sf-filecache

Simple and smart FS based cache system.

sf-filecache exists for two purposes:

• having a streameable fs based cache system
• opening only one file descriptor for cache queries

Usage

Buffer based:

var FileCache = require('sf-filecache');

var filecache = new FileCache();

var endOfLife = Date.now() + 36000;

// Set a value in the filecache for the 'plop' key
fileCache.set('plop', new Buffer('plop!'), endOfLife, function(err) {
  if(err) {
    throw err;
  }
  // Retrieve it
  fileCache.get('plop', function(err, data) {
    if(err) {
      return done(err);
    }
    console.log(data.toString()); // plop!
    done();
  });

});

Stream based:

var FileCache = require('sf-filecache');

var filecache = new FileCache();

var endOfLife = Date.now() + 36000;

// Set a stream content in the filecache for the 'plop' key
fileCache.setStream('plop', fs.createReadStream('file'), endOfLife, function(err) {
  if(err) {
    throw err;
  }
  // Retrieve it
  fileCache.getStream('plop', function(err, stream) {
    if(err) {
      return done(err);
    }
    stream.pipe(process.stdout); // plop!
    done();
  });

});

API

FileCache(options)

FileCache constructor

Kind: global function
Api: public

| Param | Type | Description | | --- | --- | --- | | options | Object | Options of the cache (dir, domain and clock) |

• FileCache(options)
  • ._keyToPath(key) ⇒ String
  • ._createHeader(header) ⇒ Buffer
  • ._readHeader(data) ⇒ Object
  • .get(key, cb) ⇒ void
  • .getStream(key, cb) ⇒ void
  • .set(key, data, eol, cb) ⇒ void
  • .setStream(key, stream, eol, cb) ⇒ void
  • .setEOL(key, eol, cb) ⇒ void

fileCache._keyToPath(key) ⇒ String

Transform a key into a path were to save/read the contents

Kind: instance method of FileCache
Returns: String - The computed path
Api: private

| Param | Type | Description | | --- | --- | --- | | key | String | The key to transform |

fileCache._createHeader(header) ⇒ Buffer

Create a bucket header

Kind: instance method of FileCache
Returns: Buffer - The header contents as a buffer
Api: private

| Param | Type | Description | | --- | --- | --- | | header | Object | Header description |

fileCache._readHeader(data) ⇒ Object

Read the header description from a buffer

Kind: instance method of FileCache
Returns: Object - The header description

| Param | Type | Description | | --- | --- | --- | | data | Buffer | The buffer |

fileCache.get(key, cb) ⇒ void

Get cached data for the given key

Kind: instance method of FileCache

| Param | Type | Description | | --- | --- | --- | | key | String | The key | | cb | function | The callback ( signature function(err:Error, data:Buffer) {}) |

fileCache.getStream(key, cb) ⇒ void

Get cached data as a stream for the given key

Kind: instance method of FileCache

| Param | Type | Description | | --- | --- | --- | | key | String | The key | | cb | function | The callback ( signature function(err:Error, stream:ReadableStream) {}) |

fileCache.set(key, data, eol, cb) ⇒ void

Set cached data at the given key

Kind: instance method of FileCache

| Param | Type | Description | | --- | --- | --- | | key | String | The key | | data | Buffer | The data to store | | eol | Number | The resource invalidity timestamp | | cb | function | The callback ( signature function(err:Error) {}) |

fileCache.setStream(key, stream, eol, cb) ⇒ void

Set cached data via a stream at the given key

Kind: instance method of FileCache

| Param | Type | Description | | --- | --- | --- | | key | String | The key | | stream | ReadableStream | The data to store as a readable stream | | eol | Number | The resource invalidity timestamp | | cb | function | The callback ( signature function(err:Error) {}) |

fileCache.setEOL(key, eol, cb) ⇒ void

Set end of life to the given key

Kind: instance method of FileCache

| Param | Type | Description | | --- | --- | --- | | key | String | The key | | eol | Number | The resource invalidity timestamp | | cb | function | The callback ( signature function(err:Error) {}) |