Find start position in large files via binary search

disk/src/aggtest.rs

@@ -12,6 +12,7 @@ pub fn make_test_node(id: u32) -> Node {
         port: 8800 + id as u16,
         port_raw: 8800 + id as u16 + 100,
         data_base_path: format!("../tmpdata/node{:02}", id).into(),
+        cache_base_path: format!("../tmpdata/node{:02}", id).into(),
         split: id,
         ksprefix: "ks".into(),
         backend: "testbackend".into(),

disk/src/cache.rs

@@ -138,7 +138,7 @@ impl CacheFileDesc {
         let hc = self.hash_channel();
         node_config
             .node
-            .data_base_path
+            .cache_base_path
             .join("cache")
             .join(&hc[0..3])
             .join(&hc[3..6])

disk/src/gen.rs

@@ -78,6 +78,7 @@ pub async fn gen_test_data() -> Result<(), Error> {
             port_raw: 7780 + i1 as u16 + 100,
             split: i1,
             data_base_path: data_base_path.join(format!("node{:02}", i1)),
+            cache_base_path: data_base_path.join(format!("node{:02}", i1)),
             ksprefix: ksprefix.clone(),
             backend: "testbackend".into(),
             bin_grain_kind: 0,