kdb

package module
v0.9.0 Latest Latest
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 Go to latest Published: Apr 27, 2017 License: MIT Imports: 14 Imported by: 7

README

Q driver in Go

Build Status

This is an implementation of kdb+ driver native in Go. It implements Q IPC protocol.

Can be used both as a client(Go program connects to kdb+ process) and as a server(kdb+ connects to Go program). In server mode no execution capabilities are available.

TODO

  • add unix sockets
  • add tls
  • compression

Documentation

Overview

Package kdb implements encoding and decoding of q ipc message format

Index

Constants

View Source 
const (
	ASYNC    int = 0
	SYNC     int = 1
	RESPONSE int = 2
)

Request type

View Source 
const (
	K0 int8 = 0 // generic type
	//      type bytes qtype     ctype  accessor
	KB int8 = 1  // 1 boolean   char   kG
	UU int8 = 2  // 16 guid     U      kU
	KG int8 = 4  // 1 byte      char   kG
	KH int8 = 5  // 2 short     short  kH
	KI int8 = 6  // 4 int       int    kI
	KJ int8 = 7  // 8 long      long   kJ
	KE int8 = 8  // 4 real      float  kE
	KF int8 = 9  // 8 float     double kF
	KC int8 = 10 // 1 char      char   kC
	KS int8 = 11 // * symbol    char*  kS

	KP int8 = 12 // 8 timestamp long   kJ (nanoseconds from 2000.01.01)
	KM int8 = 13 // 4 month     int    kI (months from 2000.01.01)
	KD int8 = 14 // 4 date      int    kI (days from 2000.01.01)
	KZ int8 = 15 // 8 datetime  double kF (DO NOT USE)
	KN int8 = 16 // 8 timespan  long   kJ (nanoseconds)
	KU int8 = 17 // 4 minute    int    kI
	KV int8 = 18 // 4 second    int    kI
	KT int8 = 19 // 4 time      int    kI (millisecond)

	// table,dict
	XT int8 = 98  //   x->k is XD
	XD int8 = 99  //   kK(x)[0] is keys. kK(x)[1] is values.
	SD int8 = 127 // sorted dict

	// function types
	KFUNC      int8 = 100
	KFUNCUP    int8 = 101 // unary primitive
	KFUNCBP    int8 = 102 // binary primitive
	KFUNCTR    int8 = 103 // ternary (operator)
	KPROJ      int8 = 104 // projection
	KCOMP      int8 = 105 // composition
	KEACH      int8 = 106 // f'
	KOVER      int8 = 107 //	f/
	KSCAN      int8 = 108 // f\
	KPRIOR     int8 = 109 // f':
	KEACHRIGHT int8 = 110 // f/:
	KEACHLEFT  int8 = 111 // f\:
	KDYNLOAD   int8 = 112 // dynamic load

	// error type
	KERR int8 = -128
)
View Source 
const Nh int16 = math.MinInt16

short nil

View Source 
const Ni int32 = math.MinInt32

int nil

View Source 
const Nj int64 = math.MinInt64

long nil

View Source 
const Wh int16 = math.MaxInt16

short infinity

View Source 
const Wi int32 = math.MaxInt32

int infinity

View Source 
const Wj int64 = math.MaxInt64

long infinity

Variables

View Source 
var ErrBadHeader = errors.New("Bad header")

msg header is invalid

View Source 
var ErrBadMsg = errors.New("Bad Message")

message is malformated or invalid

View Source 
var ErrSyncRequest = errors.New("nosyncrequest")

Cannot process sync requests

View Source 
var Nf float64 = math.NaN()

double nil

View Source 
var Wf float64 = math.Inf(1)

double infinity +ve

Functions

func Encode 

func Encode(w io.Writer, msgtype int, data *K) (err error)
func compress(b []byte) (dst []byte) {
	i := byte(0)
	var g int32
	//j := int32(len(b))
	f, h0, h, g, head := int32(0), int32(0), int32(0), int32(0), int32(17)
	dst = make([]byte, len(b)/2)
	c := 12
	d := c
	e := len(dst)
	p := 0
	q, r, s0 := 0, 0, 0
	s := int32(8)
	t := int32(len(b))
	a := make([]int32, 256)
	copy(dst[:4], b[:4])
	dst[2] = 1
	//dst[8:]=[]byte(strconv.Itoa(int(j)))
	for ; s < t; i *= 2 {
		if 0 == i {
			if d > e-17 {
				return b
			}
			i = 1
			dst[c] = byte(f)
			c = d
			d++
			f = 0
		}

		h = int(b[s] ^ b[s+1])
		p = a[h]
		g = (s > t-3) || (0 == p) || (0 != (b[s] ^ b[p]))

		if 0 < s0 {
			a[h0] = s0
			s0 = 0
		}
		if g {
			h0 = h
			s0 = s
			dst[d] = b[s]
			d++
			s++
		} else {
			a[h] = s
			f |= int32(i)
			p += 2
			s += 2
			r = s
			q = min32(s+255, t)
			for ; b[p] == b[s] && s < q; s++ {
				p++
			}
			dst[d] = byte(h)
			d++
			dst[d] = byte(s - r)
			d++
		}
	}
	dst[c] = byte(f)
	//dst[4:8]=d
	return dst
}

Encode data to ipc format as msgtype(sync/async/response) to specified writer

func HandleClientConnection 

func HandleClientConnection(conn net.Conn)

process clients requests

func UnmarshalDict 

func UnmarshalDict(t Dict, v interface{}) error

unmarshall dict to struct

func UnmarshalDictToMap 

func UnmarshalDictToMap(t Dict, v interface{}) error

Unmarshall Q dictionary to map[string]{}interface

func UnmarshalTable 

func UnmarshalTable(t Table, v interface{}) (interface{}, error)

Types

type Attr 

type Attr int8

Vector attributes 

const (
	NONE Attr = iota
	SORTED
	UNIQUE
	PARTED
	GROUPED
)

type Dict 

type Dict struct {
	Key   *K
	Value *K
}

Dictionary: ordered key->value mapping. Key and Value should be slices of the same length

func (Dict) String 

func (d Dict) String() string

type Function 

type Function struct {
	Namespace string
	Body      string
}

Struct that represents q function

type K 

type K struct {
	Type int8
	Attr Attr
	Data interface{}
}

func Atom 

func Atom(t int8, x interface{}) *K

func Decode 

func Decode(src *bufio.Reader) (data *K, msgtype int, e error)

Decodes data from src in q ipc format.

func Error 

func Error(x error) *K

func Float 

func Float(x float64) *K

func Int 

func Int(x int32) *K

func Long 

func Long(x int64) *K

func NewDict 

func NewDict(k, v *K) *K

func NewFunc 

func NewFunc(ctx, body string) *K

func NewList 

func NewList(x ...*K) *K

func NewTable 

func NewTable(cols []string, data []*K) *K

func Real 

func Real(x float32) *K

func Symbol 

func Symbol(x string) *K

func SymbolV 

func SymbolV(x []string) *K

func (*K) Index 

func (k *K) Index(i int) interface{}

func (*K) Len 

func (k *K) Len() int

func (K) String 

func (k K) String() string

type KDBConn 

type KDBConn struct {
	Host string
	Port string
	// contains filtered or unexported fields
}

KDBConn establishes connection and communicates using Q IPC protocol

func DialKDB 

func DialKDB(host string, port int, auth string) (*KDBConn, error)

Connect to host:port using supplies user:password. Wait until connected

func DialKDBTimeout 

func DialKDBTimeout(host string, port int, auth string, timeout time.Duration) (*KDBConn, error)

Connect to host:port using supplied user:password. Wait timeout for connection

func (*KDBConn) AsyncCall 

func (c *KDBConn) AsyncCall(cmd string, args ...*K) (err error)

Make asynchronous request to server

func (*KDBConn) Call 

func (c *KDBConn) Call(cmd string, args ...*K) (data *K, err error)

Make synchronous call to server similar to h(func;arg1;arg2;...)

func (*KDBConn) Close 

func (c *KDBConn) Close() error

Close connection to the server

func (*KDBConn) ReadMessage 

func (c *KDBConn) ReadMessage() (data *K, msgtype int, e error)

Read complete message from connection

func (*KDBConn) Response 

func (c *KDBConn) Response(data *K) (err error)

Send response to asynchronous request

func (*KDBConn) WriteMessage 

func (c *KDBConn) WriteMessage(msgtype int, data *K) (err error)

Write data in Q IPC format

type Minute 

type Minute time.Time

kdb minute type

func (Minute) String 

func (m Minute) String() string

type Month 

type Month int32

kdb month

func (Month) String 

func (m Month) String() string

type Second 

type Second time.Time

kdb second hh:mm:ss

func (Second) String 

func (s Second) String() string

type Table 

type Table struct {
	Columns []string
	Data    []*K
}

Table

func (*Table) Index 

func (tbl *Table) Index(i int) Dict

func (Table) String 

func (tbl Table) String() string

type Time 

type Time time.Time

kdb time hh:mm:ss.SSS

func (Time) String 

func (t Time) String() string

Source Files

View all Source files

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