Update comments across the codebase

pkg/utils/crypto/sha1/sha1.go

@@ -40,6 +40,7 @@ type digest struct {
 	len uint64
 }
 
+// Reset digest
 func (d *digest) Reset() {
 	d.h[0] = init0
 	d.h[1] = init1
@@ -68,10 +69,13 @@ func block(dig *digest, p []byte) {
 	}
 }
 
+// Return output size
 func (d *digest) Size() int { return Size }
 
+// Return checksum blocksize
 func (d *digest) BlockSize() int { return BlockSize }
 
+// Write to digest
 func (d *digest) Write(p []byte) (nn int, err error) {
 	nn = len(p)
 	d.len += uint64(nn)
@@ -95,6 +99,7 @@ func (d *digest) Write(p []byte) (nn int, err error) {
 	return
 }
 
+// Return checksum bytes
 func (d0 *digest) Sum(in []byte) []byte {
 	// Make a copy of d0 so that caller can keep writing and summing.
 	d := *d0
@@ -102,6 +107,7 @@ func (d0 *digest) Sum(in []byte) []byte {
 	return append(in, hash[:]...)
 }
 
+// Intermediate checksum function
 func (d *digest) checkSum() [Size]byte {
 	len := d.len
 	// Padding.  Add a 1 bit and 0 bits until 56 bytes mod 64.
@@ -135,8 +141,9 @@ func (d *digest) checkSum() [Size]byte {
 	return digest
 }
 
-// Convenience functions
+/// Convenience functions
 
+// Single caller sha1 helper
 func Sum1(data []byte) [Size]byte {
 	var d digest
 	d.Reset()
@@ -144,6 +151,7 @@ func Sum1(data []byte) [Size]byte {
 	return d.checkSum()
 }
 
+// io.Reader based streaming sha1 helper
 func Sum(reader io.Reader) ([]byte, error) {
 	h := New()
 	var err error

pkg/utils/crypto/sha1/sha1_gen.go

@@ -1,65 +0,0 @@
-// +build ignore
-
-//
-// Mini Object Storage, (C) 2015 Minio, Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-//
-
-package main
-
-import (
-	"crypto/sha1"
-	"encoding/hex"
-	"fmt"
-	"io"
-	"os"
-	"time"
-
-	sha1intel "github.com/minio-io/minio/pkg/utils/crypto/sha1"
-)
-
-func Sum(reader io.Reader) ([]byte, error) {
-	k := sha1.New()
-	var err error
-	for err == nil {
-		length := 0
-		byteBuffer := make([]byte, 1024*1024)
-		length, err = reader.Read(byteBuffer)
-		byteBuffer = byteBuffer[0:length]
-		k.Write(byteBuffer)
-	}
-	if err != io.EOF {
-		return nil, err
-	}
-	return k.Sum(nil), nil
-}
-
-func main() {
-	fmt.Println("-- start")
-
-	file1, _ := os.Open("filename1")
-	defer file1.Close()
-	stark := time.Now()
-	sum, _ := Sum(file1)
-	endk := time.Since(stark)
-
-	file2, _ := os.Open("filename2")
-	defer file2.Close()
-	starth := time.Now()
-	sumAVX2, _ := sha1intel.Sum(file2)
-	endh := time.Since(starth)
-
-	fmt.Println("std(", endk, ")", "avx2(", endh, ")")
-	fmt.Println(hex.EncodeToString(sum), hex.EncodeToString(sumAVX2))
-}