Directory Restructure (#1163)

* Move tests -> testing

* Directory restructure

* Update Cargo.toml during restructure

* Update Makefile during restructure

* Fix arbitrary path

consensus/state_processing/src/common/initiate_validator_exit.rs

@@ -0,0 +1,42 @@
+use std::cmp::max;
+use types::{BeaconStateError as Error, *};
+
+/// Initiate the exit of the validator of the given `index`.
+///
+/// Spec v0.11.1
+pub fn initiate_validator_exit<T: EthSpec>(
+    state: &mut BeaconState<T>,
+    index: usize,
+    spec: &ChainSpec,
+) -> Result<(), Error> {
+    if index >= state.validators.len() {
+        return Err(Error::UnknownValidator(index as u64));
+    }
+
+    // Return if the validator already initiated exit
+    if state.validators[index].exit_epoch != spec.far_future_epoch {
+        return Ok(());
+    }
+
+    // Ensure the exit cache is built.
+    state.exit_cache.build(&state.validators, spec)?;
+
+    // Compute exit queue epoch
+    let delayed_epoch = state.compute_activation_exit_epoch(state.current_epoch(), spec);
+    let mut exit_queue_epoch = state
+        .exit_cache
+        .max_epoch()?
+        .map_or(delayed_epoch, |epoch| max(epoch, delayed_epoch));
+    let exit_queue_churn = state.exit_cache.get_churn_at(exit_queue_epoch)?;
+
+    if exit_queue_churn >= state.get_churn_limit(spec)? {
+        exit_queue_epoch += 1;
+    }
+
+    state.exit_cache.record_validator_exit(exit_queue_epoch)?;
+    state.validators[index].exit_epoch = exit_queue_epoch;
+    state.validators[index].withdrawable_epoch =
+        exit_queue_epoch + spec.min_validator_withdrawability_delay;
+
+    Ok(())
+}