Fix LingBot KV metadata handling and unify KV config construction

cacheseek/reuse/exact_prefix/telefuser_lingbot.py

@@ -50,27 +50,36 @@
 from .types import ActionKey
 
 
-def make_full_kv_config(*, break_even_k: int = 1) -> WorldKVConfig:
-    """Full-length KV (local_attn_size=-1) => materialization needs the entire
-    prefix."""
-    return WorldKVConfig(
-        window_chunks=1_000_000, sink_chunks=1, break_even_k=break_even_k
-    )
-
-
-def make_rolling_config(
+def make_world_kv_config(
     *,
     local_attn_size: int = 7,  # latent frames, incl. sink (matches TeleFuser pipeline config)
     sink_size: int = 3,  # latent frames
     chunk_size: int = 3,  # latent frames per chunk
     break_even_k: int = 1,
 ) -> WorldKVConfig:
-    """Rolling window: materialization needs only the sink chunk plus the chunks
-    covering the most recent (L-S) frames -- O(W) rather than O(K)."""
-    recent_frames = max(local_attn_size - sink_size, 1)
+    """Build WorldKVConfig from TeleFuser LingBot KV geometry.
+
+    Uses local_attn_size=-1 for full-length KV. Positive values for
+    rolling KV.
+
+    Rolling window: materialization needs only the sink chunk plus the chunks
+    covering the most recent (L-S) frames -- O(W) rather than O(K).
+    """
+    if local_attn_size == -1:
+        window_chunks = 1_000_000
+        sink_chunks = 1
+    elif local_attn_size > 0:
+        recent_frames = max(local_attn_size - sink_size, 1)
+
+        window_chunks=-(-recent_frames // chunk_size)  # ceil
+        sink_chunks=-(-sink_size // chunk_size)
+    else:
+        raise ValueError(f"local_attn_size must be -1 for full KV and positive "
+                         f"for rolling, got {local_attn_size}")
+
     return WorldKVConfig(
-        window_chunks=-(-recent_frames // chunk_size),  # ceil
-        sink_chunks=-(-sink_size // chunk_size),
+        window_chunks=window_chunks,
+        sink_chunks=sink_chunks,
         break_even_k=break_even_k,
     )
 
@@ -222,8 +231,8 @@ def set_resume_depth(self, depth: int) -> None:
         rt = self._rt
         global_end = (depth + 1) * rt.chunk_size * rt.frame_tokens
         for kv in rt.self_kv_cache:
-            kv["global_end_index"][0] = global_end
-            kv["local_end_index"][0] = self._local_end_tokens
+            kv["global_end_index"] = global_end
+            kv["local_end_index"] = self._local_end_tokens
 
 
 class LingBotWorldKVBinding:
@@ -376,7 +385,7 @@ def on_chunk_finalized(
             # In rolling mode this chunk's clean KV sits at the physical tail
             # [local_end-ct : local_end] (logical position idx*ct holds only in
             # full-length mode); local_end was just advanced by the clean rewrite.
-            e = int(kv["local_end_index"][0])
+            e = int(kv["local_end_index"])
             s = e - ct
             payload.append(
                 (

examples/exact_prefix_reuse/e2e_telefuser_lingbot.py

@@ -69,7 +69,7 @@
 from cacheseek.reuse.exact_prefix import NamespaceForest, WorldKVManager
 from cacheseek.reuse.exact_prefix.telefuser_lingbot import (
     LingBotWorldKVBinding,
-    make_rolling_config,
+    make_world_kv_config,
 )
 from cacheseek.stores import InMemoryTierStore
 
@@ -246,7 +246,11 @@ def fresh_stack():
         forest = NamespaceForest()
         mgr = WorldKVManager(
             forest, shared_store,
-            make_rolling_config(local_attn_size=cfg.local_attn_size, sink_size=cfg.sink_size, chunk_size=3),
+            make_world_kv_config(
+                local_attn_size=cfg.local_attn_size,
+                sink_size=cfg.sink_size,
+                chunk_size=3
+            ),
         )
         return forest, mgr
 

tests/test_world_kv_telefuser_binding.py

@@ -29,7 +29,7 @@
 )
 from cacheseek.reuse.exact_prefix.telefuser_lingbot import (  # noqa: E402
     LingBotWorldKVBinding,
-    make_rolling_config,
+    make_world_kv_config,
 )
 
 # Tiny geometry: chunk=3 frames, frame_tokens=2; window L=7 frames including
@@ -159,7 +159,7 @@ def run_session(binding, runtime, session, *, snapshots: list | None = None):
 
 def make_stack():
     forest = NamespaceForest()
-    cfg = make_rolling_config(local_attn_size=LOCAL_ATTN, sink_size=SINK, chunk_size=CHUNK_FRAMES)
+    cfg = make_world_kv_config(local_attn_size=LOCAL_ATTN, sink_size=SINK, chunk_size=CHUNK_FRAMES)
     return forest, WorldKVManager(forest, InMemoryTierStore(), cfg)