seaweedfs/go/storage/needle.go

160 lines
3.9 KiB
Go

package storage
import (
"code.google.com/p/weed-fs/go/glog"
"code.google.com/p/weed-fs/go/util"
"encoding/hex"
"io/ioutil"
"mime"
"net/http"
"path"
"strconv"
"strings"
"time"
)
const (
NeedleHeaderSize = 16 //should never change this
NeedlePaddingSize = 8
NeedleChecksumSize = 4
)
/*
* Needle file size is limited to 4GB for now.
*/
type Needle struct {
Cookie uint32 `comment:"random number to mitigate brute force lookups"`
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
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"`
}
func ParseUpload(r *http.Request) (fileName string, data []byte, mimeType string, isGzipped bool, modifiedTime uint64, e error) {
form, fe := r.MultipartReader()
if fe != nil {
glog.V(0).Infoln("MultipartReader [ERROR]", fe)
e = fe
return
}
part, fe := form.NextPart()
if fe != nil {
glog.V(0).Infoln("Reading Multi part [ERROR]", fe)
e = fe
return
}
fileName = part.FileName()
if fileName != "" {
fileName = path.Base(fileName)
}
data, e = ioutil.ReadAll(part)
if e != nil {
glog.V(0).Infoln("Reading Content [ERROR]", e)
return
}
dotIndex := strings.LastIndex(fileName, ".")
ext, mtype := "", ""
if dotIndex > 0 {
ext = strings.ToLower(fileName[dotIndex:])
mtype = mime.TypeByExtension(ext)
}
contentType := part.Header.Get("Content-Type")
if contentType != "" && mtype != contentType {
mimeType = contentType //only return mime type if not deductable
mtype = contentType
}
if part.Header.Get("Content-Encoding") == "gzip" {
isGzipped = true
} else if IsGzippable(ext, mtype) {
if data, e = GzipData(data); e != nil {
return
}
isGzipped = true
}
if ext == ".gz" {
isGzipped = true
}
if strings.HasSuffix(fileName, ".gz") {
fileName = fileName[:len(fileName)-3]
}
modifiedTime, _ = strconv.ParseUint(r.FormValue("ts"), 10, 64)
return
}
func NewNeedle(r *http.Request) (n *Needle, e error) {
fname, mimeType, isGzipped := "", "", false
n = new(Needle)
fname, n.Data, mimeType, isGzipped, n.LastModified, e = ParseUpload(r)
if e != nil {
return
}
if len(fname) < 256 {
n.Name = []byte(fname)
n.SetHasName()
}
if len(mimeType) < 256 {
n.Mime = []byte(mimeType)
n.SetHasMime()
}
if isGzipped {
n.SetGzipped()
}
if n.LastModified == 0 {
n.LastModified = uint64(time.Now().Unix())
}
n.SetHasLastModifiedDate()
n.Checksum = NewCRC(n.Data)
commaSep := strings.LastIndex(r.URL.Path, ",")
dotSep := strings.LastIndex(r.URL.Path, ".")
fid := r.URL.Path[commaSep+1:]
if dotSep > 0 {
fid = r.URL.Path[commaSep+1 : dotSep]
}
n.ParsePath(fid)
return
}
func (n *Needle) ParsePath(fid string) {
length := len(fid)
if length <= 8 {
return
}
delta := ""
deltaIndex := strings.LastIndex(fid, "_")
if deltaIndex > 0 {
fid, delta = fid[0:deltaIndex], fid[deltaIndex+1:]
}
n.Id, n.Cookie = ParseKeyHash(fid)
if delta != "" {
d, e := strconv.ParseUint(delta, 10, 64)
if e == nil {
n.Id += d
}
}
}
func ParseKeyHash(key_hash_string string) (uint64, uint32) {
key_hash_bytes, khe := hex.DecodeString(key_hash_string)
key_hash_len := len(key_hash_bytes)
if khe != nil || key_hash_len <= 4 {
glog.V(0).Infoln("Invalid key_hash", key_hash_string, "length:", key_hash_len, "error", khe)
return 0, 0
}
key := util.BytesToUint64(key_hash_bytes[0 : key_hash_len-4])
hash := util.BytesToUint32(key_hash_bytes[key_hash_len-4 : key_hash_len])
return key, hash
}