Only keep track of recently used stacks in memory.

This should - as far as we know - eliminate unbounded memory growth.
To avoid memory leaks, we only evict "root" stacks from the cache.

console/network/src/lib.rs

@@ -202,11 +202,7 @@ pub trait Network:
 
     /// The maximum number of stacks in the process
     /// Allows for fast processing for blocks made from 4 maximally full rounds.
-    #[cfg(not(feature = "test"))]
-    const MAX_STACKS: usize = Self::MAX_TRANSMISSIONS_PER_BATCH as usize * Self::MAX_CERTIFICATES as usize * 4;
-    /// The maximum number of stacks in the process.
-    #[cfg(feature = "test")]
-    const MAX_STACKS: usize = 64;
+    const MAX_STACKS: usize = Self::MAX_PROGRAM_DEPTH * Self::MAX_IMPORTS * 10;
 
     /// The maximum number of bytes in a transaction.
     // Note: This value must **not** be decreased as it would invalidate existing transactions.

ledger/query/src/query.rs

@@ -140,7 +140,7 @@ impl<N: Network, B: BlockStorage<N>> QueryTrait<N> for Query<N, B> {
         }
     }
 
-    /// Returns a state path for the given `commitment`.
+    /// Returns the current block height.
     fn current_block_height(&self) -> Result<u32> {
         match self {
             Self::VM(block_store) => Ok(block_store.max_height().unwrap_or_default()),
@@ -159,7 +159,7 @@ impl<N: Network, B: BlockStorage<N>> QueryTrait<N> for Query<N, B> {
         }
     }
 
-    /// Returns a state path for the given `commitment`.
+    /// Returns the current block height.
     #[cfg(feature = "async")]
     async fn current_block_height_async(&self) -> Result<u32> {
         match self {