object_length.js

/*jslint node: true */
"use strict";
var _ = require('lodash');
var constants = require('./constants.js');

var PARENT_UNITS_SIZE = 2*44;
var PARENT_UNITS_KEY_SIZE = "parent_units".length;

function getLength(value, bWithKeys) {
	if (value === null)
		return 0;
	switch (typeof value){
		case "string": 
			return value.length;
		case "number": 
			if (!isFinite(value))
				throw Error("invalid number: " + value);
			return 8;
			//return value.toString().length;
		case "object":
			var len = 0;
			if (Array.isArray(value))
				value.forEach(function(element){
					len += getLength(element, bWithKeys);
				});
			else    
				for (var key in value){
					if (typeof value[key] === "undefined")
						throw Error("undefined at "+key+" of "+JSON.stringify(value));
					if (bWithKeys)
						len += key.length;
					len += getLength(value[key], bWithKeys);
				}
			return len;
		case "boolean": 
			return 1;
		default:
			throw Error("unknown type="+(typeof value)+" of "+value);
	}
}

function getHeadersSize(objUnit) {
	if (objUnit.content_hash)
		throw Error("trying to get headers size of stripped unit");
	var objHeader = _.cloneDeep(objUnit);
	delete objHeader.unit;
	delete objHeader.headers_commission;
	delete objHeader.payload_commission;
	delete objHeader.main_chain_index;
	if (objUnit.version === constants.versionWithoutTimestamp)
		delete objHeader.timestamp;
	delete objHeader.messages;
	delete objHeader.parent_units; // replaced with PARENT_UNITS_SIZE
	var bWithKeys = (objUnit.version !== constants.versionWithoutTimestamp && objUnit.version !== constants.versionWithoutKeySizes);
	return getLength(objHeader, bWithKeys) + PARENT_UNITS_SIZE + (bWithKeys ? PARENT_UNITS_KEY_SIZE : 0);
}

function getTotalPayloadSize(objUnit) {
	if (objUnit.content_hash)
		throw Error("trying to get payload size of stripped unit");
	var bWithKeys = (objUnit.version !== constants.versionWithoutTimestamp && objUnit.version !== constants.versionWithoutKeySizes);
	return getLength({ messages: objUnit.messages }, bWithKeys);
}

function getRatio(objUnit) {
	try {
		if (objUnit.version !== constants.versionWithoutTimestamp && objUnit.version !== constants.versionWithoutKeySizes)
			return 1;
		return getLength(objUnit, true) / getLength(objUnit);
	}
	catch (e) {
		return 1;
	}
}

exports.getHeadersSize = getHeadersSize;
exports.getTotalPayloadSize = getTotalPayloadSize;
exports.getRatio = getRatio;