From: "Eric Lombrozo" <elombrozo@gmail.com>
To: =?utf-8?q?Jorge=20Tim=c3=b3n?= <jtimon@jtimon.cc>,
	"Wladimir J. van der Laan" <laanwj@gmail.com>
Date: Wed, 23 Sep 2015 00:10:50 +0000
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In-Reply-To: <em9a15c95a-cdb0-451f-8b69-e73572a722d2@platinum>
Reply-To: "Eric Lombrozo" <elombrozo@gmail.com>
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Cc: Bitcoin development mailing list <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] Long-term vision for bitcoind (was libconsensus
 and bitcoin development process)
Precedence: list

I should also add that the mempool should exist in (2). This way the=20
peer services layer can manage all relay policy and mempool management.

------ Original Message ------
From: "Eric Lombrozo" <elombrozo@gmail.com>
To: "Jorge Tim=C3=B3n" <jtimon@jtimon.cc>; "Wladimir J. van der Laan"=20
<laanwj@gmail.com>
Cc: "Bitcoin development mailing list"=20
<bitcoin-dev@lists.linuxfoundation.org>
Sent: 9/22/2015 5:07:22 PM
Subject: Re: [bitcoin-dev] Long-term vision for bitcoind (was=20
libconsensus and bitcoin development process)

>Here's what I propose as a long-term plan:
>
>1) libconsensus
>=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>We should probably start by defining an API for libconsensus. It should=
=20
>support an abstract DB model, track chain state, provide query=20
>mechanisms for blocks and transactions with optional pruning and=20
>indexing, expose a subscription mechanism for events such as NEW_TIP,=20
>REORG, etc, and contain a script interpreter.
>
>We can develop the library in parallel with Bitcoin Core without too=20
>much refactoring of Bitcoin Core itself...just moving pieces of Bitcoin=
=20
>Core's consensus code into the new library, tracking code movements to=20
>make merging easier. Yes, this is a bit ugly as it requires code=20
>duplication...but it will temporarily avoid much of the downstream=20
>pushback we're getting. The idea is that we can prove out the library=20
>with some simple projects, then start removing the consensus stuff from=
=20
>Bitcoin Core once we have greater acceptance of the library and better=20
>documentation.
>
>
>2) peer services
>=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>We develop a peer services library that performs the tasks of peer=20
>discovery and relay, with the ability to connect to appropriate peers=20
>and queue messages. It uses libconsensus for all validation=20
>functionality and as a datastore for the consensus state but maintains=20
>its own database for peer history and statistics. I believe Cory has=20
>been working on this already using libevent. I've already developed an=20
>async library for this as well.
>
>
>3) API/RPC
>=3D=3D=3D=3D=3D=3D=3D
>We provide high level calls and pub/sub mechanisms. ZMQ has been=20
>implemented and added already, but we could support other transports as=
=20
>well.
>
>
>4) Wallet
>=3D=3D=3D=3D=3D=3D
>The wallet is split out into a separate process that connects to the=20
>stack via the API/RPC layer.
>
>
>- Eric
>
>------ Original Message ------
>From: "Jorge Tim=C3=B3n" <bitcoin-dev@lists.linuxfoundation.org>
>To: "Wladimir J. van der Laan" <laanwj@gmail.com>
>Cc: "Bitcoin development mailing list"=20
><bitcoin-dev@lists.linuxfoundation.org>
>Sent: 9/22/2015 11:36:14 AM
>Subject: [bitcoin-dev] Long-term vision for bitcoind (was libconsensus=20
>and bitcoin development process)
>
>>On Fri, Sep 18, 2015 at 2:07 AM, Wladimir J. van der Laan via
>>bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org> wrote:
>>>  My long-term vision of bitcoind is a P2P node with validation and=20
>>>blockchain store, with a couple of data sources that can be=20
>>>subscribed to or pulled from.
>>
>>I agree with this long term vision.
>>Here's how I think it could happen:
>>
>>1) Libconsensus is completed and moved to a subtree (which has libsecp
>>as an internal subtree)
>>
>>2) Bitcoind becomes a subtree of bitcoin-wallet (which has
>>bitcoin-wallet and bitcoin-qt)
>>
>>Without aggressively changing it for this purpose, libconsensus should
>>tend to become C, like libsecp, which is better for proving
>>correctness.
>>Hopefully at some point it won't take much to move to C.
>>
>>Upper layers should move to C++11
>>
>>Don't focus on the git subtrees, the basic architecture is bitcoin-qt
>>on top of bitcoin-wallet, bitcoin-wallet on top of bitcoind (and
>>friends like bitcoin-cli and bitcoin-tx), bitcoind on top of
>>libconsensus on top of libsecp256k1.
>>
>>I believe this would maximize the number of people who can safely
>>contribute to the project.
>>I also believe this is the architecture most contributors have in mind
>>for the long term, but I may be wrong about it.
>>
>>Criticisms to this plan?
>>_______________________________________________
>>bitcoin-dev mailing list
>>bitcoin-dev@lists.linuxfoundation.org
>>https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev