open-nomad/ui/app/utils/classes/stream-logger.js

78 lines
2.4 KiB
JavaScript

import EmberObject, { computed } from '@ember/object';
import { task } from 'ember-concurrency';
import TextDecoder from 'nomad-ui/utils/classes/text-decoder';
import AbstractLogger from './abstract-logger';
import { fetchFailure } from './log';
export default EmberObject.extend(AbstractLogger, {
reader: null,
additionalParams: computed(() => ({
follow: true,
})),
start() {
return this.get('poll').perform();
},
stop() {
const reader = this.get('reader');
if (reader) {
reader.cancel();
}
return this.get('poll').cancelAll();
},
poll: task(function*() {
const url = this.get('fullUrl');
const logFetch = this.get('logFetch');
let streamClosed = false;
let buffer = '';
const decoder = new TextDecoder();
const reader = yield logFetch(url).then(res => res.body.getReader(), fetchFailure(url));
if (!reader) {
return;
}
this.set('reader', reader);
while (!streamClosed) {
yield reader.read().then(({ value, done }) => {
streamClosed = done;
// There is no guarantee that value will be a complete JSON object,
// so it needs to be buffered.
buffer += decoder.decode(value, { stream: true });
// Only when the buffer contains a close bracket can we be sure the buffer
// is in a complete state
if (buffer.indexOf('}') !== -1) {
// The buffer can be one or more complete frames with additional text for the
// next frame
const [, chunk, newBuffer] = buffer.match(/(.*\})(.*)$/);
// Peel chunk off the front of the buffer (since it represents complete frames)
// and set the buffer to be the remainder
buffer = newBuffer;
// Assuming the logs endpoint never returns nested JSON (it shouldn't), at this
// point chunk is a series of valid JSON objects with no delimiter.
const lines = chunk.replace(/\}\{/g, '}\n{').split('\n');
const frames = lines.map(line => JSON.parse(line)).filter(frame => frame.Data);
if (frames.length) {
frames.forEach(frame => (frame.Data = window.atob(frame.Data)));
this.set('endOffset', frames[frames.length - 1].Offset);
this.get('write')(frames.mapBy('Data').join(''));
}
}
});
}
}),
}).reopenClass({
isSupported: !!window.ReadableStream,
});