govfs

A Virtual Filesystem Library written in the Go programming language. Please note that this project is still under heavy development.

Synopsis

The govfs Virtual Filesystem is a ext3/4 Unix-based heirarchy type filesystem which begins from the root folder "/". Each file is represented by a meta header which may be referenced in O(1) time, i.e. this filesystem does not use a linked list to create a filesystem "tree", but rather a hash-table which allows for the quick reference of files.

In addition, govfs makes use of golang's gothreads by implementing very quick read/writes. I.E. there is a thread dispatched for each write operation (assuming it is a different file). So writing 1000 files concurrently is possible without breaking the filesystem.

Since this is an in-memory file system, upon unmount the filesystem data is stored in a serialized stream. This, too, is concurrent. So for each file that contains data, a thread will be spawned that will perform compression on the file and serialization of the meta data.

Features

2^128 files
No file size limit
Concurrent reads/writes
O(1) reference time for finding a file header
Can print out file lists
File metadata serialization upon unmount (i.e. writing the entire filesystem to a physical file)
The filesystem file is OS independent
Creating one file will automatically create each subdirectory
Ideal for projects with heavy filesystem utilization
Compression and encryption of the raw filesystem file (unmounted file) is available

API

Main Filesystem Header

The FSHeader structure contains all data related to the virtual filesystem

type FSHeader struct {
    filename    string                             /* The raw file on disk */
    key         [16]byte                           /* RC4 key used to encrypt/decrypt the raw file */
    meta        map[string]*gofs_file              /* Hash table containing each file header */
    t_size      uint                               /* Total size of all files */
    [... Other structures/members omitted ...]
}

Create/Load Database

func CreateDatabase(name string, flags int) *FSHeader

Create New File

func (f *FSHeader) Create(name string) (*gofs_file, error)

Create I/O Reader

func (f *FSHeader) NewReader(name string) (*Reader, error)

Standard Read()

func (f *Reader) Read(p []byte) (int, error)

I/O Reader

func (f *FSHeader) Read(name string) ([]byte, error)

Delete File

func (f *FSHeader) Delete(name string) error

Write to a file

func (f *FSHeader) Write(name string, d []byte) error

Writer interface

type Writer struct {
    Name string
    File *gofs_file
    Hdr *FSHeader
}

New Writer method

func (f *FSHeader) NewWriter(name string) (*Writer, error)

Write method

func (f *Writer) Write(p []byte) (int, error)

Disclaimer

Please see the LICENSE file for the detailed MIT license. All work written by Stan Ruzin stan [dot] ruzin [at] gmail [dot] com

AlexRuzin/govfs