@brimdata/zealot/dist/cjs/ndjson/pipe_text.js

The Javascript Client for Zed Lakes

"use strict";
Object.defineProperty(exports, "__esModule", {
    value: true
});
Object.defineProperty(exports, "pipeText", {
    enumerable: true,
    get: ()=>pipeText
});
function pipeText(stream) {
    if (!stream) return noop();
    // @ts-ignore
    if (stream.getReader) {
        return browserPipeText(stream);
    } else {
        return nodePipeText(stream);
    }
}
async function* noop() {}
async function* browserPipeText(stream) {
    let reader = stream.getReader();
    let text = new TextDecoder();
    try {
        while(true){
            let { done , value  } = await reader.read();
            if (!done && value) {
                yield text.decode(value);
            } else {
                return;
            }
        }
    } finally{
        reader.releaseLock();
    }
}
function nodePipeText(stream) {
    let resolves = [];
    let pending = [];
    stream.on("data", (data)=>{
        let value = {
            done: false,
            value: data.toString()
        };
        if (resolves.length) {
            resolves.shift()(value);
        } else {
            pending.push(value);
        }
    });
    stream.on("end", ()=>{
        const value = {
            done: true,
            value: null
        };
        if (resolves.length) {
            resolves.shift()(value);
        } else {
            pending.push(value);
        }
    });
    return {
        return () {
            return Promise.resolve({
                done: true,
                value: null
            });
        },
        throw (e) {
            return Promise.reject(e);
        },
        next () {
            const result = pending.shift();
            if (result) {
                return Promise.resolve(result);
            } else {
                return new Promise((res)=>{
                    resolves.push(res);
                });
            }
        },
        [Symbol.asyncIterator]: function() {
            return this;
        }
    };
}