cachefunk

cachefunk

Use wrapper functions to cache function output in golang.

Features

• Currently supported cache adapters:
  • any GORM-supported database
  • in-memory caching
• Configurable TTL and TTL jitter
• Cleanup function for periodic removal of expired entries
• Uses go generics, in IDE type checked parameters and result
• Can ignore cached values

Getting Started

Dependencies

• go version that supports generics (tested on v1.19)

Installing

go get -u github.com/rohfle/cachefunk

Example

import (
	"fmt"
	"testing"
	"time"

	"github.com/rohfle/cachefunk"

	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
)


func main() {
	type HelloWorldParams struct {
		Name string
	}

	db, err := gorm.Open(sqlite.Open("file::memory:?cache=shared"), &gorm.Config{})
	if err != nil {
		panic("failed to connect database")
	}

	cache := cachefunk.NewGORMCache(db)

    // Define a function
	// ignoreCache is passed through if the function calls other wrapped functions.
	// Note that the only other argument supported currently is params.
	// This params argument can be any value (typically a struct) that can be serialized into JSON
	// WrapString is used to wrap this function, so it must return string or []byte
	helloWorld := func(ignoreCache bool, params *HelloWorldParams) (string, error) {
		return "Hello " + params.Name, nil
	}

    // Wrap the function
	HelloWorld := cachefunk.WrapString(helloWorld, cache, cachefunk.Config{
		Key: "hello",
		TTL: 3600,
	})

	// First call will get value from wrapped function
	value, err := HelloWorld(false, &HelloWorldParams{
		Name: "bob",
	})
	fmt.Println("First call:", value, err)

	// Second call will get value from cache
	value, err = HelloWorld(false, &HelloWorldParams{
		Name: "bob",
	})
	fmt.Println("Second call:", value, err)
}

API

• WrapString: store the result as []byte
• Wrap: encode as JSON and then store the result as []byte

Dreams for the Future

• "Unvariadicize" to allow
  • passing through set number of args
  • through wrapper which caches using variadic
  • to wrapped function that takes set number of non-variadic args
• Export wrapped functions at the package level more easily
• Allow generic methods on types

Version History

• 0.1
  • Initial Release

License

© Rohan Fletcher 2023

This project is licensed under the MIT License - see the LICENSE file for details