iota-transaction-cutter

Zero value IOTA data transactions can only be 2187 Trytes long.

This library takes a list of transfer objects and cuts them up in such a way we can easily reconstruct the messages later.

It does this by cutting up the transaction message into different identical transactions (so tag etc stays the same). It then prefixes the transactions with 12 Trytes.

Message NR   Current Index   Message Count  Split   Remainder
99           999             99A            SPLT    AAAAAAAAAAAAA

This comes down to a potential 27 * 27 = 729 Splitted messages within a bundle. With each message having a potential 27 * 27 * 27 = 19683 Transactions in them. 19683 * 2175 = 42.810.525 Trytes per message.

This is just a means to split up an already encoded tryte message inside a transfer object. It could be placed inside one bundle but it is also possible to send them as a stream in a MAM channel or Flash channel.

NOTE: It currently only works with bundles that are created by this lib, that means it expects the order of created messages to be correct.

#Building

npm run-script-build

Building produces two files one for nodejs and one for web.

#Installation

 npm install iotatransactioncutter --save

#Usage

var cutter = require("iotatransactioncutter");
//Create messages that are too long.
var msg1 = "A".repeat(1000) + "B".repeat(1000) + "C".repeat(1000) + "D".repeat(1000) + "E".repeat(1000) + "F".repeat(1000)
var msg2 = "G".repeat(3000) + "H".repeat(500) + "I".repeat(100) + "J".repeat(3000) + "K".repeat(2000) + "L".repeat(985)
var msg3 = "M".repeat(1000) + "N".repeat(2000) + "O".repeat(1000) + "P".repeat(3000) + "Q".repeat(3000) + "R".repeat(3000)

//Mock transfer object.
var transactions = [
    { value: 0, message: msg1 },
    { value: 1, message: "" },
    { value: 0, message: msg2 },
    { value: 0, message: msg3 },

];
var cutUpTransctions = cutter.cutTransactionMessages(transactions);
var gluedTranscations = cutter.glueTransactionMessages(cutUpTransctions);
var transactionsEqual = true;

for (var i = 0; i < transactions.length; i++) {
    Object.keys(transactions[i]).forEach(key => {
        if (transactions[i][key] !== gluedTranscations[i][key]) {
            transactionsEqual = false;
        }
    })
}    
console.log("Does it equal?", transactionsEqual);