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use polar_core::sources::Source;
use polar_core::terms::{Call, Symbol, Term, Value};
use std::collections::HashSet;
use std::fs::File;
use std::hash::Hash;
use std::io::Read;
use std::sync::Arc;
use crate::host::Host;
use crate::query::Query;
use crate::{FromPolar, OsoError, PolarValue, ToPolar, ToPolarList};
#[derive(Clone)]
pub struct Oso {
inner: Arc<polar_core::polar::Polar>,
host: Host,
}
impl Default for Oso {
fn default() -> Self {
Self::new()
}
}
#[derive(Clone, Debug, Hash, Eq, PartialEq)]
pub enum Action<T = String> {
Any,
Typed(T),
}
impl<T: FromPolar> FromPolar for Action<T> {
fn from_polar(val: PolarValue) -> crate::Result<Self> {
if matches!(val, PolarValue::Variable(_)) {
Ok(Action::Any)
} else {
T::from_polar(val).map(Action::Typed)
}
}
}
impl Oso {
pub fn new() -> Self {
let inner = Arc::new(polar_core::polar::Polar::new());
let host = Host::new(inner.clone());
let mut oso = Self { inner, host };
for class in crate::builtins::classes() {
oso.register_class(class)
.expect("failed to register builtin class");
}
oso.register_constant(Option::<crate::PolarValue>::None, "nil")
.expect("failed to register the constant None");
oso
}
pub fn is_allowed<Actor, Action, Resource>(
&self,
actor: Actor,
action: Action,
resource: Resource,
) -> crate::Result<bool>
where
Actor: ToPolar,
Action: ToPolar,
Resource: ToPolar,
{
let mut query = self.query_rule("allow", (actor, action, resource)).unwrap();
match query.next() {
Some(Ok(_)) => Ok(true),
Some(Err(e)) => Err(e),
None => Ok(false),
}
}
pub fn get_allowed_actions<Actor, Resource, T>(
&self,
actor: Actor,
resource: Resource,
) -> crate::Result<HashSet<T>>
where
Actor: ToPolar,
Resource: ToPolar,
T: FromPolar + Eq + Hash,
{
let mut query = self
.query_rule(
"allow",
(actor, PolarValue::Variable("action".to_owned()), resource),
)
.unwrap();
let mut set = HashSet::new();
loop {
match query.next() {
Some(Ok(result)) => {
if let Some(action) = result.get("action") {
set.insert(T::from_polar(action)?);
}
}
Some(Err(e)) => return Err(e),
None => break,
};
}
Ok(set)
}
pub fn clear_rules(&mut self) -> crate::Result<()> {
self.inner.clear_rules();
check_messages!(self.inner);
Ok(())
}
fn check_inline_queries(&self) -> crate::Result<()> {
while let Some(q) = self.inner.next_inline_query(false) {
let location = q.source_info();
let query = Query::new(q, self.host.clone());
match query.collect::<crate::Result<Vec<_>>>() {
Ok(v) if !v.is_empty() => continue,
Ok(_) => return Err(OsoError::InlineQueryFailedError { location }),
Err(e) => return lazy_error!("error in inline query: {}", e),
}
}
check_messages!(self.inner);
Ok(())
}
fn load_sources(&mut self, sources: Vec<Source>) -> crate::Result<()> {
self.host.register_mros()?;
self.inner.load(sources)?;
self.check_inline_queries()
}
#[deprecated(
since = "0.20.1",
note = "`Oso::load_file` has been deprecated in favor of `Oso::load_files` as of the 0.20 release.\n\nPlease see changelog for migration instructions: https://docs.osohq.com/project/changelogs/2021-09-15.html"
)]
pub fn load_file<P: AsRef<std::path::Path>>(&mut self, filename: P) -> crate::Result<()> {
self.load_files(vec![filename])
}
pub fn load_files<P: AsRef<std::path::Path>>(
&mut self,
filenames: Vec<P>,
) -> crate::Result<()> {
if filenames.is_empty() {
return Ok(());
}
let mut sources = Vec::with_capacity(filenames.len());
for file in filenames {
let file = file.as_ref();
let filename = file.to_string_lossy().into_owned();
if !file.extension().map_or(false, |ext| ext == "polar") {
return Err(crate::OsoError::IncorrectFileType { filename });
}
let mut f = File::open(&file)?;
let mut src = String::new();
f.read_to_string(&mut src)?;
sources.push(Source {
src,
filename: Some(filename),
});
}
self.load_sources(sources)
}
pub fn load_str(&mut self, src: &str) -> crate::Result<()> {
self.load_sources(vec![Source {
src: src.to_owned(),
filename: None,
}])
}
pub fn query(&self, s: &str) -> crate::Result<Query> {
let query = self.inner.new_query(s, false)?;
check_messages!(self.inner);
let query = Query::new(query, self.host.clone());
Ok(query)
}
#[must_use = "Query that is not consumed does nothing."]
pub fn query_rule(&self, name: &str, args: impl ToPolarList) -> crate::Result<Query> {
let mut query_host = self.host.clone();
let args = args
.to_polar_list()
.iter()
.map(|value| value.to_term(&mut query_host))
.collect();
let query_value = Value::Call(Call {
name: Symbol(name.to_string()),
args,
kwargs: None,
});
let query_term = Term::new_from_ffi(query_value);
let query = self.inner.new_query_from_term(query_term, false);
check_messages!(self.inner);
let query = Query::new(query, query_host);
Ok(query)
}
pub fn register_class(&mut self, class: crate::host::Class) -> crate::Result<()> {
let name = class.name.clone();
let class_name = self.host.cache_class(class.clone(), name)?;
for hook in &class.register_hooks {
hook.call(self)?;
}
self.register_constant(class, &class_name)
}
pub fn register_constant<V: crate::host::ToPolar + Send + Sync>(
&mut self,
value: V,
name: &str,
) -> crate::Result<()> {
self.inner.register_constant(
Symbol(name.to_string()),
value.to_polar().to_term(&mut self.host),
)?;
Ok(())
}
}
#[cfg(test)]
static_assertions::assert_impl_all!(Oso: Send, Sync);