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// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Readers and Writers for in-memory buffers
//!
//! # XXX
//!
//! * Should probably have something like this for strings.
//! * Should they implement Closable? Would take extra state.
use cmp::min;
use prelude::*;
use super::*;
use vec;
/// Writes to an owned, growable byte vector
pub struct MemWriter {
buf: ~[u8]
}
impl MemWriter {
pub fn new() -> MemWriter { MemWriter { buf: vec::with_capacity(128) } }
}
impl Writer for MemWriter {
fn write(&mut self, buf: &[u8]) {
self.buf.push_all(buf)
}
fn flush(&mut self) { /* no-op */ }
}
impl Seek for MemWriter {
fn tell(&self) -> u64 { self.buf.len() as u64 }
fn seek(&mut self, _pos: i64, _style: SeekStyle) { fail!() }
}
impl Decorator<~[u8]> for MemWriter {
fn inner(self) -> ~[u8] {
match self {
MemWriter { buf: buf } => buf
}
}
fn inner_ref<'a>(&'a self) -> &'a ~[u8] {
match *self {
MemWriter { buf: ref buf } => buf
}
}
fn inner_mut_ref<'a>(&'a mut self) -> &'a mut ~[u8] {
match *self {
MemWriter { buf: ref mut buf } => buf
}
}
}
/// Reads from an owned byte vector
pub struct MemReader {
buf: ~[u8],
pos: uint
}
impl MemReader {
pub fn new(buf: ~[u8]) -> MemReader {
MemReader {
buf: buf,
pos: 0
}
}
}
impl Reader for MemReader {
fn read(&mut self, buf: &mut [u8]) -> Option<uint> {
{ if self.eof() { return None; } }
let write_len = min(buf.len(), self.buf.len() - self.pos);
{
let input = self.buf.slice(self.pos, self.pos + write_len);
let output = buf.mut_slice(0, write_len);
assert_eq!(input.len(), output.len());
vec::bytes::copy_memory(output, input, write_len);
}
self.pos += write_len;
assert!(self.pos <= self.buf.len());
return Some(write_len);
}
fn eof(&mut self) -> bool { self.pos == self.buf.len() }
}
impl Seek for MemReader {
fn tell(&self) -> u64 { self.pos as u64 }
fn seek(&mut self, _pos: i64, _style: SeekStyle) { fail!() }
}
impl Decorator<~[u8]> for MemReader {
fn inner(self) -> ~[u8] {
match self {
MemReader { buf: buf, _ } => buf
}
}
fn inner_ref<'a>(&'a self) -> &'a ~[u8] {
match *self {
MemReader { buf: ref buf, _ } => buf
}
}
fn inner_mut_ref<'a>(&'a mut self) -> &'a mut ~[u8] {
match *self {
MemReader { buf: ref mut buf, _ } => buf
}
}
}
/// Writes to a fixed-size byte slice
struct BufWriter<'self> {
buf: &'self mut [u8],
pos: uint
}
impl<'self> BufWriter<'self> {
pub fn new<'a>(buf: &'a mut [u8]) -> BufWriter<'a> {
BufWriter {
buf: buf,
pos: 0
}
}
}
impl<'self> Writer for BufWriter<'self> {
fn write(&mut self, _buf: &[u8]) { fail!() }
fn flush(&mut self) { fail!() }
}
impl<'self> Seek for BufWriter<'self> {
fn tell(&self) -> u64 { fail!() }
fn seek(&mut self, _pos: i64, _style: SeekStyle) { fail!() }
}
/// Reads from a fixed-size byte slice
struct BufReader<'self> {
buf: &'self [u8],
pos: uint
}
impl<'self> BufReader<'self> {
pub fn new<'a>(buf: &'a [u8]) -> BufReader<'a> {
BufReader {
buf: buf,
pos: 0
}
}
}
impl<'self> Reader for BufReader<'self> {
fn read(&mut self, buf: &mut [u8]) -> Option<uint> {
{ if self.eof() { return None; } }
let write_len = min(buf.len(), self.buf.len() - self.pos);
{
let input = self.buf.slice(self.pos, self.pos + write_len);
let output = buf.mut_slice(0, write_len);
assert_eq!(input.len(), output.len());
vec::bytes::copy_memory(output, input, write_len);
}
self.pos += write_len;
assert!(self.pos <= self.buf.len());
return Some(write_len);
}
fn eof(&mut self) -> bool { self.pos == self.buf.len() }
}
impl<'self> Seek for BufReader<'self> {
fn tell(&self) -> u64 { self.pos as u64 }
fn seek(&mut self, _pos: i64, _style: SeekStyle) { fail!() }
}
///Calls a function with a MemWriter and returns
///the writer's stored vector.
pub fn with_mem_writer(writeFn:&fn(&mut MemWriter)) -> ~[u8] {
let mut writer = MemWriter::new();
writeFn(&mut writer);
writer.inner()
}
#[cfg(test)]
mod test {
use prelude::*;
use super::*;
#[test]
fn test_mem_writer() {
let mut writer = MemWriter::new();
assert_eq!(writer.tell(), 0);
writer.write([0]);
assert_eq!(writer.tell(), 1);
writer.write([1, 2, 3]);
writer.write([4, 5, 6, 7]);
assert_eq!(writer.tell(), 8);
assert_eq!(writer.inner(), ~[0, 1, 2, 3, 4, 5 , 6, 7]);
}
#[test]
fn test_mem_reader() {
let mut reader = MemReader::new(~[0, 1, 2, 3, 4, 5, 6, 7]);
let mut buf = [];
assert_eq!(reader.read(buf), Some(0));
assert_eq!(reader.tell(), 0);
let mut buf = [0];
assert_eq!(reader.read(buf), Some(1));
assert_eq!(reader.tell(), 1);
assert_eq!(buf, [0]);
let mut buf = [0, ..4];
assert_eq!(reader.read(buf), Some(4));
assert_eq!(reader.tell(), 5);
assert_eq!(buf, [1, 2, 3, 4]);
assert_eq!(reader.read(buf), Some(3));
assert_eq!(buf.slice(0, 3), [5, 6, 7]);
assert!(reader.eof());
assert_eq!(reader.read(buf), None);
assert!(reader.eof());
}
#[test]
fn test_buf_reader() {
let in_buf = ~[0, 1, 2, 3, 4, 5, 6, 7];
let mut reader = BufReader::new(in_buf);
let mut buf = [];
assert_eq!(reader.read(buf), Some(0));
assert_eq!(reader.tell(), 0);
let mut buf = [0];
assert_eq!(reader.read(buf), Some(1));
assert_eq!(reader.tell(), 1);
assert_eq!(buf, [0]);
let mut buf = [0, ..4];
assert_eq!(reader.read(buf), Some(4));
assert_eq!(reader.tell(), 5);
assert_eq!(buf, [1, 2, 3, 4]);
assert_eq!(reader.read(buf), Some(3));
assert_eq!(buf.slice(0, 3), [5, 6, 7]);
assert!(reader.eof());
assert_eq!(reader.read(buf), None);
assert!(reader.eof());
}
#[test]
fn test_with_mem_writer() {
let buf = with_mem_writer(|wr| wr.write([1,2,3,4,5,6,7]));
assert_eq!(buf, ~[1,2,3,4,5,6,7]);
}
}
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