1 files changed, 55 insertions, 0 deletions
diff --git a/weed/mq/kafka/partition_mapping.go b/weed/mq/kafka/partition_mapping.go
new file mode 100644
index 000000000..697e67386
--- /dev/null
+++ b/weed/mq/kafka/partition_mapping.go
@@ -0,0 +1,55 @@
+package kafka
+
+import (
+	"github.com/seaweedfs/seaweedfs/weed/mq/pub_balancer"
+	"github.com/seaweedfs/seaweedfs/weed/pb/schema_pb"
+)
+
+// Convenience functions for partition mapping used by production code
+// The full PartitionMapper implementation is in partition_mapping_test.go for testing
+
+// MapKafkaPartitionToSMQRange maps a Kafka partition to SeaweedMQ ring range
+func MapKafkaPartitionToSMQRange(kafkaPartition int32) (rangeStart, rangeStop int32) {
+	// Use a range size that divides evenly into MaxPartitionCount (2520)
+	// Range size 35 gives us exactly 72 Kafka partitions: 2520 / 35 = 72
+	rangeSize := int32(35)
+	rangeStart = kafkaPartition * rangeSize
+	rangeStop = rangeStart + rangeSize - 1
+	return rangeStart, rangeStop
+}
+
+// CreateSMQPartition creates a SeaweedMQ partition from a Kafka partition
+func CreateSMQPartition(kafkaPartition int32, unixTimeNs int64) *schema_pb.Partition {
+	rangeStart, rangeStop := MapKafkaPartitionToSMQRange(kafkaPartition)
+
+	return &schema_pb.Partition{
+		RingSize:   pub_balancer.MaxPartitionCount,
+		RangeStart: rangeStart,
+		RangeStop:  rangeStop,
+		UnixTimeNs: unixTimeNs,
+	}
+}
+
+// ExtractKafkaPartitionFromSMQRange extracts the Kafka partition from SeaweedMQ range
+func ExtractKafkaPartitionFromSMQRange(rangeStart int32) int32 {
+	rangeSize := int32(35)
+	return rangeStart / rangeSize
+}
+
+// ValidateKafkaPartition validates that a Kafka partition is within supported range
+func ValidateKafkaPartition(kafkaPartition int32) bool {
+	maxPartitions := int32(pub_balancer.MaxPartitionCount) / 35 // 72 partitions
+	return kafkaPartition >= 0 && kafkaPartition < maxPartitions
+}
+
+// GetRangeSize returns the range size used for partition mapping
+func GetRangeSize() int32 {
+	return 35
+}
+
+// GetMaxKafkaPartitions returns the maximum number of Kafka partitions supported
+func GetMaxKafkaPartitions() int32 {
+	return int32(pub_balancer.MaxPartitionCount) / 35 // 72 partitions
+}
+
+