replace sha1 hash with faster xxhash

Gopkg.lock

@@ -37,6 +37,12 @@
   revision = "2f1ce7a837dcb8da3ec595b1dac9d0632f0f99e8"
   version = "v1.3.1"
 
+[[projects]]
+  name = "github.com/cespare/xxhash"
+  packages = ["."]
+  revision = "5c37fe3735342a2e0d01c87a907579987c8936cc"
+  version = "v1.0.0"
+
 [[projects]]
   name = "github.com/davecgh/go-spew"
   packages = ["spew"]
@@ -189,10 +195,16 @@
 
 [[projects]]
   name = "github.com/shirou/gopsutil"
-  packages = ["host","internal/common","mem","process"]
+  packages = ["cpu","host","internal/common","mem","net","process"]
   revision = "bfe3c2e8f406bf352bc8df81f98c752224867349"
   version = "v2.17.11"
 
+[[projects]]
+  branch = "master"
+  name = "github.com/shirou/w32"
+  packages = ["."]
+  revision = "bb4de0191aa41b5507caa14b0650cdbddcd9280b"
+
 [[projects]]
   name = "github.com/sony/gobreaker"
   packages = ["."]
@@ -268,6 +280,6 @@
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  inputs-digest = "d91110a10c830f7a9cc439b9578840d97d9921e84d08242316da8d4a18c68c56"
+  inputs-digest = "53ae0cdcbfa8419b233a0544d7ebb80614af3dd04bebdc0c8f2d3620a87efa91"
   solver-name = "gps-cdcl"
   solver-version = 1

attr.go

@@ -16,13 +16,15 @@ package pilosa
 
 import (
 	"bytes"
-	"crypto/sha1"
+
 	"encoding/binary"
 	"fmt"
 	"sort"
 	"sync"
 	"time"
 
+	"github.com/cespare/xxhash"
+
 	"github.com/boltdb/bolt"
 	"github.com/gogo/protobuf/proto"
 	"github.com/pilosa/pilosa/internal"
@@ -242,7 +244,7 @@ func (s *AttrStore) Blocks() ([]AttrBlock, error) {
 		block := AttrBlock{ID: cur.blockID()}
 
 		// Compute checksum of every key/value in block.
-		h := sha1.New()
+		h := xxhash.New()
 		for k, v := cur.next(); k != nil; k, v = cur.next() {
 			h.Write(k)
 			h.Write(v)

fragment.go

@@ -20,7 +20,6 @@ import (
 	"bytes"
 	"container/heap"
 	"context"
-	"crypto/sha1"
 	"encoding/binary"
 	"errors"
 	"fmt"
@@ -36,6 +35,8 @@ import (
 	"time"
 	"unsafe"
 
+	"github.com/cespare/xxhash"
+
 	"math"
 
 	"github.com/gogo/protobuf/proto"
@@ -1020,7 +1021,7 @@ type TopOptions struct {
 // Checksum returns a checksum for the entire fragment.
 // If two fragments have the same checksum then they have the same data.
 func (f *Fragment) Checksum() []byte {
-	h := sha1.New()
+	h := xxhash.New()
 	for _, block := range f.Blocks() {
 		h.Write(block.Checksum)
 	}
@@ -1660,7 +1661,7 @@ type blockHasher struct {
 func newBlockHasher() blockHasher {
 	return blockHasher{
 		blockID: -1,
-		hash:    sha1.New(),
+		hash:    xxhash.New(),
 	}
 }
 func (h *blockHasher) Reset() {