Merge pull request #3 from emar-kar/v1.4.0

v1.4.0

copy.go

@@ -2,39 +2,50 @@ package copy
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"hash"
 	"io"
 	"io/fs"
 	"os"
 	"path"
 	"path/filepath"
+	"slices"
 	"strings"
 )
 
 // Copy copies source file/folder to destination with given options.
-func Copy(ctx context.Context, src, dst string, opts ...optFunc) error {
+func Copy(ctx context.Context, src, dst string, opts ...optFunc) (err error) {
 	opt := defaultOptions()
 	for _, fn := range opts {
 		fn(opt)
 	}
 
-	src, err := resolvePath(src)
-	if err != nil {
-		return err
+	if opt.follow {
+		src, err = resolvePath(src)
+		if err != nil {
+			return err
+		}
+	}
+
+	if excludePath(opt.exclude, src) {
+		return nil
 	}
 
 	// Attempt to rename file/folder instead of copying and then removing.
 	// If call to rename was finished with an error, it will be ignored
-	// and copy algorithm will be used.
+	// and copy algorithm will be used. In case of renaming a folder,
+	// hash is not calculated and will be empty.
 	if opt.move {
 		if err := rename(src, dst, opt.hash); err == nil {
 			return os.RemoveAll(src)
 		}
 
-		// Reset hash if rename was unsuccessful, since it will be
-		// recalculated with copy if needed.
-		opt.hash.Reset()
+		if opt.hash != nil {
+			// Reset hash if rename was unsuccessful, since it will be
+			// recalculated with copy if needed.
+			opt.hash.Reset()
+		}
 	}
 
 	return copy(ctx, src, dst, opt)
@@ -118,6 +129,10 @@ func copyFolder(ctx context.Context, src, dst string, opt *options) error {
 				return err
 			}
 
+			if excludePath(opt.exclude, root) {
+				return nil
+			}
+
 			subDst := strings.ReplaceAll(root, src, dst)
 			if info.IsDir() {
 				select {
@@ -206,7 +221,7 @@ func copyBytes(ctx context.Context, r io.Reader, w io.Writer, size int, h hash.H
 
 	for {
 		b, err := srcReader.Read(buf)
-		if err != nil && err != io.EOF {
+		if err != nil && !errors.Is(err, io.EOF) {
 			return err
 		}
 
@@ -261,3 +276,15 @@ func (w *writerWithContext) Write(b []byte) (int, error) {
 
 	return w.w.Write(b)
 }
+
+// excludePath checks if given path should be excluded.
+func excludePath(exclude []string, p string) bool {
+	if exclude != nil {
+		return false
+	}
+
+	return slices.ContainsFunc(
+		exclude,
+		func(s string) bool { return strings.Contains(p, s) },
+	)
+}

options.go

@@ -6,12 +6,14 @@ const defaultBufferSize = 4096
 
 // options allows to configure Copy behavior.
 type options struct {
+	exclude     []string
 	hash        hash.Hash
 	bufSize     int
 	force       bool
 	contentOnly bool
 	move        bool
 	revert      bool
+	follow      bool
 }
 
 func defaultOptions() *options {
@@ -32,6 +34,10 @@ func Force(o *options) { o.force = true }
 // root folder in destination.
 func ContentOnly(o *options) { o.contentOnly = true }
 
+// FollowSymlink resolves source file path before copy, to follow symlink
+// if needed.
+func FollowSymlink(o *options) { o.follow = true }
+
 // WithMove removes source after copying process is finished.
 func WithMove(o *options) { o.move = true }
 
@@ -59,3 +65,11 @@ func WithHash(h hash.Hash) optFunc {
 		o.hash = h
 	}
 }
+
+// WithExclude excludes paths from copy which includes one of the given
+// strings.
+func WithExclude(s ...string) optFunc {
+	return func(o *options) {
+		o.exclude = append(o.exclude, s...)
+	}
+}