#5 moves to slog

allgroup.go

@@ -2,6 +2,7 @@ package consumer
 
 import (
 	"context"
+	"log/slog"
 	"sync"
 	"time"
 
@@ -10,12 +11,12 @@ import (
 
 // NewAllGroup returns an initialized AllGroup for consuming
 // all shards on a stream
-func NewAllGroup(ksis kinesisClient, store Store, streamName string, logger Logger) *AllGroup {
+func NewAllGroup(kinesis kinesisClient, store Store, streamName string, logger *slog.Logger) *AllGroup {
 	return &AllGroup{
-		ksis:       ksis,
+		kinesis:    kinesis,
 		shards:     make(map[string]types.Shard),
 		streamName: streamName,
-		logger:     logger,
+		slog:       logger,
 		Store:      store,
 	}
 }
@@ -24,9 +25,9 @@ func NewAllGroup(ksis kinesisClient, store Store, streamName string, logger Logg
 // caches a local list of the shards we are already processing
 // and routinely polls the stream looking for new shards to process.
 type AllGroup struct {
-	ksis       kinesisClient
+	kinesis    kinesisClient
 	streamName string
-	logger     Logger
+	slog       *slog.Logger
 	Store
 
 	shardMu sync.Mutex
@@ -66,11 +67,11 @@ func (g *AllGroup) findNewShards(ctx context.Context, shardc chan types.Shard) {
 	g.shardMu.Lock()
 	defer g.shardMu.Unlock()
 
-	g.logger.Log("[GROUP]", "fetching shards")
+	g.slog.DebugContext(ctx, "fetch shards")
 
-	shards, err := listShards(ctx, g.ksis, g.streamName)
+	shards, err := listShards(ctx, g.kinesis, g.streamName)
 	if err != nil {
-		g.logger.Log("[GROUP] error:", err)
+		g.slog.ErrorContext(ctx, "list shards", slog.String("error", err.Error()))
 		return
 	}
 

consumer.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"log/slog"
 	"sync"
 	"time"
 
@@ -38,9 +39,7 @@ func New(streamName string, opts ...Option) (*Consumer, error) {
 		initialShardIteratorType: types.ShardIteratorTypeLatest,
 		store:                    &noopStore{},
 		counter:                  &noopCounter{},
-		logger: &noopLogger{
-			logger: log.New(io.Discard, "", log.LstdFlags),
-		},
+		logger:                   slog.New(slog.NewTextHandler(io.Discard, nil)),
 		scanInterval:             250 * time.Millisecond,
 		maxRecords:               10000,
 	}
@@ -75,7 +74,7 @@ type Consumer struct {
 	client                   kinesisClient
 	counter                  Counter
 	group                    Group
-	logger                   Logger
+	logger                   *slog.Logger
 	store                    Store
 	scanInterval             time.Duration
 	maxRecords               int64
@@ -154,9 +153,9 @@ func (c *Consumer) ScanShard(ctx context.Context, shardID string, fn ScanFunc) e
 		return fmt.Errorf("get shard iterator error: %w", err)
 	}
 
-	c.logger.Log("[CONSUMER] start scan:", shardID, lastSeqNum)
+	c.logger.DebugContext(ctx, "start scan", slog.String("shard-id", shardID), slog.String("last-sequence-number", lastSeqNum))
 	defer func() {
-		c.logger.Log("[CONSUMER] stop scan:", shardID)
+		c.logger.DebugContext(ctx, "stop scan", slog.String("shard-id", shardID))
 	}()
 
 	scanTicker := time.NewTicker(c.scanInterval)
@@ -170,12 +169,12 @@ func (c *Consumer) ScanShard(ctx context.Context, shardID string, fn ScanFunc) e
 
 		// attempt to recover from GetRecords error
 		if err != nil {
-			c.logger.Log("[CONSUMER] get records error:", err.Error())
-
 			if !isRetriableError(err) {
 				return fmt.Errorf("get records error: %v", err.Error())
 			}
 
+			c.logger.WarnContext(ctx, "get records", slog.String("error", err.Error()))
+
 			shardIterator, err = c.getShardIterator(ctx, c.streamName, shardID, lastSeqNum)
 			if err != nil {
 				return fmt.Errorf("get shard iterator error: %w", err)
@@ -216,7 +215,7 @@ func (c *Consumer) ScanShard(ctx context.Context, shardID string, fn ScanFunc) e
 			}
 
 			if isShardClosed(resp.NextShardIterator, shardIterator) {
-				c.logger.Log("[CONSUMER] shard closed:", shardID)
+				c.logger.DebugContext(ctx, "shard closed", slog.String("shard-id", shardID))
 
 				if c.shardClosedHandler != nil {
 					err := c.shardClosedHandler(c.streamName, shardID)

logger.go

@@ -1,20 +0,0 @@
-package consumer
-
-import (
-	"log"
-)
-
-// A Logger is a minimal interface to as an adaptor for external logging library to consumer
-type Logger interface {
-	Log(...interface{})
-}
-
-// noopLogger implements logger interface with discard
-type noopLogger struct {
-	logger *log.Logger
-}
-
-// Log using stdlib logger. See log.Println.
-func (l noopLogger) Log(args ...interface{}) {
-	l.logger.Println(args...)
-}

options.go

@@ -1,6 +1,7 @@
 package consumer
 
 import (
+	"log/slog"
 	"time"
 
 	"github.com/aws/aws-sdk-go-v2/service/kinesis/types"
@@ -24,7 +25,7 @@ func WithStore(store Store) Option {
 }
 
 // WithLogger overrides the default logger
-func WithLogger(logger Logger) Option {
+func WithLogger(logger *slog.Logger) Option {
 	return func(c *Consumer) {
 		c.logger = logger
 	}