stochastic-access-idb

stochastic-access-idb

random-access-compatible indexedDB storage layer

NB: This version is a fork of @substack's original random-access-idb that implements random-access-storage abstraction. It helps normalizing every random access instances and eases rai usage in modules like random-access-network.

Implements every random-access-storage method except unlink and suspend.

example

const SAI = require('stochastic-access-idb')
const random = SAI('dbname')
const cool = random('cool.txt')
cool.write(100, Buffer.from('GREETINGS'), function (err) {
  if (err) return console.error(err)
  cool.read(104, 3, function (err, buf) {
    if (err) return console.error(err)
    console.log(buf.toString()) // TIN
  })
})

api

const SAI = require('stochastic-access-idb')

var db = SAI(dbname, opts)(name)

Open an indexedDB database at dbname.

Any opts provided are forwarded to db(name, opts) as default options.

Create a handle file from name and opts. Options include:

{
  size: Number, // internal page size in bytes, default: 4096
}

You must keep opts.size the same after you've written data. If you change the size, bad things will happen.

file.read(offset, length, cb)

Read length bytes at an offset from file as cb(err, buf).

file.write(offset, buf, cb)

Write buf to file at an offset.

file.del(offset, size, [cb])

Delete the specified amount of bytes at the specified offset. Optionally pass a callback that is called with (err) when the delete has completed.

file.truncate(offset, [cb])

Truncate the storage at the specified offset. Optionally pass a callback that is called with (err) when the truncate has completed.

file.stat(cb)

Stat the storage, returns an object to callback including:

{
  size: Number, // total number of bytes in storage across all pages
}

file.open([cb])

Explicitly open the storage. If you do not call this yourself, it will automatically called before any read/write/del/stat operation.

file.close([cb])

Close the storage instance.

install

npm install stochastic-access-idb

license

BSD