4 files changed, 58 insertions, 14 deletions

diff --git a/go/storage/needle.go b/go/storage/needle.go
index 256a7c26a..9c0acc6b9 100644
--- a/go/storage/needle.go
+++ b/go/storage/needle.go
@@ -11,6 +11,7 @@ import (
 	"path"
 	"strconv"
 	"strings"
+	"time"
 )
 
 const (
@@ -24,13 +25,14 @@ type Needle struct {
 	Id     uint64 `comment:"needle id"`
 	Size   uint32 `comment:"sum of DataSize,Data,NameSize,Name,MimeSize,Mime"`
 
-	DataSize uint32 `comment:"Data size"` //version2
-	Data     []byte `comment:"The actual file data"`
-	Flags    byte   `comment:"boolean flags"` //version2
-	NameSize uint8  //version2
-	Name     []byte `comment:"maximum 256 characters"` //version2
-	MimeSize uint8  //version2
-	Mime     []byte `comment:"maximum 256 characters"` //version2
+	DataSize     uint32 `comment:"Data size"` //version2
+	Data         []byte `comment:"The actual file data"`
+	Flags        byte   `comment:"boolean flags"` //version2
+	NameSize     uint8  //version2
+	Name         []byte `comment:"maximum 256 characters"` //version2
+	MimeSize     uint8  //version2
+	Mime         []byte `comment:"maximum 256 characters"` //version2
+	LastModified uint64 //only store LastModifiedBytesLength bytes, which is 5 bytes to disk
 
 	Checksum CRC    `comment:"CRC32 to check integrity"`
 	Padding  []byte `comment:"Aligned to 8 bytes"`
@@ -88,6 +90,8 @@ func NewNeedle(r *http.Request) (n *Needle, e error) {
 		}
 		n.SetHasName()
 	}
+	n.LastModified = uint64(time.Now().Unix())
+	n.SetHasLastModifiedDate()
 
 	n.Data = data
 	n.Checksum = NewCRC(data)
diff --git a/go/storage/needle_read_write.go b/go/storage/needle_read_write.go
index c5f27ea21..bcb93f57b 100644
--- a/go/storage/needle_read_write.go
+++ b/go/storage/needle_read_write.go
@@ -9,9 +9,11 @@ import (
 )
 
 const (
-	FlagGzip    = 0x01
-	FlagHasName = 0x02
-	FlagHasMime = 0x04
+	FlagGzip                = 0x01
+	FlagHasName             = 0x02
+	FlagHasMime             = 0x04
+	FlagHasLastModifiedDate = 0x08
+	LastModifiedBytesLength = 5
 )
 
 func (n *Needle) DiskSize() uint32 {
@@ -64,6 +66,9 @@ func (n *Needle) Append(w io.Writer, version Version) (size uint32, err error) {
 			if n.HasMime() {
 				n.Size = n.Size + 1 + uint32(n.MimeSize)
 			}
+			if n.HasLastModifiedDate() {
+				n.Size = n.Size + LastModifiedBytesLength
+			}
 		}
 		size = n.DataSize
 		util.Uint32toBytes(header[12:16], n.Size)
@@ -101,6 +106,12 @@ func (n *Needle) Append(w io.Writer, version Version) (size uint32, err error) {
 				return
 			}
 		}
+		if n.HasLastModifiedDate() {
+			util.Uint64toBytes(header[0:8], n.LastModified)
+			if _, err = w.Write(header[8-LastModifiedBytesLength : 8]); err != nil {
+				return
+			}
+		}
 		padding := NeedlePaddingSize - ((NeedleHeaderSize + n.Size + NeedleChecksumSize) % NeedlePaddingSize)
 		util.Uint32toBytes(header[0:NeedleChecksumSize], n.Checksum.Value())
 		_, err = w.Write(header[0 : NeedleChecksumSize+padding])
@@ -172,6 +183,11 @@ func (n *Needle) readNeedleDataVersion2(bytes []byte) {
 		n.MimeSize = uint8(bytes[index])
 		index = index + 1
 		n.Mime = bytes[index : index+int(n.MimeSize)]
+		index = index + int(n.MimeSize)
+	}
+	if index < lenBytes && n.HasLastModifiedDate() {
+		n.LastModified = util.BytesToUint64(bytes[index : index+LastModifiedBytesLength])
+		index = index + LastModifiedBytesLength
 	}
 }
 
@@ -236,3 +252,9 @@ func (n *Needle) HasMime() bool {
 func (n *Needle) SetHasMime() {
 	n.Flags = n.Flags | FlagHasMime
 }
+func (n *Needle) HasLastModifiedDate() bool {
+	return n.Flags&FlagHasLastModifiedDate > 0
+}
+func (n *Needle) SetHasLastModifiedDate() {
+	n.Flags = n.Flags | FlagHasLastModifiedDate
+}
diff --git a/go/weed/volume.go b/go/weed/volume.go
index 6282b0bc8..039212793 100644
--- a/go/weed/volume.go
+++ b/go/weed/volume.go
@@ -145,6 +145,17 @@ func GetOrHeadHandler(w http.ResponseWriter, r *http.Request, isGetMethod bool)
 		w.WriteHeader(http.StatusNotFound)
 		return
 	}
+	if n.LastModified != 0 {
+		w.Header().Set("Last-Modified", time.Unix(int64(n.LastModified), 0).UTC().Format(http.TimeFormat))
+		if r.Header.Get("If-Modified-Since") != "" {
+			if t, parseError := time.Parse(http.TimeFormat, r.Header.Get("If-Modified-Since")); parseError == nil {
+				if t.Unix() <= int64(n.LastModified) {
+					w.WriteHeader(http.StatusNotModified)
+					return
+				}
+			}
+		}
+	}
 	if n.NameSize > 0 {
 		fname := string(n.Name)
 		dotIndex := strings.LastIndex(fname, ".")
@@ -165,10 +176,6 @@ func GetOrHeadHandler(w http.ResponseWriter, r *http.Request, isGetMethod bool)
 	if n.NameSize > 0 {
 		w.Header().Set("Content-Disposition", "filename="+fileNameEscaper.Replace(string(n.Name)))
 	}
-	if n.LastModified != 0 {
-		println("file time is", n.LastModified)
-		w.Header().Set("Last-Modified", time.Unix(int64(n.LastModified), 0).Format(http.TimeFormat))
-	}
 	if ext != ".gz" {
 		if n.IsGzipped() {
 			if strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
diff --git a/go/weed/volume_test.go b/go/weed/volume_test.go
new file mode 100644
index 000000000..09340910b
--- /dev/null
+++ b/go/weed/volume_test.go
@@ -0,0 +1,11 @@
+package main
+
+import (
+	"net/http"
+	"testing"
+	"time"
+)
+
+func TestXYZ(t *testing.T) {
+	println("Last-Modified", time.Unix(int64(1373273596), 0).UTC().Format(http.TimeFormat))
+}