imag/libimagcounter/src/counter.rs

144 lines
5 KiB
Rust

use std::convert::From;
use std::convert::Into;
use std::ops::DerefMut;
use std::ops::Deref;
use toml::Value;
use std::collections::BTreeMap;
use libimagstore::store::Store;
use libimagstore::store::FileLockEntry;
use libimagstore::storeid::StoreId;
use libimagstore::error::StoreError;
use libimagstore::store::Entry;
use libimagstore::storeid::IntoStoreId;
use module_path::ModuleEntryPath;
use result::Result;
use error::CounterError as CE;
use error::CounterErrorKind as CEK;
pub type CounterName = String;
pub struct Counter<'a> {
fle: FileLockEntry<'a>,
}
impl<'a> Counter<'a> {
pub fn new(store: &Store, name: CounterName, init: i64) -> Result<Counter> {
use std::ops::DerefMut;
debug!("Creating new counter: '{}' with value: {}", name, init);
let fle = {
let mut lockentry = store.create(ModuleEntryPath::new(name.clone()).into_storeid());
if lockentry.is_err() {
return Err(CE::new(CEK::StoreWriteError, Some(Box::new(lockentry.err().unwrap()))));
}
let mut lockentry = lockentry.unwrap();
{
let mut entry = lockentry.deref_mut();
let mut header = entry.get_header_mut();
let setres = header.set("counter", Value::Table(BTreeMap::new()));
if setres.is_err() {
return Err(CE::new(CEK::StoreWriteError, Some(Box::new(setres.err().unwrap()))));
}
let setres = header.set("counter.name", Value::String(name));
if setres.is_err() {
return Err(CE::new(CEK::StoreWriteError, Some(Box::new(setres.err().unwrap()))));
}
let setres = header.set("counter.value", Value::Integer(init));
if setres.is_err() {
return Err(CE::new(CEK::StoreWriteError, Some(Box::new(setres.err().unwrap()))));
}
}
lockentry
};
Ok(Counter { fle: fle })
}
pub fn inc(&mut self) -> Result<()> {
let mut header = self.fle.deref_mut().get_header_mut();
match header.read("counter.value") {
Ok(Some(Value::Integer(i))) => {
header.set("counter.value", Value::Integer(i + 1))
.map_err(|e| CE::new(CEK::StoreWriteError, Some(Box::new(e))))
.map(|_| ())
},
Err(e) => Err(CE::new(CEK::StoreReadError, Some(Box::new(e)))),
_ => Err(CE::new(CEK::StoreReadError, None)),
}
}
pub fn dec(&mut self) -> Result<()> {
let mut header = self.fle.deref_mut().get_header_mut();
match header.read("counter.value") {
Ok(Some(Value::Integer(i))) => {
header.set("counter.value", Value::Integer(i - 1))
.map_err(|e| CE::new(CEK::StoreWriteError, Some(Box::new(e))))
.map(|_| ())
},
Err(e) => Err(CE::new(CEK::StoreReadError, Some(Box::new(e)))),
_ => Err(CE::new(CEK::StoreReadError, None)),
}
}
pub fn reset(&mut self) -> Result<()> {
let mut header = self.fle.deref_mut().get_header_mut();
header.set("counter.value", Value::Integer(0))
.map_err(|e| CE::new(CEK::StoreWriteError, Some(Box::new(e))))
.map(|_| ())
}
pub fn set(&mut self, v: i64) -> Result<()> {
let mut header = self.fle.deref_mut().get_header_mut();
header.set("counter.value", Value::Integer(v))
.map_err(|e| CE::new(CEK::StoreWriteError, Some(Box::new(e))))
.map(|_| ())
}
pub fn name(&self) -> Result<CounterName> {
let mut header = self.fle.deref().get_header();
header.read("counter.name")
.map_err(|e| CE::new(CEK::StoreWriteError, Some(Box::new(e))))
.and_then(|v| {
match v {
Some(Value::String(s)) => Ok(s),
_ => Err(CE::new(CEK::HeaderTypeError, None)),
}
})
}
pub fn value(&self) -> Result<i64> {
let mut header = self.fle.deref().get_header();
header.read("counter.value")
.map_err(|e| CE::new(CEK::StoreWriteError, Some(Box::new(e))))
.and_then(|v| {
match v {
Some(Value::Integer(i)) => Ok(i),
_ => Err(CE::new(CEK::HeaderTypeError, None)),
}
})
}
pub fn load(name: CounterName, store: &Store) -> Result<Counter> {
debug!("Loading counter: '{}'", name);
match store.retrieve(ModuleEntryPath::new(name).into_storeid()) {
Err(e) => Err(CE::new(CEK::StoreReadError, Some(Box::new(e)))),
Ok(c) => Ok(Counter { fle: c }),
}
}
pub fn delete(name: CounterName, store: &Store) -> Result<()> {
debug!("Deleting counter: '{}'", name);
store.delete(ModuleEntryPath::new(name).into_storeid())
.map_err(|e| CE::new(CEK::StoreWriteError, Some(Box::new(e))))
}
}