From e9eba76591b621e7a043e78b0facb337fdbb6b1a Mon Sep 17 00:00:00 2001
From: Nikhil Garg <nikhilgarg28@gmail.com>
Date: Sat, 1 Aug 2015 14:19:42 -0700
Subject: [PATCH] bitset : remove all replication code

Moving all replication related code to a different package built on top of
bitset.
---
 bitset.go      | 97 +++-----------------------------------------------
 bitset_test.go | 13 ++++---
 2 files changed, 10 insertions(+), 100 deletions(-)

diff --git a/bitset.go b/bitset.go
index fdd99ac..3d17513 100644
--- a/bitset.go
+++ b/bitset.go
@@ -1,109 +1,23 @@
 package bitset
 
-import (
-	"bufio"
-	"encoding/binary"
-	"fmt"
-	"os"
-	"time"
-)
-
 const word = uint64(64)
 const logword = uint(6)
-const bufsize = 1 << 16
-
-// each channel write is 9 bytes, so if we were to write full disk sector
-// of 64K bytes at once, we'd flush ~7112 writes
-const channelsize = 7200
-
-const (
-	new = iota
-	set
-	clear
-	flip
-)
-
-type command struct {
-	code  uint8
-	index uint64
-}
 
 type BitSet struct {
-	length     uint64
-	bits       []uint64
-	writes     chan command
-	binlogfile string
+	length uint64
+	bits   []uint64
 }
 
 func getSize(length uint64) uint64 {
 	return uint64((length + word - 1) / word)
 }
 
-func flush(filename string, writes chan command) {
-	f, err := os.Create(filename)
-	if err != nil {
-		panic(err)
-	}
-
-	defer func() {
-		if err := f.Close(); err != nil {
-			panic(err)
-		}
-	}()
-
-	// make a buffered writer
-	w := bufio.NewWriterSize(f, bufsize)
-
-	ticker := time.NewTimer(time.Second)
-
-	buf := make([]byte, bufsize)
-	long := make([]byte, 8)
-
-	put := func(w *command) {
-		binary.BigEndian.PutUint64(long, w.index)
-		buf = append(buf, w.code)
-		buf = append(buf, long...)
-	}
-
-	for t := range ticker.C {
-		_ = t
-		b := 0
-
-	drain:
-		for b+9 < bufsize {
-			select {
-			case write := <-writes:
-				put(&write)
-				b += 9
-			default:
-				break drain
-			}
-		}
-
-		if b > 0 {
-			// write a chunk
-			if _, err := w.Write(buf[:b]); err != nil {
-				panic(err)
-			}
-
-			if err = w.Flush(); err != nil {
-				panic(err)
-			}
-		}
-	}
-}
-
-func New(length uint64, binlogfile string) *BitSet {
+func New(length uint64) *BitSet {
 	size := getSize(length)
-	ret := &BitSet{
+	return &BitSet{
 		length,
 		make([]uint64, size),
-		make(chan command, channelsize),
-		binlogfile,
 	}
-	ret.writes <- command{new, length}
-	go flush(binlogfile, ret.writes)
-	return ret
 }
 
 func getIndex(pos uint64) (q uint64, r uint) {
@@ -126,7 +40,6 @@ func (b *BitSet) Set(pos uint64) bool {
 	current := b.Get(pos)
 	q, r := getIndex(pos)
 	b.bits[q] |= (1 << r)
-	b.writes <- command{set, pos}
 	return current
 }
 
@@ -134,7 +47,6 @@ func (b *BitSet) Clear(pos uint64) bool {
 	current := b.Get(pos)
 	q, r := getIndex(pos)
 	b.bits[q] &= ^(1 << r)
-	b.writes <- command{clear, pos}
 	return current
 }
 
@@ -142,6 +54,5 @@ func (b *BitSet) Flip(pos uint64) bool {
 	current := b.Get(pos)
 	q, r := getIndex(pos)
 	b.bits[q] ^= (1 << r)
-	b.writes <- command{flip, pos}
 	return current
 }
diff --git a/bitset_test.go b/bitset_test.go
index fc64d64..2a3c75b 100644
--- a/bitset_test.go
+++ b/bitset_test.go
@@ -2,11 +2,10 @@ package bitset
 
 import (
 	"testing"
-	"time"
 )
 
 func TestInit(t *testing.T) {
-	bs := New(1000, "/tmp/bitset.log")
+	bs := New(1000)
 	// initially all bits should be zero
 	for i := uint64(0); i < 1000; i++ {
 		if bs.Get(i) {
@@ -16,7 +15,7 @@ func TestInit(t *testing.T) {
 }
 
 func TestGetSet(t *testing.T) {
-	bs := New(1000, "/tmp/bitset.log")
+	bs := New(1000)
 	if bs.Set(0) == true {
 		t.Error("Set on bit %d returned true when it should return false", 0)
 	}
@@ -32,7 +31,7 @@ func TestGetSet(t *testing.T) {
 
 func TestLargeSetGet(t *testing.T) {
 	size := uint64(1) << 35
-	bs := New(size, "/tmp/bitset.log")
+	bs := New(size)
 
 	positions := []uint64{0, 1, 10, 1000, 1 << 32, size - 1}
 	for _, position := range positions {
@@ -52,7 +51,7 @@ func TestLength(t *testing.T) {
 
 	sizes := []uint64{0, 1, 10, 1000, 1 << 32, 1 << 33}
 	for _, size := range sizes {
-		bs := New(size, "/tmp/bitset.log")
+		bs := New(size)
 		if bs.Length() != size {
 			t.Errorf("Length should be %d", size)
 		}
@@ -60,7 +59,7 @@ func TestLength(t *testing.T) {
 }
 
 func TestClear(t *testing.T) {
-	bs := New(1000, "/tmp/bitset.log")
+	bs := New(1000)
 	pos := uint64(1)
 	bs.Set(pos)
 
@@ -78,7 +77,7 @@ func TestClear(t *testing.T) {
 }
 
 func TestFlip(t *testing.T) {
-	bs := New(1000, "/tmp/bitset.log")
+	bs := New(1000)
 	pos := uint64(1)
 
 	if bs.Get(pos) {