From a926686445929d091c2d9e019b017600168e9e47 Mon Sep 17 00:00:00 2001
From: obscuren <obscuren@obscura.com>
Date: Sun, 29 Dec 2013 23:54:50 +0100
Subject: [PATCH] Added sample server, genesis block, and database interface

---
 database.go      | 94 ++++++++++++++++++++++++++++++++++++++++++++++++
 database_test.go | 43 ++++++++++++++++++++++
 genesis.go       | 36 +++++++++++++++++++
 server.go        | 55 ++++++++++++++++++++++++++++
 4 files changed, 228 insertions(+)
 create mode 100644 database.go
 create mode 100644 database_test.go
 create mode 100644 genesis.go
 create mode 100644 server.go

diff --git a/database.go b/database.go
new file mode 100644
index 000000000..f74c1dc7f
--- /dev/null
+++ b/database.go
@@ -0,0 +1,94 @@
+package main
+
+import (
+  "path"
+  "os/user"
+  "github.com/syndtr/goleveldb/leveldb"
+  "fmt"
+)
+
+type Database struct {
+  db        *leveldb.DB
+  trie      *Trie
+}
+
+func NewDatabase() (*Database, error) {
+  // This will eventually have to be something like a resource folder.
+  // it works on my system for now. Probably won't work on Windows
+  usr, _ := user.Current()
+  dbPath := path.Join(usr.HomeDir, ".ethereum", "database")
+
+  // Open the db
+  db, err := leveldb.OpenFile(dbPath, nil)
+  if err != nil {
+    return nil, err
+  }
+
+  database := &Database{db: db}
+
+  // Bootstrap database. Sets a few defaults; such as the last block
+  database.Bootstrap()
+
+  return database, nil
+}
+
+func (db *Database) Bootstrap() error {
+  db.trie = NewTrie(db)
+
+  return nil
+}
+
+func (db *Database) Put(key []byte, value []byte) {
+  err := db.db.Put(key, value, nil)
+  if err != nil {
+    fmt.Println("Error put", err)
+  }
+}
+
+func (db *Database) Close() {
+  // Close the leveldb database
+  db.db.Close()
+}
+
+type Trie struct {
+  root       string
+  db         *Database
+}
+
+func NewTrie(db *Database) *Trie {
+  return &Trie{db: db, root: ""}
+}
+
+func (t *Trie) Update(key string, value string) {
+  k := CompactHexDecode(key)
+
+  t.root = t.UpdateState(t.root, k, value)
+}
+
+func (t *Trie) Get(key []byte) ([]byte, error) {
+  return nil, nil
+}
+
+// Inserts a new sate or delete a state based on the value
+func (t *Trie) UpdateState(node, key, value string) string {
+  if value != "" {
+    return t.InsertState(node, key, value)
+  } else {
+    // delete it
+  }
+
+  return ""
+}
+
+func (t *Trie) InsertState(node, key, value string) string {
+  return ""
+}
+
+func (t *Trie) Put(node []byte) []byte {
+  enc := Encode(node)
+  sha := Sha256Bin(enc)
+
+  t.db.Put([]byte(sha), enc)
+
+  return sha
+}
diff --git a/database_test.go b/database_test.go
new file mode 100644
index 000000000..c1a6c7d16
--- /dev/null
+++ b/database_test.go
@@ -0,0 +1,43 @@
+package main
+
+import (
+  "testing"
+  _"fmt"
+)
+
+func TestTriePut(t *testing.T) {
+  db, err := NewDatabase()
+  defer db.Close()
+
+  if err != nil {
+    t.Error("Error starting db")
+  }
+
+  key := db.trie.Put([]byte("testing node"))
+
+  data, err := db.db.Get(key, nil)
+  if err != nil {
+    t.Error("Nothing at node")
+  }
+
+  s, _ := Decode(data, 0)
+  if str, ok := s.([]byte); ok {
+    if string(str) != "testing node" {
+      t.Error("Wrong value node", str)
+    }
+  } else {
+    t.Error("Invalid return type")
+  }
+}
+
+func TestTrieUpdate(t *testing.T) {
+  db, err := NewDatabase()
+  defer db.Close()
+
+  if err != nil {
+    t.Error("Error starting db")
+  }
+
+  db.trie.Update("test", "test")
+}
+
diff --git a/genesis.go b/genesis.go
new file mode 100644
index 000000000..aae9cd1cf
--- /dev/null
+++ b/genesis.go
@@ -0,0 +1,36 @@
+package main
+
+import (
+  "math"
+)
+
+/*
+ * This is the special genesis block.
+ */
+
+var GenisisHeader = []interface{}{
+  // Block number
+  uint32(0),
+  // Previous hash (none)
+  "",
+  // Sha of uncles
+  string(Sha256Bin(Encode([]interface{}{}))),
+  // Coinbase
+  "",
+  // Root state
+  "",
+  // Sha of transactions
+  string(Sha256Bin(Encode([]interface{}{}))),
+  // Difficulty
+  uint32(math.Pow(2, 36)),
+  // Time
+  uint64(1),
+  // Nonce
+  uint32(0),
+  // Extra
+  "",
+}
+
+var Genesis = []interface{}{ GenisisHeader, []interface{}{}, []interface{}{} }
+
+var GenisisBlock = NewBlock( Encode(Genesis) )
diff --git a/server.go b/server.go
new file mode 100644
index 000000000..0c7488787
--- /dev/null
+++ b/server.go
@@ -0,0 +1,55 @@
+package main
+
+import (
+  "container/list"
+  "time"
+)
+
+type Server struct {
+  // Channel for shutting down the server
+  shutdownChan chan bool
+  // DB interface
+  db          *Database
+  // Peers (NYI)
+  peers       *list.List
+}
+
+func NewServer() (*Server, error) {
+  db, err := NewDatabase()
+  if err != nil {
+    return nil, err
+  }
+
+  server := &Server{
+    shutdownChan:    make(chan bool),
+    db:              db,
+    peers:           list.New(),
+  }
+
+  return server, nil
+}
+
+// Start the server
+func (s *Server) Start() {
+  // For now this function just blocks the main thread
+  for {
+    time.Sleep( time.Second )
+  }
+}
+
+func (s *Server) Stop() {
+  // Close the database
+  defer s.db.Close()
+
+  // Loop thru the peers and close them (if we had them)
+  for e := s.peers.Front(); e != nil; e = e.Next() {
+    // peer close etc
+  }
+
+  s.shutdownChan <- true
+}
+
+// This function will wait for a shutdown and resumes main thread execution
+func (s *Server) WaitForShutdown() {
+  <- s.shutdownChan
+}