Vendor things

third-party/vendor/flate2/src/bufreader.rs

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+// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// <https://github.com/rust-lang/rust/blob/HEAD/COPYRIGHT>.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::cmp;
+use std::io;
+use std::io::prelude::*;
+use std::mem;
+
+pub struct BufReader<R> {
+    inner: R,
+    buf: Box<[u8]>,
+    pos: usize,
+    cap: usize,
+}
+
+impl<R> ::std::fmt::Debug for BufReader<R>
+where
+    R: ::std::fmt::Debug,
+{
+    fn fmt(&self, fmt: &mut ::std::fmt::Formatter) -> Result<(), ::std::fmt::Error> {
+        fmt.debug_struct("BufReader")
+            .field("reader", &self.inner)
+            .field(
+                "buffer",
+                &format_args!("{}/{}", self.cap - self.pos, self.buf.len()),
+            )
+            .finish()
+    }
+}
+
+impl<R: Read> BufReader<R> {
+    pub fn new(inner: R) -> BufReader<R> {
+        BufReader::with_buf(vec![0; 32 * 1024], inner)
+    }
+
+    pub fn with_buf(buf: Vec<u8>, inner: R) -> BufReader<R> {
+        BufReader {
+            inner,
+            buf: buf.into_boxed_slice(),
+            pos: 0,
+            cap: 0,
+        }
+    }
+}
+
+impl<R> BufReader<R> {
+    pub fn get_ref(&self) -> &R {
+        &self.inner
+    }
+
+    pub fn get_mut(&mut self) -> &mut R {
+        &mut self.inner
+    }
+
+    pub fn into_inner(self) -> R {
+        self.inner
+    }
+
+    pub fn reset(&mut self, inner: R) -> R {
+        self.pos = 0;
+        self.cap = 0;
+        mem::replace(&mut self.inner, inner)
+    }
+}
+
+impl<R: Read> Read for BufReader<R> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        // If we don't have any buffered data and we're doing a massive read
+        // (larger than our internal buffer), bypass our internal buffer
+        // entirely.
+        if self.pos == self.cap && buf.len() >= self.buf.len() {
+            return self.inner.read(buf);
+        }
+        let nread = {
+            let mut rem = self.fill_buf()?;
+            rem.read(buf)?
+        };
+        self.consume(nread);
+        Ok(nread)
+    }
+}
+
+impl<R: Read> BufRead for BufReader<R> {
+    fn fill_buf(&mut self) -> io::Result<&[u8]> {
+        // If we've reached the end of our internal buffer then we need to fetch
+        // some more data from the underlying reader.
+        if self.pos == self.cap {
+            self.cap = self.inner.read(&mut self.buf)?;
+            self.pos = 0;
+        }
+        Ok(&self.buf[self.pos..self.cap])
+    }
+
+    fn consume(&mut self, amt: usize) {
+        self.pos = cmp::min(self.pos + amt, self.cap);
+    }
+}