Fulcrum

A fast & nimble SPV server for Bitcoin Cash.

Copyright

License:

GPLv3. See the included LICENSE.txt file or visit gnu.org and read the license.

Highlights:

Fast: Written in 100% modern C++17 using multi-threaded and asynchronous programming techniques.
A drop-in replacement for ElectronX/ElectrumX: The initial release of this server is 100% protocol-level compatible with the ElectronX/ElectrumX 1.4.2 protocol. Existing server admins should feel right at home with this software since installation and management of it is nearly identical to ElectronX/ElectrumX server.
Cross-platform: While this codebase was mainly developed and tested on MacOS, Windows and Linux, it should theoretically work on any modern OS (such as *BSD) that has Qt5 Core and Qt5 Networking available.

Requirements

Qt Core & Qt Networking libraries 5.11 or above (I use 5.13.2 myself).
A modern, 64-bit C++17 compiler. clang is recommended but G++ also works. MSVC on Windows is not supported (please use MinGW G++ instead, which ships with Qt Open Source Edition for Windows).

How To Compile

It's recommended you use Qt Creator.

Get the latest version of Qt Open Source Edition for your platform.
Point the Qt Creator IDE at the Fulcrum.pro file.
Set the build configuration to "Release". Hit Build. It should "just work".

You may also build from the CLI (on Linux and MacOS):

Make sure you have qmake in your path and all the requisite Qt5 dev libs installed.
qmake (to generate the Makefile)
make -j8 (replace 8 here with the number of cores in your machine)

A note for Linux users: Qt 5.11 or above is required (5.13 is recommended). You may have to install the Qt5 networking package separately such as libqt5network5 (depending on your distribution). You also need libbz2-dev otherwise compilation will fail.

A note for Windows users: Qt 5.13.2 (or above) with MinGW G++ 7.x.x is the compiler/Qt kit you should be using. MSVC is not supported by this codebase at the present time.

What to do if compiling fails

If you have problems compiling, the most likely culprit would be your compiler not being C++17 compliant (please use a recent verson of GCC or clang on Linux, Apple's Xcode on Mac, or MinGW G++ 7.x on Windows).

The other likely culprit is the fact that at the present time I have included a statically-built librocksdb in the codebase. There are versions of this library for Windows, Mac, and Linux included right in the source tree, and Fulcrum.pro looks for them and links to them. Instructions are included within the Fulcrum.pro project file about how to build your own static librocksdb if the bundled one does not work on your system.

If you are still having trouble, file an issue here in this github.

Running Fulcrum

Execute the binary, with -h to see the built-in help, e.g. ./Fulcrum -h.

Fulcrum requires a bitcoind instance running either on testnet or mainnet (or regtest for testing), which you must tell it about via the CLI options. You also need to tell it what port(s) to listen on and optionally what SSL certificates to use (if using SSL). Note: Electron Cash at this time no longer supports connecting to non-SSL servers, so you should probably configure SSL for production use.

It is recommender you specify a data dir (-D) on an SSD drive for best results. Synching against testnet should take you about 10-20 minutes (more on slower machines), and mainnet can take anywhere from 4 hours to 20+ hours, depending on machine and drive speed. I have not tried synching against mainnet on an HDD and it will probably take days if you are lucky.

Once the server finishes synching it will behave like an ElectronX/ElectrumX server and it can receive requests from Electron Cash.

(This section is incomplete for now, all apologies -- more documentation is coming soon!)

Platform Notes

Big Endian Architectures

The code is more or less configured to assume a "little endian" architecture by default (which is what all Intel x86/x86_64 are). If you're on a big endian machine, on Linux it should just auto-detect that fact. However, on other OS's such as BSD, if you're on a big endian machine, you may need to uncomment this line from the .pro file:

# DEFINES += WORDS_BIGENDIAN

Windows

This codebase will not compile correctly (or at all) using MSVC. Please use the MinGW and/or G++ kit in Qt Creator to build this software.

Linux

If you have clang on your system, configure the project to use it as the compiler preferentially over G++. G++ works too, but clang is preferred.

MacOS

Everything should just work (I use MacOS as my dev machine).

F.A.Q.

Q: Why Qt? This isn't a GUI app!

A: Yes, I know. However, Qt is a very robust, cross-platform and fast application framework. You can use its "Core" library for console apps, servers, etc. It has great network support and other basic things a programmer needs to get stuff done.

Donations

Sure! Send BCH here:

bitcoincash:qphax4s4n9h60jxj2fkrjs35w2tvgd4wzvf52cgtzc

VitaeTeam/Fulcrum