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Commit e12d17e4 authored by Manish R Jain's avatar Manish R Jain
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Transform to Flatbuffer + write to and read from leveldb

parent 2038c06e
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/plist
package main
import (
"fmt"
"io/ioutil"
"time"
"github.com/Sirupsen/logrus"
"github.com/google/flatbuffers/go"
"github.com/manishrjain/dgraph/types"
"github.com/syndtr/goleveldb/leveldb"
"github.com/syndtr/goleveldb/leveldb/filter"
"github.com/syndtr/goleveldb/leveldb/opt"
)
var log = logrus.WithField("package", "plist")
type Triple struct {
Entity string
Attribute string
Value interface{}
ValueId string
Source string
Timestamp time.Time
}
/*
func addTriple(w http.ResponseWriter, r *http.Request) {
if r.Method != "POST" {
x.SetStatus(w, x.E_INVALID_METHOD, "Should be POST")
return
}
var t Triple
if ok := x.ParseRequest(w, r, &t); !ok {
return
}
log.Debug(t)
}
*/
func main() {
path, err := ioutil.TempDir("", "dgraphldb_")
if err != nil {
log.Fatal(err)
return
}
opt := &opt.Options{
Filter: filter.NewBloomFilter(10),
}
db, err := leveldb.OpenFile(path, opt)
if err != nil {
log.Fatal(err)
return
}
fmt.Println("Using path", path)
batch := new(leveldb.Batch)
b := flatbuffers.NewBuilder(0)
oi := b.CreateString("mrjn is a smart kid")
on := b.CreateString("His name is jain")
types.UidStart(b)
types.UidAddId(b, oi)
types.UidAddName(b, on)
oe := types.UidEnd(b)
b.Finish(oe)
fmt.Println("Value byte size:", len(b.Bytes))
key := "Some long id"
batch.Put([]byte(key), b.Bytes[b.Head():])
if err := db.Write(batch, nil); err != nil {
log.Fatal(err)
return
}
fmt.Println("Wrote key value out to leveldb. Reading back")
if err := db.Close(); err != nil {
log.Fatal(err)
return
}
db, err = leveldb.OpenFile(path, opt)
if err != nil {
log.Fatal(err)
return
}
val, err := db.Get([]byte(key), nil)
if err != nil {
log.Fatal(err)
return
}
fmt.Println("Value byte size from Leveldb:", len(val))
uid := types.GetRootAsUid(val, 0)
fmt.Println("buffer.uid id =", string(uid.Id()))
fmt.Println("buffer.uid name =", string(uid.Name()))
// http.HandleFunc("/add", addTriple)
// http.ListenAndServe(":8080", nil)
}
namespace types;
table Uid {
id:string;
name:string;
}
root_type Uid;
// automatically generated, do not modify
package types
import (
flatbuffers "github.com/google/flatbuffers/go"
)
type Uid struct {
_tab flatbuffers.Table
}
func GetRootAsUid(buf []byte, offset flatbuffers.UOffsetT) *Uid {
n := flatbuffers.GetUOffsetT(buf[offset:])
x := &Uid{}
x.Init(buf, n + offset)
return x
}
func (rcv *Uid) Init(buf []byte, i flatbuffers.UOffsetT) {
rcv._tab.Bytes = buf
rcv._tab.Pos = i
}
func (rcv *Uid) Id() []byte {
o := flatbuffers.UOffsetT(rcv._tab.Offset(4))
if o != 0 {
return rcv._tab.ByteVector(o + rcv._tab.Pos)
}
return nil
}
func (rcv *Uid) Name() []byte {
o := flatbuffers.UOffsetT(rcv._tab.Offset(6))
if o != 0 {
return rcv._tab.ByteVector(o + rcv._tab.Pos)
}
return nil
}
func UidStart(builder *flatbuffers.Builder) { builder.StartObject(2) }
func UidAddId(builder *flatbuffers.Builder, id flatbuffers.UOffsetT) { builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(id), 0) }
func UidAddName(builder *flatbuffers.Builder, name flatbuffers.UOffsetT) { builder.PrependUOffsetTSlot(1, flatbuffers.UOffsetT(name), 0) }
func UidEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT { return builder.EndObject() }
x/x.go 0 → 100644
package x
import (
"encoding/json"
"fmt"
"net/http"
"github.com/Sirupsen/logrus"
)
const (
E_OK = "E_OK"
E_UNAUTHORIZED = "E_UNAUTHORIZED"
E_INVALID_METHOD = "E_INVALID_METHOD"
E_INVALID_REQUEST = "E_INVALID_REQUEST"
E_MISSING_REQUIRED = "E_MISSING_REQUIRED"
E_ERROR = "E_ERROR"
E_NODATA = "E_NODATA"
E_UPTODATE = "E_UPTODATE"
E_NOPERMISSION = "E_NOPERMISSION"
DUMMY_UUID = "00000000-0000-0000-0000-000000000000"
)
type Status struct {
Code string `json:"code"`
Message string `json:"message"`
}
func Err(entry *logrus.Entry, err error) *logrus.Entry {
return entry.WithField("error", err)
}
func SetStatus(w http.ResponseWriter, code, msg string) {
r := &Status{Code: code, Message: msg}
if js, err := json.Marshal(r); err == nil {
fmt.Fprint(w, string(js))
} else {
panic(fmt.Sprintf("Unable to marshal: %+v", r))
}
}
func Reply(w http.ResponseWriter, rep interface{}) {
if js, err := json.Marshal(rep); err == nil {
w.Header().Set("Content-Type", "application/json")
fmt.Fprint(w, string(js))
} else {
SetStatus(w, E_ERROR, "Internal server error")
}
}
func ParseRequest(w http.ResponseWriter, r *http.Request, data interface{}) bool {
defer r.Body.Close()
decoder := json.NewDecoder(r.Body)
if err := decoder.Decode(&data); err != nil {
SetStatus(w, E_ERROR, fmt.Sprintf("While parsing request: %v", err))
return false
}
return true
}
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