From 81911ae3998f760578a0fb2fe303f23fda1ab188 Mon Sep 17 00:00:00 2001
From: Matt Bell <mappum@gmail.com>
Date: Thu, 14 Nov 2024 21:09:42 -0600
Subject: [PATCH 1/3] Check for root key in a format version-agnostic way

---
 src/merk/mod.rs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/merk/mod.rs b/src/merk/mod.rs
index bfc6cec..0f737b9 100644
--- a/src/merk/mod.rs
+++ b/src/merk/mod.rs
@@ -86,9 +86,8 @@ impl Merk {
 
         let mut db = rocksdb::DB::open_cf_descriptors(&db_opts, &path_buf, column_families())?;
         let format_version = load_format_version(&db)?;
-        let has_root = load_root(&db)?.is_some();
 
-        if has_root {
+        if has_root(&db)? {
             if format_version == 0 {
                 log::info!("Migrating store from version 0 to {}...", FORMAT_VERSION);
 
@@ -578,6 +577,11 @@ where
     Ok(bytes)
 }
 
+fn has_root(db: &DB) -> Result<bool> {
+    let internal_cf = db.cf_handle(INTERNAL_CF_NAME).unwrap();
+    Ok(db.get_pinned_cf(internal_cf, ROOT_KEY_KEY)?.is_some())
+}
+
 fn load_root(db: &DB) -> Result<Option<Tree>> {
     let internal_cf = db.cf_handle(INTERNAL_CF_NAME).unwrap();
     db.get_pinned_cf(internal_cf, ROOT_KEY_KEY)?

From d30c427663cd8be99963ae9ee196b86f538a50a5 Mon Sep 17 00:00:00 2001
From: Matt Bell <mappum@gmail.com>
Date: Thu, 14 Nov 2024 21:10:00 -0600
Subject: [PATCH 2/3] Change migration to use raw iterator and store operations

---
 src/merk/mod.rs | 55 ++++++++++++++-----------------------------------
 1 file changed, 15 insertions(+), 40 deletions(-)

diff --git a/src/merk/mod.rs b/src/merk/mod.rs
index 0f737b9..e1deb13 100644
--- a/src/merk/mod.rs
+++ b/src/merk/mod.rs
@@ -304,54 +304,29 @@ impl Merk {
     }
 
     pub fn migrate_from_v0<P: AsRef<Path>>(path: P) -> Result<()> {
-        use rocksdb::IteratorMode;
-
         let path = path.as_ref().to_path_buf();
         let db =
             rocksdb::DB::open_cf_descriptors(&Merk::default_db_opts(), &path, column_families())?;
 
-        let create_path = |suffix| {
-            let mut tmp_path = path.clone();
-            let tmp_file_name =
-                format!("{}-{}", path.file_name().unwrap().to_str().unwrap(), suffix);
-            tmp_path.set_file_name(tmp_file_name);
-            tmp_path
-        };
+        let mut iter = db.raw_iterator();
+        iter.seek_to_first();
 
-        let tmp_path = create_path("migrate1");
-        let tmp = Merk::open(&tmp_path)?;
-        tmp.destroy()?;
+        while iter.valid() {
+            let key = iter.key().unwrap();
+            let mut value = iter.value().unwrap();
 
-        // TODO: split up batch
-        let batch: Vec<_> = db
-            .iterator(IteratorMode::Start)
-            .map(|entry| -> Result<_> {
-                dbg!();
-                let (key, node_bytes) = entry.unwrap(); // TODO
-                dbg!(&key, node_bytes.len());
-                let node = Tree::decode_v0(&mut &node_bytes[..])?;
-                dbg!();
-                Ok((key.to_vec(), Op::Put(node.value().to_vec())))
-            })
-            .collect::<Result<_>>()?;
+            let node = Tree::decode_v0(&mut value)?;
+            let new_value = node.encode();
+            db.put(key, new_value.as_slice())?;
 
-        let aux_cf = db.cf_handle(AUX_CF_NAME).unwrap();
-        let aux: Vec<_> = db
-            .iterator_cf(aux_cf, IteratorMode::Start)
-            .map(|entry| {
-                let (key, value) = entry.unwrap(); // TODO
-                (key.to_vec(), Op::Put(value.to_vec()))
-            })
-            .collect();
-
-        let mut tmp = Self::open(&tmp_path)?;
-        tmp.apply(&batch, &aux)?;
-        drop(tmp);
+            iter.next();
+        }
 
-        let tmp_path2 = create_path("migrate2");
-        std::fs::rename(&path, &tmp_path2)?;
-        std::fs::rename(&tmp_path, &path)?;
-        std::fs::remove_dir_all(&tmp_path2)?;
+        db.put_cf(
+            db.cf_handle(INTERNAL_CF_NAME).unwrap(),
+            FORMAT_VERSION_KEY,
+            FORMAT_VERSION.to_be_bytes(),
+        )?;
 
         Ok(())
     }

From d975c8336aec3d2bc9f30402555dd3153efc4aef Mon Sep 17 00:00:00 2001
From: Matt Bell <mappum@gmail.com>
Date: Fri, 15 Nov 2024 18:34:37 -0600
Subject: [PATCH 3/3] Clippy fix

---
 src/merk/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/merk/mod.rs b/src/merk/mod.rs
index e1deb13..88834b2 100644
--- a/src/merk/mod.rs
+++ b/src/merk/mod.rs
@@ -306,7 +306,7 @@ impl Merk {
     pub fn migrate_from_v0<P: AsRef<Path>>(path: P) -> Result<()> {
         let path = path.as_ref().to_path_buf();
         let db =
-            rocksdb::DB::open_cf_descriptors(&Merk::default_db_opts(), &path, column_families())?;
+            rocksdb::DB::open_cf_descriptors(&Merk::default_db_opts(), path, column_families())?;
 
         let mut iter = db.raw_iterator();
         iter.seek_to_first();