11 KiB
bitcoind.js
A Node.js module that adds a native interface to Bitcoin Core for querying information about the Bitcoin blockchain. Bindings are linked to Bitcore Core compiled as a shared library.
Install
git clone https://github.com/bitpay/bitcoind.js.git
cd bitcoind.js
npm install
Example Usage
var BitcoinNode = require('bitcoind.js');
var configuration = {
datadir: '~/.bitcoin',
network: 'testnet'
};
var node = new BitcoinNode(configuration);
node.on('ready', function() {
console.log('Bitcoin Node Ready');
});
node.on('error', function(err) {
console.error(err);
});
node.chain.on('addblock', function(block) {
console.log('New Best Tip:', block.hash);
});
API Documentation
Get Unspent Outputs
var address = '15vkcKf7gB23wLAnZLmbVuMiiVDc1Nm4a2';
var includeMempool = true;
node.getUnspentOutputs(address, includeMempool, function(err, unspentOutputs) {
//...
});
View Balances
var address = '15vkcKf7gB23wLAnZLmbVuMiiVDc1Nm4a2';
var includeMempool = true;
node.getBalance(address, includeMempool, function(err, balance) {
//...
});
Get Outputs
var address = '15vkcKf7gB23wLAnZLmbVuMiiVDc1Nm4a2';
var includeMempool = true;
node.getOutputs(address, includeMempool, function(err, outputs) {
//...
});
Get Transaction
var txid = 'c349b124b820fe6e32136c30e99f6c4f115fce4d750838edf0c46d3cb4d7281e';
var includeMempool = true;
node.getTransaction(txid, includeMempool, function(err, transaction) {
//...
});
Get Block
var blockHash = '00000000d17332a156a807b25bc5a2e041d2c730628ceb77e75841056082a2c2';
node.getBlock(blockHash, function(err, block) {
//...
});
You can log output from the daemon using:
$ tail -f ~/.bitcoin/debug.log
^C (SIGINT) will call StartShutdown()
in bitcoind on the node thread pool.
Modules
Bitcoind.js has a module system where additional information can be indexed and queried from the blockchain. One built-in module is the address module which exposes the API methods for getting balances and outputs.
Writing a Module
A new module can be created by inheriting from BitcoindJS.Module
, implementing the methods blockHandler()
, getAPIMethods()
, getPublishEvents()
and any additional methods for querying the data. Here is an example:
var inherits = require('util').inherits;
var BitcoindJS = require('bitcoind.js');
var MyModule = function(options) {
BitcoindJS.Module.call(this, options);
};
inherits(MyModule, BitcoindJS.Module);
/**
* blockHandler
* @param {Block} block - the block being added or removed from the chain
* @param {Boolean} add - whether the block is being added or removed
* @param {Function} callback - call with the leveldb database operations to perform
*/
MyModule.prototype.blockHandler = function(block, add, callback) {
var transactions = this.db.getTransactionsFromBlock(block);
// loop through transactions and outputs
// call the callback with leveldb database operations
var operations = [];
if(add) {
operations.push({
type: 'put',
key: 'key',
value: 'value'
});
} else {
operations.push({
type: 'del',
key: 'key'
});
}
// If your function is not asynchronous, it is important to use setImmediate.
setImmediate(function() {
callback(null, operations);
});
};
/**
* the API methods to expose
* @return {Array} return array of methods
*/
MyModule.prototype.getAPIMethods = function() {
return [
['getData', this, this.getData, 1]
];
};
/**
* the bus events available for subscription
* @return {Array} array of events
*/
MyModule.prototype.getPublishEvents = function() {
return [
{
name: 'custom',
scope: this,
subscribe: this.subscribeCustom,
unsubscribe: this.unsubscribeCustom
}
]
};
/**
* Will keep track of event listeners to later publish and emit events.
*/
MyModule.prototype.subscribeCustom = function(emitter, param) {
if(!this.subscriptions[param]) {
this.subscriptions[param] = [];
}
this.subscriptions[param].push(emitter);
}
MyModule.prototype.getData = function(arg1, callback) {
// You can query the data by reading from the leveldb store on db
this.db.store.get(arg1, callback);
};
module.exports = MyModule;
The module can then be used when running a node:
var configuration = {
datadir: process.env.BITCOINDJS_DIR || '~/.bitcoin',
db: {
modules: [MyModule]
}
};
var node = new BitcoindJS.Node(configuration);
node.on('ready', function() {
node.getData('key', function(err, value) {
console.log(err || value);
});
});
Note that if you already have a bitcoind.js database, and you want to query data from previous blocks in the blockchain, you will need to reindex. Reindexing right now means deleting your bitcoind.js database and resyncing.
Daemon Documentation
daemon.start([options], [callback])
- Start the JavaScript Bitcoin node.daemon.getBlock(blockHash|blockHeight, callback)
- Get any block asynchronously by block hash or height as a node buffer.daemon.getTransaction(txid, blockhash, callback)
- Get any tx asynchronously by reading it from disk.daemon.log(message), daemon.info(message)
- Log to standard output.daemon.error(message)
- Log to stderr.daemon.close([callback])
- Stop the JavaScript bitcoin node safely, the callback will be called when bitcoind is closed. This will also be done automatically onprocess.exit
. It also takes the bitcoind node off the libuv event loop. If the daemon object is the only thing on the event loop. Node will simply close.
Building
There are two main parts of the build, compiling Bitcoin Core and the Node.js bindings. You can run both by using npm install
and set environment variable, $BITCOINDJS_ENV to 'test' or 'debug'. Both 'test' and 'debug' build libbitcoind with debug symbols whereas 'test' adds wallet capability so that regtest can be used.
Node.js Bindings
$ node-gyp rebuild
And then with debug:
$ node-gyp -d rebuild
To be able to debug you'll need to have gdb
and node
compiled for debugging with gdb using --gdb
(node_g), and you can then run:
$ gdb --args node_g path/to/example.js
To run mocha from within gdb (notice _mocha
and not mocha
so that the tests run in the same process):
$ gdb --args node /path/to/_mocha -R spec integration/index.js
To run integration tests against testnet or livenet data:
$ cd integration
// modify index.js configuration, and then run mocha
$ mocha -R spec index.js
To run the benchmarks (also with livenet or testnet data):
$ cd benchmarks
$ node index.js
Bitcoin Core
Dependencies
Most of all the dependencies for building Bitcoin Core are needed, for more information please see the build notes for Unix and Mac OS X. These dependencies are needed:
-
Boost
- Boost Header Files (
/usr/include/boost
) - The Boost header files can be from your distro (like Debian or Ubuntu), just be sure to install the "-dev" versions of Boost (
sudo apt-get install libboost-all-dev
).
- Boost Header Files (
-
OpenSSL headers and libraries (-lcrypto and -lssl), this is used to compile Bitcoin.
-
If target platform is Mac OS X, then OS X >= 10.9, Clang and associated linker.
Shared Library Patch
To provide native bindings to JavaScript (or any other language for that matter), Bitcoin code, itself, must be linkable. Currently, Bitcoin Core provides a JSON RPC interface to bitcoind as well as a shared library for script validation (and hopefully more) called libbitcoinconsensus. There is a node module, node-libbitcoinconsensus, that exposes these methods. While these interfaces are useful for several use cases, there are additional use cases that are not fulfilled, and being able to implement customized interfaces is necessary. To be able to do this a few simple changes need to be made to Bitcoin Core to compile as a shared library.
The patch is located at etc/bitcoin.patch
and adds a configure option --enable-daemonlib
to compile all object files with -fPIC
(Position Independent Code - needed to create a shared object), exposes leveldb variables and objects, exposes the threadpool to the bindings, and conditionally includes the main function.
Every effort will be made to ensure that this patch stays up-to-date with the latest release of Bitcoin. At the very least, this project began supporting Bitcoin Core v0.10.2.
Building
There is a build script that will download Bitcoin Core v0.10.2 and apply the necessary patch, compile libbitcoind.{so|dylib}
and copy the artifact into platform/<os_dir>
. Unix/Linux uses the file extension "so" whereas Mac OSX uses "dylib" (bitcoind compiled as a shared library).
$ cd /path/to/bitcoind.js
$ ./bin/build-libbitcoind
The PATCH_VERSION
file dictates what version/tag the patch goes clean against.
There is a config_options.sh that has the configure options used to build libbitcoind. make
will then compile libbitcoind/src/.libs/libbitcoind.{so|dylib}
. This will completely ignore compiling tests, QT object files and the wallet features in bitcoind/libbitcoind.{so|dylib}
.
Or you can also manually compile using:
configure and make (Linux/Unix)
$ cd libbitcoind
$ ./configure --enable-tests=no --enable-daemonlib --with-gui=no --without-qt --without-miniupnpc --without-bdb --enable-debug --disable-wallet --without-utils
$ make
configure and make (Mac OS X) --note the addition of prefix to the location where the libbitcoind library will be installed.
$ cd libbitcoind
$ ./configure --enable-tests=no --enable-daemonlib --with-gui=no --without-qt --without-miniupnpc --without-bdb --enable-debug --disable-wallet --without-utils --prefix=<os_dir/lib>
$ make
And then copy the files (with Unix/Linux):
$ cp -P libbitcoind/src/.libs/libbitcoind.so* platform/<os_dir>
With Mac OS X:
$ cp -R libbitcoind/src/.libs/libbitcoind.*dylib platform/osx/lib
License
Code released under the MIT license.
Copyright 2013-2015 BitPay, Inc.
- bitcoin: Copyright (c) 2009-2015 Bitcoin Core Developers (MIT License)
- bcoin (some code borrowed temporarily): Copyright Fedor Indutny, 2014.