1 // Copyright 2013 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Readers and Writers for in-memory buffers
15 //! * Should probably have something like this for strings.
16 //! * Should they implement Closable? Would take extra state.
23 /// Writes to an owned, growable byte vector
24 pub struct MemWriter {
29 pub fn new() -> MemWriter { MemWriter { buf: vec::with_capacity(128) } }
32 impl Writer for MemWriter {
33 fn write(&mut self, buf: &[u8]) {
34 self.buf.push_all(buf)
37 fn flush(&mut self) { /* no-op */ }
40 impl Seek for MemWriter {
41 fn tell(&self) -> u64 { self.buf.len() as u64 }
43 fn seek(&mut self, _pos: i64, _style: SeekStyle) { fail!() }
46 impl Decorator<~[u8]> for MemWriter {
48 fn inner(self) -> ~[u8] {
50 MemWriter { buf: buf } => buf
54 fn inner_ref<'a>(&'a self) -> &'a ~[u8] {
56 MemWriter { buf: ref buf } => buf
60 fn inner_mut_ref<'a>(&'a mut self) -> &'a mut ~[u8] {
62 MemWriter { buf: ref mut buf } => buf
67 /// Reads from an owned byte vector
68 pub struct MemReader {
74 pub fn new(buf: ~[u8]) -> MemReader {
82 impl Reader for MemReader {
83 fn read(&mut self, buf: &mut [u8]) -> Option<uint> {
84 { if self.eof() { return None; } }
86 let write_len = min(buf.len(), self.buf.len() - self.pos);
88 let input = self.buf.slice(self.pos, self.pos + write_len);
89 let output = buf.mut_slice(0, write_len);
90 assert_eq!(input.len(), output.len());
91 vec::bytes::copy_memory(output, input, write_len);
93 self.pos += write_len;
94 assert!(self.pos <= self.buf.len());
96 return Some(write_len);
99 fn eof(&mut self) -> bool { self.pos == self.buf.len() }
102 impl Seek for MemReader {
103 fn tell(&self) -> u64 { self.pos as u64 }
105 fn seek(&mut self, _pos: i64, _style: SeekStyle) { fail!() }
108 impl Decorator<~[u8]> for MemReader {
110 fn inner(self) -> ~[u8] {
112 MemReader { buf: buf, _ } => buf
116 fn inner_ref<'a>(&'a self) -> &'a ~[u8] {
118 MemReader { buf: ref buf, _ } => buf
122 fn inner_mut_ref<'a>(&'a mut self) -> &'a mut ~[u8] {
124 MemReader { buf: ref mut buf, _ } => buf
130 /// Writes to a fixed-size byte slice
131 struct BufWriter<'self> {
132 buf: &'self mut [u8],
136 impl<'self> BufWriter<'self> {
137 pub fn new<'a>(buf: &'a mut [u8]) -> BufWriter<'a> {
145 impl<'self> Writer for BufWriter<'self> {
146 fn write(&mut self, _buf: &[u8]) { fail!() }
148 fn flush(&mut self) { fail!() }
151 impl<'self> Seek for BufWriter<'self> {
152 fn tell(&self) -> u64 { fail!() }
154 fn seek(&mut self, _pos: i64, _style: SeekStyle) { fail!() }
158 /// Reads from a fixed-size byte slice
159 struct BufReader<'self> {
164 impl<'self> BufReader<'self> {
165 pub fn new<'a>(buf: &'a [u8]) -> BufReader<'a> {
173 impl<'self> Reader for BufReader<'self> {
174 fn read(&mut self, _buf: &mut [u8]) -> Option<uint> { fail!() }
176 fn eof(&mut self) -> bool { fail!() }
179 impl<'self> Seek for BufReader<'self> {
180 fn tell(&self) -> u64 { fail!() }
182 fn seek(&mut self, _pos: i64, _style: SeekStyle) { fail!() }
191 fn test_mem_writer() {
192 let mut writer = MemWriter::new();
193 assert_eq!(writer.tell(), 0);
195 assert_eq!(writer.tell(), 1);
196 writer.write([1, 2, 3]);
197 writer.write([4, 5, 6, 7]);
198 assert_eq!(writer.tell(), 8);
199 assert_eq!(writer.inner(), ~[0, 1, 2, 3, 4, 5 , 6, 7]);
203 fn test_mem_reader() {
204 let mut reader = MemReader::new(~[0, 1, 2, 3, 4, 5, 6, 7]);
206 assert_eq!(reader.read(buf), Some(0));
207 assert_eq!(reader.tell(), 0);
209 assert_eq!(reader.read(buf), Some(1));
210 assert_eq!(reader.tell(), 1);
211 assert_eq!(buf, [0]);
212 let mut buf = [0, ..4];
213 assert_eq!(reader.read(buf), Some(4));
214 assert_eq!(reader.tell(), 5);
215 assert_eq!(buf, [1, 2, 3, 4]);
216 assert_eq!(reader.read(buf), Some(3));
217 assert_eq!(buf.slice(0, 3), [5, 6, 7]);
218 assert!(reader.eof());
219 assert_eq!(reader.read(buf), None);
220 assert!(reader.eof());