pyority_queue/src/queue/paired.rs

110 lines
3.3 KiB
Rust

/// A "paired" priority queue that links some data to a priority and supports duplicates, but not arbitrary deletions or weight updates
use crate::backing::{
item::Item,
pure::{BinaryHeap, PureBacking},
};
use pyo3::{
exceptions::{PyIndexError, PyStopIteration, PyTypeError},
prelude::*,
types::{PyDict, PyType},
};
#[pyclass]
pub struct PairedQueue {
backing: Box<dyn PureBacking<Item<Py<PyAny>, f64>>>,
}
#[pymethods]
impl PairedQueue {
#[classmethod]
fn __class_getitem__(cls_: Bound<'_, PyType>, _key: Py<PyAny>) -> Bound<'_, PyType> {
cls_
}
#[new]
#[pyo3(signature = (items=None))]
fn new(items: Option<Py<PyAny>>) -> PyResult<Self> {
if let Some(py_object) = items {
Python::with_gil(|py| Self::from_any(py_object.bind(py))).and_then(|vec| {
Ok(Self {
backing: Box::new(BinaryHeap::from_iter(vec)),
})
})
} else {
Ok(Self {
backing: Box::new(BinaryHeap::new()),
})
}
}
fn __len__(self_: PyRef<'_, Self>) -> usize {
self_.backing.len()
}
fn __iter__(self_: PyRef<'_, Self>) -> PyRef<'_, Self> {
self_
}
fn __next__(mut self_: PyRefMut<'_, Self>) -> PyResult<Py<PyAny>> {
if let Some(item) = self_.backing.pop() {
Ok(item.data())
} else {
Err(PyErr::new::<PyStopIteration, _>(()))
}
}
fn pop(mut self_: PyRefMut<'_, Self>) -> PyResult<Py<PyAny>> {
if let Some(item) = self_.backing.pop() {
Ok(item.data())
} else {
Err(PyErr::new::<PyIndexError, _>(()))
}
}
fn __setitem__(mut self_: PyRefMut<'_, Self>, key: Py<PyAny>, value: f64) {
self_.backing.add(Item::new(key, value));
}
}
impl<'py> PairedQueue {
fn from_any(object: &Bound<'py, PyAny>) -> PyResult<Vec<Item<Py<PyAny>, f64>>> {
if let Ok(vec) = object.extract::<Vec<(Py<PyAny>, f64)>>() {
Ok(Self::from_vec(vec))
} else {
if object.is_instance_of::<PyDict>() {
if let Ok(dict) = object.downcast::<PyDict>() {
Self::from_dict(dict)
} else {
Err(PyErr::new::<PyTypeError, _>(
"Argument claimed to be a dict but wasn't",
))
}
} else {
Err(PyErr::new::<PyTypeError, _>(
"Argument was not a properly-formed dict, list, or tuple",
))
}
}
}
fn from_vec(list: Vec<(Py<PyAny>, f64)>) -> Vec<Item<Py<PyAny>, f64>> {
list.into_iter()
.map(|(data, priority)| Item::new(data, priority))
.collect()
}
fn from_dict(dict: &Bound<'py, PyDict>) -> PyResult<Vec<Item<Py<PyAny>, f64>>> {
if let Ok(items) = dict
.into_iter()
.map(|(data, priority)| match priority.extract::<f64>() {
Ok(value) => Ok(Item::new(data.unbind(), value)),
Err(err) => Err(err),
})
.collect::<Result<Vec<_>, _>>()
{
Ok(items)
} else {
Err(PyErr::new::<PyTypeError, _>("Dict keys were not floats"))
}
}
}