fix(go): update stats field and its deserialization logic to align with rust SDK

examples/go/go.sum

@@ -2,6 +2,8 @@ github.com/avast/retry-go/v5 v5.0.0 h1:kf1Qc2UsTZ4qq8elDymqfbISvkyMuhgRxuJqX2NHP
 github.com/avast/retry-go/v5 v5.0.0/go.mod h1://d+usmKWio1agtZfS1H/ltTqwtIfBnRq9zEwjc3eH8=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
+github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/klauspost/compress v1.18.5 h1:/h1gH5Ce+VWNLSWqPzOVn6XBO+vJbCNGvjoaGBFW2IE=

foreign/go/client/tcp/tcp_utilities.go

@@ -18,7 +18,6 @@
 package tcp
 
 import (
-	binaryserialization "github.com/apache/iggy/foreign/go/binary_serialization"
 	iggcon "github.com/apache/iggy/foreign/go/contracts"
 	"github.com/apache/iggy/foreign/go/internal/command"
 )
@@ -29,10 +28,10 @@ func (c *IggyTcpClient) GetStats() (*iggcon.Stats, error) {
 		return nil, err
 	}
 
-	stats := &binaryserialization.TcpStats{}
-	err = stats.Deserialize(buffer)
+	s := &iggcon.Stats{}
+	err = s.UnmarshalBinary(buffer)
 
-	return &stats.Stats, err
+	return s, err
 }
 
 func (c *IggyTcpClient) Ping() error {

foreign/go/contracts/stats.go

@@ -17,27 +17,124 @@
 
 package iggcon
 
+import (
+	"fmt"
+
+	"github.com/apache/iggy/foreign/go/internal/codec"
+)
+
+// CacheMetrics holds cache hit/miss statistics for a single partition.
+type CacheMetrics struct {
+	StreamId    uint32  `json:"stream_id"`
+	TopicId     uint32  `json:"topic_id"`
+	PartitionId uint32  `json:"partition_id"`
+	Hits        uint64  `json:"hits"`
+	Misses      uint64  `json:"misses"`
+	HitRatio    float32 `json:"hit_ratio"`
+}
+
+// cacheMetricsWireSize is the fixed size of a CacheMetrics entry on the wire:
+// stream_id(4) + topic_id(4) + partition_id(4) + hits(8) + misses(8) + hit_ratio(4) = 32.
+const cacheMetricsWireSize = 4 + 4 + 4 + 8 + 8 + 4
+
 type Stats struct {
-	ProcessId           uint32  `json:"process_id"`
-	CpuUsage            float32 `json:"cpu_usage"`
-	TotalCpuUsage       float32 `json:"total_cpu_usage"`
-	MemoryUsage         uint64  `json:"memory_usage"`
-	TotalMemory         uint64  `json:"total_memory"`
-	AvailableMemory     uint64  `json:"available_memory"`
-	RunTime             uint64  `json:"run_time"`
-	StartTime           uint64  `json:"start_time"`
-	ReadBytes           uint64  `json:"read_bytes"`
-	WrittenBytes        uint64  `json:"written_bytes"`
-	MessagesSizeBytes   uint64  `json:"messages_size_bytes"`
-	StreamsCount        uint32  `json:"streams_count"`
-	TopicsCount         uint32  `json:"topics_count"`
-	PartitionsCount     uint32  `json:"partitions_count"`
-	SegmentsCount       uint32  `json:"segments_count"`
-	MessagesCount       uint64  `json:"messages_count"`
-	ClientsCount        uint32  `json:"clients_count"`
-	ConsumerGroupsCount uint32  `json:"consumer_groups_count"`
-	Hostname            string  `json:"hostname"`
-	OsName              string  `json:"os_name"`
-	OsVersion           string  `json:"os_version"`
-	KernelVersion       string  `json:"kernel_version"`
+	ProcessId           uint32         `json:"process_id"`
+	CpuUsage            float32        `json:"cpu_usage"`
+	TotalCpuUsage       float32        `json:"total_cpu_usage"`
+	MemoryUsage         uint64         `json:"memory_usage"`
+	TotalMemory         uint64         `json:"total_memory"`
+	AvailableMemory     uint64         `json:"available_memory"`
+	RunTime             uint64         `json:"run_time"`
+	StartTime           uint64         `json:"start_time"`
+	ReadBytes           uint64         `json:"read_bytes"`
+	WrittenBytes        uint64         `json:"written_bytes"`
+	MessagesSizeBytes   uint64         `json:"messages_size_bytes"`
+	StreamsCount        uint32         `json:"streams_count"`
+	TopicsCount         uint32         `json:"topics_count"`
+	PartitionsCount     uint32         `json:"partitions_count"`
+	SegmentsCount       uint32         `json:"segments_count"`
+	MessagesCount       uint64         `json:"messages_count"`
+	ClientsCount        uint32         `json:"clients_count"`
+	ConsumerGroupsCount uint32         `json:"consumer_groups_count"`
+	Hostname            string         `json:"hostname"`
+	OsName              string         `json:"os_name"`
+	OsVersion           string         `json:"os_version"`
+	KernelVersion       string         `json:"kernel_version"`
+	IggyServerVersion   string         `json:"iggy_server_version"`
+	IggyServerSemver    uint32         `json:"iggy_server_semver"`
+	CacheMetrics        []CacheMetrics `json:"cache_metrics"`
+	ThreadsCount        uint32         `json:"threads_count"`
+	FreeDiskSpace       uint64         `json:"free_disk_space"`
+	TotalDiskSpace      uint64         `json:"total_disk_space"`
+}
+
+func (cm *CacheMetrics) MarshalBinary() ([]byte, error) {
+	w := codec.NewWriterCap(32)
+	w.U32(cm.StreamId)
+	w.U32(cm.TopicId)
+	w.U32(cm.PartitionId)
+	w.U64(cm.Hits)
+	w.U64(cm.Misses)
+	w.F32(cm.HitRatio)
+	return w.Bytes(), w.Err()
+}
+
+func (cm *CacheMetrics) UnmarshalBinary(data []byte) error {
+	r := codec.NewReader(data)
+	cm.StreamId = r.U32()
+	cm.TopicId = r.U32()
+	cm.PartitionId = r.U32()
+	cm.Hits = r.U64()
+	cm.Misses = r.U64()
+	cm.HitRatio = r.F32()
+	return r.Err()
+}
+
+func (s *Stats) UnmarshalBinary(payload []byte) error {
+	r := codec.NewReader(payload)
+	s.ProcessId = r.U32()
+	s.CpuUsage = r.F32()
+	s.TotalCpuUsage = r.F32()
+	s.MemoryUsage = r.U64()
+	s.TotalMemory = r.U64()
+	s.AvailableMemory = r.U64()
+	s.RunTime = r.U64()
+	s.StartTime = r.U64()
+	s.ReadBytes = r.U64()
+	s.WrittenBytes = r.U64()
+	s.MessagesSizeBytes = r.U64()
+	s.StreamsCount = r.U32()
+	s.TopicsCount = r.U32()
+	s.PartitionsCount = r.U32()
+	s.SegmentsCount = r.U32()
+	s.MessagesCount = r.U64()
+	s.ClientsCount = r.U32()
+	s.ConsumerGroupsCount = r.U32()
+	s.Hostname = r.U32LenStr()
+	s.OsName = r.U32LenStr()
+	s.OsVersion = r.U32LenStr()
+	s.KernelVersion = r.U32LenStr()
+	s.IggyServerVersion = r.U32LenStr()
+	s.IggyServerSemver = r.U32()
+	cacheCount := int(r.U32())
+	if r.Err() != nil {
+		return r.Err()
+	}
+
+	if cacheCount > r.Remaining()/cacheMetricsWireSize {
+		return fmt.Errorf("stats: cache metrics count %d exceeds remaining bytes %d", cacheCount, r.Remaining())
+	}
+
+	if cacheCount > 0 {
+		s.CacheMetrics = make([]CacheMetrics, cacheCount)
+		for i := range s.CacheMetrics {
+			r.Obj(cacheMetricsWireSize, &s.CacheMetrics[i])
+		}
+	}
+
+	s.ThreadsCount = r.U32()
+	s.FreeDiskSpace = r.U64()
+	s.TotalDiskSpace = r.U64()
+
+	return r.Err()
 }