Skip to content

Commit

Permalink
Add back in more specific error messages
Browse files Browse the repository at this point in the history
  • Loading branch information
@LPGhatguy @andrewhickman
LPGhatguy authored and andrewhickman committed Feb 19, 2020
1 parent 1f12fe9 commit 52bc2f6
Show file tree
Hide file tree
Showing 2 changed files with 81 additions and 30 deletions.
37 changes: 35 additions & 2 deletions src/errors.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,21 +3,38 @@ use std::fmt;
use std::io;
use std::path::PathBuf;

#[derive(Debug, Clone, Copy)]
pub(crate) enum ErrorKind {
OpenFile,
CreateFile,
SyncFile,
SetLen,
Metadata,
Clone,
SetPermissions,
Read,
Seek,
Write,
Flush,
}

/// Contains an IO error that has a file path attached.
///
/// This type is never returned directly, but is instead wrapped inside yet
/// another IO error.
#[derive(Debug)]
pub(crate) struct Error {
kind: ErrorKind,
source: io::Error,
path: PathBuf,
}

impl Error {
pub fn new<P: Into<PathBuf>>(source: io::Error, path: P) -> io::Error {
pub fn new<P: Into<PathBuf>>(source: io::Error, kind: ErrorKind, path: P) -> io::Error {
io::Error::new(
source.kind(),
Self {
kind,
source,
path: path.into(),
},
Expand All @@ -27,7 +44,23 @@ impl Error {

impl fmt::Display for Error {
fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
write!(formatter, "{} in path {}", self.source, self.path.display())
use ErrorKind::*;

let path = self.path.display();

match self.kind {
OpenFile => write!(formatter, "failed to open file `{}`", path),
CreateFile => write!(formatter, "failed to create file `{}`", path),
SyncFile => write!(formatter, "failed to sync file `{}`", path),
SetLen => write!(formatter, "failed to set length of file `{}`", path),
Metadata => write!(formatter, "failed to query metadata of file `{}`", path),
Clone => write!(formatter, "failed to clone handle for file `{}`", path),
SetPermissions => write!(formatter, "failed to set permissions for file `{}`", path),
Read => write!(formatter, "failed to read from file `{}`", path),
Seek => write!(formatter, "failed to seek in file `{}`", path),
Write => write!(formatter, "failed to write to file `{}`", path),
Flush => write!(formatter, "failed to flush file `{}`", path),
}
}
}

Expand Down
74 changes: 46 additions & 28 deletions src/lib.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,7 @@ use std::fs;
use std::io::{self, Read, Seek, Write};
use std::path::{Path, PathBuf};

use errors::Error;
use errors::{Error, ErrorKind};

/// A wrapper around a file handle and its path which wraps all
/// operations with more helpful error messages.
Expand All @@ -29,7 +29,7 @@ impl File {
{
match fs::File::open(path.as_ref()) {
Ok(file) => Ok(File::from_parts(file, path.into())),
Err(source) => Err(Error::new(source, path)),
Err(source) => Err(Error::new(source, ErrorKind::OpenFile, path)),
}
}

Expand All @@ -40,7 +40,7 @@ impl File {
{
match fs::File::create(path.as_ref()) {
Ok(file) => Ok(File::from_parts(file, path.into())),
Err(source) => Err(Error::new(source, path)),
Err(source) => Err(Error::new(source, ErrorKind::CreateFile, path)),
}
}

Expand All @@ -51,36 +51,36 @@ impl File {
{
match options.open(path.as_ref()) {
Ok(file) => Ok(File::from_parts(file, path.into())),
Err(source) => Err(Error::new(source, path)),
Err(source) => Err(Error::new(source, ErrorKind::OpenFile, path)),
}
}

/// Wrapper for [`File::sync_all`](https://doc.rust-lang.org/stable/std/fs/struct.File.html#method.sync_all).
pub fn sync_all(&self) -> Result<(), io::Error> {
self.file
.sync_all()
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::SyncFile))
}

/// Wrapper for [`File::sync_data`](https://doc.rust-lang.org/stable/std/fs/struct.File.html#method.sync_data).
pub fn sync_data(&self) -> Result<(), io::Error> {
self.file
.sync_data()
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::SyncFile))
}

/// Wrapper for [`File::set_len`](https://doc.rust-lang.org/stable/std/fs/struct.File.html#method.set_len).
pub fn set_len(&self, size: u64) -> Result<(), io::Error> {
self.file
.set_len(size)
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::SetLen))
}

/// Wrapper for [`File::metadata`](https://doc.rust-lang.org/stable/std/fs/struct.File.html#method.metadata).
pub fn metadata(&self) -> Result<fs::Metadata, io::Error> {
self.file
.metadata()
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::Metadata))
}

/// Wrapper for [`File::try_clone`](https://doc.rust-lang.org/stable/std/fs/struct.File.html#method.try_clone).
Expand All @@ -91,14 +91,14 @@ impl File {
file,
path: self.path.clone(),
})
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::Clone))
}

/// Wrapper for [`File::set_permissions`](https://doc.rust-lang.org/stable/std/fs/struct.File.html#method.set_permissions).
pub fn set_permissions(&self, perm: fs::Permissions) -> Result<(), io::Error> {
self.file
.set_permissions(perm)
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::SetPermissions))
}

/// Creates a [`File`](struct.File.html) from a raw file and its
Expand All @@ -122,106 +122,124 @@ impl File {
pub fn path(&self) -> &Path {
&self.path
}

/// Wrap the error in information specific to this `File` object.
fn error(&self, source: io::Error, kind: ErrorKind) -> io::Error {
Error::new(source, kind, &self.path)
}
}

impl Read for File {
fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
self.file
.read(buf)
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::Read))
}

fn read_vectored(&mut self, bufs: &mut [std::io::IoSliceMut<'_>]) -> std::io::Result<usize> {
self.file
.read_vectored(bufs)
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::Read))
}
}

impl<'a> Read for &'a File {
fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
(&(**self).file)
.read(buf)
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::Read))
}

fn read_vectored(&mut self, bufs: &mut [std::io::IoSliceMut<'_>]) -> std::io::Result<usize> {
(&(**self).file)
.read_vectored(bufs)
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::Read))
}
}

impl Seek for File {
fn seek(&mut self, pos: std::io::SeekFrom) -> std::io::Result<u64> {
self.file
.seek(pos)
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::Seek))
}
}

impl<'a> Seek for &'a File {
fn seek(&mut self, pos: std::io::SeekFrom) -> std::io::Result<u64> {
(&(**self).file)
.seek(pos)
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::Seek))
}
}

impl Write for File {
fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
self.file
.write(buf)
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::Write))
}

fn write_vectored(&mut self, bufs: &[std::io::IoSlice<'_>]) -> std::io::Result<usize> {
self.file
.write_vectored(bufs)
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::Write))
}

fn flush(&mut self) -> std::io::Result<()> {
self.file
.flush()
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::Flush))
}
}

impl<'a> Write for &'a File {
fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
(&(**self).file)
.write(buf)
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::Write))
}

fn write_vectored(&mut self, bufs: &[std::io::IoSlice<'_>]) -> std::io::Result<usize> {
(&(**self).file)
.write_vectored(bufs)
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::Write))
}

fn flush(&mut self) -> std::io::Result<()> {
(&(**self).file)
.flush()
.map_err(|source| Error::new(source, &self.path))
.map_err(|source| self.error(source, ErrorKind::Flush))
}
}

fn initial_buffer_size(file: &File) -> usize {
file.file()
.metadata()
.map(|m| m.len() as usize + 1)
.unwrap_or(0)
}

/// Wrapper for [`fs::read`](https://doc.rust-lang.org/stable/std/fs/fn.read.html).
pub fn read<P: AsRef<Path> + Into<PathBuf>>(path: P) -> std::io::Result<Vec<u8>> {
fs::read(path.as_ref()).map_err(|source| Error::new(source, path))
pub fn read<P: AsRef<Path> + Into<PathBuf>>(path: P) -> io::Result<Vec<u8>> {
let mut file = File::open(path)?;
let mut bytes = Vec::with_capacity(initial_buffer_size(&file));
file.read_to_end(&mut bytes)?;
Ok(bytes)
}

/// Wrapper for [`fs::read_to_string`](https://doc.rust-lang.org/stable/std/fs/fn.read_to_string.html).
pub fn read_to_string<P: AsRef<Path> + Into<PathBuf>>(path: P) -> std::io::Result<String> {
fs::read_to_string(path.as_ref()).map_err(|source| Error::new(source, path))
pub fn read_to_string<P: AsRef<Path> + Into<PathBuf>>(path: P) -> io::Result<String> {
let mut file = File::open(path)?;
let mut string = String::with_capacity(initial_buffer_size(&file));
file.read_to_string(&mut string)?;
Ok(string)
}

/// Wrapper for [`fs::write`](https://doc.rust-lang.org/stable/std/fs/fn.write.html).
pub fn write<P: AsRef<Path> + Into<PathBuf>, C: AsRef<[u8]>>(
path: P,
contents: C,
) -> std::io::Result<()> {
fs::write(path.as_ref(), contents).map_err(|source| Error::new(source, path))
) -> io::Result<()> {
File::create(path)?.write_all(contents.as_ref())
}

0 comments on commit 52bc2f6

Please sign in to comment.