Skip to content
This repository has been archived by the owner on Jan 6, 2020. It is now read-only.

Commit

Permalink
Merge pull request #9 from canndrew/refactor
Browse files Browse the repository at this point in the history 
Refactor
  • Loading branch information
Fraser Hutchison committed Mar 7, 2016
2 parents b18d532 + ea33577 commit af083f2
Show file tree
Hide file tree
Showing 2 changed files with 123 additions and 49 deletions.
169 changes: 122 additions & 47 deletions src/file_handler.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -16,14 +16,14 @@
// relating to use of the SAFE Network Software.

use error::Error;
use memmap::{Mmap, Protection};
use rustc_serialize::{Decodable, Encodable};
use rustc_serialize::json::{self, Json, Decoder};
use std::env;
use std::ffi::{OsStr, OsString};
use std::fs::{self, File, OpenOptions};
use std::io::{self, Write};
use std::path::{Path, PathBuf};
use std::marker::PhantomData;

/// Struct for reading and writing config files.
///
Expand All @@ -49,12 +49,14 @@ use std::path::{Path, PathBuf};
/// mutually-exclusive to all other such binaries, and that each config file to be managed by
/// `FileHandler` is placed in each binary's [`current_bin_dir()`](fn.current_bin_dir.html). In
/// this way, each process should be the only one accessing that file.
pub struct FileHandler {
pub struct FileHandler<T> {
path: PathBuf,
_ph: PhantomData<T>,
}

impl FileHandler {
impl<T> FileHandler<T> {
/// Constructor taking the required file name (not the full path)
/// This function will return an error if the file does not exist.
///
/// This function tests whether it has write access to the file in the following locations in
/// this order (see also [an example config file flowchart]
Expand All @@ -66,78 +68,151 @@ impl FileHandler {
///
/// See [Thread- and Process-Safety](#thread--and-process-safety) for notes on thread- and
/// process-safety.
pub fn new<S: AsRef<OsStr> + ?Sized>(name: &S) -> Result<FileHandler, Error> {
pub fn open<S: AsRef<OsStr> + ?Sized>(name: &S) -> Result<FileHandler<T>, Error> {
let name = name.as_ref();
let mut path = try!(current_bin_dir());
path.push(name);
match OpenOptions::new().write(true).create(true).open(&path) {
Ok(_) => return Ok(FileHandler { path: path }),
match OpenOptions::new().write(true).open(&path) {
Ok(_) => return Ok(FileHandler {
path: path,
_ph: PhantomData,
}),
Err(_) => (),
};

let mut path = try!(user_app_dir());
path.push(name);
match OpenOptions::new().write(true).create(true).open(&path) {
Ok(_) => return Ok(FileHandler { path: path }),
match OpenOptions::new().write(true).open(&path) {
Ok(_) => return Ok(FileHandler {
path: path,
_ph: PhantomData,
}),
Err(_) => (),
};

let mut path = try!(system_cache_dir());
path.push(name);
match OpenOptions::new().write(true).create(true).open(&path) {
Ok(_) => Ok(FileHandler { path: path }),
match OpenOptions::new().write(true).open(&path) {
Ok(_) => Ok(FileHandler {
path: path,
_ph: PhantomData,
}),
Err(e) => Err(From::from(e)),
}
}

/// Remove the file from every location where it can be read.
pub fn cleanup<S: AsRef<OsStr>>(name: &S) -> io::Result<()> {
let name = name.as_ref();
let i1 = current_bin_dir().into_iter();
let i2 = user_app_dir().into_iter();
let i3 = system_cache_dir().into_iter();
/// Get the full path to the file.
pub fn path(&self) -> &Path {
&self.path
}
}

let dirs = i1.chain(i2.chain(i3));
impl<T> FileHandler<T>
where T: Default + Encodable
{
/// Constructor taking the required file name (not the full path)
/// The config file will be initialised to a default if it does not exist.
///
/// This function tests whether it has write access to the file in the following locations in
/// this order (see also [an example config file flowchart]
/// (https://github.com/maidsafe/crust/blob/master/docs/vault_config_file_flowchart.pdf)):
///
/// 1. [`current_bin_dir()`](fn.current_bin_dir.html)
/// 2. [`user_app_dir()`](fn.user_app_dir.html)
/// 3. [`system_cache_dir()`](fn.system_cache_dir.html)
///
/// See [Thread- and Process-Safety](#thread--and-process-safety) for notes on thread- and
/// process-safety.
pub fn new<S: AsRef<OsStr> + ?Sized>(name: &S) -> Result<FileHandler<T>, Error> {
match FileHandler::open(name) {
Ok(fh) => return Ok(fh),
Err(_) => (),
};

for mut path in dirs {
path.push(name);
if path.exists() {
try!(fs::remove_file(path));
}
}
let contents = format!("{}", json::as_pretty_json(&T::default())).into_bytes();
let name = name.as_ref();
let mut path = try!(current_bin_dir());
path.push(name);
match OpenOptions::new().write(true).create(true).open(&path) {
Ok(mut f) => {
try!(f.write_all(&contents));
return Ok(FileHandler {
path: path,
_ph: PhantomData,
});
},
Err(_) => (),
};

Ok(())
}
let mut path = try!(user_app_dir());
path.push(name);
match OpenOptions::new().write(true).create(true).open(&path) {
Ok(mut f) => {
try!(f.write_all(&contents));
return Ok(FileHandler {
path: path,
_ph: PhantomData,
});
},
Err(_) => (),
};

/// Get the full path to the file.
pub fn path(&self) -> &Path {
&self.path
let mut path = try!(system_cache_dir());
path.push(name);
match OpenOptions::new().write(true).create(true).open(&path) {
Ok(mut f) => {
try!(f.write_all(&contents));
Ok(FileHandler {
path: path,
_ph: PhantomData,
})
},
Err(e) => Err(From::from(e)),
}
}
}

impl<T> FileHandler<T>
where T: Decodable
{
/// Read the contents of the file and decode it as JSON.
#[allow(unsafe_code)]
pub fn read_file<Contents: Decodable>(&self) -> Result<Contents, Error> {
let file = try!(File::open(&self.path));
// TODO Replace with facilitites from fs2
let file = try!(Mmap::open(&file, Protection::Read));
let bytes: &[u8] = unsafe { file.as_slice() };
let mut cursor = io::Cursor::new(bytes);
let json = try!(Json::from_reader(&mut cursor));
let contents = try!(Contents::decode(&mut Decoder::new(json)));
pub fn read_file(&self) -> Result<T, Error> {
let mut file = try!(File::open(&self.path));
let json = try!(Json::from_reader(&mut file));
let contents = try!(T::decode(&mut Decoder::new(json)));
Ok(contents)
}
}

impl<T> FileHandler<T>
where T: Encodable
{
/// Write `contents` to the file as JSON.
#[allow(unsafe_code)]
pub fn write_file<Contents: Encodable>(&self, contents: &Contents) -> Result<(), Error> {
pub fn write_file(&self, contents: &T) -> Result<(), Error> {
let contents = format!("{}", json::as_pretty_json(contents)).into_bytes();
let file = try!(OpenOptions::new().read(true).write(true).create(true).open(&self.path));
try!(file.set_len(contents.len() as u64));
let mut mmap = try!(Mmap::open(&file, Protection::ReadWrite));
// TODO Replace with facilitites from fs2
try!(unsafe { mmap.as_mut_slice() }.write_all(&contents[..]));
mmap.flush().map_err(Error::IoError)
let mut file = try!(OpenOptions::new().write(true).create(true).open(&self.path));
try!(file.write_all(&contents));
Ok(())
}
}

/// Remove the file from every location where it can be read.
pub fn cleanup<S: AsRef<OsStr>>(name: &S) -> io::Result<()> {
let name = name.as_ref();
let i1 = current_bin_dir().into_iter();
let i2 = user_app_dir().into_iter();
let i3 = system_cache_dir().into_iter();

let dirs = i1.chain(i2.chain(i3));

for mut path in dirs {
path.push(name);
if path.exists() {
try!(fs::remove_file(path));
}
}

Ok(())
}

/// The full path to the directory containing the currently-running binary. See also [an example
Expand Down Expand Up @@ -248,8 +323,8 @@ mod test {
};
let test_value = 123456789u64;

let _ = file_handler.write_file::<u64>(&test_value);
let read_value = match file_handler.read_file::<u64>() {
let _ = file_handler.write_file(&test_value);
let read_value = match file_handler.read_file() {
Ok(result) => result,
Err(err) => panic!("failed reading file with error {:?}", err),
};
Expand Down
3 changes: 1 addition & 2 deletions src/lib.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -43,12 +43,11 @@
#![cfg_attr(feature="clippy", deny(clippy, clippy_pedantic))]
#![cfg_attr(feature="clippy", allow(use_debug))]

extern crate memmap;
extern crate rustc_serialize;

mod error;
mod file_handler;

pub use error::Error;
pub use file_handler::{FileHandler, ScopedUserAppDirRemover, current_bin_dir, user_app_dir,
system_cache_dir, exe_file_stem};
system_cache_dir, exe_file_stem, cleanup};

0 comments on commit af083f2

Please sign in to comment.