use std::ops::{Bound, RangeBounds};
/// `Range` header, defined in [RFC7233](
https://tools.ietf.org/html/rfc7233#section-3.1)
///
/// The "Range" header field on a GET request modifies the method
/// semantics to request transfer of only one or more subranges of the
/// selected representation data, rather than the entire selected
/// representation data.
///
/// # ABNF
///
/// ```text
/// Range = byte-ranges-specifier / other-ranges-specifier
/// other-ranges-specifier = other-range-unit "=" other-range-set
/// other-range-set = 1*VCHAR
///
/// bytes-unit = "bytes"
///
/// byte-ranges-specifier = bytes-unit "=" byte-range-set
/// byte-range-set = 1#(byte-range-spec / suffix-byte-range-spec)
/// byte-range-spec = first-byte-pos "-" [last-byte-pos]
/// first-byte-pos = 1*DIGIT
/// last-byte-pos = 1*DIGIT
/// ```
///
/// # Example values
///
/// * `bytes=1000-`
/// * `bytes=-2000`
/// * `bytes=0-1,30-40`
/// * `bytes=0-10,20-90,-100`
///
/// # Examples
///
/// ```
/// # extern crate headers;
/// use headers::Range;
///
///
/// let range = Range::bytes(0..1234).unwrap();
/// ```
#[derive(Clone, Debug, PartialEq)]
pub struct Range(::HeaderValue);
error_type!(InvalidRange);
impl Range {
/// Creates a `Range` header from bounds.
pub fn bytes(bounds: impl RangeBounds<u64>) -> Result<Self, InvalidRange> {
let v = match (bounds.start_bound(), bounds.end_bound()) {
(Bound::Unbounded, Bound::Included(end)) => format!("bytes=-{}", end),
(Bound::Unbounded, Bound::Excluded(&end)) => format!("bytes=-{}", end - 1),
(Bound::Included(start), Bound::Included(end)) => format!("bytes={}-{}", start, end),
(Bound::Included(start), Bound::Excluded(&end)) => {
format!("bytes={}-{}", start, end - 1)
}
(Bound::Included(start), Bound::Unbounded) => format!("bytes={}-", start),
_ => return Err(InvalidRange { _inner: () }),
};
Ok(Range(::HeaderValue::from_str(&v).unwrap()))
}
/// Iterate the range sets as a tuple of bounds.
pub fn iter<'a>(&'a self) -> impl Iterator<Item = (Bound<u64>, Bound<u64>)> + 'a {
let s = self
.0
.to_str()
.expect("valid string checked in Header::decode()");
s["bytes=".len()..].split(',').filter_map(|spec| {
let mut iter = spec.trim().splitn(2, '-');
Some((parse_bound(iter.next()?)?, parse_bound(iter.next()?)?))
})
}
}
fn parse_bound(s: &str) -> Option<Bound<u64>> {
if s.is_empty() {
return Some(Bound::Unbounded);
}
s.parse().ok().map(Bound::Included)
}
impl ::Header for Range {
fn name() -> &'static ::HeaderName {
&::http::header::RANGE
}
fn decode<'i, I: Iterator<Item = &'i ::HeaderValue>>(values: &mut I) -> Result<Self, ::Error> {
values
.next()
.and_then(|val| {
if val.to_str().ok()?.starts_with("bytes=") {
Some(Range(val.clone()))
} else {
None
}
})
.ok_or_else(::Error::invalid)
}
fn encode<E: Extend<::HeaderValue>>(&self, values: &mut E) {
values.extend(::std::iter::once(self.0.clone()));
}
}
/*
impl ByteRangeSpec {
/// Given the full length of the entity, attempt to normalize the byte range
/// into an satisfiable end-inclusive (from, to) range.
///
/// The resulting range is guaranteed to be a satisfiable range within the bounds
/// of `0 <= from <= to < full_length`.
///
/// If the byte range is deemed unsatisfiable, `None` is returned.
/// An unsatisfiable range is generally cause for a server to either reject
/// the client request with a `416 Range Not Satisfiable` status code, or to
/// simply ignore the range header and serve the full entity using a `200 OK`
/// status code.
///
/// This function closely follows [RFC 7233][1] section 2.1.
/// As such, it considers ranges to be satisfiable if they meet the following
/// conditions:
///
/// > If a valid byte-range-set includes at least one byte-range-spec with
/// a first-byte-pos that is less than the current length of the
/// representation, or at least one suffix-byte-range-spec with a
/// non-zero suffix-length, then the byte-range-set is satisfiable.
/// Otherwise, the byte-range-set is unsatisfiable.
///
/// The function also computes remainder ranges based on the RFC:
///
/// > If the last-byte-pos value is
/// absent, or if the value is greater than or equal to the current
/// length of the representation data, the byte range is interpreted as
/// the remainder of the representation (i.e., the server replaces the
/// value of last-byte-pos with a value that is one less than the current
/// length of the selected representation).
///
/// [1]:
https://tools.ietf.org/html/rfc7233
pub fn to_satisfiable_range(&self, full_length: u64) -> Option<(u64, u64)> {
// If the full length is zero, there is no satisfiable end-inclusive range.
if full_length == 0 {
return None;
}
match self {
&ByteRangeSpec::FromTo(from, to) => {
if from < full_length && from <= to {
Some((from, ::std::cmp::min(to, full_length - 1)))
} else {
None
}
},
&ByteRangeSpec::AllFrom(from) => {
if from < full_length {
Some((from, full_length - 1))
} else {
None
}
},
&ByteRangeSpec::Last(last) => {
if last > 0 {
// From the RFC: If the selected representation is shorter
// than the specified suffix-length,
// the entire representation is used.
if last > full_length {
Some((0, full_length - 1))
} else {
Some((full_length - last, full_length - 1))
}
} else {
None
}
}
}
}
}
impl Range {
/// Get the most common byte range header ("bytes=from-to")
pub fn bytes(from: u64, to: u64) -> Range {
Range::Bytes(vec![ByteRangeSpec::FromTo(from, to)])
}
/// Get byte range header with multiple subranges
/// ("bytes=from1-to1,from2-to2,fromX-toX")
pub fn bytes_multi(ranges: Vec<(u64, u64)>) -> Range {
Range::Bytes(ranges.iter().map(|r| ByteRangeSpec::FromTo(r.0, r.1)).collect())
}
}
impl fmt::Display for ByteRangeSpec {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
ByteRangeSpec::FromTo(from, to) => write!(f, "{}-{}", from, to),
ByteRangeSpec::Last(pos) => write!(f, "-{}", pos),
ByteRangeSpec::AllFrom(pos) => write!(f, "{}-", pos),
}
}
}
impl fmt::Display for Range {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
Range::Bytes(ref ranges) => {
try!(write!(f, "bytes="));
for (i, range) in ranges.iter().enumerate() {
if i != 0 {
try!(f.write_str(","));
}
try!(Display::fmt(range, f));
}
Ok(())
},
Range::Unregistered(ref unit, ref range_str) => {
write!(f, "{}={}", unit, range_str)
},
}
}
}
impl FromStr for Range {
type Err = ::Error;
fn from_str(s: &str) -> ::Result<Range> {
let mut iter = s.splitn(2, '=');
match (iter.next(), iter.next()) {
(Some("bytes"), Some(ranges)) => {
let ranges = from_comma_delimited(ranges);
if ranges.is_empty() {
return Err(::Error::Header);
}
Ok(Range::Bytes(ranges))
}
(Some(unit), Some(range_str)) if unit != "" && range_str != "" => {
Ok(Range::Unregistered(unit.to_owned(), range_str.to_owned()))
},
_ => Err(::Error::Header)
}
}
}
impl FromStr for ByteRangeSpec {
type Err = ::Error;
fn from_str(s: &str) -> ::Result<ByteRangeSpec> {
let mut parts = s.splitn(2, '-');
match (parts.next(), parts.next()) {
(Some(""), Some(end)) => {
end.parse().or(Err(::Error::Header)).map(ByteRangeSpec::Last)
},
(Some(start), Some("")) => {
start.parse().or(Err(::Error::Header)).map(ByteRangeSpec::AllFrom)
},
(Some(start), Some(end)) => {
match (start.parse(), end.parse()) {
(Ok(start), Ok(end)) if start <= end => Ok(ByteRangeSpec::FromTo(start, end)),
_ => Err(::Error::Header)
}
},
_ => Err(::Error::Header)
}
}
}
fn from_comma_delimited<T: FromStr>(s: &str) -> Vec<T> {
s.split(',')
.filter_map(|x| match x.trim() {
"" => None,
y => Some(y)
})
.filter_map(|x| x.parse().ok())
.collect()
}
impl Header for Range {
fn header_name() -> &'static str {
static NAME: &'static str = "Range";
NAME
}
fn parse_header(raw: &Raw) -> ::Result<Range> {
from_one_raw_str(raw)
}
fn fmt_header(&self, f: &mut ::Formatter) -> fmt::Result {
f.fmt_line(self)
}
}
#[test]
fn test_parse_bytes_range_valid() {
let r: Range = Header::parse_header(&"bytes=1-100".into()).unwrap();
let r2: Range = Header::parse_header(&"bytes=1-100,-".into()).unwrap();
let r3 = Range::bytes(1, 100);
assert_eq!(r, r2);
assert_eq!(r2, r3);
let r: Range = Header::parse_header(&"bytes=1-100,200-".into()).unwrap();
let r2: Range = Header::parse_header(&"bytes= 1-100 , 101-xxx, 200- ".into()).unwrap();
let r3 = Range::Bytes(
vec![ByteRangeSpec::FromTo(1, 100), ByteRangeSpec::AllFrom(200)]
);
assert_eq!(r, r2);
assert_eq!(r2, r3);
let r: Range = Header::parse_header(&"bytes=1-100,-100".into()).unwrap();
let r2: Range = Header::parse_header(&"bytes=1-100, ,,-100".into()).unwrap();
let r3 = Range::Bytes(
vec![ByteRangeSpec::FromTo(1, 100), ByteRangeSpec::Last(100)]
);
assert_eq!(r, r2);
assert_eq!(r2, r3);
let r: Range = Header::parse_header(&"custom=1-100,-100".into()).unwrap();
let r2 = Range::Unregistered("custom".to_owned(), "1-100,-100".to_owned());
assert_eq!(r, r2);
}
#[test]
fn test_parse_unregistered_range_valid() {
let r: Range = Header::parse_header(&"custom=1-100,-100".into()).unwrap();
let r2 = Range::Unregistered("custom".to_owned(), "1-100,-100".to_owned());
assert_eq!(r, r2);
let r: Range = Header::parse_header(&"custom=abcd".into()).unwrap();
let r2 = Range::Unregistered("custom".to_owned(), "abcd".to_owned());
assert_eq!(r, r2);
let r: Range = Header::parse_header(&"custom=xxx-yyy".into()).unwrap();
let r2 = Range::Unregistered("custom".to_owned(), "xxx-yyy".to_owned());
assert_eq!(r, r2);
}
#[test]
fn test_parse_invalid() {
let r: ::Result<Range> = Header::parse_header(&"bytes=1-a,-".into());
assert_eq!(r.ok(), None);
let r: ::Result<Range> = Header::parse_header(&"bytes=1-2-3".into());
assert_eq!(r.ok(), None);
let r: ::Result<Range> = Header::parse_header(&"abc".into());
assert_eq!(r.ok(), None);
let r: ::Result<Range> = Header::parse_header(&"bytes=1-100=".into());
assert_eq!(r.ok(), None);
let r: ::Result<Range> = Header::parse_header(&"bytes=".into());
assert_eq!(r.ok(), None);
let r: ::Result<Range> = Header::parse_header(&"custom=".into());
assert_eq!(r.ok(), None);
let r: ::Result<Range> = Header::parse_header(&"=1-100".into());
assert_eq!(r.ok(), None);
}
#[test]
fn test_fmt() {
use Headers;
let mut headers = Headers::new();
headers.set(
Range::Bytes(
vec![ByteRangeSpec::FromTo(0, 1000), ByteRangeSpec::AllFrom(2000)]
));
assert_eq!(&headers.to_string(), "Range: bytes=0-1000,2000-\r\n");
headers.clear();
headers.set(Range::Bytes(vec![]));
assert_eq!(&headers.to_string(), "Range: bytes=\r\n");
headers.clear();
headers.set(Range::Unregistered("custom".to_owned(), "1-xxx".to_owned()));
assert_eq!(&headers.to_string(), "Range: custom=1-xxx\r\n");
}
#[test]
fn test_byte_range_spec_to_satisfiable_range() {
assert_eq!(Some((0, 0)), ByteRangeSpec::FromTo(0, 0).to_satisfiable_range(3));
assert_eq!(Some((1, 2)), ByteRangeSpec::FromTo(1, 2).to_satisfiable_range(3));
assert_eq!(Some((1, 2)), ByteRangeSpec::FromTo(1, 5).to_satisfiable_range(3));
assert_eq!(None, ByteRangeSpec::FromTo(3, 3).to_satisfiable_range(3));
assert_eq!(None, ByteRangeSpec::FromTo(2, 1).to_satisfiable_range(3));
assert_eq!(None, ByteRangeSpec::FromTo(0, 0).to_satisfiable_range(0));
assert_eq!(Some((0, 2)), ByteRangeSpec::AllFrom(0).to_satisfiable_range(3));
assert_eq!(Some((2, 2)), ByteRangeSpec::AllFrom(2).to_satisfiable_range(3));
assert_eq!(None, ByteRangeSpec::AllFrom(3).to_satisfiable_range(3));
assert_eq!(None, ByteRangeSpec::AllFrom(5).to_satisfiable_range(3));
assert_eq!(None, ByteRangeSpec::AllFrom(0).to_satisfiable_range(0));
assert_eq!(Some((1, 2)), ByteRangeSpec::Last(2).to_satisfiable_range(3));
assert_eq!(Some((2, 2)), ByteRangeSpec::Last(1).to_satisfiable_range(3));
assert_eq!(Some((0, 2)), ByteRangeSpec::Last(5).to_satisfiable_range(3));
assert_eq!(None, ByteRangeSpec::Last(0).to_satisfiable_range(3));
assert_eq!(None, ByteRangeSpec::Last(2).to_satisfiable_range(0));
}
bench_header!(bytes_multi, Range, { vec![b"bytes=1-1001,2001-3001,10001-".to_vec()]
});
bench_header!(custom_unit, Range, { vec![b"other=0-100000".to_vec()]});
*/
