FC Buffer

Serialization library geared towards immutable data storage such as blockchains.

For EOS compatible implementation use this library from eosjs instead.

FC Buffer is a recent refactor from serialization code used in Bitshares and
Steem. Some of the serialization code was reduced and the definitions language
added. The definition format may change.

Features

- Validation and error reporting
- Concise and intuitive binary format
- Compatible with the FC library used in Graphene blockchains
- Extendable JSON structure definitions
- Binary and JSON string serialization
- Unit testing and code coverage

Non Features

- Consider Cap'n Proto or Protocol Buffers if your data structures need to
be extended at the serialization layer.
- No streams, smaller blockchain sized objects are used

Example

``javascript
Fcbuffer = require('fcbuffer') // or: Fcbuffer = require('./src')

assert = require('assert')

definitions = {
message_type: 'fixed_string16', // CustomType: built-in type
account_name: 'fixed_string32', // CustomType: built-in type
message: { // struct
fields: {
from: 'account_name',
to: 'account_name',
cc: 'account_name[]',
type: 'message_type',
data: 'bytes' // built-in type
}
}
}

// Warning: Do not use {defaults: true} in production
fcbuffer = Fcbuffer(definitions, {defaults: true})

// Check for errors anywhere in the definitions structure
assert(fcbuffer.errors.length === 0, fcbuffer.errors)

// If there are no errors, you'll get your structs
var {message} = fcbuffer.structs

// Create JSON serializable object
// returns { from: '', to: '', cc: [ '' ], type: '', data: '' }
message.toObject()

// Convert JSON into a more compact fcbuffer serializable object
msg = { from: 'jc', to: 'dan', cc: [ 'abc' ], type: '', data: '0f0f0f' }

// Serialize fcbuffer object into a single binary buffer
buf = Fcbuffer.toBuffer(message, msg)
// returns

// Convert binary back into a new (cloned) object
obj = Fcbuffer.fromBuffer(message, buf)

// Check that the new object matches the original
assert.deepEqual(msg, obj)

// A definition may extend and define other definitions. This works in the initial
// definition or later via the extend function.
fcbuffer2 = fcbuffer.extend({
permission_name: 'fixed_string16',
permission_level: {
fields: {
actor: 'account_name',
permission: 'permission_name'
}
}
})

assert(fcbuffer2.errors.length === 0, fcbuffer2.errors)

var {permission_level} = fcbuffer2.structs
permission_level.toObject()
// toObject returns: { actor: '', permission: '' }

``

References

- Built-in Types: types.js
- EOS Definitions: schema

Environment

Node 6+ and browser (browserify, webpack, etc)