"use strict";
module.exports = function(UNICACHE) {
var PROTO = 'prototype', _ = UNICACHE._, fs = require('fs');
var FileCache = UNICACHE.FileCache = function() { };
// extend UNICACHE.Cache class
FileCache[PROTO] = Object.create(UNICACHE.Cache[PROTO]);
FileCache.isSupported = function() {
return true;
};
FileCache[PROTO].encoding = 'utf8';
FileCache[PROTO].cachedir = '';
FileCache[PROTO].supportsSync = function() {
// can read/write/etc using sync operations as well
return true;
};
FileCache[PROTO].put = function(key, data, ttl, cb) {
// write sync or async here
ttl = +ttl;
if ('function' === typeof cb)
{
fs.writeFile(this.getFileName(key), _.serialize([_.time() + ttl, data]), {encoding:this.encoding}, function(err) {
cb(err, err ? false : true);
});
}
else
{
fs.writeFileSync(this.getFileName(key), _.serialize([_.time() + ttl, data]), {encoding:this.encoding});
}
};
FileCache[PROTO].get = function(key, cb) {
// read sync or async here
var file = this.getFileName(key);
if ('function' === typeof cb)
{
fs.readFile(file, {encoding:this.encoding}, function(err, data) {
if (err || !data)
{
cb(err, false);
}
else
{
data = _.unserialize(''+data);
if (!data || (_.time() > data[0]))
{
// Unlinking when the file was expired
fs.unlink(file, function(err) {});
cb(null, false);
}
else
{
cb(null, data[1]);
}
}
});
}
else
{
var data = _.unserialize(''+fs.readFileSync(file, {encoding:this.encoding}));
if (!data || (_.time() > data[0]))
{
// Unlinking when the file was expired
// use async here as we do not need to wait, whenever it finishes it is fine
fs.unlink(file, function(err) {});
return false;
}
return data[1];
}
};
FileCache[PROTO].remove = function(key, cb) {
// remove sync or async here
var filename = this.getFileName(key);
if ('function' === typeof cb)
{
fs.unlink(filename, function(err) {
cb(err, err ? false : true);
});
}
else
{
fs.unlinkSync(filename);
return true;
}
};
FileCache[PROTO].clear = function(cb) {
// clear sync or async here
if ('function' === typeof cb)
{
var self = this;
fs.readdir(this.cachedir, function(err, files) {
if (err || !files || !files.length)
{
// return true with a small delay to finish all files
setTimeout(function() {cb(err, err ? false : true);}, 10);
return;
}
var pl = self.prefix.length, filename, file, i, l;
for (i=0,l=files.length; i<l; ++i)
{
filename = files[i];
if (pl && (0 !== filename.indexOf(self.prefix))) continue;
file = self.cachedir + '/' + filename;
fs.lstat(file, (function(file) {
// closure
return function(err, stat) {
if (!err && stat.isFile())
{
// delete
fs.unlink(file, function(err) {});
}
};
})(file));
}
// return true with a small delay to finish all files
setTimeout(function() {cb(null, true);}, 10);
});
}
else
{
var files = fs.readdirSync(this.cachedir), pl = this.prefix.length,
file, filename, i, l, stat;
if (!files || !files.length) return true;
for (i=0,l=files.length; i<l; ++i)
{
filename = files[i];
if (pl && (0 !== filename.indexOf(this.prefix))) continue;
file = this.cachedir + '/' + filename;
stat = fs.lstatSync(file);
if (stat && stat.isFile())
{
// expired, delete
fs.unlinkSync(file);
}
}
return true;
}
};
FileCache[PROTO].gc = function(maxlifetime, cb) {
// use async here by default as we do not need to wait, whenever it finishes it is fine
maxlifetime = +maxlifetime;
var self = this, currenttime = _.time();
fs.readdir(this.cachedir, function(err, files) {
if (err || !files || !files.length) return;
var pl = self.prefix.length, filename, file, i, l;
for (i=0,l=files.length; i<l; ++i)
{
filename = files[i];
if (pl && (0 !== filename.indexOf(self.prefix))) continue;
file = self.cachedir + '/' + filename;
fs.lstat(file, (function(file) {
// closure
return function(err, stat) {
if (!err && stat.isFile()) {
var mtime = stat.mtime;
if (!mtime) return;
if (mtime < currenttime-maxlifetime)
{
// expired, delete
fs.unlink(file, function(err) {});
}
}
};
})(file));
}
});
if ('function' === typeof cb)
{
// return true with a small delay to finish all files
setTimeout(function() {cb(null, true);}, 100);
}
else
{
return true;
}
};
FileCache[PROTO].setEncoding = function(encoding) {
this.encoding = !!encoding ? (''+encoding) : 'utf8';
return this;
};
FileCache[PROTO].setCacheDir = function(dir) {
// use sync here by default as it is needed immediately on initialization
this.cachedir = _.rtrim(dir, '/\\');
if (!fs.existsSync(this.cachedir))
fs.mkdirSync(this.cachedir, {recursive:true, mode:parseInt('0755', 8)}); // recursive
return this;
};
FileCache[PROTO].getFileName = function(key) {
return this.cachedir + '/' + this.prefix + _.md5(key);
};
return FileCache;
};
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