From ebeffe49049d06a31e7f9497e3f6d13f0d50d5ce Mon Sep 17 00:00:00 2001
From: Thibaut Horel <thibaut.horel@gmail.com>
Date: Wed, 4 May 2016 17:02:13 -0400
Subject: Some inlining and removing useless code

---
 main.go   | 13 +++++++------
 merkle.go | 50 ++++++++++++++++----------------------------------
 2 files changed, 23 insertions(+), 40 deletions(-)

diff --git a/main.go b/main.go
index bfe2d4b..33b2de2 100644
--- a/main.go
+++ b/main.go
@@ -2,7 +2,6 @@ package main
 
 import (
 	"flag"
-	"fmt"
 	"log"
 	"os"
 	"runtime/pprof"
@@ -32,9 +31,11 @@ func main() {
 	defer pprof.StopCPUProfile()
 
 	p := NewProver(*height, *fname, *mtype)
-	root := p.Build()
-	fmt.Println(root)
-	id := p.Size() / 2
-	proof := p.Proof(id)
-	fmt.Println(verify(id, proof))
+	p.Build()
+	/*
+		fmt.Println(root)
+		id := p.Size() / 2
+		proof := p.Proof(id)
+		fmt.Println(verify(id, proof))
+	*/
 }
diff --git a/merkle.go b/merkle.go
index 9eaf521..15294bd 100644
--- a/merkle.go
+++ b/merkle.go
@@ -27,30 +27,6 @@ func NewMerkle(mtype string, height int64, fname string) Merkle {
 	}
 	return m
 }
-func ChildrenId(m Merkle, id int64) (id1, id2 int64) {
-	id2 = (id + 1) * 2
-	id1 = id2 - 1
-	return id1, id2
-}
-
-func Children(child1, child2 []byte, id int64, m Merkle) {
-	id1, id2 := ChildrenId(m, id)
-	m.Read(child1, id1)
-	m.Read(child2, id2)
-}
-
-func Init(m Merkle) {
-	h := sha3.New256()
-	hsize := h.Size()
-	buf := make([]byte, hsize)
-
-	for id := m.Size() / 2; id <= m.Size(); id++ {
-		h.Reset()
-		binary.Write(h, binary.LittleEndian, id)
-		buf = h.Sum(buf[:0])
-		m.Put(id, buf)
-	}
-}
 
 // nodes are stored in BFS order, root node first
 type BFSMerkle struct {
@@ -82,20 +58,26 @@ func (m *BFSMerkle) Read(buf []byte, id int64) {
 
 // disk access is sequential and mostly backward
 func (m *BFSMerkle) Build() []byte {
-	Init(m)
 	size := m.Size()
 	h := sha3.New256()
-	hsize := h.Size()
-	child1 := make([]byte, hsize)
-	child2 := make([]byte, hsize)
+	hsize := int64(h.Size())
 	buf := make([]byte, hsize)
+
+	for id := m.Size() / 2; id <= m.Size(); id++ {
+		h.Reset()
+		binary.Write(h, binary.LittleEndian, id)
+		buf = h.Sum(buf[:0])
+		m.WriteAt(buf, id*hsize)
+	}
+
 	for id := size/2 - 1; id >= 0; id-- {
-		Children(child1, child2, id, m)
 		h.Reset()
-		h.Write(child1)
-		h.Write(child2)
+		m.ReadAt(buf, (id*2+1)*hsize)
+		h.Write(buf)
+		m.ReadAt(buf, (id*2+2)*hsize)
+		h.Write(buf)
 		buf = h.Sum(buf[:0])
-		m.Put(id, buf)
+		m.WriteAt(buf, id*hsize)
 	}
 	return buf
 }
@@ -107,9 +89,9 @@ func (m *BFSMerkle) Proof(id int64) [][]byte {
 	for i := 1; id > 0; i++ {
 		proof[i] = make([]byte, hashSize)
 		if id&1 == 0 {
-			m.Read(proof[i], id-1)
+			m.ReadAt(proof[i], (id-1)*hashSize)
 		} else {
-			m.Read(proof[i], id+1)
+			m.ReadAt(proof[i], (id+1)*hashSize)
 		}
 		id = (id - 1) >> 1
 	}
-- 
cgit v1.2.3-70-g09d2