Feature: Truncate transaction bytes before persisting them to the database

[luca-moser]

Description

Lets the Transaction Persistable truncate the transaction bytes up on saving it by removing zero bytes from the signature message fragment (from the right). Up on loading a transaction, the bytes are back expanded to their full capacity (1604 bytes). This reduces the stored size of a transaction up to 81% (given a complete empty signature message fragment).

Fixes # (issue)
#1626

Type of change

• Enhancement (a non-breaking change which adds functionality)

How Has This Been Tested?

Moved the expand/truncate methods from the Protocol class to a new separate class called TransactionTruncator and writing relevant unit tests for it.

Checklist:

• My code follows the style guidelines for this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[DyrellC]

Overall it looks good, the regression tests failed however as a result of the expansion logic. I made it work locally with a quick patch so adding those few lines should finish it off.

[DyrellC]

@luca-moser Tests fail due to this line right here. Now that you have the expandTransaction() call taking in variable sizes of transaction you need to also have a conditional here that varies the size of the sigMsgFragBytesToCopy. When gossiping you still need the Protocol.GOSSIP_REQUESTED_TX_HASH_BYTES_LENGTH to be subtracted from the data.length. When expanding for other parts of the code (i.e. Transaction.read()) this current logic works.

I tested the following locally and it started gossiping and registering gossiped transactions properly:

if(referenceSize == Transaction.SIZE) {
    sigMsgFragBytesToCopy = data.length - TransactionTruncator.NON_SIG_TX_PART_BYTES_LENGTH;
} else {
    sigMsgFragBytesToCopy = data.length - Protocol.GOSSIP_REQUESTED_TX_HASH_BYTES_LENGTH - TransactionTruncator.NON_SIG_TX_PART_BYTES_LENGTH;
}

[GalRogozinski]

💯