@metarhia/filestorage

FileStorage

FileStorage is a library that allows to easily store a large number of binary files. Data will be spread across the file tree to optimize read and write speeds and can be accessed by a unique id. Large files can be compressed using either ZIP or GZIP and automatically decompressed on reading.

It is strongly recommended to use filestorage.create to get new FileStorage instance because it will also create a root directory if it does not yet exist in the file system.

Example with existing directory:

const { FileStorage } = require('filestorage');

const storage = new FileStorage({ dir: './root-directory', minCompressSize: 2048 });

Example with create:

const { create } = require('filestorage');

create({ dir: './root' }, (err, storage) => { ... });

Interface: filestorage

Create new FileStorage

FileStorage(options)

• options: <Object>
  • dir: <string> data storage directory, which should be created before FileStorage is used
  • minCompressSize: <number> minimal file size to be compressed, default = 1024

Write file to storage

FileStorage.prototype.write(id, data, opts, cb)

• id <common.Uint64>id of file
• data: <string>|<Uint8Array> <Buffer>data to be written
• opts: <Object>
  • checksum: <string> checksum type
  • dedupHash: <string> second checksum type
• cb: <Function> callback
  • err: <Error>
  • stats: <Object>
    • checksum: <string> data checksum
    • dedupHash: <string> second data checksum
    • size: <number> data size

Throws: <TypeError> if opts.checksum or opts.dedupHash is incorrect

Update or write file in the storage

FileStorage.prototype.update(id, data, opts, cb)

• id <common.Uint64>id of file
• data: <string>|<Uint8Array> <Buffer>data to be written
• opts: <Object>
  • checksum: <string> checksum type
  • dedupHash: <string> second checksum type
• cb: <Function> callback
  • err: <Error>
  • stats: <Object>
    • checksum: <string> data checksum
    • dedupHash: <string> second data checksum
    • size: <number> data size
    • originalSize: <number> size of original file

Throws: <TypeError> if opts.checksum or opts.dedupHash is incorrect

Get information about file

FileStorage.prototype.stat(id, cb)

• id <common.Uint64>id of file
• cb: <Function> callback
  • err: <Error>
  • stats <fs.Stats>

Read file from storage

FileStorage.prototype.read(id, opts, cb)

• id <common.Uint64>id of file
• opts: <Object>
  • encoding: <string>
  • compression: <string>
• cb: <Function> callback
  • err: <Error>
  • data: <string> <Buffer>

Delete file from storage

FileStorage.prototype.rm(id, cb)

• id <common.Uint64>id of file
• cb: <Function> callback
  • err: <Error>

Compress file in storage

FileStorage.prototype.compress(id, compression, cb)

• id <common.Uint64>id of file
• compression: <string> compression type
• cb: <Function> callback
  • err: <Error>
  • compressed: <boolean> whether file was compressed

Throws: <TypeError> if compression is incorrect

Create new Filestorage and root directory if it doesn't exits

create(options, cb)

• options: <Object>
  • dir: <string> data storage directory
  • minCompressSize: <number> minimal file size to be compressed
• cb: <Function> callback
  • err: <Error>
  • storage <FileStorage>