cache

README

cache

I got tired of rewriting HTTP response caching logic for all my microservices so I hacked together this library that saves HTTP responses as local .txt files containing JSON data. cache is smart enough to return the contents of the cache file if it's only been a bit since the last call to that endpoint (cache filenames are generated as a hash of the HTTP method, URL, and headers). If the cache is expired, it remakes the call, saves the response to a file, and returns the contents either as a string or a struct.

Installation

go get github.com/jessemillar/cache

Usage

import "github.com/jessemillar/cache"

See cache_test.go for usage examples.

Documentation

Index

• func BasicHttpRequestReturnStruct(httpMethod string, url string, target interface{}) (int, error)
• func BasicHttpRequestWithNameReturnStruct(httpMethod string, url string, cacheName string, target interface{}) (int, error)
• func GetCacheAndStalenessReturnStruct(cacheFilename string, cacheTTLOverride time.Duration, allowCacheUpdate bool, ...) (bool, error)
• func GetCacheFileAsString(filename string) (string, error)
• func GetCacheFileAsStruct(filename string, target interface{}) error
• func HttpRequestReturnStruct(httpMethod string, url string, headers map[string][]string, ...) (int, error)
• func HttpRequestReturnStructWithName(httpMethod string, url string, headers map[string][]string, ...) (int, error)
• func WriteStringToCacheFile(filename string, value string) error
• func WriteStructToCacheFile(filename string, rawStruct interface{}) error
• type Response
  • func BasicHttpRequest(httpMethod string, url string) (Response, error)
  • func BasicHttpRequestWithName(httpMethod string, url string, cacheName string) (Response, error)
  • func GetCacheAndStaleness(cacheFilename string, cacheTTLOverride time.Duration, allowCacheUpdate bool) (Response, bool, error)
  • func HttpRequest(httpMethod string, url string, headers map[string][]string, ...) (Response, error)
  • func HttpRequestWithName(httpMethod string, url string, headers map[string][]string, ...) (Response, error)

Functions

func BasicHttpRequestReturnStruct

func BasicHttpRequestReturnStruct(httpMethod string, url string, target interface{}) (int, error)

BasicHttpRequestReturnStruct makes a request with default parameters

func BasicHttpRequestWithNameReturnStruct

func BasicHttpRequestWithNameReturnStruct(httpMethod string, url string, cacheName string, target interface{}) (int, error)

NamedHttpRequestReturnStruct makes a request with a custom cache name and returns the result as a struct

func GetCacheAndStalenessReturnStruct

func GetCacheAndStalenessReturnStruct(cacheFilename string, cacheTTLOverride time.Duration, allowCacheUpdate bool, target interface{}) (bool, error)

GetCacheAndStalenessReturnStruct is the same as GetCacheAndStaleness but it returns the result as a specified struct. GetCacheAndStalenessReturnStruct returns the contents of the cache file as a struct and whether or not the cache is stale (this does not make an HTTP request)

func GetCacheFileAsString

func GetCacheFileAsString(filename string) (string, error)

GetCacheFileAsString reads the content of a file and returns it as a string.

func GetCacheFileAsStruct

func GetCacheFileAsStruct(filename string, target interface{}) error

GetCacheFileAsStruct reads the content of a file, unmarshals it as JSON into the target structure.

func HttpRequestReturnStruct

func HttpRequestReturnStruct(httpMethod string, url string, headers map[string][]string, cacheTTLOverride time.Duration, allowCacheUpdate bool, target interface{}) (int, error)

HttpRequestReturnStruct is the same as HttpRequest but it returns the result as a specified struct. HttpRequest sends an HTTP request to the specified URL and returns the HTTP response. The response is cached for a duration specified by cacheTTL. If cacheTTLOverride is zero, the default cache TTL value is used.

func HttpRequestReturnStructWithName

func HttpRequestReturnStructWithName(httpMethod string, url string, headers map[string][]string, cacheTTLOverride time.Duration, allowCacheUpdate bool, customCacheName string, target interface{}) (int, error)

HttpRequestReturnStructWithName is the same as HttpRequest but it returns the result as a specified struct. HttpRequest sends an HTTP request to the specified URL and returns the HTTP response. The response is cached for a duration specified by cacheTTL. If cacheTTLOverride is zero, the default cache TTL value is used. If customCacheName is provided, it will be used as the cache filename instead of generating a hash from the request.

func WriteStringToCacheFile

func WriteStringToCacheFile(filename string, value string) error

func WriteStructToCacheFile

func WriteStructToCacheFile(filename string, rawStruct interface{}) error

Types

type Response

type Response struct {
	StatusCode int    `json:"status"`
	Body       string `json:"body"`
}

func BasicHttpRequest

func BasicHttpRequest(httpMethod string, url string) (Response, error)

BasicHttpRequest makes a request with default parameters

func BasicHttpRequestWithName

func BasicHttpRequestWithName(httpMethod string, url string, cacheName string) (Response, error)

NamedHttpRequest makes a request with a custom cache name

func GetCacheAndStaleness

func GetCacheAndStaleness(cacheFilename string, cacheTTLOverride time.Duration, allowCacheUpdate bool) (Response, bool, error)

GetCacheAndStaleness returns the contents of the cache file and whether or not the cache is stale (this does not make an HTTP request)

func HttpRequest

func HttpRequest(httpMethod string, url string, headers map[string][]string, cacheTTLOverride time.Duration, allowCacheUpdate bool) (Response, error)

HttpRequest sends an HTTP request to the specified URL and returns the HTTP response. The response is cached for a duration specified by cacheTTL. If cacheTTLOverride is zero, the default cache TTL value is used.

func HttpRequestWithName

func HttpRequestWithName(httpMethod string, url string, headers map[string][]string, cacheTTLOverride time.Duration, allowCacheUpdate bool, customCacheName string) (Response, error)

HttpRequestWithName sends an HTTP request to the specified URL and returns the HTTP response. The response is cached for a duration specified by cacheTTL. If cacheTTLOverride is zero, the default cache TTL value is used. If customCacheName is provided, it will be used as the cache filename instead of generating a hash from the request.