Files
aquavm/crates/air-lib/trace-handler/src/data_keeper/trace_slider.rs
raftedproc b480e018b4 chore(trace-handler): sub/-trace len dedicated alias to replace usize [fixes VM-282] (#569)
feat(trace-handler): sub/-trace len dedicated alias to replace usize [fixes VM-282]
2023-05-02 16:32:18 +03:00

122 lines
3.8 KiB
Rust

/*
* Copyright 2021 Fluence Labs Limited
*
* 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 air_interpreter_data::TraceLen;
use super::ExecutedState;
use super::ExecutionTrace;
use super::KeeperError::*;
use super::KeeperResult;
use crate::TracePos;
type SeenElements = u32;
/// This slider is intended to slide on a subtrace inside provided trace. This subtrace
/// is identified by position and len.
// TODO: check for overflow
#[derive(Debug, Default, Clone, PartialEq, Eq)]
pub struct TraceSlider {
/// Trace that slider slide on.
trace: ExecutionTrace,
/// Position of current subtrace inside trace.
position: TracePos,
/// Length of a current subtrace.
subtrace_len: TraceLen,
/// Count of seen elements since the last position update.
seen_elements: SeenElements,
}
impl TraceSlider {
pub(crate) fn new(trace: impl Into<ExecutionTrace>) -> Self {
let trace = trace.into();
let subtrace_len = trace.trace_states_count();
Self {
trace,
subtrace_len,
..<_>::default()
}
}
/// Returns the next state if current interval length hasn't been reached
/// and None otherwise.
#[allow(clippy::suspicious_operation_groupings)]
pub(crate) fn next_state(&mut self) -> Option<ExecutedState> {
if self.seen_elements >= self.subtrace_len || self.position >= self.trace.trace_states_count().into() {
return None;
}
let result = self.trace[self.position].clone();
self.position += 1;
self.seen_elements += 1;
Some(result)
}
pub(crate) fn set_position_and_len(&mut self, position: TracePos, subtrace_len: TraceLen) -> KeeperResult<()> {
// it's possible to set empty subtrace_len and inconsistent position
if subtrace_len != 0 && position + subtrace_len > self.trace.trace_states_count().into() {
return Err(SetSubtraceLenAndPosFailed {
requested_pos: position,
requested_subtrace_len: subtrace_len,
trace_len: self.trace.trace_states_count(),
});
}
self.position = position;
self.subtrace_len = subtrace_len;
self.seen_elements = 0;
Ok(())
}
pub(crate) fn set_subtrace_len(&mut self, subtrace_len: TraceLen) -> KeeperResult<()> {
let trace_remainder: TraceLen = (TracePos::from(self.trace_len()) - self.position).into();
if trace_remainder < subtrace_len {
return Err(SetSubtraceLenFailed {
requested_subtrace_len: subtrace_len,
trace_position: self.position,
trace_len: self.trace.trace_states_count(),
});
}
self.seen_elements = 0;
self.subtrace_len = subtrace_len;
Ok(())
}
pub(crate) fn position(&self) -> TracePos {
self.position
}
pub(crate) fn subtrace_len(&self) -> TraceLen {
debug_assert!(self.subtrace_len >= self.seen_elements);
self.subtrace_len - self.seen_elements
}
pub(crate) fn state_at_position(&self, position: TracePos) -> Option<&ExecutedState> {
// it would be nice to have the `impl SliceIndex for TracePos`, but it is unstable
self.trace.get(position)
}
pub(super) fn trace_len(&self) -> TraceLen {
self.trace.trace_states_count()
}
}