Provide a method to allow reading advice from file

basic/src/bin/valida.rs

@@ -9,7 +9,10 @@ use p3_baby_bear::BabyBear;
 
 use p3_fri::{FriConfig, TwoAdicFriPcs, TwoAdicFriPcsConfig};
 use valida_cpu::MachineWithCpuChip;
-use valida_machine::{Machine, MachineProof, ProgramROM, StdinAdviceProvider, StoppingFlag};
+use valida_machine::{
+    AdviceProvider, GlobalAdviceProvider, Machine, MachineProof, ProgramROM, StdinAdviceProvider,
+    StoppingFlag,
+};
 use valida_memory::MachineWithMemoryChip;
 
 use valida_elf::{load_executable_file, Program};
@@ -51,6 +54,10 @@ struct Args {
     /// Stack height (which is also the initial frame pointer value)
     #[arg(long, default_value = "16777216")]
     stack_height: u32,
+
+    /// Advice file
+    #[arg(name = "Advice file")]
+    advice: Option<String>,
 }
 
 struct Context {
@@ -61,6 +68,7 @@ struct Context {
     last_fp_: u32,
     recorded_current_fp_: u32,
     last_fp_size_: u32,
+    advice: GlobalAdviceProvider,
 }
 
 impl Context {
@@ -73,6 +81,7 @@ impl Context {
             last_fp_: args.stack_height,
             recorded_current_fp_: args.stack_height,
             last_fp_size_: 0,
+            advice: GlobalAdviceProvider::new(&args.advice),
         };
 
         let Program { code, data } = load_executable_file(
@@ -93,7 +102,7 @@ impl Context {
         if self.stopped_ == StoppingFlag::DidStop {
             return (StoppingFlag::DidStop, 0);
         }
-        let state = self.machine_.step(&mut StdinAdviceProvider);
+        let state = self.machine_.step(&mut self.advice);
         let pc = self.machine_.cpu().pc;
         let fp = self.machine_.cpu().fp;
 
@@ -332,7 +341,7 @@ fn main() {
     machine.static_data_mut().load(data);
 
     // Run the program
-    machine.run(&code, &mut StdinAdviceProvider);
+    machine.run(&code, &mut GlobalAdviceProvider::new(&args.advice));
 
     type Val = BabyBear;
     type Challenge = BinomialExtensionField<Val, 5>;

machine/src/advice.rs

@@ -1,4 +1,5 @@
 use core::slice;
+use std::fs::File;
 use std::io;
 use std::io::Read;
 
@@ -12,6 +13,20 @@ pub struct FixedAdviceProvider {
     index: usize,
 }
 
+enum AdviceProviderType {
+    Stdin(StdinAdviceProvider),
+    Fixed(FixedAdviceProvider),
+}
+
+impl AdviceProviderType {
+    fn get_advice(&mut self) -> Option<u8> {
+        match self {
+            AdviceProviderType::Stdin(provider) => provider.get_advice(),
+            AdviceProviderType::Fixed(provider) => provider.get_advice(),
+        }
+    }
+}
+
 impl FixedAdviceProvider {
     pub fn empty() -> Self {
         Self::new(vec![])
@@ -20,6 +35,12 @@ impl FixedAdviceProvider {
     pub fn new(advice: Vec<u8>) -> Self {
         Self { advice, index: 0 }
     }
+    pub fn from_file(file: &mut File) -> Self {
+        // read the entire file into self::advice:
+        let mut advice = Vec::new();
+        file.read_to_end(&mut advice).unwrap();
+        Self { advice, index: 0 }
+    }
 }
 
 impl AdviceProvider for FixedAdviceProvider {
@@ -47,3 +68,28 @@ impl AdviceProvider for StdinAdviceProvider {
         }
     }
 }
+
+pub struct GlobalAdviceProvider {
+    provider: AdviceProviderType,
+}
+impl GlobalAdviceProvider {
+    pub fn new(file_name: &Option<String>) -> Self {
+        match file_name {
+            Some(file_name) => {
+                let mut file = File::open(file_name).unwrap();
+                let provider = AdviceProviderType::Fixed(FixedAdviceProvider::from_file(&mut file));
+                Self { provider }
+            }
+            None => {
+                let provider = AdviceProviderType::Stdin(StdinAdviceProvider);
+                Self { provider }
+            }
+        }
+    }
+}
+
+impl AdviceProvider for GlobalAdviceProvider {
+    fn get_advice(&mut self) -> Option<u8> {
+        self.provider.get_advice()
+    }
+}