Optimize hash calculation (#3)

Signed-off-by: Igor Shishkin <[email protected]>

database/legacy/database.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/fatih/color"
+	"github.com/pkg/errors"
 )
 
 // DataObject is a file object in JSON database
@@ -52,25 +53,25 @@ func NewDatabase(path string) (*Database, error) {
 			Data: make(map[string]*DataObject),
 		})
 		if err != nil {
-			return nil, fmt.Errorf("Error marshaling initial JSON: %s", err)
+			return nil, errors.Errorf("Error marshaling initial JSON: %s", err)
 		}
 
 		err = ioutil.WriteFile(path, js, 0644)
 		if err != nil {
-			return nil, fmt.Errorf("Error creating schema: %s", err)
+			return nil, errors.Errorf("Error creating schema: %s", err)
 		}
 	}
 
 	fp, err := os.Open(path)
 	if err != nil {
-		return nil, fmt.Errorf("Error opening file: %s", err)
+		return nil, errors.Errorf("Error opening file: %s", err)
 	}
 	defer fp.Close()
 
 	decoder := json.NewDecoder(fp)
 	err = decoder.Decode(&database.Schema)
 	if err != nil {
-		return nil, fmt.Errorf("Error decoding JSON data: %s", err)
+		return nil, errors.Errorf("Error decoding JSON data: %s", err)
 	}
 
 	return &database, nil

go.mod

@@ -6,6 +6,8 @@ require (
 	github.com/cosiner/flag v0.5.2
 	github.com/fatih/color v1.17.0
 	github.com/mattn/go-runewidth v0.0.15 // indirect
+	github.com/pkg/errors v0.9.1
 	github.com/stretchr/testify v1.9.0
+	golang.org/x/sync v0.7.0
 	gopkg.in/cheggaaa/pb.v1 v1.0.28
 )

go.sum

@@ -14,6 +14,8 @@ github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWE
 github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/mattn/go-runewidth v0.0.15 h1:UNAjwbU9l54TA3KzvqLGxwWjHmMgBUVhBiTjelZgg3U=
 github.com/mattn/go-runewidth v0.0.15/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rivo/uniseg v0.2.0 h1:S1pD9weZBuJdFmowNwbpi7BJ8TNftyUImj/0WQi72jY=
@@ -27,6 +29,8 @@ github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
+golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4=

main.go

@@ -1,27 +1,24 @@
 package main
 
 import (
-	"bytes"
 	"flag"
 	"fmt"
 	"log"
 	"os"
 	"path/filepath"
 	"regexp"
 	"sort"
-	"sync"
 	"sync/atomic"
 	"time"
 
 	"github.com/fatih/color"
+	"golang.org/x/sync/errgroup"
 	"gopkg.in/cheggaaa/pb.v1"
 
 	database "github.com/teran/checksum/database/legacy"
 )
 
 var (
-	wg sync.WaitGroup
-
 	appVersion     = "No version specified(probably trunk build)"
 	buildTimestamp = "0000-00-00T00:00:00Z"
 
@@ -60,7 +57,6 @@ func main() {
 	}
 
 	if !cfg.GenerateChecksumOnly {
-		sem := make(chan bool, cfg.Concurrency)
 		var bar *pb.ProgressBar
 		if cfg.Progressbar {
 			bar = pb.New(db.Count())
@@ -80,94 +76,83 @@ func main() {
 		}
 		sort.Strings(keys)
 
-		for _, key := range keys {
-			sem <- true
-			wg.Add(1)
-			go func(file string, obj *database.DataObject) {
-				if cfg.Progressbar {
-					defer func() {
-						bar.Increment()
-					}()
-				}
-				defer func() {
-					<-sem
-				}()
-				defer wg.Done()
-
-				if _, err := os.Stat(file); os.IsNotExist(err) {
-					if !cfg.SkipMissed {
-						fmt.Printf("%s %s\n", color.RedString("[MISS]"), file)
-					}
+		wg := &errgroup.Group{}
+		wg.SetLimit(cfg.Concurrency)
 
-					if cfg.DeleteMissed {
-						fmt.Printf("%s DeleteMissed requested: deleting file `%s` from database\n", color.BlueString("[NOTE]"), file)
-						db.DeleteOne(file)
-						atomic.AddUint64(&cntDeleted, 1)
+		for _, key := range keys {
+			wg.Go(func(file string, obj *database.DataObject) func() error {
+				return func() error {
+					if cfg.Progressbar {
+						defer func() {
+							bar.Increment()
+						}()
 					}
 
-					atomic.AddUint64(&cntMissed, 1)
-					return
-				}
+					if _, err := os.Stat(file); os.IsNotExist(err) {
+						if !cfg.SkipMissed {
+							fmt.Printf("%s %s\n", color.RedString("[MISS]"), file)
+						}
 
-				isChanged := false
+						if cfg.DeleteMissed {
+							fmt.Printf("%s DeleteMissed requested: deleting file `%s` from database\n", color.BlueString("[NOTE]"), file)
+							db.DeleteOne(file)
+							atomic.AddUint64(&cntDeleted, 1)
+						}
 
-				if obj.Length == 0 {
-					obj.Length = flength(file)
-					isChanged = true
-				}
+						atomic.AddUint64(&cntMissed, 1)
+						return nil
+					}
 
-				data, err := readFile(file)
-				if err != nil {
-					log.Fatalf("error reading data: %s", err)
-				}
+					isChanged := false
 
-				if obj.SHA1 == "" {
-					obj.SHA1, err = SHA1(bytes.NewReader(data))
-					if err != nil {
-						log.Fatalf("error calculating SHA1: %s", err)
+					if obj.Length == 0 {
+						obj.Length = flength(file)
+						isChanged = true
 					}
 
-					isChanged = true
-				}
+					if obj.SHA1 == "" || obj.SHA256 == "" {
+						sha1, sha256, err := generateActualChecksum(file)
+						if err != nil {
+							return err
+						}
 
-				if obj.SHA256 == "" {
-					obj.SHA256, err = SHA256(bytes.NewReader(data))
-					if err != nil {
-						log.Fatalf("error calculating SHA256: %s", err)
-					}
+						obj.SHA1 = sha1
+						obj.SHA256 = sha256
 
-					isChanged = true
-				}
+						isChanged = true
+					}
 
-				res := verify(file, obj.Length, obj.SHA1, obj.SHA256)
+					res := verify(file, obj.Length, obj.SHA1, obj.SHA256)
 
-				if isChanged {
-					db.WriteOne(file, &database.DataObject{
-						Length:   obj.Length,
-						SHA1:     obj.SHA1,
-						SHA256:   obj.SHA256,
-						Modified: time.Now().UTC(),
-					})
-				}
+					if isChanged {
+						db.WriteOne(file, &database.DataObject{
+							Length:   obj.Length,
+							SHA1:     obj.SHA1,
+							SHA256:   obj.SHA256,
+							Modified: time.Now().UTC(),
+						})
+					}
 
-				if res {
-					if !cfg.SkipOk {
-						fmt.Printf("%s %s\n", color.GreenString("[ OK ]"), file)
+					if res {
+						if !cfg.SkipOk {
+							fmt.Printf("%s %s\n", color.GreenString("[ OK ]"), file)
+						}
+						atomic.AddUint64(&cntPassed, 1)
+						return nil
 					}
-					atomic.AddUint64(&cntPassed, 1)
-					return
-				}
-				if !cfg.SkipFailed {
-					fmt.Printf("%s %s\n", color.RedString("[FAIL]"), file)
+					if !cfg.SkipFailed {
+						fmt.Printf("%s %s\n", color.RedString("[FAIL]"), file)
+					}
+					atomic.AddUint64(&cntFailed, 1)
+					return nil
 				}
-				atomic.AddUint64(&cntFailed, 1)
-			}(key, objects[key])
+			}(key, objects[key]))
 		}
 
-		for i := 0; i < cap(sem); i++ {
-			sem <- true
+		err = wg.Wait()
+		if err != nil {
+			log.Fatalf("error handling threads")
 		}
-		wg.Wait()
 
 		if cfg.Progressbar {
 			bar.Finish()
@@ -179,24 +164,16 @@ func main() {
 	if cfg.DataDir != "" {
 		fmt.Printf("%s Checking for new files on %s\n", color.CyanString("[INFO]"), cfg.DataDir)
 
+		// TODO: check data dir for existence
+
 		err = filepath.Walk(cfg.DataDir, func(path string, info os.FileInfo, err error) error {
 			if info.IsDir() {
 				return nil
 			}
 			if isApplicable(path) {
-				data, err := readFile(path)
-				if err != nil {
-					log.Fatalf("error reading file: %s", err)
-				}
-
-				sha1, err := SHA1(bytes.NewReader(data))
-				if err != nil {
-					log.Fatalf("error calculating SHA1: %s", err)
-				}
-
-				sha256, err := SHA256(bytes.NewReader(data))
+				sha1, sha256, err := generateActualChecksum(path)
 				if err != nil {
-					log.Fatalf("error calculating SHA256: %s", err)
+					return err
 				}
 
 				db.WriteOne(path, &database.DataObject{

operations.go

@@ -1,17 +1,19 @@
 package main
 
 import (
-	"bytes"
+	"context"
 	"crypto/sha1"
 	"crypto/sha256"
+	"encoding/hex"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"os"
 	"path/filepath"
 	"runtime"
 	"strings"
+
+	"github.com/teran/checksum/utils/concurrent"
 )
 
 func completeArgs(word string) {
@@ -28,63 +30,50 @@ func completeArgs(word string) {
 	}, " "))
 }
 
-func readFile(fn string) ([]byte, error) {
-	fp, err := os.Open(fn)
+func flength(filename string) int64 {
+	stat, err := os.Stat(filename)
 	if err != nil {
-		return nil, err
+		log.Fatal(err)
 	}
-	defer fp.Close()
 
-	return ioutil.ReadAll(fp)
+	return stat.Size()
 }
 
-// SHA256 ...
-func SHA256(rd io.Reader) (string, error) {
-	h := sha256.New()
-	_, err := io.Copy(h, rd)
+func generateActualChecksum(filename string) (sha1sum string, sha256sum string, err error) {
+	fi, err := os.Stat(filename)
 	if err != nil {
-		return "", err
+		return "", "", err
 	}
 
-	return fmt.Sprintf("%x", h.Sum(nil)), nil
-}
-
-// SHA1 ...
-func SHA1(rd io.Reader) (string, error) {
-	h := sha1.New()
-	_, err := io.Copy(h, rd)
+	fp, err := os.Open(filename)
 	if err != nil {
-		return "", err
+		return "", "", err
 	}
+	defer fp.Close()
 
-	return fmt.Sprintf("%x", h.Sum(nil)), nil
-}
+	sha1hasher := sha1.New()
+	sha256hasher := sha256.New()
 
-func flength(filename string) int64 {
-	stat, err := os.Stat(filename)
+	w, err := concurrent.NewConcurrentMultiWriter(context.TODO(), sha1hasher, sha256hasher)
 	if err != nil {
-		log.Fatal(err)
+		return "", "", err
 	}
 
-	return stat.Size()
-}
-
-func verify(path string, length int64, sha1, sha256 string) bool {
-	data, err := readFile(path)
+	n, err := io.Copy(w, fp)
 	if err != nil {
-		log.Printf("error reading file: %s", err)
-		return false
+		return "", "", err
 	}
 
-	actSHA1, err := SHA1(bytes.NewReader(data))
-	if err != nil {
-		log.Printf("error calculating SHA1: %s", err)
-		return false
+	if n != fi.Size() {
+		return "", "", io.ErrShortWrite
 	}
 
-	actSHA256, err := SHA256(bytes.NewReader(data))
+	return hex.EncodeToString(sha1hasher.Sum(nil)), hex.EncodeToString(sha256hasher.Sum(nil)), nil
+}
+
+func verify(path string, length int64, sha1, sha256 string) bool {
+	actSHA1, actSHA256, err := generateActualChecksum(path)
 	if err != nil {
-		log.Printf("error calculating SHA256: %s", err)
 		return false
 	}