https://github.com/heapwolf/skipfile

Append data, seek forward and seek backward inside a binary file.
https://github.com/heapwolf/skipfile

Last synced: 25 days ago
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Append data, seek forward and seek backward inside a binary file.

• Host: GitHub
• URL: https://github.com/heapwolf/skipfile
• Owner: heapwolf
• Created: 2014-08-08T23:13:15.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2018-12-22T15:06:41.000Z (almost 6 years ago)
• Last Synced: 2024-04-14T22:13:32.144Z (7 months ago)
• Language: JavaScript
• Size: 27.3 KB
• Stars: 10
• Watchers: 4
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# SYNOPSIS

Append only binary data file store.

# FORMAT

Each block consists of a `sequence` (index), a `length` (length) and a

chunk of variable length of data. Because of this, only the sequence and

length need to be read, making it possible to "skip" through the file to

find a specific sequence. Both sequence and length are encoded as varints.

```

[SEQUENCE][LENGTH][DATA...]...

```

# API

## CONSTRUCTOR

The constructor accepts an options object. `{ filename: path }` specifies the

target file to read and write to.

```js

const { err, handle } = await new Skipfile()

```

## INSTANCE METHODS

Instance methods do not throw, they return an object which may contain `{ err }`.

### async append(value)

Appends a value to the file specified in the constructor.

```js

const { err, bytesWritten } = await handle.append(Buffer.from('Hello, world'))

```

### async next(bytes)

Iterate forward.

```js

while (true) {

  const { err, buffer, index } = await handle.next()

  if (err || !buffer) {

    break

  }

  console.log(buffer.toString())

}

```

### async seek(index)

TODO

```js

const { err, buffer } = await handle.seek(index)

```

### async close()

Closes the file descriptor opened by the constructor.

```javascript

await skip.close()

```

## INSTANCE MEMBERS

### size

Tracks the size of the file opened by the constructor.