@worker-tools/json-stream/esm/json-parse-stream.js

Utilities for working with streaming JSON in Worker Runtimes such as Cloudflare Workers, Deno Deploy and Service Workers.

var __classPrivateFieldSet = (this && this.__classPrivateFieldSet) || function (receiver, state, value, kind, f) {
    if (kind === "m") throw new TypeError("Private method is not writable");
    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a setter");
    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot write private member to an object whose class did not declare it");
    return (kind === "a" ? f.call(receiver, value) : f ? f.value = value : state.set(receiver, value)), value;
};
var __classPrivateFieldGet = (this && this.__classPrivateFieldGet) || function (receiver, state, kind, f) {
    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a getter");
    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot read private member from an object whose class did not declare it");
    return kind === "m" ? f : kind === "a" ? f.call(receiver) : f ? f.value : state.get(receiver);
};
var _JSONParseStream_jsonPath, _JSONParseNexus_queues, _JSONParseNexus_reader;
// deno-lint-ignore-file no-explicit-any no-cond-assign ban-unused-ignore no-unused-vars
import { streamToAsyncIter } from 'whatwg-stream-to-async-iter';
import { JSONParser } from './json-parser.js';
import { TaskPromise } from './task-promise.js';
import { normalize, match } from './json-path.js';
// FIXME: avoid string concatenation/joining
const mkPath = (parser) => {
    const path = [...parser.stack.map((_) => _.key), parser.key]; // TODO: modify parser to provide key efficiently
    path[0] = path[0] || '$';
    return normalize(path.join('.')); // FIXME: avoid string concatenation/joining
};
export class JSONParseStream extends TransformStream {
    constructor(jsonPath = '$.*') {
        let parser;
        const expr = normalize(jsonPath);
        super({
            start: (controller) => {
                parser = new JSONParser();
                parser.onValue = (value) => {
                    const path = mkPath(parser);
                    if (match(expr, path)) {
                        controller.enqueue(value);
                    }
                    else if (expr.startsWith(path + ';')) {
                        controller.terminate();
                    }
                };
            },
            transform: (chunk) => {
                parser.write(chunk);
            },
        });
        _JSONParseStream_jsonPath.set(this, void 0);
        __classPrivateFieldSet(this, _JSONParseStream_jsonPath, expr, "f");
    }
    get path() { return __classPrivateFieldGet(this, _JSONParseStream_jsonPath, "f"); }
}
_JSONParseStream_jsonPath = new WeakMap();
const remove = (m, k) => { const v = m.get(k); m.delete(k); return v; };
/** @deprecated Rename!!! */
export class JSONParseNexus extends TransformStream {
    constructor() {
        let parser;
        super({
            start: (controller) => {
                parser = new JSONParser();
                parser.onValue = (value) => {
                    const path = mkPath(parser);
                    for (const expr of __classPrivateFieldGet(this, _JSONParseNexus_queues, "f").keys()) {
                        if (match(expr, path)) {
                            __classPrivateFieldGet(this, _JSONParseNexus_queues, "f").get(expr).enqueue(value);
                        } // no else if => can both be true
                        if (expr.startsWith(path + ';')) {
                            remove(__classPrivateFieldGet(this, _JSONParseNexus_queues, "f"), expr).close();
                        }
                    }
                    controller.enqueue([path, value]);
                };
            },
            transform(buffer) {
                // console.log('transform', buffer, controller.desiredSize)
                parser.write(buffer);
            },
        });
        _JSONParseNexus_queues.set(this, new Map());
        _JSONParseNexus_reader.set(this, void 0);
        __classPrivateFieldSet(this, _JSONParseNexus_reader, this.readable.getReader(), "f");
    }
    promise(jsonPath) {
        const reader = this.stream(jsonPath).getReader();
        return TaskPromise.from(async () => {
            const x = await reader.read();
            return x.done ? undefined : x.value;
        });
    }
    stream(jsonPath) {
        const path = normalize(jsonPath);
        return new ReadableStream({
            start: (queue) => {
                __classPrivateFieldGet(this, _JSONParseNexus_queues, "f").set(path, queue);
            },
            pull: async () => {
                while (true) {
                    const { done, value } = await __classPrivateFieldGet(this, _JSONParseNexus_reader, "f").read();
                    // FIXME: avoid duplicate match
                    if (done || match(value[0], path))
                        break;
                }
            },
            cancel: (err) => {
                // If one of the child streams errors, error the whole pipeline.
                // TODO: Or should it?
                __classPrivateFieldGet(this, _JSONParseNexus_reader, "f").cancel(err);
            },
        }, { highWaterMark: 0 }); // does not pull on its own
    }
    iterable(jsonPath) {
        return streamToAsyncIter(this.stream(jsonPath));
    }
}
_JSONParseNexus_queues = new WeakMap(), _JSONParseNexus_reader = new WeakMap();
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