Metarhia KievJS 22-Feb-2018
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Metarhia is a technology stack and community for building distributed, high-load applications and data storage. It includes an Impress application server, the JSTP protocol, GlobalStorage distributed database, and other tools. The goals of Metarhia include unifying APIs, data, and contracts across server infrastructure with an open source approach and no vendor lock-in. Key people behind Metarhia include Timur Shemsedinov and Alexey Orlenko, who are both Node.js contributors and open source advocates.
![const projection = (meta, obj) => (
Object.keys(meta).reduce((hash, key) => (
hash[key] = meta[key].reduce(
(val, fn, i) => (i === 0 ? obj[fn] : fn(val)), null
), hash
), {})
);
const persons = [
{ name: 'Marcus Aurelius', city: 'Rome', born: 121 },
{ name: 'Victor Glushkov', city: 'Rostov on Don', born: 1923 },
{ name: 'Ibn Arabi', city: 'Murcia', born: 1165 },
{ name: 'Mao Zedong', city: 'Shaoshan', born: 1893 },
{ name: 'Rene Descartes', city: 'La Haye en Touraine', born: 1596 }
];
const md = {
name: ['name'],
place: ['city', upper, s => '<' + s + '>'],
age: ['born', age]
};
const p1 = curry(projection)(md);
const data = persons.map(p1);
console.dir(data);
const projection = (meta) => {
const keys = Object.keys(meta);
return obj => {
const hash = {};
let name, key, def, val, fn;
for (key of keys) {
def = meta[key];
[name, fn] = def;
val = obj[name];
if (fn) val = fn(val);
hash[key] = val;
}
return hash;
};
};](https://image.slidesharecdn.com/metarhia-kievjs-22-feb-2018-180222214816/85/Metarhia-KievJS-22-Feb-2018-13-320.jpg)
![// EventEmitter
const emitter = (events = {}) => ({
on: (name, fn) => (events[name] = events[name] || []).push(fn),
emit: (name, ...data) => (events[name] || []).forEach(fn => fn(...data))
});
const emitter = (l, o) => (l = {}, o = {
on: (n, f) => (l[n] = l[n] || []).push(f),
emit: (n, ...d) => (l[n] || []).map(f => f(...d)),
once: (n, f, g) => o.on(n, g = (...a) => (f(...a), o.remove(n, g))),
remove: (n, f, e) => (e = l[n] || [], e.splice(e.indexOf(f), 1)),
clear: (n) => (n ? delete l[n] : l = {}),
count: (n) => (l[n] || []).length,
listeners: (n) => (l[n] || []).slice(),
names: () => Object.keys(l)
});](https://image.slidesharecdn.com/metarhia-kievjs-22-feb-2018-180222214816/85/Metarhia-KievJS-22-Feb-2018-16-320.jpg)
![Asynchronous composition
const fx = metasync(
[f1, f2, f3, [[f4, f5, [f6, f7], f8]], f9]
);](https://image.slidesharecdn.com/metarhia-kievjs-22-feb-2018-180222214816/85/Metarhia-KievJS-22-Feb-2018-20-320.jpg)
![Collector
const dc1 = metasync
.collect(3)
.timeout(5000)
.done((err, data) => {});
dc1(item);
const dc2 = metasync
.collect(['key1', 'key2', 'key3'])
.timeout(5000)
.done((err, data) => {});
dc2(key, value);](https://image.slidesharecdn.com/metarhia-kievjs-22-feb-2018-180222214816/85/Metarhia-KievJS-22-Feb-2018-22-320.jpg)
Metarhia KievJS 22-Feb-2018
- 1. Metarhia
- 2. Metarhia Community and Technology Stack for Distributed Highload Applications and Data Storage
- 4. ● Open Lectures (>1000 stud/year), 75 lect/semester ● Meetups ○ meetup.com/KievNodeJS (1349) 19 since 2014 ○ meetup.com/NodeUA (1679) 13 ○ meetup.com/HowProgrammingWorks (1206) 54 ● Channels ○ t.me/metarhia (640) ○ t.me/HowProgrammingWorks (865) ● Groups ○ t.me/nodeua (358) ○ t.me/MetarhiaHPW (352)
- 6. ● Conceptual code ○ It’s short and impressive parts, I’ll show you ○ conceptual code becomes libs and examples ● Examples ○ github.com/HowProgrammingWorks ○ github.com/HowProgrammingWorks/Dictionary ○ contributors: 36, repos: 87, >500 examples ● Open Source ○ Technology stack: github.com/metarhia ● Contribution ○ Node.js and other projects contribution
- 10. ● Impress Application Server for highload clusters and private clouds with Node.js ● JSTP protocol: RPC, event bus, db sync on TCP, TLS, WebSocket and JSON5; with SDK for mobile and desktop: JavaScript, Java, Swift, C++, Haskell, Python, Objective-C, PHP, Golang, C# ● GlobalStorage: distributed reactive in-memory DBMS, work in progress ● Metasync: asynchronous programming abstractions ● Maojian: testing framework
- 11. ● Impress Application Server https://github.com/metarhia/impress ● JSTP protocol https://github.com/metarhia/jstp ● GlobalStorage https://github.com/metarhia/globalstorage ● Metasync https://github.com/metarhia/metasync ● Maojian https://github.com/metarhia/maojian
- 13. const projection = (meta, obj) => ( Object.keys(meta).reduce((hash, key) => ( hash[key] = meta[key].reduce( (val, fn, i) => (i === 0 ? obj[fn] : fn(val)), null ), hash ), {}) ); const persons = [ { name: 'Marcus Aurelius', city: 'Rome', born: 121 }, { name: 'Victor Glushkov', city: 'Rostov on Don', born: 1923 }, { name: 'Ibn Arabi', city: 'Murcia', born: 1165 }, { name: 'Mao Zedong', city: 'Shaoshan', born: 1893 }, { name: 'Rene Descartes', city: 'La Haye en Touraine', born: 1596 } ]; const md = { name: ['name'], place: ['city', upper, s => '<' + s + '>'], age: ['born', age] }; const p1 = curry(projection)(md); const data = persons.map(p1); console.dir(data); const projection = (meta) => { const keys = Object.keys(meta); return obj => { const hash = {}; let name, key, def, val, fn; for (key of keys) { def = meta[key]; [name, fn] = def; val = obj[name]; if (fn) val = fn(val); hash[key] = val; } return hash; }; };
- 16. // EventEmitter const emitter = (events = {}) => ({ on: (name, fn) => (events[name] = events[name] || []).push(fn), emit: (name, ...data) => (events[name] || []).forEach(fn => fn(...data)) }); const emitter = (l, o) => (l = {}, o = { on: (n, f) => (l[n] = l[n] || []).push(f), emit: (n, ...d) => (l[n] || []).map(f => f(...d)), once: (n, f, g) => o.on(n, g = (...a) => (f(...a), o.remove(n, g))), remove: (n, f, e) => (e = l[n] || [], e.splice(e.indexOf(f), 1)), clear: (n) => (n ? delete l[n] : l = {}), count: (n) => (l[n] || []).length, listeners: (n) => (l[n] || []).slice(), names: () => Object.keys(l) });
- 18. Problems of Software Engineering ● Not scientific decision-making ● Voluntarism, no answers ● Fundamental knowledge is not popular ● Quality is not a goal for business ● No sense in work, coded for trash
- 19. Functor + Chaining + composition const c1 = chain() .do(readConfig, 'myConfig') .do(doQuery, 'select * from cities') .do(httpGet, 'http://kpi.ua') .do(readFile, 'README.md'); c1(); function chain(prev = null) { const cur = () => { if (cur.prev) { cur.prev.next = cur; cur.prev(); } else { cur.forward(); } }; cur.prev = prev; cur.fn = null; cur.args = null; cur.do = (fn, ...args) => { cur.fn = fn; cur.args = args; return chain(cur); }; cur.forward = () => { if (cur.fn) { cur.fn(cur.args, () => { if (cur.next) { cur.next.forward(); } }); } }; return cur; }
- 20. Asynchronous composition const fx = metasync( [f1, f2, f3, [[f4, f5, [f6, f7], f8]], f9] );
- 21. Concurrent Queue const cq = metasync.queue(3) .wait(2000) .timeout(5000) .throttle(100, 1000) .process((item, cb) => cb(err, result)) .success((item) => {}) .failure((item) => {}) .done(() => {}) .drain(() => {});
- 22. Collector const dc1 = metasync .collect(3) .timeout(5000) .done((err, data) => {}); dc1(item); const dc2 = metasync .collect(['key1', 'key2', 'key3']) .timeout(5000) .done((err, data) => {}); dc2(key, value);
- 23. ● Websocket Chat https://github.com/HowProgrammingWorks/WebsocketChat ● LiveTable (interactive, multiuser) https://github.com/HowProgrammingWorks/LiveTable ● Abstraction Layers https://github.com/HowProgrammingWorks/AbstractionLayers ● IoC and DI https://github.com/HowProgrammingWorks/InversionOfControl https://github.com/HowProgrammingWorks/DependencyInjection ● Transactions https://github.com/HowProgrammingWorks/Transaction
- 24. Metarhia Technology Stack Key Ideas ● Unification: API, data, contracts ● Homogeneity of server infrastructure ● No back compatibility ● Open Source & no vendor lock ● Architectural decisions ● Community and trainings
- 25. Node.js ● 3 Node.js contributors @tshemsedinov, @aqrln, @belochub ● 1 Node.js core collaborator @aqrln ● Notable contributions: keepAliveTimeout for HTTP, substantially faster Unix domain sockets, faster base64 decoding, pushing N-API adoption forward, community work
- 28. N-API (Node.js API) for Rust
- 29. M E M bI
- 31. Metarhia