Cleanup blocks from db (incl. forked blocks)

chain/src/chain.rs

@@ -1026,38 +1026,18 @@ impl Chain {
 		}
 
 		let mut count = 0;
-
 		let tail_hash = txhashset.get_header_hash_by_height(head.height - horizon)?;
 		let tail = batch.get_block_header(&tail_hash)?;
 
-		let current_hash = txhashset.get_header_hash_by_height(head.height - horizon - 1)?;
-		let mut current = batch.get_block_header(&current_hash)?;
-
-		loop {
-			// Go to the store directly so we can handle NotFoundErr robustly.
-			match self.store.get_block(&current.hash()) {
-				Ok(b) => {
-					batch.delete_block(&b.hash())?;
-					count += 1;
-				}
-				Err(NotFoundErr(_)) => {
-					break;
-				}
-				Err(e) => {
-					return Err(
-						ErrorKind::StoreErr(e, "retrieving block to compact".to_owned()).into(),
-					);
-				}
-			}
-			if current.height <= 1 {
-				break;
-			}
-			match batch.get_previous_header(&current) {
-				Ok(h) => current = h,
-				Err(NotFoundErr(_)) => break,
-				Err(e) => return Err(From::from(e)),
+		// Remove old blocks (including short lived fork blocks) which height < tail.height
+		// here b is a block
+		for (_, b) in batch.blocks_iter()? {
+			if b.header.height < tail.height {
+				let _ = batch.delete_block(&b.hash());
+				count += 1;
 			}
 		}
+
 		batch.save_body_tail(&Tip::from_header(&tail))?;
 
 		debug!(

chain/src/store.rs

@@ -22,7 +22,7 @@ use crate::types::Tip;
 use crate::util::secp::pedersen::Commitment;
 use croaring::Bitmap;
 use grin_store as store;
-use grin_store::{option_to_not_found, to_key, Error};
+use grin_store::{option_to_not_found, to_key, Error, SerIterator};
 use std::sync::Arc;
 
 const STORE_SUBPATH: &'static str = "chain";
@@ -378,6 +378,13 @@ impl<'a> Batch<'a> {
 			db: self.db.child()?,
 		})
 	}
+
+	/// An iterator to all block in db
+	pub fn blocks_iter(&self) -> Result<SerIterator<Block>, Error> {
+		let key = to_key(BLOCK_PREFIX, &mut "".to_string().into_bytes());
+		self.db.iter(&key)
+	}
+
 }
 
 /// An iterator on blocks, from latest to earliest, specialized to return