# fcbuffer

> Serialization library geared towards immutable data storage such as blockchains.

Latest version **2.2.2** (published 2018-09-23) · MIT license · 0 weekly downloads

## Install

```sh
npm install fcbuffer
pnpm add fcbuffer
yarn add fcbuffer
bun add fcbuffer
```

## Health

**Score 15/100 (F)** — status: abandoned.

Positive: no vulnerabilities.

Warnings: low downloads; no types; no esm support.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 2.2.2 |
| Published | 2018-09-23 |
| First published | 2017-07-01 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | none |
| Module format | CommonJS |
| Dependencies | 3 |
| Unpacked size | 72.2 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 25 |
| Maintainers | jamesc, smetelin |

## Links

- npm: https://www.npmjs.com/package/fcbuffer
- Repository: https://github.com/EOSIO/fcbuffer
- Homepage: https://github.com/EOSIO/fcbuffer#readme
- Issues: https://github.com/EOSIO/fcbuffer/issues
- npm.io page: https://npm.io/package/fcbuffer

## Dependencies (3)

- [bn.js](https://npm.io/package/bn.js.md) ^4.11.8
- [bytebuffer](https://npm.io/package/bytebuffer.md) ^5.0.1
- [ieee-float](https://npm.io/package/ieee-float.md) ^0.6.0

## Recent versions

- 2.2.2 (latest) — 2018-09-23
- 2.1.5 (dawn3) — 2018-04-18
- 2.2.1 — 2018-08-19
- 2.2.0 — 2018-05-15
- 2.1.4 — 2018-04-03
- 2.1.3 — 2018-03-26
- 2.1.2 — 2018-03-23
- 2.1.1 — 2018-03-12
- 2.1.0 — 2018-03-09
- 2.0.7 — 2018-03-08
- 2.0.6 — 2018-02-14
- 2.0.5 — 2018-02-12
- 2.0.4 — 2018-02-08
- 2.0.3 — 2018-02-06
- 2.0.2 — 2018-02-01
- … 18 more at https://npm.io/package/fcbuffer/versions

## README

[![Build Status](https://travis-ci.org/EOSIO/eosjs-fcbuffer.svg?branch=master)](https://travis-ci.org/EOSIO/eosjs-fcbuffer)
[![Coverage Status](https://coveralls.io/repos/github/EOSIO/eosjs-fcbuffer/badge.svg?branch=master)](https://coveralls.io/github/EOSIO/eosjs-fcbuffer?branch=master)
[![NPM](https://img.shields.io/npm/v/fcbuffer.svg)](https://www.npmjs.org/package/fcbuffer)

# FC Buffer

Serialization library geared towards immutable data storage such as blockchains.

For EOS compatible implementation use this library from [eosjs](https://github.com/eosio/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 <Buffer 02 6a 63 07 63 68 61 72 6c 65 73 01 03 61 62 63 00 03 0f 0f 0f>

// 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](./src/types.js)
- EOS Definitions: [schema](https://github.com/EOSIO/eosjs-json/blob/master/schema)

# Environment

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

---
_Source: https://npm.io/package/fcbuffer · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._