@brimdata/zealot/dist/cjs/query/channel.js

The Javascript Client for Zed Lakes

"use strict";
Object.defineProperty(exports, "__esModule", {
    value: true
});
Object.defineProperty(exports, "Channel", {
    enumerable: true,
    get: ()=>Channel
});
const _events = /*#__PURE__*/ _interopRequireDefault(require("events"));
const _zed = /*#__PURE__*/ _interopRequireWildcard(require("../zed"));
const _decodeStream = require("../zed/decode-stream");
function _defineProperty(obj, key, value) {
    if (key in obj) {
        Object.defineProperty(obj, key, {
            value: value,
            enumerable: true,
            configurable: true,
            writable: true
        });
    } else {
        obj[key] = value;
    }
    return obj;
}
function _interopRequireDefault(obj) {
    return obj && obj.__esModule ? obj : {
        default: obj
    };
}
function _getRequireWildcardCache(nodeInterop) {
    if (typeof WeakMap !== "function") return null;
    var cacheBabelInterop = new WeakMap();
    var cacheNodeInterop = new WeakMap();
    return (_getRequireWildcardCache = function(nodeInterop) {
        return nodeInterop ? cacheNodeInterop : cacheBabelInterop;
    })(nodeInterop);
}
function _interopRequireWildcard(obj, nodeInterop) {
    if (!nodeInterop && obj && obj.__esModule) {
        return obj;
    }
    if (obj === null || typeof obj !== "object" && typeof obj !== "function") {
        return {
            default: obj
        };
    }
    var cache = _getRequireWildcardCache(nodeInterop);
    if (cache && cache.has(obj)) {
        return cache.get(obj);
    }
    var newObj = {};
    var hasPropertyDescriptor = Object.defineProperty && Object.getOwnPropertyDescriptor;
    for(var key in obj){
        if (key !== "default" && Object.prototype.hasOwnProperty.call(obj, key)) {
            var desc = hasPropertyDescriptor ? Object.getOwnPropertyDescriptor(obj, key) : null;
            if (desc && (desc.get || desc.set)) {
                Object.defineProperty(newObj, key, desc);
            } else {
                newObj[key] = obj[key];
            }
        }
    }
    newObj.default = obj;
    if (cache) {
        cache.set(obj, newObj);
    }
    return newObj;
}
class Channel extends _events.default {
    get shapes() {
        return Object.values(this.shapesMap);
    }
    addRow(row) {
        this.rows.push(row);
        this.emit("row", row);
    }
    addShape(id, type) {
        this.shapesMap[id] = type;
        this.emit("shape", type);
    }
    hasShape(id) {
        return id in this.shapesMap;
    }
    done() {
        this.emit("end");
    }
    consume(json) {
        const value = this.stream.decode(json);
        if ("id" in json.type && !this.hasShape(json.type.id)) {
            this.addShape(json.type.id, value.type);
        } else if (json.type.kind === "primitive") {
            this.addShape(json.type.name, value.type);
        }
        this.addRow(value);
    }
    collect(collector) {
        /**
     * The goal here is to get the first batch of results out
     * to the collector as soon as possible. Then, only give
     * updates every timeThres. This allows the UI to avoid
     * frequent, expensive updates.
     */ let first = true;
        let count = 0;
        let countThresh = 2000;
        let timeThresh = 2000;
        let timeId = 0;
        const flush = ()=>{
            collector({
                rows: this.rows,
                shapesMap: this.shapesMap
            });
            first = false;
            count = 0;
            clearTimeout(timeId);
        };
        const startTimer = ()=>{
            timeId = setTimeout(()=>{
                if (count > 0) flush();
                startTimer();
            }, timeThresh);
        };
        this.on("row", ()=>{
            count += 1;
            if (first && count >= countThresh) flush();
        });
        this.on("end", ()=>flush());
        startTimer();
    }
    constructor(...args){
        super(...args);
        _defineProperty(this, "rows", []);
        _defineProperty(this, "shapesMap", {});
        _defineProperty(this, "stream", new _decodeStream.DecodeStream(_zed.DefaultContext));
    }
}