WIP

Cargo.lock

@@ -1640,6 +1640,7 @@ dependencies = [
  "hyper",
  "itertools",
  "lazy_static",
+ "libloading",
  "metrics",
  "nix",
  "once_cell",
@@ -2148,6 +2149,10 @@ dependencies = [
  "yasna",
 ]
 
+[[package]]
+name = "redo"
+version = "0.1.0"
+
 [[package]]
 name = "redox_syscall"
 version = "0.2.10"

libs/redo/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "redo"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

libs/redo/src/main.rs

@@ -0,0 +1,16 @@
+
+
+// This will look for `int redo()` in `libredo.a`
+#[link(name = "redo")]
+extern "C" {
+    fn redo() -> i32;
+}
+
+
+// To compile this, run:
+// rustc libs/redo/src/main.rs -L /home/bojan/src/neondatabase/neon/tmp_install/lib/
+fn main() {
+    unsafe {
+        dbg!(redo());
+    }
+}

pageserver/Cargo.toml

@@ -62,6 +62,7 @@ postgres_ffi = { path = "../libs/postgres_ffi" }
 metrics = { path = "../libs/metrics" }
 utils = { path = "../libs/utils" }
 workspace_hack = { version = "0.1", path = "../workspace_hack" }
+libloading = "0.7.0"
 
 [dev-dependencies]
 hex-literal = "0.3"

pageserver/src/bin/linked_redo.rs

@@ -0,0 +1,4 @@
+
+fn main() {
+    pageserver::walredo::linked_redo().unwrap();
+}

pageserver/src/walredo.rs

@@ -163,6 +163,23 @@ pub enum WalRedoError {
     InvalidRecord,
 }
 
+pub fn linked_redo(
+    // key: Key,
+    // lsn: Lsn,
+    // base_img: Option<Bytes>,
+    // records: Vec<(Lsn, ZenithWalRecord)>,
+) -> Result<Bytes, WalRedoError> {
+    unsafe {
+        let pg_path = "/home/bojan/src/neondatabase/neon/tmp_install/bin/postgres";
+        let pg_lib = libloading::Library::new(pg_path).expect("failed loading pg");
+        // TODO add stringinfo arg
+        let apply_record_fn: libloading::Symbol<unsafe extern fn()> =
+            pg_lib.get(b"ApplyRecord").expect("failed loading ApplyRecord fn");
+    }
+    // TODO actually return something
+    Ok(Bytes::new())
+}
+
 ///
 /// Public interface of WAL redo manager
 ///
@@ -185,6 +202,8 @@ impl WalRedoManager for PostgresRedoManager {
             return Err(WalRedoError::InvalidRequest);
         }
 
+        // return linked_redo(key, lsn, base_img, records);
+
         let mut img: Option<Bytes> = base_img;
         let mut batch_zenith = can_apply_in_zenith(&records[0].1);
         let mut batch_start = 0;