node-q
Q interfacing with Node.js. Supports decompression. Can deserialize all q data types (including guid) to JavaScript. Can serialize all JavaScript data types to q.
Installation
npm install node-q
Usage
Create Connection
var nodeq = require("node-q");
nodeq.connect({host: "localhost", port: 5000}, function(err, con) {
if (err) throw err;
console.log("connected");
// interact with con like demonstrated below
});Create TLS Connection
var nodeq = require("node-q");
nodeq.connect({host: "localhost", port: 6000, useTLS: true}, function(err, con) {
if (err) throw err;
console.log("connected");
// interact with con like demonstrated below
});Create Connection with user and password auth
var nodeq = require("node-q");
nodeq.connect({host: "localhost", port: 5000, user: "user", password: "password"}, function(err, con) {
if (err) throw err;
console.log("connected");
// interact with con like demonstrated below
});Create Connection with Unix Domain Socket (Doesn't support abstract namespace sockets: KDB 3.5+ on Linux)
nodeq.connect({ unixSocket: "/path/to/socket" }, function(err, con) {
if (err) throw err;
console.log("connected");
});Execute Q code and receive result
con.k("sum 1 2 3", function(err, res) {
if (err) throw err;
console.log("result", res); // 6
});Execute function with one parameter and receive result
con.k("sum", [1, 2, 3], function(err, res) {
if (err) throw err;
console.log("result", res); // 6
});Execute function with two parameters and receive result
con.k("cor", [1, 2, 3], [4, 5, 6], function(err, res) {
if (err) throw err;
console.log("result", res); // 1
});Async execute Q code
con.ks("show 1 2 3", function(err) {
if (err) throw err;
});Async execute function with parameters
con.ks("show", [1, 2, 3], function(err) {
if (err) throw err;
});Listen to a handle
con.k(function(err, res) {
if (err) throw err;
console.log("result", res);
});Subscribe to kdb+tick
con.on("upd", function(table, data) {
console.log(table, data);
});
con.ks(".u.sub[`;`]", function(err) { // subscribe to all tables and all symbols
if (err) throw err;
});Close connection
con.close(function() {
console.log("con closed");
});Types
q has more data types than JavaScript. Therefore you need to know how types are converted.
From q to JavaScript (deserialization)
| q type | JavaScript type | Null | +Infinity | -Infinity |
|---|---|---|---|---|
| boolean | Boolean | |||
| guid | String | Null | ||
| byte | Number | |||
| short | Number | Null | Infinity | -Infinity |
| int | Number | Null | Infinity | -Infinity |
| long | Number 5 | Null | Infinity | -Infinity |
| real | Number | Null | Infinity | -Infinity |
| float | Number | Null | Infinity | -Infinity |
| char | String | Null 4 | ||
| symbol | String | Null | ||
| timestamp | Date 1, 2 | Null | ||
| month | Date 2 | Null | ||
| date | Date 2 | Null | ||
| datetime | Date 2 | Null | ||
| timespan | Date 1, 2, 3 | Null | ||
| minute | Date 2, 3 | Null | ||
| second | Date 2, 3 | Null | ||
| time | Date 2, 3 | Null |
- 1: q comes with nanoseconds precision. JavaScript only with milliseconds. You can disable
nanos2datedeserialization duringconnect(params, cb)to get the nanoseconds timestamp as a plain Number. - 2: think about running your Node.js process with
TZ=UTC node ...to run in UTC timezone. q doesn't know timezones. - 3: date is set to
2000-01-01in the Date object. Only evaluate the time part. - 4: You can disable
emptyChar2nulldeserialization duringconnect(params, cb)to keep the empty char. - 5: You can disable
long2numberdeserialization duringconnect(params, cb)to represent longs as long.js.
dict
q) (`a`b`c)!(1 2 3i)
becomes Object
{
a: 1,
b: 2,
c: 3
}list
q) 1 2 3i
becomes Array
[1, 2, 3]table
q) ([] sym:`a`b`c; size:(1 2 3i))
becomes Array of Object per row.
[
{sym: "a", size: 1},
{sym: "b", size: 2},
{sym: "c", size: 3}
]You can disable flipTables during connect(params, cb) to get a table as an Object with an Array per column.
{
sym: ["a", "b", "c"],
size: [1, 2, 3]
}From JavaScript to q (serialization)
Simple (infer type)
| JavaScript type | q type |
|---|---|
| Boolean | boolean |
| String starting with ` | symbol |
| String | list[char] |
| Number | float |
| Date | datetime |
| Object | dict |
| Array[*] | list[*] |
| Null | unary primitive |
| Infinity | float |
| -Infinity | float |
Advanced (explicit types)
If you want to explicitly serialize a JavaScript type as a q type you need to use the typed API.
Let's start with two examples:
con.k("type", nodeq.short(1), function(err, res) {
if (err) throw err;
console.log("result", res); // -5
});
con.k("type", nodeq.shorts([1, 2, 3]), function(err, res) {
if (err) throw err;
console.log("result", res); // 5
});For every primitive type in q, this module exports a method to wrap the JavaScript value. You can also wrap a JavaScript array into a q type by appending an s to the primitive wrapper's name.
| q type | primitive wrapper | array wrapper |
|---|---|---|
| boolean | boolean(Boolean) |
booleans(Array[Boolean]) |
| guid | guid(String) |
guids(Array[String]) |
| byte | byte(Number) |
bytes(Array[Number]) |
| short | short(Number) |
shorts(Array[Number]) |
| int | int(Number) |
ints(Array[Number]) |
| long | long(long) 1 |
longs(Array[long]) 1 |
| real | real(Number) |
reals(Array[Number]) |
| float | float(Number) |
floats(Array[Number]) |
| char | char(String) |
chars(Array[String]) |
| symbol | symbol(String) |
symbols(Array[String]) |
| timestamp | timestamp(Date) |
timestamps(Array[Date]) |
| month | month(Date) |
months(Array[Date]) |
| date | date(Date) |
dates(Array[Date]) |
| datetime | datetime(Date) |
datetimes(Array[Date]) |
| timespan | timespan(Date) |
timespans(Array[Date]) |
| minute | minute(Date) |
minutes(Array[Date]) |
| second | second(Date) |
seconds(Array[Date]) |
| time | time(Date) |
times(Array[Date]) |
- 1: JavaScript can not represent 64bit longs. Therefore this module uses the long.js module to represent longs.
API
connect(params, cb)
params: Objecthost: String (e. g. "localhost") (optional)port: Number (e. g. 5000) (optional)unixSocket: String (e. g. "/path/to/socket") (optional)user: String (optional)password: String (optional)useTLS: Boolean (optional)ca: Buffer | String (e.g. fs.readFileSync('path\to\cert.pem')) (optional)socketNoDelay: Boolean (optional, see http://nodejs.org/api/net.html#net_socket_setnodelay_nodelay)socketTimeout: Number (optional, see http://nodejs.org/api/net.html#net_socket_settimeout_timeout_callback)nanos2date: Boolean (optional, default: true)flipTables: Boolean (optional, default: true)emptyChar2null: Boolean (optional, default: true)long2number: Boolean (optional, default: true)
cb: Function(err,con)err:Errororundefinedconn:Connectionorundefined
@deprecated connect(host, port, [user, password,] cb)
This is deprecated. Please use the new, mor flexible API above!
host: String (e. g. "localhost")port: Number (e. g. 5000)user: String (optional)password: String (optional)
Connection
Is an EventEmitter.
k(s, [x, [y, [z, [...,] ] ] ] cb)
Sync request/response.
s: Stringx: Object (optional)y: Object (optional)z: Object (optional)...: Object (optional)cb: Function(err,res)err:Errororundefinedres:Objectorundefined
ks(s, [x, [y, [z, [...,] ] ] ] cb)
Async request.
s: Stringx: Object (optional)y: Object (optional)z: Object (optional)...: Object (optional)cb: Function(err)err:Errororundefined
close(cb)
cb: Function(err) (optional)err:Errororundefined
Events
upd(table, data)
If you use kdb+tick and subscribe like con.ks(".u.sub[;]", function(err) { throw err; }) you will receive all Updates via upd Event.
error(err)
If the socket emit an error event.
err:Error
end()
If the socket emit an end event.
timeout()
If the socket emit a timeout event.
close(had_error)
If the socket emit a close event.
had_error: Boolean (true if the socket had a transmission error)
Contribution
If you want to create a Pull-Request please make sure that make test runs without failures.
If you have a kdb+tick setup please also run make mochait.
Code Style
make jshint
Unit Tests
make mocha
Integration Test
Assumes a running q process on port 5000 with kdb+tick available in QHOME (QHOME=~/q ~/q/m32/q -p 5000). For the tls tests you will also need a running q process on port 6000 set up to require tls. Instructions for this can be found here. If you are using a self signed certificate you will also need to set the NODE_TLS_REJECT_UNAUTHORIZED environment variable to 0.
make mochait
Circular depdendencies
make circular
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent