function-cache

Cache serializable function calls results.

This module uses Promises (provided by Q).

Installation

npm install --save function-cache

Usage

var cache = require("function-cache");

function foo(param) {
console.log("foo has been called.");
return "Foo" + param;
}

var cachedFoo = cache(foo);

cachedFoo("Bar") // Prints "foo has been called." because no cache is available yet.
.then(function(result) {
console.log(result); // Prints "FooBar"

return cachedFoo("Bar"); // Prints nothing because the result is already cached.
})
.then(function(result) {
console.log(result); // Prints "FooBar"

return cachedFoo("Plop"); // Prints "foo has been called." because no cache is available yet for this argument.
})
.done();

Options

The cache function can take a second parameter :

var cachedFoo = cache(foo, {
tmpDir: os.tmpdir(),
useMemoryCache: true,
useFileCache: true,
serializer: JSON.stringify,
unserializer: JSON.parse,
hasher: farmhash.hash32,
tmpPrefix: "function-cache"
});

$3

If set to true, a memory cache is used.
Defaults to true.

$3

If set to true, files are written and read from the temporary directory.
Defaults to true.

$3

This is the path to the folder in which the cache files will be stored (if useFileCache == true).
Defaults to os.tmpdir().

$3

This is a prefix used in cache files names.
Defaults to "function-cache".

$3

A synchronous function to generate unique hash from given string.
Defaults to string-hash.

$3

A synchronous function to serialize function arguments and result for cache storage.
Defaults to JSON.stringify.

$3

A synchronous function to unserialize cached function arguments and result.
Defaults to JSON.parse.