feat: Add log options (#10)

buffer.go

@@ -29,12 +29,12 @@ func bufferBatchRefresh[T any](c *Client[T], ids []string, keyFn KeyFn, fetchFn
 		c.batchMutex.Unlock()
 
 		// These IDs are the size we want, so we'll refresh them immediately.
-		safeGo(func() {
+		c.safeGo(func() {
 			c.refreshBatch(idsToRefresh, keyFn, fetchFn)
 		})
 
 		// We'll continue to process the remaining IDs recursively.
-		safeGo(func() {
+		c.safeGo(func() {
 			bufferBatchRefresh(c, overflowingIDs, keyFn, fetchFn)
 		})
 
@@ -55,7 +55,7 @@ func bufferBatchRefresh[T any](c *Client[T], ids []string, keyFn KeyFn, fetchFn
 		case channel <- ids:
 			stop()
 		case <-timer:
-			safeGo(func() {
+			c.safeGo(func() {
 				bufferBatchRefresh(c, ids, keyFn, fetchFn)
 			})
 			return
@@ -70,7 +70,7 @@ func bufferBatchRefresh[T any](c *Client[T], ids []string, keyFn KeyFn, fetchFn
 	c.bufferPermutationIDs[permutationString] = ids
 	c.batchMutex.Unlock()
 
-	safeGo(func() {
+	c.safeGo(func() {
 		timer, stop := c.clock.NewTimer(c.bufferTimeout)
 
 		for {
@@ -87,7 +87,7 @@ func bufferBatchRefresh[T any](c *Client[T], ids []string, keyFn KeyFn, fetchFn
 				deleteBuffer(c, permutationString)
 				c.batchMutex.Unlock()
 
-				safeGo(func() {
+				c.safeGo(func() {
 					c.refreshBatch(permIDs, keyFn, fetchFn)
 				})
 				return
@@ -121,13 +121,13 @@ func bufferBatchRefresh[T any](c *Client[T], ids []string, keyFn KeyFn, fetchFn
 				overflowingIDs := permIDs[c.bufferSize:]
 
 				// Refresh the first batch of IDs immediately.
-				safeGo(func() {
+				c.safeGo(func() {
 					c.refreshBatch(idsToRefresh, keyFn, fetchFn)
 				})
 
 				// If we exceeded the batch size, we'll continue to process the remaining IDs recursively.
 				if len(overflowingIDs) > 0 {
-					safeGo(func() {
+					c.safeGo(func() {
 						bufferBatchRefresh(c, overflowingIDs, keyFn, fetchFn)
 					})
 				}

cache.go

@@ -2,6 +2,7 @@ package sturdyc
 
 import (
 	"context"
+	"log/slog"
 	"sync"
 	"time"
 
@@ -36,6 +37,7 @@ type Config struct {
 	clock            Clock
 	evictionInterval time.Duration
 	metricsRecorder  MetricsRecorder
+	log              Logger
 
 	refreshInBackground bool
 	minRefreshTime      time.Duration
@@ -84,6 +86,7 @@ func New[T any](capacity, numShards int, ttl time.Duration, evictionPercentage i
 		clock:            NewClock(),
 		evictionInterval: ttl / time.Duration(numShards),
 		getSize:          client.Size,
+		log:              slog.Default(),
 	}
 	// Apply the options to the configuration.
 	client.Config = cfg

fetch.go

@@ -43,7 +43,7 @@ func (c *Client[T]) GetFetch(ctx context.Context, key string, fetchFn FetchFn[T]
 	value, ok, shouldIgnore, shouldRefresh := c.get(key)
 
 	if shouldRefresh {
-		safeGo(func() {
+		c.safeGo(func() {
 			c.refresh(key, fetchFn)
 		})
 	}
@@ -74,7 +74,7 @@ func (c *Client[T]) GetFetchBatch(ctx context.Context, ids []string, keyFn KeyFn
 
 	// If any records need to be refreshed, we'll do so in the background.
 	if len(idsToRefresh) > 0 {
-		safeGo(func() {
+		c.safeGo(func() {
 			if c.bufferRefreshes {
 				bufferBatchRefresh(c, idsToRefresh, keyFn, fetchFn)
 				return

keys.go

@@ -86,15 +86,20 @@ func (c *Client[T]) handleStruct(permutationStruct interface{}) string {
 	}
 
 	if v.Kind() != reflect.Struct {
-		panic("val must be a struct")
+		panic("permutationStruct must be a struct")
 	}
 
 	for i := 0; i < v.NumField(); i++ {
 		field := v.Field(i)
 
-		// Check if the field is exported
+		// Skip unexported fields
 		if !field.CanInterface() {
-			continue // Skip unexported fields
+			message := fmt.Sprintf(
+				"sturdyc: permutationStruct contains unexported field: %s which won't be part of the cache key",
+				v.Type().Field(i).Name,
+			)
+			c.log.Warn(message)
+			continue
 		}
 
 		if i > 0 {

log.go

@@ -0,0 +1,11 @@
+package sturdyc
+
+type Logger interface {
+	Warn(msg string, args ...any)
+	Error(msg string, args ...any)
+}
+
+type NoopLogger struct{}
+
+func (l *NoopLogger) Warn(_ string, _ ...any)  {}
+func (l *NoopLogger) Error(_ string, _ ...any) {}

options.go

@@ -66,6 +66,15 @@ func WithRelativeTimeKeyFormat(truncation time.Duration) Option {
 	}
 }
 
+// WithLog allows you to set a custom logger for the cache. The cache isn't chatty,
+// and will only log warnings and errors that would be a nightmare to debug. If you
+// absolutely don't want any logs, you can pass in the sturydc.NoopLogger.
+func WithLog(log Logger) Option {
+	return func(c *Config) {
+		c.log = log
+	}
+}
+
 // validateConfig is a helper function that panics if the cache has been configured incorrectly.
 func validateConfig(capacity, numShards int, ttl time.Duration, evictionPercentage int, cfg *Config) {
 	if capacity <= 0 {

safe.go

@@ -2,19 +2,16 @@ package sturdyc
 
 import (
 	"context"
-	"log/slog"
+	"fmt"
 )
 
 // safeGo is a helper that prevents panics in any of the goroutines
 // that are running in the background from crashing the process.
-func safeGo(fn func()) {
+func (c *Client[T]) safeGo(fn func()) {
 	go func() {
 		defer func() {
 			if err := recover(); err != nil {
-				// If we ever reach here it's because one of the functions that the user
-				// passed us panicked. I don't think packages should log like this, but
-				// failing silently here would make it an absolute nightmare to debug.
-				slog.Error("panic recovered: %v", err)
+				c.log.Error(fmt.Sprintf("sturdyc: panic recovered: %v", err))
 			}
 		}()
 		fn()