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#![allow(non_snake_case)]
//Copyright 2021 #UlinProject Денис Котляров
//Licensed under the Apache License, Version 2.0 (the "License");
//you may not use this file except in compliance with the License.
//You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//Unless required by applicable law or agreed to in writing, software
//distributed under the License is distributed on an "AS IS" BASIS,
//WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//See the License for the specific language governing permissions and
// limitations under the License.
//#Ulin Project 2021
//
/*!
Installation and subsequent safe removal of `flock` locks for data streams.
# Use
1. Exclusive LockFile
```rust
use cluFlock::ToFlock;
use std::fs::File;
use std::io;
fn main() -> Result<(), io::Error> {
let file_lock = File::create("./file")?.wait_exclusive_lock()?;
println!("{:?}", file_lock);
Ok( () )
}
```
2. Exclusive LockFile (FnOnce)
```rust
use std::io::Write;
use cluFlock::ToFlock;
use std::fs::File;
use std::io;
fn main() -> Result<(), io::Error> {
File::create("./file")?.wait_exclusive_lock_fn(
// valid exclusive lock
|mut file| write!(file, "Test."), // result: Ok(usize)/Err(std::io::Error)
// invalid lock
|err| Err(err.into_err()) // into_err: FlockErr -> std::io::Error
)?;
Ok(())
}
```
3. Exclusive LockFile (&File)
```rust
use cluFlock::ExclusiveFlock;
use std::fs::File;
fn main() -> Result<(), std::io::Error> {
let file = File::create("./file")?;
{
let file_lock = ExclusiveFlock::wait_lock(&file)?;
// file_lock, type: FlockLock<&File>
println!("{:?}", file_lock);
} // auto unlock ExclusiveFlock
file.sync_all()?;
Ok( () )
}
```
4. Shared LockFile (&File)
```rust
use std::fs::File;
use cluFlock::SharedFlock;
use std::io;
fn main() -> Result<(), io::Error> {
let file = File::create("./test_file")?;
let shared = SharedFlock::wait_lock(&file);
println!("#1shared {:?}", shared);
let shared2 = SharedFlock::try_lock(&file);
println!("#2shared {:?}", shared2);
assert_eq!(shared.is_ok(), true);
assert_eq!(shared2.is_ok(), true);
// manual or automatic unlock SharedFlock_x2
// drop(shared);
// drop(shared2);
Ok( () )
}
```
# Support of platforms:
1. Unix, Linux: Full support: SharedFlock (Wait, Try), ExclusiveFlock (Wait, Try), Unlock (Wait, Try).
1. Windows: Full support: SharedFlock (Wait, Try), ExclusiveFlock (Wait, Try), Unlock (Wait, !Try). Unlock Try is not implemented and is considered additional unsafe functionality.
# Features of platforms:
1. Unix, Linux: The flock system call only works between processes, there are no locks inside the process.
2. Windows: System calls (LockFileEx UnlockFileEx) work between processes and within the current process. If you use Shared and Exclusive locks, you can lock yourself in the same process.
# License
Copyright 2021 #UlinProject Denis Kotlyarov (Денис Котляров)
Licensed under the Apache License, Version 2.0
*/
use crate::data::err::FlockError;
use crate::data::unlock::WaitFlockUnlock;
use crate::element::FlockElement;
// os_release
mod os_release {
#[cfg(unix)]
pub mod unix;
#[cfg(windows)]
pub mod windows;
}
#[doc(hidden)]
pub (crate) mod sys {
#[cfg(unix)]
pub use crate::os_release::unix::*;
#[cfg(windows)]
pub use crate::os_release::windows::*;
}
mod data {
pub mod err;
pub mod unlock;
mod lock;
pub use self::lock::*;
}
pub use self::data::*;
mod to;
pub use self::to::*;
pub mod element;
/// Set exclusive lock. Only one process can hold a data flow lock.
pub trait ExclusiveFlock where Self: FlockElement + WaitFlockUnlock + Sized {
#[inline]
fn try_lock(self) -> Result<FlockLock<Self>, FlockError<Self>> {
ExclusiveFlock::try_lock_fn(
self,
|sself| Ok(sself),
|e| Err(e)
)
}
#[inline]
fn wait_lock(self) -> Result<FlockLock<Self>, FlockError<Self>> {
ExclusiveFlock::wait_lock_fn(
self,
|sself| Ok(sself),
|e| Err(e)
)
}
fn try_lock_fn<F: FnOnce(FlockLock<Self>) -> R, FE: FnOnce(FlockError<Self>) -> R, R>(self, next: F, errf: FE) -> R;
fn wait_lock_fn<F: FnOnce(FlockLock<Self>) -> R, FE: FnOnce(FlockError<Self>) -> R, R>(self, next: F, errf: FE) -> R;
}
/// Set common lock, common locks can be many. An exclusive lock will wait for all shared locks to complete.
pub trait SharedFlock where Self: FlockElement + WaitFlockUnlock + Sized {
#[inline]
fn try_lock(self) -> Result<FlockLock<Self>, FlockError<Self>> {
SharedFlock::try_lock_fn(
self,
|sself| Ok(sself),
|e| Err(e)
)
}
#[inline]
fn wait_lock(self) -> Result<FlockLock<Self>, FlockError<Self>> {
SharedFlock::wait_lock_fn(
self,
|sself| Ok(sself),
|e| Err(e)
)
}
fn try_lock_fn<F: FnOnce(FlockLock<Self>) -> R, FE: FnOnce(FlockError<Self>) -> R, R>(self, next: F, errf: FE) -> R;
fn wait_lock_fn<F: FnOnce(FlockLock<Self>) -> R, FE: FnOnce(FlockError<Self>) -> R, R>(self, next: F, errf: FE) -> R;
}