Stub code for #222

crypto/dynamic-generator/src/lib.rs

@@ -0,0 +1,62 @@
+#![cfg_attr(docsrs, feature(doc_cfg))]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+
+use core::any::{TypeId, Any};
+
+use std::{
+  thread::{self, ThreadId},
+  sync::RwLock,
+  collections::HashMap,
+};
+
+use group::Group;
+
+type Stack = Option<HashMap<ThreadId, HashMap<TypeId, Vec<Box<dyn Any>>>>>;
+static mut GENERATORS: RwLock<Stack> = RwLock::new(None);
+
+fn stack<G: Group>(map: &mut Stack) -> &mut Vec<Box<dyn Any>> {
+  map
+    .get_or_insert_with(HashMap::new)
+    .entry(thread::current().id())
+    .or_insert(HashMap::new())
+    .entry(TypeId::of::<G>())
+    .or_insert(Vec::new())
+}
+
+#[doc(hidden)]
+pub fn push<G: Group>(generator: G) {
+  stack::<G>(&mut unsafe { GENERATORS.write() }.unwrap()).push(Box::new(generator));
+}
+
+#[doc(hidden)]
+pub fn pop<G: Group>() {
+  stack::<G>(&mut unsafe { GENERATORS.write() }.unwrap()).pop().unwrap();
+}
+
+#[doc(hidden)]
+fn get<G: Group>() {
+  stack::<G>(&mut unsafe { GENERATORS.write() }.unwrap()).get(0).unwrap_or(G::generator());
+}
+
+macro_rules! dynamic_generator {
+  ($Name: ident, $Base: ident, $generator: expr) => {
+    #[derive(Clone, Copy, PartialEq, Eq, Debug)]
+    struct $Name($Base);
+  }
+}
+
+// type G: Group<Scalar = Self::F> + GroupOps + PrimeGroup + Zeroize + ConstantTimeEq;
+macro_rules! complete_dynamic_generator {
+  ($Name: ident, $Base: ident, $generator: expr) => {
+    #[derive(Clone, Copy, PartialEq, Eq, Debug, ConstantTimeEq, Zeroize)]
+    struct $Name($Base);
+    impl Group for DynamicGenerator {}
+    impl GroupEncoding for DynamicGenerator {}
+    impl PrimeGroup for DynamicGenerator {}
+  }
+}
+
+/*
+struct DynamicGenerator<G: Group> { _phantom: PhantomData<G> }
+impl DynamicGenerator {}
+*/