json-joy/esm/json-crdt-patch/codec/compact/decode.js

Collection of libraries for building collaborative editing apps.

import { JsonCrdtPatchOpcode } from '../../constants';
import { fromBase64 } from '@jsonjoy.com/base64/lib/fromBase64';
import { ClockVector, ServerClockVector, Timespan, Timestamp, } from '../../clock';
import { PatchBuilder } from '../../PatchBuilder';
import { SESSION } from '../../constants';
const timestamp = (sid, x) => {
    return Array.isArray(x) ? new Timestamp(x[0], x[1]) : new Timestamp(sid, x);
};
const timespan = (sid, span) => {
    return span.length === 3 ? new Timespan(span[0], span[1], span[2]) : new Timespan(sid, span[0], span[1]);
};
/**
 * Decodes a JSON CRDT Patch from a "compact" POJO into a {@link Patch} instance.
 *
 * @param data A JavaScript POJO array in the compact codec format.
 * @returns A decoded patch.
 */
export const decode = (data) => {
    const header = data[0];
    const x = header[0];
    const clock = Array.isArray(x) ? new ClockVector(x[0], x[1]) : new ServerClockVector(SESSION.SERVER, x);
    const sid = clock.sid;
    const time = clock.time;
    const builder = new PatchBuilder(clock);
    const length = data.length;
    for (let i = 1; i < length; i++) {
        const op = data[i];
        switch (op[0]) {
            case JsonCrdtPatchOpcode.new_con: {
                const [, value, isTimestamp] = op;
                builder.const(isTimestamp ? timestamp(sid, value) : value);
                break;
            }
            case JsonCrdtPatchOpcode.new_val: {
                builder.val();
                break;
            }
            case JsonCrdtPatchOpcode.new_obj: {
                builder.obj();
                break;
            }
            case JsonCrdtPatchOpcode.new_vec: {
                builder.vec();
                break;
            }
            case JsonCrdtPatchOpcode.new_str: {
                builder.str();
                break;
            }
            case JsonCrdtPatchOpcode.new_bin: {
                builder.bin();
                break;
            }
            case JsonCrdtPatchOpcode.new_arr: {
                builder.arr();
                break;
            }
            case JsonCrdtPatchOpcode.ins_val: {
                builder.setVal(timestamp(sid, op[1]), timestamp(sid, op[2]));
                break;
            }
            case JsonCrdtPatchOpcode.ins_obj: {
                const obj = timestamp(sid, op[1]);
                const tuples = [];
                const value = op[2];
                const length = value.length;
                for (let j = 0; j < length; j++) {
                    const [key, x] = value[j];
                    tuples.push([key, timestamp(sid, x)]);
                }
                builder.insObj(obj, tuples);
                break;
            }
            case JsonCrdtPatchOpcode.ins_vec: {
                const obj = timestamp(sid, op[1]);
                const tuples = [];
                const value = op[2];
                const length = value.length;
                for (let j = 0; j < length; j++) {
                    const [key, x] = value[j];
                    tuples.push([key, timestamp(sid, x)]);
                }
                builder.insVec(obj, tuples);
                break;
            }
            case JsonCrdtPatchOpcode.ins_str: {
                builder.insStr(timestamp(sid, op[1]), timestamp(sid, op[2]), op[3]);
                break;
            }
            case JsonCrdtPatchOpcode.ins_bin: {
                builder.insBin(timestamp(sid, op[1]), timestamp(sid, op[2]), fromBase64(op[3]));
                break;
            }
            case JsonCrdtPatchOpcode.ins_arr: {
                const obj = timestamp(sid, op[1]);
                const ref = timestamp(sid, op[2]);
                const value = op[3];
                const elements = [];
                const length = value.length;
                for (let j = 0; j < length; j++)
                    elements.push(timestamp(sid, value[j]));
                builder.insArr(obj, ref, elements);
                break;
            }
            case JsonCrdtPatchOpcode.del: {
                const obj = timestamp(sid, op[1]);
                const spans = op[2];
                const what = [];
                const length = spans.length;
                for (let i = 0; i < length; i++)
                    what.push(timespan(sid, spans[i]));
                builder.del(obj, what);
                break;
            }
            case JsonCrdtPatchOpcode.nop: {
                builder.nop(op[1] || 1);
                break;
            }
        }
    }
    const patch = builder.patch;
    patch.meta = header[1];
    return patch;
};