port hasher pool to leveldb

graph/leveldb/iterator.go

@@ -43,7 +43,7 @@ type Iterator struct {
 
 func NewIterator(prefix string, d quad.Direction, value graph.Value, qs *TripleStore) *Iterator {
 	vb := value.(Token)
-	p := make([]byte, 0, 2+qs.hasherSize)
+	p := make([]byte, 0, 2+hashSize)
 	p = append(p, []byte(prefix)...)
 	p = append(p, []byte(vb[1:])...)
 
@@ -169,9 +169,9 @@ func PositionOf(prefix []byte, d quad.Direction, qs *TripleStore) int {
 		case quad.Subject:
 			return 2
 		case quad.Predicate:
-			return qs.hasherSize + 2
+			return hashSize + 2
 		case quad.Object:
-			return 2*qs.hasherSize + 2
+			return 2*hashSize + 2
 		case quad.Label:
 			return -1
 		}
@@ -179,11 +179,11 @@ func PositionOf(prefix []byte, d quad.Direction, qs *TripleStore) int {
 	if bytes.Equal(prefix, []byte("po")) {
 		switch d {
 		case quad.Subject:
-			return 2*qs.hasherSize + 2
+			return 2*hashSize + 2
 		case quad.Predicate:
 			return 2
 		case quad.Object:
-			return qs.hasherSize + 2
+			return hashSize + 2
 		case quad.Label:
 			return -1
 		}
@@ -191,9 +191,9 @@ func PositionOf(prefix []byte, d quad.Direction, qs *TripleStore) int {
 	if bytes.Equal(prefix, []byte("os")) {
 		switch d {
 		case quad.Subject:
-			return qs.hasherSize + 2
+			return hashSize + 2
 		case quad.Predicate:
-			return 2*qs.hasherSize + 2
+			return 2*hashSize + 2
 		case quad.Object:
 			return 2
 		case quad.Label:
@@ -203,11 +203,11 @@ func PositionOf(prefix []byte, d quad.Direction, qs *TripleStore) int {
 	if bytes.Equal(prefix, []byte("cp")) {
 		switch d {
 		case quad.Subject:
-			return 2*qs.hasherSize + 2
+			return 2*hashSize + 2
 		case quad.Predicate:
-			return qs.hasherSize + 2
+			return hashSize + 2
 		case quad.Object:
-			return 3*qs.hasherSize + 2
+			return 3*hashSize + 2
 		case quad.Label:
 			return 2
 		}

graph/leveldb/triplestore.go

@@ -21,6 +21,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"hash"
+	"sync"
 
 	"github.com/barakmich/glog"
 	"github.com/syndtr/goleveldb/leveldb"
@@ -42,6 +43,13 @@ const (
 	DefaultWriteBufferSize = 20
 )
 
+var (
+	hashPool = sync.Pool{
+		New: func() interface{} { return sha1.New() },
+	}
+	hashSize = sha1.Size
+)
+
 type Token []byte
 
 func (t Token) Key() interface{} {
@@ -49,15 +57,13 @@ func (t Token) Key() interface{} {
 }
 
 type TripleStore struct {
-	dbOpts     *opt.Options
+	dbOpts    *opt.Options
-	db         *leveldb.DB
+	db        *leveldb.DB
-	path       string
+	path      string
-	open       bool
+	open      bool
-	size       int64
+	size      int64
-	hasherSize int
+	writeopts *opt.WriteOptions
-	makeHasher func() hash.Hash
+	readopts  *opt.ReadOptions
-	writeopts  *opt.WriteOptions
-	readopts   *opt.ReadOptions
 }
 
 func createNewLevelDB(path string, _ graph.Options) error {
@@ -94,8 +100,6 @@ func newTripleStore(path string, options graph.Options) (graph.TripleStore, erro
 		write_buffer_mb = val
 	}
 	qs.dbOpts.WriteBuffer = write_buffer_mb * opt.MiB
-	qs.hasherSize = sha1.Size
-	qs.makeHasher = sha1.New
 	qs.writeopts = &opt.WriteOptions{
 		Sync: false,
 	}
@@ -125,33 +129,30 @@ func (qs *TripleStore) Size() int64 {
 }
 
 func (qs *TripleStore) createKeyFor(d [3]quad.Direction, triple quad.Quad) []byte {
-	hasher := qs.makeHasher()
+	key := make([]byte, 0, 2+(hashSize*3))
-	key := make([]byte, 0, 2+(qs.hasherSize*3))
 	// TODO(kortschak) Remove dependence on String() method.
 	key = append(key, []byte{d[0].Prefix(), d[1].Prefix()}...)
-	key = append(key, qs.convertStringToByteHash(triple.Get(d[0]), hasher)...)
+	key = append(key, qs.convertStringToByteHash(triple.Get(d[0]))...)
-	key = append(key, qs.convertStringToByteHash(triple.Get(d[1]), hasher)...)
+	key = append(key, qs.convertStringToByteHash(triple.Get(d[1]))...)
-	key = append(key, qs.convertStringToByteHash(triple.Get(d[2]), hasher)...)
+	key = append(key, qs.convertStringToByteHash(triple.Get(d[2]))...)
 	return key
 }
 
 func (qs *TripleStore) createProvKeyFor(d [3]quad.Direction, triple quad.Quad) []byte {
-	hasher := qs.makeHasher()
+	key := make([]byte, 0, 2+(hashSize*4))
-	key := make([]byte, 0, 2+(qs.hasherSize*4))
 	// TODO(kortschak) Remove dependence on String() method.
 	key = append(key, []byte{quad.Label.Prefix(), d[0].Prefix()}...)
-	key = append(key, qs.convertStringToByteHash(triple.Get(quad.Label), hasher)...)
+	key = append(key, qs.convertStringToByteHash(triple.Get(quad.Label))...)
-	key = append(key, qs.convertStringToByteHash(triple.Get(d[0]), hasher)...)
+	key = append(key, qs.convertStringToByteHash(triple.Get(d[0]))...)
-	key = append(key, qs.convertStringToByteHash(triple.Get(d[1]), hasher)...)
+	key = append(key, qs.convertStringToByteHash(triple.Get(d[1]))...)
-	key = append(key, qs.convertStringToByteHash(triple.Get(d[2]), hasher)...)
+	key = append(key, qs.convertStringToByteHash(triple.Get(d[2]))...)
 	return key
 }
 
 func (qs *TripleStore) createValueKeyFor(s string) []byte {
-	hasher := qs.makeHasher()
+	key := make([]byte, 0, 1+hashSize)
-	key := make([]byte, 0, 1+qs.hasherSize)
 	key = append(key, []byte("z")...)
-	key = append(key, qs.convertStringToByteHash(s, hasher)...)
+	key = append(key, qs.convertStringToByteHash(s)...)
 	return key
 }
 
@@ -336,11 +337,13 @@ func (qs *TripleStore) Quad(k graph.Value) quad.Quad {
 	return triple
 }
 
-func (qs *TripleStore) convertStringToByteHash(s string, hasher hash.Hash) []byte {
+func (qs *TripleStore) convertStringToByteHash(s string) []byte {
-	hasher.Reset()
+	h := hashPool.Get().(hash.Hash)
-	key := make([]byte, 0, qs.hasherSize)
+	h.Reset()
-	hasher.Write([]byte(s))
+	defer hashPool.Put(h)
-	key = hasher.Sum(key)
+	key := make([]byte, 0, hashSize)
+	h.Write([]byte(s))
+	key = h.Sum(key)
 	return key
 }
 
@@ -446,7 +449,7 @@ func (qs *TripleStore) TripleDirection(val graph.Value, d quad.Direction) graph.
 	v := val.(Token)
 	offset := PositionOf(v[0:2], d, qs)
 	if offset != -1 {
-		return Token(append([]byte("z"), v[offset:offset+qs.hasherSize]...))
+		return Token(append([]byte("z"), v[offset:offset+hashSize]...))
 	} else {
 		return Token(qs.Quad(val).Get(d))
 	}