Error budget pruning strategy in resource estimator core

resource_estimator/examples/basic_logical_counts.rs

@@ -52,11 +52,13 @@ fn main() {
 
     // After we have set up all required inputs for the resource estimation
     // task, we can set up an estimation instance.
-    let estimation = PhysicalResourceEstimation::new(code, qubit, builder, logical_counts, budget);
+    let estimation = PhysicalResourceEstimation::new(code, qubit, builder, logical_counts);
 
     // In this example, we perform a standard estimation without any further
     // constraints.
-    let result = estimation.estimate().expect("estimation does not fail");
+    let result = estimation
+        .estimate(&budget)
+        .expect("estimation does not fail");
 
     // There is a lot of data contained in the resource estimation result
     // object, but in this sample we are only printing the total number of

resource_estimator/src/estimates.rs

@@ -4,7 +4,7 @@
 mod error;
 pub use error::Error;
 mod error_budget;
-pub use error_budget::ErrorBudget;
+pub use error_budget::{ErrorBudget, ErrorBudgetStrategy};
 mod error_correction;
 pub use error_correction::{
     CodeWithThresholdAndDistance, CodeWithThresholdAndDistanceEvaluator, ErrorCorrection,

resource_estimator/src/estimates/error_budget.rs

@@ -1,7 +1,7 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
-#[derive(Clone)]
+#[derive(Debug, Clone)]
 pub struct ErrorBudget {
     /// Probability of at least one logical error
     logical: f64,
@@ -36,15 +36,34 @@ impl ErrorBudget {
         self.logical
     }
 
+    pub fn set_logical(&mut self, logical: f64) {
+        self.logical = logical;
+    }
+
     /// Get the error budget's tstates.
     #[must_use]
     pub fn magic_states(&self) -> f64 {
         self.magic_states
     }
 
+    pub fn set_magic_states(&mut self, magic_states: f64) {
+        self.magic_states = magic_states;
+    }
+
     /// Get the error budget's rotations.
     #[must_use]
     pub fn rotations(&self) -> f64 {
         self.rotations
     }
+
+    pub fn set_rotations(&mut self, rotations: f64) {
+        self.rotations = rotations;
+    }
+}
+
+#[derive(Default, Copy, Clone)]
+pub enum ErrorBudgetStrategy {
+    #[default]
+    Static,
+    PruneLogicalAndRotations,
 }

resource_estimator/src/estimates/layout.rs

@@ -3,7 +3,7 @@
 
 use serde::Serialize;
 
-use super::ErrorBudget;
+use super::{ErrorBudget, ErrorBudgetStrategy};
 
 /// Trait to model post-layout logical overhead
 pub trait Overhead {
@@ -23,6 +23,11 @@ pub trait Overhead {
     /// The index is used to indicate the type of magic states and must be
     /// supported by available factory builders in the physical estimation.
     fn num_magic_states(&self, budget: &ErrorBudget, index: usize) -> u64;
+
+    /// When implemented, prunes the error budget with respect to the provided
+    /// strategy
+    #[allow(unused_variables)]
+    fn prune_error_budget(&self, budget: &mut ErrorBudget, strategy: ErrorBudgetStrategy) {}
 }
 
 /// This is the realized logical overhead after applying an error budget.  This