fix(rpc-trace): add after and count to trace_filter (paradigmxyz#9662)

Co-authored-by: Matthias Seitz <[email protected]>

crates/rpc/rpc/src/trace.rs

@@ -251,7 +251,7 @@ where
         filter: TraceFilter,
     ) -> EthResult<Vec<LocalizedTransactionTrace>> {
         let matcher = filter.matcher();
-        let TraceFilter { from_block, to_block, .. } = filter;
+        let TraceFilter { from_block, to_block, after, count, .. } = filter;
         let start = from_block.unwrap_or(0);
         let end = if let Some(to_block) = to_block {
             to_block
@@ -341,6 +341,20 @@ where
             }
         }
 
+        // apply after and count to traces if specified, this allows for a pagination style.
+        // only consider traces after
+        if let Some(after) = after.map(|a| a as usize).filter(|a| *a < all_traces.len()) {
+            all_traces = all_traces.split_off(after);
+        }
+
+        // at most, return count of traces
+        if let Some(count) = count {
+            let count = count as usize;
+            if count < all_traces.len() {
+                all_traces.truncate(count);
+            }
+        };
+
         Ok(all_traces)
     }