perf(runtime): fast-path non-overlapping aggregation

opf/_core/runtime.py

@@ -297,6 +297,27 @@ def predict_text(
         if log_probs.shape[0] != len(window.tokens):
             raise ValueError("Logprob output length does not match window length")
 
+        # Fast path for the common non-overlapping configuration
+        # (example_to_windows produces stride == window_size, so every
+        # token sits in exactly one window). Skip the per-token Python
+        # loop entirely and bulk-extend the aggregation lists. On
+        # long inputs this removes O(N_tokens) iterations per window,
+        # each running ensure_capacity / logaddexp / record_token_id
+        # on count == 1 data — purely no-op work.
+        first_offset = int(window.offsets[0])
+        if (
+            all(window.mask)
+            and first_offset == aggregation.length
+            and tuple(int(o) for o in window.offsets)
+            == tuple(range(first_offset, first_offset + len(window.tokens)))
+        ):
+            aggregation.logprob_logsumexp.extend(log_probs.unbind(0))
+            aggregation.counts.extend([1] * len(window.tokens))
+            aggregation.labels.extend([None] * len(window.tokens))
+            aggregation.token_ids.extend(int(t) for t in window.tokens)
+            aggregation.length = first_offset + len(window.tokens)
+            continue
+
         for token_pos, is_valid in enumerate(window.mask):
             if not bool(is_valid):
                 continue