handle comments

src/lib/homestore_backend/hs_homeobject.hpp

@@ -127,7 +127,7 @@ class HSHomeObject : public HomeObjectImpl {
         ShardInfo info;
         homestore::chunk_num_t chunk_id;
     };
-
+    //TODO this blk is used to store snapshot metadata/status for recovery
     struct snapshot_info_superblk {};
 #pragma pack()
 

src/lib/homestore_backend/replication_message.hpp

@@ -15,36 +15,33 @@ VENUM(SyncMessageType, uint16_t, PG_META = 0, SHARD_META = 1, SHARD_BATCH = 2,
 
 // magic num comes from the first 8 bytes of 'echo homeobject_replication | md5sum'
 static constexpr uint64_t HOMEOBJECT_REPLICATION_MAGIC = 0x11153ca24efc8d34;
+// magic num comes from the first 8 bytes of 'echo homeobject_resync | md5sum'
+static constexpr uint64_t HOMEOBJECT_RESYNC_MAGIC = 0xbb6813cb4a339f30;
 static constexpr uint32_t HOMEOBJECT_REPLICATION_PROTOCOL_VERSION_V1 = 0x01;
 static constexpr uint32_t HOMEOBJECT_RESYNC_PROTOCOL_VERSION_V1 = 0x01;
 static constexpr uint32_t init_crc32 = 0;
 static constexpr uint64_t LAST_OBJ_ID =ULLONG_MAX;
 
 #pragma pack(1)
+template<typename Header>
 struct BaseMessageHeader {
     uint64_t magic_num{HOMEOBJECT_REPLICATION_MAGIC};
     uint32_t protocol_version;
     uint32_t payload_size;
     uint32_t payload_crc;
     mutable uint32_t header_crc;
-    uint8_t reserved_pad[4]{};
-
-    virtual uint32_t expected_protocol_version() const = 0;
 
     void seal() {
         header_crc = 0;
         header_crc = calculate_crc();
     }
 
     uint32_t calculate_crc() const {
-        return crc32_ieee(init_crc32, reinterpret_cast<const unsigned char*>(this), sizeof(*this));
+        const auto* hdr=static_cast<const Header*>(this);
+        return crc32_ieee(init_crc32, reinterpret_cast<const unsigned char*>(hdr), sizeof(*hdr));
     }
 
     bool corrupted() const {
-        if (magic_num != HOMEOBJECT_REPLICATION_MAGIC || protocol_version != expected_protocol_version()) {
-            return true;
-        }
-
         auto saved_crc = header_crc;
         header_crc = 0;
         bool is_corrupted = (saved_crc != calculate_crc());
@@ -59,14 +56,21 @@ struct BaseMessageHeader {
     }
 };
 
-struct ReplicationMessageHeader : public BaseMessageHeader{
-    uint32_t protocol_version{HOMEOBJECT_REPLICATION_PROTOCOL_VERSION_V1};
-    ReplicationMessageType msg_type; // message type
+struct ReplicationMessageHeader : public BaseMessageHeader<ReplicationMessageHeader>{
+    ReplicationMessageHeader(): BaseMessageHeader() {
+        magic_num = HOMEOBJECT_REPLICATION_MAGIC;
+        protocol_version = HOMEOBJECT_REPLICATION_PROTOCOL_VERSION_V1;
+    }
+    ReplicationMessageType msg_type;
     pg_id_t pg_id{0};
+    uint8_t reserved_pad[4]{};
     shard_id_t shard_id{0};
 
-    uint32_t expected_protocol_version() const override {
-        return HOMEOBJECT_REPLICATION_PROTOCOL_VERSION_V1;  // Specific version for sync messages
+    bool corrupted() const{
+        if (magic_num != HOMEOBJECT_REPLICATION_MAGIC || protocol_version != HOMEOBJECT_REPLICATION_PROTOCOL_VERSION_V1) {
+            return true;
+        }
+        return BaseMessageHeader::corrupted();
     }
 
     std::string to_string() const {
@@ -76,12 +80,19 @@ struct ReplicationMessageHeader : public BaseMessageHeader{
     }
 };
 
-struct SyncMessageHeader : public BaseMessageHeader {
-    uint32_t protocol_version{HOMEOBJECT_RESYNC_PROTOCOL_VERSION_V1};
-    SyncMessageType msg_type; // message type
+struct SyncMessageHeader : public BaseMessageHeader<SyncMessageHeader> {
+    SyncMessageHeader() : BaseMessageHeader() {
+        magic_num = HOMEOBJECT_RESYNC_MAGIC;
+        protocol_version = HOMEOBJECT_RESYNC_PROTOCOL_VERSION_V1;
+    }
+    SyncMessageType msg_type;
+    uint8_t reserved_pad[6]{};
 
-    uint32_t expected_protocol_version() const override {
-        return HOMEOBJECT_RESYNC_PROTOCOL_VERSION_V1;  // Specific version for sync messages
+    bool corrupted() const{
+        if (magic_num != HOMEOBJECT_RESYNC_MAGIC || protocol_version != HOMEOBJECT_RESYNC_PROTOCOL_VERSION_V1) {
+            return true;
+        }
+        return BaseMessageHeader::corrupted();
     }
 
     std::string to_string() const {

src/lib/homestore_backend/resync_blob_data.fbs

@@ -5,12 +5,12 @@ namespace homeobject;
 table ResyncBlobData {
     blob_id : uint64;
     is_deleted: bool;
-    data : [ubyte]; // Raw blob data loaded from drive, include BlobHeader, user_key and payload
+    data : [ubyte];    // Raw blob data loaded from drive, include BlobHeader, user_key and payload
 }
 
 table ResyncBlobDataBatch {
-    blob_list : [ResyncBlobData];   // List of blobs in the batch
-    is_last_batch: bool;                       // Is the last batch of the shard?
+    blob_list : [ResyncBlobData];    // List of blobs in the batch
+    is_last_batch: bool;                    // Is the last batch of the shard
 }
 
 // ResyncBlobData schema is the batch message in data resync

src/lib/homestore_backend/resync_pg_data.fbs

@@ -3,18 +3,18 @@ native_include "sisl/utility/non_null_ptr.hpp";
 namespace homeobject;
 
 table Member {
-   uuid : [ubyte];
-   name : [ubyte];
-   priority: int;
+    uuid : [ubyte];
+    name : [ubyte];
+    priority: int;
 }
 
 table ResyncPGMetaData {
-    pg_id : uint16;                               // only low 16 bit is used for pg_id;
-    replica_set_uuid : [ubyte];           // uuid of replica set
-    blob_seq_num : uint64;               // blob sequence number, used to assign next blob id;
-    shard_seq_num: uint64;              // shard sequence number, used to assign next shard id;
-    members : [Member];                 // peers;
-    shard_ids : [uint64];                    // shard ids to transmit;
+    pg_id : uint16;                        // only low 16 bit is used for pg_id;
+    replica_set_uuid : [ubyte];    // uuid of replica set
+    blob_seq_num : uint64;        // blob sequence number, used to assign next blob id;
+    shard_seq_num: uint64;       // shard sequence number, used to assign next shard id;
+    members : [Member];           // peers;
+    shard_ids : [uint64];              // shard ids to transmit;
 }
 
 // ResyncPGMetaData schema is the first message(ObjID=0) in the resync data stream

src/lib/homestore_backend/resync_shard_data.fbs

@@ -3,14 +3,14 @@ native_include "sisl/utility/non_null_ptr.hpp";
 namespace homeobject;
 
 table ResyncShardMetaData {
-    shard_id : uint64;                   // shard id to be created with;
-    pg_id : uint16;                         // pg id which this shard belongs to;
-    state : ubyte;                          // shard state;
-    created_lsn : uint64;              // lsn on shard creation;
-	created_time : uint64;            // shard creation time
-	last_modified_time : ulong;     // shard last modify time
-	total_capacity_bytes : ulong;  // total capacity of the shard
-	vchunk_id : uint16;                   // vchunk id
+    shard_id : uint64;                      // shard id to be created with;
+    pg_id : uint16;                            // pg id which this shard belongs to;
+    state : ubyte;                             // shard state;
+    created_lsn : uint64;                 // lsn on shard creation;
+    created_time : uint64;               // shard creation time
+    last_modified_time : ulong;       // shard last modify time
+    total_capacity_bytes : ulong;    // total capacity of the shard
+    vchunk_id : uint16;                     // vchunk id
 }
 
 //ShardMetaData schema is the first batch(batch=0) in the shard transmission