feat(hash): support sha256 verification

README.md

@@ -1,6 +1,6 @@
 # oget
 
-oget is a Golang download library. It supports parallel downloads, resuming after failures, SHA512 verification, and download progress monitoring.
+oget is a Golang download library. It supports parallel downloads, resuming after failures, Hash verification, and download progress monitoring.
 
 ## Installation
 
@@ -83,22 +83,23 @@ if err != nil {
 }
 ```
 
-### SHA512 Verification
+### Hash Verification
 
-After downloading, the library performs a SHA512 checksum on the entire file. If the checksum fails, an `oget.SHA512Error` is thrown.
+After downloading, the library performs a Hash checksum on the entire file. If the checksum fails, an `oget.HashError` is thrown.
 
 ```go
 import "github.com/oomol-lab/oget"
 
-_, err := (&OGet{
+_, err := (&oget.OGet{
     URL:      "https://github.com/oomol-lab/oget/raw/main/tests/target.bin",
     FilePath: "/path/to/save/file.bin",
-    SHA512:    "d286fbb1fab9014fdbc543d09f54cb93da6e0f2c809e62ee0c81d69e4bf58eec44571fae192a8da9bc772ce1340a0d51ad638cdba6118909b555a12b005f2930",
+	HashType: oget.SHA512,
+    Hash:    "d286fbb1fab9014fdbc543d09f54cb93da6e0f2c809e62ee0c81d69e4bf58eec44571fae192a8da9bc772ce1340a0d51ad638cdba6118909b555a12b005f2930",
 }).Get()
 
 if err != nil {
-    if sha512Error, ok := err.(oget.SHA512Error); ok {
-        // Failed due to SHA512 verification failure
+    if hashError, ok := err.(oget.HashError); ok {
+        // Failed due to hash verification failure
     }
     panic(err)
 }
@@ -113,15 +114,15 @@ import "github.com/oomol-lab/oget"
 success := false
 
 for i := 0; i < 10; i++ {
-    clean, err := (&OGet{
+    clean, err := (&oget.OGet{
         URL:      "https://github.com/oomol-lab/oget/raw/main/tests/target.bin",
         FilePath: "/path/to/save/file.bin",
         Parts:    4,
     }).Get()
     if err != nil {
-        if sha512Error, ok := err.(oget.SHA512Error); ok {
+        if hashError, ok := err.(oget.HashError); ok {
             clean()
-            panic(sha512Error)
+            panic(hashError)
         }
         fmt.Printf("download failed with error and retry %s", err)
     } else {
@@ -147,7 +148,7 @@ if err != nil {
 }
 ```
 
-Then, call `task.Get()` to initiate the download. Check if the error is of type `oget.SHA512Error`. If not, it is likely due to network issues and should be retried.
+Then, call `task.Get()` to initiate the download. Check if the error is of type `oget.HashError`. If not, it is likely due to network issues and should be retried.
 
 Note that the first return value of `task.Get()` is a function `clean` that deletes the temporary download files. Call it to free up disk space if you don't want to keep these files for the next download attempt after a download failure.
 
@@ -160,9 +161,9 @@ for i := 0; i < 10; i++ {
         Parts:    4,
     })
     if err != nil {
-        if sha512Error, ok := err.(oget.SHA512Error); ok {
+        if hashError, ok := err.(oget.HashError); ok {
             clean()
-            panic(sha512Error)
+            panic(hashError)
         }
         fmt.Printf("download failed with error and retry %s", err)
     } else {

config.go

@@ -30,9 +30,10 @@ type RemoteFile struct {
 type GettingConfig struct {
 	// the path to save the downloaded file.
 	FilePath string
-	// the SHA512 code of the file.
-	// if the code is empty, the file will not be checked.
-	SHA512 string
+	// the Hash code of the file.
+	// if the hash is empty, the file will not be checked.
+	HashType HashType
+	Hash     string
 	// PartsPath is the path to save the temp files of downloaded parts.
 	// if the value is empty, the temp files will be saved in the same directory as the FilePath.
 	PartsPath string

get.go

@@ -25,9 +25,10 @@ type OGet struct {
 	// the maximum number of idle (keep-alive) connections to keep per-host.
 	// the default is 16.
 	MaxIdleConnsPerHost int
-	// the SHA512 code of the file.
-	// if the code is empty, the file will not be checked.
-	SHA512 string
+	// the Hash code of the file.
+	// if the hash is empty, the file will not be checked.
+	HashType HashType
+	Hash     string
 	// PartsPath is the path to save the temp files of downloaded parts.
 	// if the value is empty, the temp files will be saved in the same directory as the FilePath.
 	PartsPath string
@@ -57,7 +58,8 @@ func (o *OGet) Get() (func() error, error) {
 	}
 	return task.Get(&GettingConfig{
 		FilePath:       o.FilePath,
-		SHA512:         o.SHA512,
+		HashType:       o.HashType,
+		Hash:           o.Hash,
 		PartsPath:      o.PartsPath,
 		PartName:       o.PartName,
 		Parts:          o.Parts,

hash.go

@@ -0,0 +1,61 @@
+package oget
+
+import (
+	"crypto/sha256"
+	"crypto/sha512"
+	"fmt"
+	"hash"
+	"io"
+	"os"
+)
+
+type HashType string
+
+const (
+	SHA256 HashType = "sha256"
+	SHA512 HashType = "sha512"
+)
+
+func supportHashType(s HashType) bool {
+	return s == SHA256 || s == SHA512
+}
+
+func SHA(path string, ht HashType) (string, error) {
+	return shaOfFiles(&[]string{path}, ht)
+}
+
+func shaOfFiles(pathList *[]string, ht HashType) (string, error) {
+	var h hash.Hash
+
+	switch ht {
+	case SHA256:
+		h = sha256.New()
+	case SHA512:
+		h = sha512.New()
+	}
+
+	for _, path := range *pathList {
+		file, err := os.Open(path)
+		if err != nil {
+			return "", err
+		}
+		defer file.Close()
+		io.Copy(h, file)
+	}
+	hashInBytes := h.Sum(nil)
+	hashStr := fmt.Sprintf("%x", hashInBytes)
+
+	return hashStr, nil
+}
+
+type HashError struct {
+	message string
+}
+
+func (e HashError) Error() string {
+	return e.message
+}
+
+func createHashError(message string) HashError {
+	return HashError{message}
+}

task.go

@@ -7,9 +7,8 @@ import (
 	"mime"
 	"net/http"
 	"os"
-	"time"
-
 	"path/filepath"
+	"time"
 
 	"github.com/pkg/errors"
 	"golang.org/x/sync/errgroup"
@@ -201,15 +200,16 @@ func (t *GettingTask) mergeFile(c *GettingConfig, prog *progress) error {
 		partPath := filepath.Join(c.PartsPath, c.partFileName(i))
 		partPathList = append(partPathList, partPath)
 	}
-	if c.SHA512 != "" {
-		code, err := sha512OfFiles(&partPathList)
+	if c.Hash != "" && supportHashType(c.HashType) {
+		code, err := shaOfFiles(&partPathList, c.HashType)
 		if err != nil {
-			return errors.Wrapf(err, "failed to get sha512 code")
+			return errors.Wrapf(err, fmt.Sprintf("failed to get %s code", c.HashType))
 		}
-		if code != c.SHA512 {
-			return createSHA512Error("sha512 code does not match")
+		if code != c.Hash {
+			return createHashError(fmt.Sprintf("%s code does not match", c.HashType))
 		}
 	}
+
 	if len(partPathList) == 1 {
 		partPath := partPathList[0]
 		err := os.Rename(partPath, c.FilePath)

tests/oget_test.go

@@ -50,7 +50,8 @@ func TestAll(t *testing.T) {
 		_, err = task.Get(&oget.GettingConfig{
 			FilePath:  filepath.Join(outputPath, "target.bin"),
 			PartsPath: partsPath,
-			SHA512:    sha512Code,
+			HashType:  oget.SHA512,
+			Hash:      sha512Code,
 		})
 		if err != nil {
 			t.Fatalf("download file: %s", err)
@@ -70,12 +71,13 @@ func TestAll(t *testing.T) {
 			FilePath:  savedFilePath,
 			PartsPath: partsPath,
 			Parts:     4,
-			SHA512:    sha512Code,
+			HashType:  oget.SHA512,
+			Hash:      sha512Code,
 		})
 		if err != nil {
 			t.Fatalf("download file: %s", err)
 		}
-		savedFileCode, err := oget.SHA512(savedFilePath)
+		savedFileCode, err := oget.SHA(savedFilePath, oget.SHA512)
 
 		if err != nil {
 			t.Fatalf("get code of sha512 fail: %s", err)
@@ -100,7 +102,8 @@ func TestAll(t *testing.T) {
 			FilePath:  savedFilePath,
 			PartsPath: partsPath,
 			Parts:     4,
-			SHA512:    sha512Code,
+			HashType:  oget.SHA512,
+			Hash:      sha512Code,
 			ListenProgress: func(event oget.ProgressEvent) {
 				mux.Lock()
 				events = append(events, event)
@@ -157,7 +160,8 @@ func TestAll(t *testing.T) {
 				FilePath:  savedFilePath,
 				PartsPath: partsPath,
 				Parts:     3,
-				SHA512:    sha512Code,
+				HashType:  oget.SHA512,
+				Hash:      sha512Code,
 			})
 			return err
 		}