refactor

tools/iface/src/db.rs

@@ -0,0 +1,43 @@
+pub mod sled;
+pub mod sqlite;
+
+use itertools::Itertools;
+
+pub type KVIter<'a> = Box<dyn Iterator<Item = (Vec<u8>, Vec<u8>)> + 'a>;
+
+pub type TreeKVIter<'a> = Box<dyn Iterator<Item = (Vec<u8>, KVIter<'a>)> + 'a>;
+
+pub trait Database {
+    fn iter<'a>(&'a self) -> TreeKVIter<'a>;
+
+    fn segment<'a>(&'a mut self, name: Vec<u8>) -> Option<Box<dyn Segment + 'a>>; // change return type to Result
+}
+
+pub trait Segment {
+    fn batch_insert<'a>(
+        &'a mut self,
+        batch: Box<dyn Iterator<Item = (Vec<u8>, Vec<u8>)> + 'a>,
+    ) -> anyhow::Result<()>;
+}
+
+pub fn copy_database(
+    src: &impl Database,
+    dst: &mut impl Database,
+    chunk_size: usize,
+) -> anyhow::Result<()> {
+    for (tree, i) in src.iter() {
+        dbg!(&tree);
+
+        let mut t = dst.segment(tree).unwrap(); // todo remove unwrap
+
+        let mut x: usize = 0;
+
+        for chunk in &i.chunks(chunk_size) {
+            dbg!(&x);
+            t.batch_insert(Box::new(chunk))?;
+            x += chunk_size;
+        }
+    }
+
+    Ok(())
+}