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use libc::{mmap, munmap, PROT_READ, MAP_PRIVATE};
use std::fmt;
use std::fs;
use std::io;
use std::os::unix::io::AsRawFd;
use std::slice;
use std::path::{Path, PathBuf};
use std::ptr;
use super::*;
use crate::file_error::FileError;
const MMAP_THRESHOLD: u64 = 16 * 4096;
pub struct File<'a, C: fmt::Debug + Sync + Send>(Imp<'a, C>, PathBuf);
assert_send_and_sync!(File<'_, C>
where C: fmt::Debug);
impl<'a, C: fmt::Debug + Sync + Send> fmt::Display for File<'a, C> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{} {:?}", self.0, self.1.display())
}
}
impl<'a, C: fmt::Debug + Sync + Send> fmt::Debug for File<'a, C> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_tuple("File")
.field(&self.0)
.field(&self.1)
.finish()
}
}
enum Imp<'a, C: fmt::Debug + Sync + Send> {
Generic(Generic<fs::File, C>),
Mmap {
reader: Memory<'a, C>,
}
}
impl<'a, C: fmt::Debug + Sync + Send> Drop for Imp<'a, C> {
fn drop(&mut self) {
match self {
Imp::Generic(_) => (),
Imp::Mmap { reader, } => {
let buf = reader.source_buffer();
unsafe {
munmap(buf.as_ptr() as *mut _, buf.len());
}
},
}
}
}
impl<'a, C: fmt::Debug + Sync + Send> fmt::Display for Imp<'a, C> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "File(")?;
match self {
Imp::Generic(_) => write!(f, "Generic")?,
Imp::Mmap { .. } => write!(f, "Memory")?,
};
write!(f, ")")
}
}
impl<'a, C: fmt::Debug + Sync + Send> fmt::Debug for Imp<'a, C> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
Imp::Generic(ref g) =>
f.debug_tuple("Generic")
.field(&g)
.finish(),
Imp::Mmap { reader, } =>
f.debug_struct("Mmap")
.field("addr", &reader.source_buffer().as_ptr())
.field("length", &reader.source_buffer().len())
.field("reader", reader)
.finish(),
}
}
}
impl<'a> File<'a, ()> {
pub fn new<P: AsRef<Path>>(file: fs::File, path: P) -> io::Result<Self> {
Self::new_with_cookie(file, path.as_ref(), ())
}
pub fn open<P: AsRef<Path>>(path: P) -> io::Result<Self> {
Self::with_cookie(path, ())
}
}
impl<'a, C: fmt::Debug + Sync + Send> File<'a, C> {
pub fn new_with_cookie<P: AsRef<Path>>(file: fs::File, path: P, cookie: C)
-> io::Result<Self> {
let path = path.as_ref();
let generic = |file, cookie| {
Ok(File(
Imp::Generic(
Generic::with_cookie(file, None, cookie)),
path.into()))
};
if ::std::env::var_os("SEQUOIA_DONT_MMAP").is_some() {
return generic(file, cookie);
}
let length =
file.metadata().map_err(|e| FileError::new(path, e))?.len();
if length < MMAP_THRESHOLD {
return generic(file, cookie);
}
let length: usize = match length.try_into() {
Ok(v) => v,
Err(_) => return generic(file, cookie),
};
let fd = file.as_raw_fd();
let addr = unsafe {
mmap(ptr::null_mut(), length, PROT_READ, MAP_PRIVATE,
fd, 0)
};
if addr == libc::MAP_FAILED {
return generic(file, cookie);
}
let slice = unsafe {
slice::from_raw_parts(addr as *const u8, length)
};
Ok(File(
Imp::Mmap {
reader: Memory::with_cookie(slice, cookie),
},
path.into(),
))
}
pub fn with_cookie<P: AsRef<Path>>(path: P, cookie: C) -> io::Result<Self> {
let path = path.as_ref();
let file = fs::File::open(path).map_err(|e| FileError::new(path, e))?;
Self::new_with_cookie(file, path, cookie)
}
}
impl<'a, C: fmt::Debug + Sync + Send> io::Read for File<'a, C> {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
match self.0 {
Imp::Generic(ref mut reader) => reader.read(buf),
Imp::Mmap { ref mut reader, .. } => reader.read(buf),
}.map_err(|e| FileError::new(&self.1, e))
}
}
impl<'a, C: fmt::Debug + Sync + Send> BufferedReader<C> for File<'a, C> {
fn buffer(&self) -> &[u8] {
match self.0 {
Imp::Generic(ref reader) => reader.buffer(),
Imp::Mmap { ref reader, .. } => reader.buffer(),
}
}
fn data(&mut self, amount: usize) -> io::Result<&[u8]> {
let path = &self.1;
match self.0 {
Imp::Generic(ref mut reader) => reader.data(amount),
Imp::Mmap { ref mut reader, .. } => reader.data(amount),
}.map_err(|e| FileError::new(path, e))
}
fn data_hard(&mut self, amount: usize) -> io::Result<&[u8]> {
let path = &self.1;
match self.0 {
Imp::Generic(ref mut reader) => reader.data_hard(amount),
Imp::Mmap { ref mut reader, .. } => reader.data_hard(amount),
}.map_err(|e| FileError::new(path, e))
}
fn consume(&mut self, amount: usize) -> &[u8] {
match self.0 {
Imp::Generic(ref mut reader) => reader.consume(amount),
Imp::Mmap { ref mut reader, .. } => reader.consume(amount),
}
}
fn data_consume(&mut self, amount: usize) -> io::Result<&[u8]> {
let path = &self.1;
match self.0 {
Imp::Generic(ref mut reader) => reader.data_consume(amount),
Imp::Mmap { ref mut reader, .. } => reader.data_consume(amount),
}.map_err(|e| FileError::new(path, e))
}
fn data_consume_hard(&mut self, amount: usize) -> io::Result<&[u8]> {
let path = &self.1;
match self.0 {
Imp::Generic(ref mut reader) => reader.data_consume_hard(amount),
Imp::Mmap { ref mut reader, .. } => reader.data_consume_hard(amount),
}.map_err(|e| FileError::new(path, e))
}
fn get_mut(&mut self) -> Option<&mut dyn BufferedReader<C>> {
None
}
fn get_ref(&self) -> Option<&dyn BufferedReader<C>> {
None
}
fn into_inner<'b>(self: Box<Self>) -> Option<Box<dyn BufferedReader<C> + 'b>>
where Self: 'b {
None
}
fn cookie_set(&mut self, cookie: C) -> C {
match self.0 {
Imp::Generic(ref mut reader) => reader.cookie_set(cookie),
Imp::Mmap { ref mut reader, .. } => reader.cookie_set(cookie),
}
}
fn cookie_ref(&self) -> &C {
match self.0 {
Imp::Generic(ref reader) => reader.cookie_ref(),
Imp::Mmap { ref reader, .. } => reader.cookie_ref(),
}
}
fn cookie_mut(&mut self) -> &mut C {
match self.0 {
Imp::Generic(ref mut reader) => reader.cookie_mut(),
Imp::Mmap { ref mut reader, .. } => reader.cookie_mut(),
}
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn error_contains_path() {
let p = "/i/do/not/exist";
let e = File::open(p).unwrap_err();
assert!(e.to_string().contains(p));
}
}