chore(execution-engine): remove unnecessary value_to_pos logic (#527)

remove unncessary value_to_pos logic

air/src/execution_step/boxed_value/stream.rs

@@ -20,12 +20,9 @@ use crate::ExecutionError;
 use crate::JValue;
 use crate::UncatchableError;
 
-use air_interpreter_data::TracePos;
 use air_trace_handler::merger::ValueSource;
 use air_trace_handler::TraceHandler;
 
-use std::collections::HashMap;
-
 /// Streams are CRDT-like append only data structures. They are guaranteed to have the same order
 /// of values on each peer.
 #[derive(Debug, Default, Clone)]
@@ -38,10 +35,6 @@ pub struct Stream {
 
     /// Count of values from previous data.
     previous_gens_count: usize,
-
-    /// This map is intended to support canonicalized stream creation, such streams has
-    /// corresponding value positions in a data and this field are used to create such streams.
-    values_by_pos: HashMap<TracePos, StreamValueLocation>,
 }
 
 impl Stream {
@@ -56,20 +49,15 @@ impl Stream {
         Self {
             values: vec![vec![]; overall_count],
             previous_gens_count: previous_count,
-            values_by_pos: HashMap::new(),
         }
     }
 
     // streams created with this ctor assumed to have only one generation,
     // for streams that have values in
     pub(crate) fn from_value(value: ValueAggregate) -> Self {
-        let values_by_pos = maplit::hashmap! {
-            value.trace_pos => StreamValueLocation::new(0, 0),
-        };
         Self {
             values: vec![vec![value]],
             previous_gens_count: 0,
-            values_by_pos,
         }
     }
 
@@ -95,12 +83,7 @@ impl Stream {
             .into());
         }
 
-        let values = &mut self.values[generation_number];
-        self.values_by_pos.insert(
-            value.trace_pos,
-            StreamValueLocation::new(generation_number, values.len()),
-        );
-        values.push(value);
+        self.values[generation_number].push(value);
         Ok(generation_number as u32)
     }
 
@@ -175,16 +158,6 @@ impl Stream {
         Some(JValue::Array(jvalue_array))
     }
 
-    #[allow(dead_code)]
-    pub(crate) fn get_value_by_pos(&self, position: TracePos) -> Option<&ValueAggregate> {
-        let StreamValueLocation {
-            generation,
-            position_in_generation,
-        } = self.values_by_pos.get(&position)?;
-        let value = &self.values[*generation][*position_in_generation];
-        Some(value)
-    }
-
     pub(crate) fn iter(&self, generation: Generation) -> Option<StreamIter<'_>> {
         let iter: Box<dyn Iterator<Item = &ValueAggregate>> = match generation {
             Generation::Nth(generation) if generation as usize >= self.generations_count() => return None,
@@ -295,21 +268,6 @@ impl<'slice> Iterator for StreamSliceIter<'slice> {
     }
 }
 
-#[derive(Clone, Copy, Debug, Default)]
-struct StreamValueLocation {
-    pub generation: usize,
-    pub position_in_generation: usize,
-}
-
-impl StreamValueLocation {
-    pub(super) fn new(generation: usize, position_in_generation: usize) -> Self {
-        Self {
-            generation,
-            position_in_generation,
-        }
-    }
-}
-
 use std::fmt;
 
 impl fmt::Display for Stream {

air/src/execution_step/errors/uncatchable_errors.rs

@@ -20,7 +20,6 @@ use crate::JValue;
 use crate::ToErrorCode;
 
 use air_interpreter_cid::CidCalculationError;
-use air_interpreter_data::TracePos;
 use air_interpreter_data::ValueRef;
 use air_trace_handler::GenerationCompatificationError;
 use air_trace_handler::TraceHandlerError;
@@ -77,12 +76,6 @@ pub enum UncatchableError {
     #[error("new end block tries to pop up a variable '{scalar_name}' that wasn't defined at depth {depth}")]
     ScalarsStateCorrupted { scalar_name: String, depth: usize },
 
-    /// Variable with such a position wasn't defined during AIR script execution.
-    /// Canon instruction requires this value to be present in data, otherwise it's considered
-    /// as a hard error.
-    #[error("variable with position '{0}' wasn't defined during script execution")]
-    VariableNotFoundByPos(TracePos),
-
     #[error("can't deserialize stream {canonicalized_stream:?} with error: {de_error}")]
     InvalidCanonStreamInData {
         canonicalized_stream: JValue,