ extern crate httparse;
 
 use httparse::{Error, Request, Status, EMPTY_HEADER};
 
+#[cfg(feature="std")]
+use httparse::DynRequest;
+
 const NUM_OF_HEADERS: usize = 4;
 
 macro_rules! req {
@@ -23,6 +26,25 @@ macro_rules! req {
     }
     )
 }
+macro_rules! req_dyn {
+    ($name:ident, $buf:expr, |$arg:ident| $body:expr) => (
+        req_dyn! {$name, $buf, Ok(Status::Complete($buf.len())), |$arg| $body }
+    );
+    ($name:ident, $buf:expr, $len:expr, |$arg:ident| $body:expr) => (
+    #[test]
+    #[cfg(feature = "std")]
+    fn $name() {
+        let mut req = DynRequest::new(None);
+        let status = req.parse($buf.as_ref());
+        assert_eq!(status, $len);
+        closure(req.get_request($buf.as_ref()));
+
+        fn closure($arg: Request) {
+            $body
+        }
+    }
+    )
+}
 
 req! {
     urltest_001,
@@ -36,6 +58,18 @@ req! {
         assert_eq!(req.headers[0].value, b"foo");
     }
 }
+req_dyn! {
+    urltest_001_dyn,
+    b"GET /bar;par?b HTTP/1.1\r\nHost: foo\r\n\r\n",
+    |req| {
+        assert_eq!(req.method.unwrap(), "GET");
+        assert_eq!(req.path.unwrap(), "/bar;par?b");
+        assert_eq!(req.version.unwrap(), 1);
+        assert_eq!(req.headers.len(), 1);
+        assert_eq!(req.headers[0].name, "Host");
+        assert_eq!(req.headers[0].value, b"foo");
+    }
+}
 
 
 req! {