@narumir/amf/build/deserialize.js

Action Message Format for nodejs

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.AMF0Deserialize = void 0;

var _constants = require("./constants");

class AMF0Deserialize {
  cursor = 0;
  references = [];

  constructor(data) {
    this.data = data;
  }

  readData() {
    const type = this.readUInt8();

    switch (type) {
      case _constants.AMF0DataType.NUMBER_MARKER:
        return this.readNumberMarker();

      case _constants.AMF0DataType.BOOLEAN_MARKER:
        return this.readBooleanMarker();

      case _constants.AMF0DataType.STRING_MARKER:
        return this.readStringMarker();

      case _constants.AMF0DataType.OBJECT_MARKER:
        return this.readObjectMarker();

      case _constants.AMF0DataType.MOVIECLIP_MARKER:
        throw new Error("Sorry. this type not support, reserved for future.");

      case _constants.AMF0DataType.NULL_MARKER:
        return null;

      case _constants.AMF0DataType.UNDEFINED_MARKER:
        return undefined;

      case _constants.AMF0DataType.REFERENCE_MARKER:
        return this.readReferenceMarker();

      case _constants.AMF0DataType.ECMA_ARRAY_MARKER:
        return this.readECMAArrayMarker();

      case _constants.AMF0DataType.OBJECT_END_MARKER:
        return type;

      case _constants.AMF0DataType.STRICT_ARRAY_MARKER:
        return this.readStrictArrayMarker();

      case _constants.AMF0DataType.DATE_MARKER:
        return this.readDateMarker();

      case _constants.AMF0DataType.LONG_STRING_MARKER:
        return this.readLongStringMarker();

      case _constants.AMF0DataType.UNSUPPORT_MARKER:
        return;

      case _constants.AMF0DataType.RECOREDSET_MARKER:
        throw new Error("Sorry. this type not support, reserved for future.");

      case _constants.AMF0DataType.XML_DOCUMENT_MARKER:
        return this.readXMLDocumentMarker();

      case _constants.AMF0DataType.TYPED_OBJECT_MARKER:
        return this.readTypedObjectMarker();

      case _constants.AMF0DataType.AVMPLUS_OBJECT_MARKER:
      default:
        throw new Error("Unknown AMF0 type error.");
    }
  }

  readNumberMarker() {
    const buf = this.data.readDoubleBE(this.cursor);
    this.cursor += 8;
    return buf;
  }

  readBooleanMarker() {
    const buf = this.readUInt8();
    return buf === 0 ? false : true;
  }

  readStringMarker() {
    const len = this.readUInt16();
    const str = this.data.toString("utf8", this.cursor, this.cursor + len);
    this.cursor += len;
    return str;
  }

  readObjectMarker() {
    const ref = {};

    while (true) {
      const key = this.readStringMarker();
      const value = this.readData();

      if (value === _constants.AMF0DataType.OBJECT_END_MARKER) {
        break;
      }

      ref[key] = value;
    }

    return ref;
  }

  readReferenceMarker() {
    const idx = this.readUInt16();
    const value = this.references[idx];

    if (value == null) {
      throw new Error("Reference value not found.");
    }

    return value;
  }

  readECMAArrayMarker() {
    this.readUint32();
    return this.readObjectMarker();
  }

  readStrictArrayMarker() {
    const arr = [];

    for (let len = this.readUint32(); len; len--) {
      const key = this.readStringMarker();
      const val = this.readData();
      arr.push(val);
    }

    return arr;
  }

  readDateMarker() {
    this.readUInt8();
    const time = this.readNumberMarker();
    this.readUInt16();
    return new Date(time);
  }

  readLongStringMarker() {
    const len = this.readUInt16();
    const str = this.data.toString("utf-8", this.cursor, this.cursor + len);
    this.cursor += len;
    return str;
  }

  readTypedObjectMarker() {
    const name = this.readStringMarker();
    const obj = {
      __name: name
    };
    Object.assign(obj, this.readObjectMarker());
    return obj;
  }

  readXMLDocumentMarker() {
    return this.readLongStringMarker();
  }

  readUInt8() {
    const buf = this.data.readUint8(this.cursor);
    this.cursor += 1;
    return buf;
  }

  readUInt16() {
    const buf = this.data.readUint16BE(this.cursor);
    this.cursor += 2;
    return buf;
  }

  readUint32() {
    const buf = this.data.readUint32BE(this.cursor);
    this.cursor += 4;
    return buf;
  }

}

exports.AMF0Deserialize = AMF0Deserialize;