feat(starknet_os): implement compression hint

crates/starknet_os/src/hints/hint_implementation/stateless_compression.rs

@@ -1,5 +1,4 @@
 pub mod implementation;
 #[cfg(test)]
 pub mod tests;
-#[allow(dead_code)]
 pub mod utils;

crates/starknet_os/src/hints/hint_implementation/stateless_compression/implementation.rs

@@ -9,6 +9,7 @@ use cairo_vm::hint_processor::builtin_hint_processor::hint_utils::{
 use cairo_vm::types::relocatable::MaybeRelocatable;
 use starknet_types_core::felt::Felt;
 
+use super::utils::compress;
 use crate::hints::error::OsHintResult;
 use crate::hints::hint_implementation::stateless_compression::utils::TOTAL_N_BUCKETS;
 use crate::hints::types::HintArgs;
@@ -41,8 +42,23 @@ pub(crate) fn get_prev_offset<S: StateReader>(
     Ok(())
 }
 
-pub(crate) fn compression_hint<S: StateReader>(HintArgs { .. }: HintArgs<'_, S>) -> OsHintResult {
-    todo!()
+pub(crate) fn compression_hint<S: StateReader>(
+    HintArgs { vm, ids_data, ap_tracking, .. }: HintArgs<'_, S>,
+) -> OsHintResult {
+    let data_start = get_ptr_from_var_name(Ids::DataStart.into(), vm, ids_data, ap_tracking)?;
+    let data_end = get_ptr_from_var_name(Ids::DataEnd.into(), vm, ids_data, ap_tracking)?;
+    let data_size = (data_end - data_start)?;
+
+    let compressed_dst =
+        get_ptr_from_var_name(Ids::CompressedDst.into(), vm, ids_data, ap_tracking)?;
+    let data =
+        vm.get_integer_range(data_start, data_size)?.into_iter().map(|f| *f).collect::<Vec<_>>();
+    let compress_result =
+        compress(&data).into_iter().map(MaybeRelocatable::Int).collect::<Vec<_>>();
+
+    vm.write_arg(compressed_dst, &compress_result)?;
+
+    Ok(())
 }
 
 pub(crate) fn set_decompressed_dst<S: StateReader>(

crates/starknet_os/src/hints/vars.rs

@@ -49,8 +49,11 @@ pub enum Ids {
     BucketIndex,
     CompiledClass,
     CompiledClassFact,
+    CompressedDst,
     CompressedStart,
     ContractStateChanges,
+    DataEnd,
+    DataStart,
     DictPtr,
     FullOutput,
     Hash,
@@ -73,8 +76,11 @@ impl From<Ids> for &'static str {
             Ids::BucketIndex => "bucket_index",
             Ids::CompiledClass => "compiled_class",
             Ids::CompiledClassFact => "compiled_class_fact",
+            Ids::CompressedDst => "compressed_dst",
             Ids::CompressedStart => "compressed_start",
             Ids::ContractStateChanges => "contract_state_changes",
+            Ids::DataEnd => "data_end",
+            Ids::DataStart => "data_start",
             Ids::DictPtr => "dict_ptr",
             Ids::FullOutput => "full_output",
             Ids::Hash => "hash",