json-joy
Version:
Collection of libraries for building collaborative editing apps.
185 lines • 6.83 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.Decoder = void 0;
const CrdtReader_1 = require("../../util/binary/CrdtReader");
const clock_1 = require("../../clock");
const PatchBuilder_1 = require("../../PatchBuilder");
const CborDecoder_1 = require("@jsonjoy.com/json-pack/lib/cbor/CborDecoder");
/**
* JSON CRDT Patch "binary" codec decoder.
*/
class Decoder extends CborDecoder_1.CborDecoder {
/**
* Creates a new JSON CRDT patch decoder.
*
* @param reader An optional custom implementation of a CRDT decoder.
*/
constructor(reader = new CrdtReader_1.CrdtReader()) {
super(reader);
}
/**
* Decodes a JSON CRDT patch from a binary blob.
*
* @param data Binary data to decode.
* @returns A JSON CRDT patch.
*/
decode(data) {
this.reader.reset(data);
return this.readPatch();
}
readPatch() {
const reader = this.reader;
const sid = reader.vu57();
const time = reader.vu57();
const isServerClock = sid === 1 /* SESSION.SERVER */;
const clock = isServerClock ? new clock_1.ServerClockVector(1 /* SESSION.SERVER */, time) : new clock_1.ClockVector(sid, time);
this.patchSid = clock.sid;
const builder = (this.builder = new PatchBuilder_1.PatchBuilder(clock));
const map = this.val();
if (Array.isArray(map))
builder.patch.meta = map[0];
this.decodeOperations();
return builder.patch;
}
decodeId() {
const reader = this.reader;
const [isSessionDifferent, x] = reader.b1vu56();
return isSessionDifferent ? new clock_1.Timestamp(reader.vu57(), x) : new clock_1.Timestamp(this.patchSid, x);
}
decodeTss() {
const id = this.decodeId();
const span = this.reader.vu57();
return (0, clock_1.interval)(id, 0, span);
}
decodeOperations() {
const reader = this.reader;
const length = reader.vu57();
for (let i = 0; i < length; i++)
this.decodeOperation();
}
decodeOperation() {
const builder = this.builder;
const reader = this.reader;
const octet = reader.u8();
const opcode = octet >> 3;
switch (opcode) {
case 0 /* JsonCrdtPatchOpcode.new_con */: {
const length = octet & 0b111;
builder.con(!length ? this.val() : this.decodeId());
break;
}
case 1 /* JsonCrdtPatchOpcode.new_val */: {
builder.val();
break;
}
case 2 /* JsonCrdtPatchOpcode.new_obj */: {
builder.obj();
break;
}
case 3 /* JsonCrdtPatchOpcode.new_vec */: {
builder.vec();
break;
}
case 4 /* JsonCrdtPatchOpcode.new_str */: {
builder.str();
break;
}
case 5 /* JsonCrdtPatchOpcode.new_bin */: {
builder.bin();
break;
}
case 6 /* JsonCrdtPatchOpcode.new_arr */: {
builder.arr();
break;
}
case 9 /* JsonCrdtPatchOpcode.ins_val */: {
const obj = this.decodeId();
const val = this.decodeId();
builder.setVal(obj, val);
break;
}
case 10 /* JsonCrdtPatchOpcode.ins_obj */: {
const length = octet & 0b111 || reader.vu57();
const obj = this.decodeId();
const tuples = [];
for (let i = 0; i < length; i++) {
const key = this.val();
if (typeof key !== 'string')
continue;
const value = this.decodeId();
tuples.push([key, value]);
}
builder.insObj(obj, tuples);
break;
}
case 11 /* JsonCrdtPatchOpcode.ins_vec */: {
const length = octet & 0b111 || reader.vu57();
const obj = this.decodeId();
const tuples = [];
for (let i = 0; i < length; i++) {
const index = this.val();
if (typeof index !== 'number')
continue;
const value = this.decodeId();
tuples.push([index, value]);
}
builder.insVec(obj, tuples);
break;
}
case 12 /* JsonCrdtPatchOpcode.ins_str */: {
const length = octet & 0b111 || reader.vu57();
const obj = this.decodeId();
const after = this.decodeId();
const str = reader.utf8(length);
builder.insStr(obj, after, str);
break;
}
case 13 /* JsonCrdtPatchOpcode.ins_bin */: {
const length = octet & 0b111 || reader.vu57();
const obj = this.decodeId();
const after = this.decodeId();
const buf = reader.buf(length);
if (!(buf instanceof Uint8Array))
return;
builder.insBin(obj, after, buf);
break;
}
case 14 /* JsonCrdtPatchOpcode.ins_arr */: {
const length = octet & 0b111 || reader.vu57();
const obj = this.decodeId();
const after = this.decodeId();
const elements = [];
for (let i = 0; i < length; i++)
elements.push(this.decodeId());
builder.insArr(obj, after, elements);
break;
}
case 15 /* JsonCrdtPatchOpcode.upd_arr */: {
const obj = this.decodeId();
const ref = this.decodeId();
const val = this.decodeId();
builder.updArr(obj, ref, val);
break;
}
case 16 /* JsonCrdtPatchOpcode.del */: {
const length = octet & 0b111 || reader.vu57();
const obj = this.decodeId();
const what = [];
for (let i = 0; i < length; i++)
what.push(this.decodeTss());
builder.del(obj, what);
break;
}
case 17 /* JsonCrdtPatchOpcode.nop */: {
const length = octet & 0b111 || reader.vu57();
builder.nop(length);
break;
}
default: {
throw new Error('UNKNOWN_OP');
}
}
}
}
exports.Decoder = Decoder;
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