From 84b872819ed68e044e25e763365e4d359388b97b Mon Sep 17 00:00:00 2001 From: debris Date: Mon, 30 Nov 2015 17:23:52 +0100 Subject: [PATCH] rlp lifetimes --- src/rlp.rs | 45 +++++++++++++++++++++++++++++++++++---------- 1 file changed, 35 insertions(+), 10 deletions(-) diff --git a/src/rlp.rs b/src/rlp.rs index e8562828a..b74651799 100644 --- a/src/rlp.rs +++ b/src/rlp.rs @@ -132,7 +132,7 @@ pub enum Prototype { List(usize), } -impl<'a> Rlp<'a> { +impl<'a, 'view> Rlp<'a> where 'a: 'view { /// Create a new instance of `Rlp` pub fn new(bytes: &'a [u8]) -> Rlp<'a> { Rlp { @@ -162,12 +162,11 @@ impl<'a> Rlp<'a> { /// fn main () { /// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g']; /// let rlp = Rlp::new(&data); - /// let view = rlp.at(1); - /// let dog = view.data(); + /// let dog = rlp.at(1).data(); /// assert_eq!(dog, &[0x83, b'd', b'o', b'g']); /// } /// ``` - pub fn data(&self) -> &[u8] { + pub fn data(&'view self) -> &'a [u8] { self.rlp.data() } @@ -223,7 +222,7 @@ impl<'a> Rlp<'a> { /// assert_eq!(dog, "dog".to_string()); /// } /// ``` - pub fn at(&self, index: usize) -> Rlp<'a> { + pub fn at(&'view self, index: usize) -> Rlp<'a> { From::from(self.rlp.at(index).unwrap()) } @@ -325,7 +324,7 @@ impl<'a> Rlp<'a> { } } -impl<'a> UntrustedRlp<'a> { +impl<'a, 'view> UntrustedRlp<'a> where 'a: 'view { /// returns new instance of `UntrustedRlp` pub fn new(bytes: &'a [u8]) -> UntrustedRlp<'a> { UntrustedRlp { @@ -343,12 +342,11 @@ impl<'a> UntrustedRlp<'a> { /// fn main () { /// let data = vec![0xc8, 0x83, b'c', b'a', b't', 0x83, b'd', b'o', b'g']; /// let rlp = UntrustedRlp::new(&data); - /// let view = rlp.at(1).unwrap(); - /// let dog = view.data(); + /// let dog = rlp.at(1).unwrap().data(); /// assert_eq!(dog, &[0x83, b'd', b'o', b'g']); /// } /// ``` - pub fn data(&self) -> &[u8] { + pub fn data(&'view self) -> &'a [u8] { self.bytes } @@ -410,7 +408,7 @@ impl<'a> UntrustedRlp<'a> { /// assert_eq!(dog, "dog".to_string()); /// } /// ``` - pub fn at(&self, index: usize) -> Result, DecoderError> { + pub fn at(&'view self, index: usize) -> Result, DecoderError> { if !self.is_list() { return Err(DecoderError::RlpExpectedToBeList); } @@ -1452,4 +1450,31 @@ mod tests { vec![0xc5, 0xc4, 0x83, b'c', b'a', b't'])]; run_decode_tests(tests); } + + #[test] + fn test_view() { + struct View<'a> { + bytes: &'a [u8] + } + + impl <'a, 'view> View<'a> where 'a: 'view { + fn new(bytes: &'a [u8]) -> View<'a> { + View { + bytes: bytes + } + } + + fn offset(&'view self, len: usize) -> View<'a> { + View::new(&self.bytes[len..]) + } + + fn data(&'view self) -> &'a [u8] { + self.bytes + } + } + + let data = vec![0, 1, 2, 3]; + let view = View::new(&data); + let _data_slice = view.offset(1).data(); + } }