keymod

Documentation

Overview

Package keymod provides functions for modifying keys.

This package is particularly useful when working with distributed caching systems like Redis Cluster, where keys containing "{hashTag}" are ensured to exist on the same node. This allows related keys to be stored together, enabling multi-key operations like transactions and Lua scripts.

Index

• func Modify(key string, modifiers ...Mod) string
• type Mod
  • func WithChain(modifiers ...Mod) Mod
  • func WithHashTag(text string) Mod
  • func WithPrefix(prefix string, separator string) Mod
  • func WithSuffix(suffix string, separator string) Mod

Functions

func Modify

func Modify(key string, modifiers ...Mod) string

Modify applies the given Mod functions to a key.

This can be used to apply multiple modifications to a key, such as adding a prefix and a hash tag.

Example:

key := Modify("profile", PrefixModifier("user123", ":"), HashTagModifier("user123")) // "{user123}user123:profile"

Types

type Mod

type Mod func(string) string

Mod is a function that modifies a key.

This can be used to add prefixes, suffixes, or hash tags to keys.

func WithChain

func WithChain(modifiers ...Mod) Mod

WithChain chains multiple Mod functions together into a single Mod.

This can be used to create complex key modifications in a more readable way.

Example:

modifier := WithChain(PrefixModifier("user123", ":"), HashTagModifier("user123"))
key := modifier("profile") // "{user123}user123:profile"

func WithHashTag

func WithHashTag(text string) Mod

WithHashTag wraps the given text in curly braces and prepends it to the key.

This is useful when working with Redis Cluster, as keys with the same hash tag are guaranteed to be on the same node. This allows for multi-key operations to be performed atomically.

Example:

userHashTagModifier := WithHashTag("user123")
userKey := userHashTagModifier("profile") // "{user123}profile"

func WithPrefix

func WithPrefix(prefix string, separator string) Mod

WithPrefix prepends the given prefix to the key.

This is useful when working with namespaced keys, where the prefix represents a namespace. The separator is used to separate the prefix from the key.

Example:

userPrefixModifier := WithPrefix("user123", ":")
userKey := userPrefixModifier("profile") // "user123:profile"

func WithSuffix

func WithSuffix(suffix string, separator string) Mod

WithSuffix appends the given suffix to the key.

This is useful when working with namespaced keys, where the suffix represents a namespace. The separator is used to separate the key from the suffix.

Example:

userSuffixModifier := WithSuffix("profile", ":")
userKey := userSuffixModifier("user123") // "user123:profile"