@graffy/server/src/httpServer.js

Node.js library for building an API for a Graffy store.

import url from 'url';
import { decodeUrl } from '@graffy/common';

export default function server(store) {
  if (!store) throw new Error('server.store_undef');
  return async (req, res) => {
    const parsed = url.parse(req.url, true);
    const query = parsed.query.q && decodeUrl(parsed.query.q);
    const options =
      parsed.query.opts && JSON.parse(decodeURIComponent(parsed.query.opts));

    if (req.method === 'GET') {
      try {
        if (req.headers['accept'] === 'text/event-stream') {
          res.setHeader('content-type', 'text/event-stream');

          const keepAlive = setInterval(() => {
            if (req.aborted || res.finished) {
              clearInterval(keepAlive);
              return;
            }
            res.write(': \n\n');
          }, 29000);

          // TODO: Resumable subscriptions using timestamp ID.
          // const lastId = req.headers['last-event-id'];
          try {
            const stream = store.call('watch', query, {
              ...options,
              raw: true,
            });
            for await (const value of stream) {
              if (req.aborted || res.finished) break;
              res.write(`data: ${JSON.stringify(value)}\n\n`);
            }
          } catch (e) {
            res.write(`event: graffyerror\ndata: ${e.message}\n\n`);
          }
          res.end();
        } else {
          const value = await store.call('read', query, {
            ...options,
            raw: true,
          });
          res.writeHead(200);
          res.end(JSON.stringify(value));
        }
      } catch (e) {
        res.writeHead(400);
        res.end(`${e.message}\n\n`);
        return;
      }
    } else if (req.method === 'POST') {
      try {
        const chunks = [];
        for await (const chunk of req) chunks.push(chunk);
        const change = JSON.parse(Buffer.concat(chunks).toString());
        const value = await store.call('write', change, options);
        res.writeHead(200);
        res.end(JSON.stringify(value));
      } catch (e) {
        res.writeHead(400);
        res.end(`${e.message}\n\n`);
        return;
      }
    } else {
      res.writeHead(501);
      res.end('Not implemented');
    }
  };
}

// TODO: Write tests!