68 lines
1.9 KiB
Go
68 lines
1.9 KiB
Go
// Package cache implement a simple cache redis client.
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// It define a type [Cache] that represent the cache client and
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// It define the methods Get to get a valur from a cache key.
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package cache
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import (
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"context"
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"errors"
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"fmt"
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"github.com/go-redis/redis/v8"
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"go.uber.org/zap"
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)
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var (
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ErrCacheNotEnabled = errors.New("CACHE NOT ENABLED")
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ErrNotFound = errors.New("KEY NOT FOUND IN CACHE")
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ErrInternal = errors.New("INTERNAL CACHE ERROR")
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)
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// CacheClient redis cache client.
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type CacheClient struct {
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Client *redis.Client
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Enabled bool
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logger *zap.Logger
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}
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// CacheReadable is the interface for notiona cache client.
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type CacheReadable interface {
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Get(ctx context.Context, key string) (string, error)
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Close() error
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}
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type CacheGetFunc func(ctx context.Context, key string) (string, error)
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// NewCacheClient init a new cache client.
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func NewCacheClient(redisClient *redis.Client, enabled bool, log *zap.Logger) (*CacheClient, error) {
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if redisClient == nil {
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return nil, errors.New("redis client is nil")
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}
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return &CacheClient{Client: redisClient, Enabled: enabled, logger: log}, nil
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}
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// Get get a cache value or error from a key.
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// If the cache is not enabled, the error value
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// If the cache not contain a value from a key, the error value errors.ErrNotFound is returned.
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// If exist some internal error in the cache, the error value errros.ErrInternalError is returned.
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func (c *CacheClient) Get(ctx context.Context, key string) (string, error) {
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if !c.Enabled {
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return "", ErrCacheNotEnabled
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}
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value, err := c.Client.Get(ctx, key).Result()
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if err != nil {
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if err != redis.Nil {
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requestID := fmt.Sprintf("%v", ctx.Value("requestid"))
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c.logger.Error("key does not exist in cache",
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zap.Error(err), zap.String("key", key), zap.String("requestID", requestID))
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return "", ErrNotFound
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}
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return "", ErrInternal
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}
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return value, nil
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}
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func (c *CacheClient) Close() error {
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return c.Client.Close()
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}
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