fix: reduce using memory and temporary files. (#17206)

internal/hash/errors.go

@@ -42,13 +42,33 @@ func (e BadDigest) Error() string {
 	return "Bad digest: Expected " + e.ExpectedMD5 + " does not match calculated " + e.CalculatedMD5
 }
 
-// ErrSizeMismatch error size mismatch
-type ErrSizeMismatch struct {
+// SizeTooSmall reader size too small
+type SizeTooSmall struct {
 	Want int64
 	Got  int64
 }
 
-func (e ErrSizeMismatch) Error() string {
+func (e SizeTooSmall) Error() string {
+	return fmt.Sprintf("Size small: got %d, want %d", e.Got, e.Want)
+}
+
+// SizeTooLarge reader size too large
+type SizeTooLarge struct {
+	Want int64
+	Got  int64
+}
+
+func (e SizeTooLarge) Error() string {
+	return fmt.Sprintf("Size large: got %d, want %d", e.Got, e.Want)
+}
+
+// SizeMismatch error size mismatch
+type SizeMismatch struct {
+	Want int64
+	Got  int64
+}
+
+func (e SizeMismatch) Error() string {
 	return fmt.Sprintf("Size mismatch: got %d, want %d", e.Got, e.Want)
 }
 

internal/hash/reader.go

@@ -39,8 +39,10 @@ import (
 // are not empty then it will check whether the computed
 // match the reference values.
 type Reader struct {
-	src       io.Reader
-	bytesRead int64
+	src         io.Reader
+	bytesRead   int64
+	expectedMin int64
+	expectedMax int64
 
 	size       int64
 	actualSize int64
@@ -111,7 +113,7 @@ func newReader(src io.Reader, size int64, md5Hex, sha256Hex string, actualSize i
 			}
 		}
 		if r.size >= 0 && size >= 0 && r.size != size {
-			return nil, ErrSizeMismatch{Want: r.size, Got: size}
+			return nil, SizeMismatch{Want: r.size, Got: size}
 		}
 
 		r.checksum = MD5
@@ -171,6 +173,16 @@ func NewLimitReader(src io.Reader, size int64, md5Hex, sha256Hex string, actualS
 // ErrInvalidChecksum is returned when an invalid checksum is provided in headers.
 var ErrInvalidChecksum = errors.New("invalid checksum")
 
+// SetExpectedMin set expected minimum data expected from reader
+func (r *Reader) SetExpectedMin(expectedMin int64) {
+	r.expectedMin = expectedMin
+}
+
+// SetExpectedMax set expected max data expected from reader
+func (r *Reader) SetExpectedMax(expectedMax int64) {
+	r.expectedMax = expectedMax
+}
+
 // AddChecksum will add checksum checks as specified in
 // https://docs.aws.amazon.com/AmazonS3/latest/userguide/checking-object-integrity.html
 // Returns ErrInvalidChecksum if a problem with the checksum is found.
@@ -209,6 +221,17 @@ func (r *Reader) Read(p []byte) (int, error) {
 	}
 
 	if err == io.EOF { // Verify content SHA256, if set.
+		if r.expectedMin > 0 {
+			if r.bytesRead < r.expectedMin {
+				return 0, SizeTooSmall{Want: r.expectedMin, Got: r.bytesRead}
+			}
+		}
+		if r.expectedMax > 0 {
+			if r.bytesRead > r.expectedMax {
+				return 0, SizeTooLarge{Want: r.expectedMax, Got: r.bytesRead}
+			}
+		}
+
 		if r.sha256 != nil {
 			if sum := r.sha256.Sum(nil); !bytes.Equal(r.contentSHA256, sum) {
 				return n, SHA256Mismatch{