From 33b1e6ddf446674f9ccd8d5d0e6346845013ff2b Mon Sep 17 00:00:00 2001
From: Paul Hauner <paul@paulhauner.com>
Date: Mon, 17 Sep 2018 17:52:32 +1000
Subject: [PATCH] Partially implemented db wrapper

Addresses issue #12
---
 lighthouse/client/mod.rs       |  8 +++++---
 lighthouse/db/mod.rs           | 27 +++++++++++++++++----------
 lighthouse/sync/block.rs       |  5 +++--
 lighthouse/sync/network.rs     |  8 ++++----
 lighthouse/sync/sync_future.rs |  4 ++--
 5 files changed, 31 insertions(+), 21 deletions(-)

diff --git a/lighthouse/client/mod.rs b/lighthouse/client/mod.rs
index 89b1729ba..f76f87aef 100644
--- a/lighthouse/client/mod.rs
+++ b/lighthouse/client/mod.rs
@@ -1,6 +1,6 @@
 use std::sync::Arc;
 use std::thread;
-use super::db::{ DB, open_db };
+use super::db::{ DiskDB };
 use super::config::LighthouseConfig;
 use super::futures::sync::mpsc::{
     unbounded,
@@ -10,10 +10,12 @@ use super::network_libp2p::state::NetworkState;
 use super::slog::Logger;
 use super::sync::run_sync_future;
 
+use super::db::ClientDB;
+
 /// Represents the co-ordination of the
 /// networking, syncing and RPC (not-yet-implemented) threads.
 pub struct Client {
-    pub db: Arc<DB>,
+    pub db: Arc<ClientDB>,
     pub network_thread: thread::JoinHandle<()>,
     pub sync_thread: thread::JoinHandle<()>,
 }
@@ -29,7 +31,7 @@ impl Client {
     {
         // Open the local db
         let db = {
-            let db = open_db(&config.data_dir);
+            let db = DiskDB::open(&config.data_dir);
             Arc::new(db)
         };
 
diff --git a/lighthouse/db/mod.rs b/lighthouse/db/mod.rs
index 92323b3ac..23ddb9a37 100644
--- a/lighthouse/db/mod.rs
+++ b/lighthouse/db/mod.rs
@@ -1,14 +1,21 @@
 extern crate rocksdb;
 
-use std::fs;
-use std::path::Path;
-pub use self::rocksdb::DB;
+mod disk_db;
 
-pub fn open_db(path: &Path) -> DB {
-    let db_path = path.join("rocksdb");
-    fs::create_dir_all(&db_path)
-        .expect(&format!("Unable to create {:?}", &db_path));
-    let db = DB::open_default(db_path.join("lighthouse.rdb"))
-        .expect("Unable to open local database.");
-    db
+pub use self::disk_db::DiskDB;
+
+#[derive(Debug)]
+pub struct DBError {
+    message: String
+}
+
+impl DBError {
+    fn new(message: String) -> Self {
+        Self { message }
+    }
+}
+
+pub trait ClientDB: Sync + Send {
+    fn get(&self, col: &str, key: &[u8])
+        -> Result<Option<&[u8]>, DBError>;
 }
diff --git a/lighthouse/sync/block.rs b/lighthouse/sync/block.rs
index 2612ca8b1..72d827285 100644
--- a/lighthouse/sync/block.rs
+++ b/lighthouse/sync/block.rs
@@ -1,4 +1,5 @@
-use super::db::DB;
+use std::sync::Arc;
+use super::db::ClientDB;
 use slog::Logger;
 
 pub enum BlockStatus {
@@ -14,7 +15,7 @@ pub enum BlockStatus {
 
 pub fn process_unverified_blocks(
     _serialized_block: &[u8],
-    _db: &DB,
+    _db: Arc<ClientDB>,
     _log: Logger)
 {
     //
diff --git a/lighthouse/sync/network.rs b/lighthouse/sync/network.rs
index 99d178ff0..1383b5040 100644
--- a/lighthouse/sync/network.rs
+++ b/lighthouse/sync/network.rs
@@ -1,5 +1,5 @@
 use std::sync::Arc;
-use super::db::DB;
+use super::db::ClientDB;
 use slog::Logger;
 
 use super::network_libp2p::message::{
@@ -25,7 +25,7 @@ use super::futures::sync::mpsc::{
 /// (e.g., libp2p) has an event to push up to the sync process.
 pub fn handle_network_event(
     event: NetworkEvent,
-    db: Arc<DB>,
+    db: Arc<ClientDB>,
     network_tx: UnboundedSender<OutgoingMessage>,
     log: Logger)
     -> Result<(), ()>
@@ -39,7 +39,7 @@ pub fn handle_network_event(
                 if let Some(data) = event.data {
                     handle_network_message(
                         data,
-                        &db,
+                        db,
                         network_tx,
                         log)
                 } else {
@@ -56,7 +56,7 @@ pub fn handle_network_event(
 /// (e.g., libp2p) has sent a message to us.
 fn handle_network_message(
     message: Vec<u8>,
-    db: &DB,
+    db: Arc<ClientDB>,
     _network_tx: UnboundedSender<OutgoingMessage>,
     log: Logger)
     -> Result<(), ()>
diff --git a/lighthouse/sync/sync_future.rs b/lighthouse/sync/sync_future.rs
index 06836fb30..0e46e9e50 100644
--- a/lighthouse/sync/sync_future.rs
+++ b/lighthouse/sync/sync_future.rs
@@ -10,7 +10,7 @@ use super::network_libp2p::message::{
 };
 use super::network::handle_network_event;
 use std::sync::Arc;
-use super::db::DB;
+use super::db::ClientDB;
 use slog::Logger;
 
 type NetworkSender = UnboundedSender<OutgoingMessage>;
@@ -25,7 +25,7 @@ type SyncReceiver = UnboundedReceiver<Vec<u8>>;
 /// from the network and the RPC and update
 /// the state.
 pub fn run_sync_future(
-    db: Arc<DB>,
+    db: Arc<ClientDB>,
     network_tx: NetworkSender,
     network_rx: NetworkReceiver,
     _sync_tx: SyncSender,