Split Store trait into its R/W parts

src/index.rs

@@ -12,7 +12,7 @@ use std::sync::{Arc, RwLock};
 use std::time::{Duration, Instant};
 
 use daemon::Daemon;
-use store::{Row, Store};
+use store::{DBStore, ReadStore, Row, WriteStore};
 use util::{full_hash, hash_prefix, Bytes, FullHash, HashPrefix, HeaderEntry, HeaderList,
            HeaderMap, HASH_PREFIX_LEN};
 
@@ -198,7 +198,7 @@ fn index_block(block: &Block, height: usize) -> Vec<Row> {
     rows
 }
 
-fn read_indexed_headers(store: &Store) -> HeaderMap {
+fn read_indexed_headers(store: &ReadStore) -> HeaderMap {
     let mut headers = HeaderMap::new();
     for row in store.scan(b"B") {
         let key: BlockKey = bincode::deserialize(&row.key).unwrap();
@@ -208,7 +208,7 @@ fn read_indexed_headers(store: &Store) -> HeaderMap {
     headers
 }
 
-fn read_last_indexed_blockhash(store: &Store) -> Option<Sha256dHash> {
+fn read_last_indexed_blockhash(store: &ReadStore) -> Option<Sha256dHash> {
     let row = store.get(b"L")?;
     let blockhash: Sha256dHash = deserialize(&row).unwrap();
     Some(blockhash)
@@ -365,7 +365,7 @@ impl Index {
         missing_headers
     }
 
-    pub fn update(&self, store: &Store, daemon: &Daemon) -> Sha256dHash {
+    pub fn update(&self, store: &DBStore, daemon: &Daemon) -> Sha256dHash {
         let mut indexed_headers: Arc<HeaderList> = self.headers_list();
         let no_indexed_headers = indexed_headers.headers().is_empty();
         if no_indexed_headers {
@@ -383,7 +383,7 @@ impl Index {
             /*use_progress_bar=*/ no_indexed_headers,
         )) {
             // TODO: add timing
-            store.persist(rows);
+            store.write(rows);
         }
         let tip = current_headers.tip();
         *(self.headers.write().unwrap()) = Arc::new(current_headers);

src/mempool.rs

@@ -9,7 +9,7 @@ use std::time::{Duration, Instant};
 
 use daemon::{Daemon, MempoolEntry};
 use index::index_transaction;
-use store::{Row, Store};
+use store::{ReadStore, Row};
 use util::Bytes;
 
 error_chain!{}
@@ -21,18 +21,19 @@ struct MempoolStore {
 }
 
 impl MempoolStore {
-    fn new() -> MempoolStore {
-        MempoolStore {
-            map: RwLock::new(BTreeMap::new()),
+    fn new(rows: Vec<Row>) -> MempoolStore {
+        let mut map = BTreeMap::new();
+        for row in rows {
+            let (key, value) = row.into_pair();
+            map.insert(key, value);
+        }
+        MempoolStore {
+            map: RwLock::new(map),
         }
-    }
-
-    fn clear(&self) {
-        self.map.write().unwrap().clear()
     }
 }
 
-impl Store for MempoolStore {
+impl ReadStore for MempoolStore {
     fn get(&self, key: &[u8]) -> Option<Bytes> {
         self.map.read().unwrap().get(key).map(|v| v.to_vec())
     }
@@ -51,13 +52,6 @@ impl Store for MempoolStore {
         }
         rows
     }
-    fn persist(&self, rows: Vec<Row>) {
-        let mut map = self.map.write().unwrap();
-        for row in rows {
-            let (key, value) = row.into_pair();
-            map.insert(key, value);
-        }
-    }
 }
 
 pub struct Stats {
@@ -80,7 +74,7 @@ impl Tracker {
     pub fn new() -> Tracker {
         Tracker {
             stats: HashMap::new(),
-            index: MempoolStore::new(),
+            index: MempoolStore::new(vec![]),
         }
     }
 
@@ -134,14 +128,11 @@ impl Tracker {
         for txid in old_txids.difference(&new_txids) {
             self.remove(txid);
         }
-
         let mut rows = Vec::new();
         for stats in self.stats.values() {
             index_transaction(&stats.tx, 0, &mut rows)
         }
-        self.index.clear();
-        self.index.persist(rows);
-
+        self.index = MempoolStore::new(rows);
         debug!(
             "mempool update took {:.1} ms ({} txns)",
             t.elapsed().in_seconds() * 1e3,
@@ -158,7 +149,7 @@ impl Tracker {
         self.stats.remove(txid);
     }
 
-    pub fn index(&self) -> &Store {
+    pub fn index(&self) -> &ReadStore {
         &self.index
     }
 }

src/query.rs

@@ -10,7 +10,7 @@ use std::sync::RwLock;
 use daemon::Daemon;
 use index::{compute_script_hash, Index, TxInRow, TxOutRow, TxRow};
 use mempool::Tracker;
-use store::Store;
+use store::ReadStore;
 use util::{FullHash, HashPrefix, HeaderEntry};
 
 error_chain!{}
@@ -84,8 +84,8 @@ fn merklize(left: Sha256dHash, right: Sha256dHash) -> Sha256dHash {
     Sha256dHash::from_data(&data)
 }
 
-// TODO: the 3 functions below can be part of Store.
-fn txrows_by_prefix(store: &Store, txid_prefix: &HashPrefix) -> Vec<TxRow> {
+// TODO: the 3 functions below can be part of ReadStore.
+fn txrows_by_prefix(store: &ReadStore, txid_prefix: &HashPrefix) -> Vec<TxRow> {
     store
         .scan(&TxRow::filter(&txid_prefix))
         .iter()
@@ -93,7 +93,7 @@ fn txrows_by_prefix(store: &Store, txid_prefix: &HashPrefix) -> Vec<TxRow> {
         .collect()
 }
 
-fn txids_by_script_hash(store: &Store, script_hash: &[u8]) -> Vec<HashPrefix> {
+fn txids_by_script_hash(store: &ReadStore, script_hash: &[u8]) -> Vec<HashPrefix> {
     store
         .scan(&TxOutRow::filter(script_hash))
         .iter()
@@ -102,7 +102,7 @@ fn txids_by_script_hash(store: &Store, script_hash: &[u8]) -> Vec<HashPrefix> {
 }
 
 fn txids_by_funding_output(
-    store: &Store,
+    store: &ReadStore,
     txn_id: &Sha256dHash,
     output_index: usize,
 ) -> Vec<HashPrefix> {
@@ -116,13 +116,13 @@ fn txids_by_funding_output(
 pub struct Query<'a> {
     daemon: &'a Daemon,
     index: &'a Index,
-    index_store: &'a Store, // TODO: should be a part of index
+    index_store: &'a ReadStore, // TODO: should be a part of index
     tracker: RwLock<Tracker>,
 }
 
 // TODO: return errors instead of panics
 impl<'a> Query<'a> {
-    pub fn new(index_store: &'a Store, daemon: &'a Daemon, index: &'a Index) -> Query<'a> {
+    pub fn new(index_store: &'a ReadStore, daemon: &'a Daemon, index: &'a Index) -> Query<'a> {
         Query {
             daemon,
             index,
@@ -135,7 +135,7 @@ impl<'a> Query<'a> {
         self.daemon
     }
 
-    fn load_txns(&self, store: &Store, prefixes: Vec<HashPrefix>) -> Vec<TxnHeight> {
+    fn load_txns(&self, store: &ReadStore, prefixes: Vec<HashPrefix>) -> Vec<TxnHeight> {
         let mut txns = Vec::new();
         for txid_prefix in prefixes {
             for tx_row in txrows_by_prefix(store, &txid_prefix) {
@@ -150,7 +150,11 @@ impl<'a> Query<'a> {
         txns
     }
 
-    fn find_spending_input(&self, store: &Store, funding: &FundingOutput) -> Option<SpendingInput> {
+    fn find_spending_input(
+        &self,
+        store: &ReadStore,
+        funding: &FundingOutput,
+    ) -> Option<SpendingInput> {
         let spending_txns: Vec<TxnHeight> = self.load_txns(
             store,
             txids_by_funding_output(store, &funding.txn_id, funding.output_index),

src/store.rs

@@ -15,10 +15,13 @@ impl Row {
     }
 }
 
-pub trait Store: Sync {
+pub trait ReadStore: Sync {
     fn get(&self, key: &[u8]) -> Option<Bytes>;
     fn scan(&self, prefix: &[u8]) -> Vec<Row>;
-    fn persist(&self, rows: Vec<Row>);
+}
+
+pub trait WriteStore: Sync {
+    fn write(&self, rows: Vec<Row>);
 }
 
 pub struct DBStore {
@@ -66,7 +69,7 @@ impl DBStore {
     }
 }
 
-impl Store for DBStore {
+impl ReadStore for DBStore {
     fn get(&self, key: &[u8]) -> Option<Bytes> {
         self.db.get(key).unwrap().map(|v| v.to_vec())
     }
@@ -89,8 +92,10 @@ impl Store for DBStore {
         }
         rows
     }
+}
 
-    fn persist(&self, rows: Vec<Row>) {
+impl WriteStore for DBStore {
+    fn write(&self, rows: Vec<Row>) {
         let mut batch = rocksdb::WriteBatch::default();
         for row in rows {
             batch.put(row.key.as_slice(), row.value.as_slice()).unwrap();