Changes list:

• Refactoring of Proof-of-Stake checkings code;
• Remove some redundant messages from debug.log output;
• Make stake related DoS checkings harder;
• Database code is updated, direct CCoins links approach is implemented to decrease count of worthless flush and copy events;
• Initial block download optimization, transaction hashes are cached now to make blocks validation faster;
• Multiple CChainDB instantiations were replaced with a single CBlockTreeDB instance;
• CCoinsDB and CBlockTreeDB are updated to use LevelDB storage;
• gettxout and gettxoutsetinfo RPC calls added;
• getblock and getblockbynumber RPC calls are now providing generator public key for proof-of-stake blocks.

Continue reading →

Testing branch has been updated.

https://github.com/CryptoManiac/novacoin/tree/novacoin-next

screenshot

Switch to unspent coins approach

This commit replaces old transactions index with unspent coins database
which contains a basic metadata like heights, amounts, coinstake/coinbase 
flags and timestamps.

We still need access to blockchain for proof-of-stake blocks validation. 
Currently CheckProofOfStake() uses the coin database to find the block height, 
and then scans that block to find the dependency of coinstake kernel.

Continue reading →

• Core: Proof-of-Stake miner optimizations and cleanup;
• Core: Remove BDB support;
• Core: Automatically remove old transactions index database if that’s necessary, no runaway exceptions anymore.

P.S. Mac OS X build was replaced too.

Stress test in the TestNet

http://s006.radikal.ru/i213/1401/21/22b9e8099046.png

Proof-of-Work and Proof-of-Stake mining using more than 1 million coins and almost 20k transactions. Stake miner eats one CPU core but there is absolutely no performance issues.

It actually doesn’t matter, but we’ll try to decrease CPU usage in the future.

Experimental builds are updated again.  [AMD64  | i686 | src]

Changes list:

• Core: New proof-of-stake miner implementation. Performance issues resolved, almost 100x faster with massive inputs amount;
• Qt: Coinbase/coinstake transaction records appearance unification;
• Lib: update to Berkeley DB 6.0.20.

It was decided to update some libraries, which are used for Windows builds

libminiupnpc 1.6 -> 1.8
openssl 1.0.1c -> 1.0.1f
libdb 4.8.30 -> 5.3.21

New builds are backward-compatible, but wallet.dat becomes unreadable for old builds once it was opened by new client.

Testing builds for compatibility checking: [AMD64  | i686]

Changes planned for 0.4.4.8:

• Separate databases for private keys and transactions, instead of wallet.dat;
• Moving the public data to separate folder (e.g. move blockchain database to AppData\Local\Novacoin on Windows);
• Switching to UTXO storage (similar to used in the Bitcoin, but with extended metadata) instead of the current full transaction logs approach;
• Switching to deterministic keys, and possibly withdrawal of the keypool approach;
• Withdrawal of the Berkeley DB support (LevelDB is used by default for a long time).

This changes will be implemented in the 0.4.4.7 testing branch, the 0.4.4.7 binaries will be rebuilt and published sometimes, just for testing purposes.

Parts of this functionality are already available for testing.

NovaCoin 0.4.4.6 client update builds, some testing wold be helpful.

Linux x86_64 static:
http://sourceforge.net/projects/novacoin/files/novacoin-0.4.4.6.ubuntu-lts-x86_64.tar.bz2/download

Win32 static:
http://sourceforge.net/projects/novacoin/files/novacoin-0.4.4.6-nosetup-win32.zip/download

Windows 64 bit installer:
http://sourceforge.net/projects/novacoin/files/novacoin-setup-win32-amd64-0.4.4.6.exe/download

Windows 32 bit installer:
http://sourceforge.net/projects/novacoin/files/novacoin-setup-win32-0.4.4.6.exe/download

Please check README file before running.