ucg/src/build/opcode/cache.rs

46 lines
1.3 KiB
Rust

// Copyright 2019 Jeremy Wall
//
// 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.
use std::collections::btree_map;
use std::collections::BTreeMap;
use std::rc::Rc;
use std::path::PathBuf;
use super::{Op, OpPointer};
/// A Cache of Op codes.
pub struct Ops {
ops: BTreeMap<String, Rc<Vec<Op>>>,
}
impl Ops {
pub fn new() -> Self {
Self {
ops: BTreeMap::new(),
}
}
pub fn entry<'a, S: Into<String>>(&'a mut self, path: S) -> Entry<'a> {
Entry(self.ops.entry(path.into()))
}
}
pub struct Entry<'a>(btree_map::Entry<'a, String, Rc<Vec<Op>>>);
impl<'a> Entry<'a> {
pub fn get_pointer_or_else<F: FnOnce() -> Vec<Op>, P: Into<PathBuf>>(self, f: F, path: P) -> OpPointer {
let cached = self.0.or_insert_with(|| Rc::new(f())).clone();
OpPointer::new(cached).with_path(path.into())
}
}