fix: comments

Signed-off-by: usamoi <usamoi@outlook.com>

crates/service/src/worker.rs

@@ -1,5 +1,4 @@
 use crate::instance::*;
-use crate::version::Version;
 use arc_swap::ArcSwap;
 use base::index::*;
 use base::search::*;
@@ -31,7 +30,6 @@ impl Worker {
         });
         let protect = WorkerProtect { startup, indexes };
         sync_dir(&path);
-        Version::write(path.join("metadata"));
         Arc::new(Worker {
             path,
             protect: Mutex::new(protect),

src/index/am.rs

@@ -143,12 +143,42 @@ pub unsafe extern "C" fn ambuild(
         index_relation,
         Some((heap_relation, index_info, result.as_ptr())),
     );
+    make_well_formed(index_relation);
     result.into_pg()
 }
 
 #[pgrx::pg_guard]
-pub unsafe extern "C" fn ambuildempty(index_relation: pgrx::pg_sys::Relation) {
-    am_build::build(index_relation, None);
+pub unsafe extern "C" fn ambuildempty(_index: pgrx::pg_sys::Relation) {}
+
+unsafe fn make_well_formed(index_relation: pgrx::pg_sys::Relation) {
+    unsafe {
+        let meta_buffer = pgrx::pg_sys::ReadBuffer(index_relation, 0xFFFFFFFF /* P_NEW */);
+        pgrx::pg_sys::LockBuffer(meta_buffer, pgrx::pg_sys::BUFFER_LOCK_EXCLUSIVE as _);
+        assert!(pgrx::pg_sys::BufferGetBlockNumber(meta_buffer) == 0);
+        let state = pgrx::pg_sys::GenericXLogStart(index_relation);
+        let meta_page = pgrx::pg_sys::GenericXLogRegisterBuffer(
+            state,
+            meta_buffer,
+            pgrx::pg_sys::GENERIC_XLOG_FULL_IMAGE as _,
+        );
+        meta_page.write_bytes(0, pgrx::pg_sys::BLCKSZ as usize);
+        pgrx::pg_sys::GenericXLogFinish(state);
+        pgrx::pg_sys::UnlockReleaseBuffer(meta_buffer);
+    }
+}
+
+unsafe fn check_well_formed(index_relation: pgrx::pg_sys::Relation) {
+    if !test_well_formed(index_relation) {
+        am_build::build(index_relation, None);
+        make_well_formed(index_relation);
+    }
+}
+
+unsafe fn test_well_formed(index_relation: pgrx::pg_sys::Relation) -> bool {
+    pgrx::pg_sys::RelationGetNumberOfBlocksInFork(
+        index_relation,
+        pgrx::pg_sys::ForkNumber_MAIN_FORKNUM,
+    ) == 1
 }
 
 #[pgrx::pg_guard]
@@ -162,6 +192,7 @@ pub unsafe extern "C" fn aminsert(
     _index_unchanged: bool,
     _index_info: *mut pgrx::pg_sys::IndexInfo,
 ) -> bool {
+    check_well_formed(index_relation);
     let oid = (*index_relation).rd_id;
     let id = get_handle(oid);
     let vector = from_datum(*values.add(0), *is_null.add(0));
@@ -177,6 +208,7 @@ pub unsafe extern "C" fn ambeginscan(
     n_keys: std::os::raw::c_int,
     n_orderbys: std::os::raw::c_int,
 ) -> pgrx::pg_sys::IndexScanDesc {
+    check_well_formed(index_relation);
     assert!(n_keys == 0);
     assert!(n_orderbys == 1);
     am_scan::make_scan(index_relation)
@@ -218,6 +250,9 @@ pub unsafe extern "C" fn ambulkdelete(
     callback: pgrx::pg_sys::IndexBulkDeleteCallback,
     callback_state: *mut std::os::raw::c_void,
 ) -> *mut pgrx::pg_sys::IndexBulkDeleteResult {
+    if !test_well_formed((*info).index) {
+        pgrx::warning!("The vector index is not initialized.");
+    }
     let oid = (*(*info).index).rd_id;
     let id = get_handle(oid);
     if let Some(callback) = callback {
@@ -234,9 +269,12 @@ pub unsafe extern "C" fn ambulkdelete(
 
 #[pgrx::pg_guard]
 pub unsafe extern "C" fn amvacuumcleanup(
-    _info: *mut pgrx::pg_sys::IndexVacuumInfo,
+    info: *mut pgrx::pg_sys::IndexVacuumInfo,
     _stats: *mut pgrx::pg_sys::IndexBulkDeleteResult,
 ) -> *mut pgrx::pg_sys::IndexBulkDeleteResult {
+    if !test_well_formed((*info).index) {
+        pgrx::warning!("The vector index is not initialized.");
+    }
     let result = pgrx::PgBox::<pgrx::pg_sys::IndexBulkDeleteResult>::alloc0();
     result.into_pg()
 }

src/index/hook_maintain.rs

@@ -80,7 +80,7 @@ pub unsafe fn maintain_index_in_object_access(
         pgrx::pg_sys::ObjectAccessType_OAT_DROP => {
             let search = pgrx::pg_catalog::PgClass::search_reloid(object_id).unwrap();
             if let Some(pg_class) = search.get() {
-                if let Some(()) = check(pg_class) {
+                if let Some(()) = check_vector_index(pg_class) {
                     let handle = get_handle(object_id);
                     let mut t = TRANSACTION.borrow_mut();
                     match t.index.get(&handle) {
@@ -110,7 +110,7 @@ pub unsafe fn maintain_index_in_object_access(
     }
 }
 
-fn check(pg_class: pgrx::pg_catalog::PgClass<'_>) -> Option<()> {
+fn check_vector_index(pg_class: pgrx::pg_catalog::PgClass<'_>) -> Option<()> {
     if pg_class.relkind() != pgrx::pg_catalog::PgClassRelkind::Index {
         return None;
     }
@@ -124,10 +124,10 @@ fn check(pg_class: pgrx::pg_catalog::PgClass<'_>) -> Option<()> {
         return None;
     }
     // probably a vector index, so enter a slow path to ensure it
-    slow_path(pg_am)
+    check_vector_index_slow_path(pg_am)
 }
 
-fn slow_path(pg_am: pgrx::pg_catalog::PgAm<'_>) -> Option<()> {
+fn check_vector_index_slow_path(pg_am: pgrx::pg_catalog::PgAm<'_>) -> Option<()> {
     let amhandler = pg_am.amhandler();
     let mut flinfo = unsafe {
         let mut flinfo = pgrx::pg_sys::FmgrInfo::default();