class org.apache.cassandra.streaming.messages.FileMessageHeader$FileMessageHeaderSerializer
minor version: 0
major version: 59
flags: flags: (0x0020) ACC_SUPER
this_class: org.apache.cassandra.streaming.messages.FileMessageHeader$FileMessageHeaderSerializer
super_class: java.lang.Object
{
void <init>();
descriptor: ()V
flags: (0x0000)
Code:
stack=1, locals=1, args_size=1
start local 0 0: aload 0
invokespecial java.lang.Object.<init>:()V
return
end local 0 LocalVariableTable:
Start End Slot Name Signature
0 1 0 this Lorg/apache/cassandra/streaming/messages/FileMessageHeader$FileMessageHeaderSerializer;
public org.apache.cassandra.streaming.compress.CompressionInfo serialize(org.apache.cassandra.streaming.messages.FileMessageHeader, org.apache.cassandra.io.util.DataOutputPlus, int);
descriptor: (Lorg/apache/cassandra/streaming/messages/FileMessageHeader;Lorg/apache/cassandra/io/util/DataOutputPlus;I)Lorg/apache/cassandra/streaming/compress/CompressionInfo;
flags: (0x0001) ACC_PUBLIC
Code:
stack=4, locals=6, args_size=4
start local 0 start local 1 start local 2 start local 3 0: getstatic org.apache.cassandra.utils.UUIDSerializer.serializer:Lorg/apache/cassandra/utils/UUIDSerializer;
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.cfId:Ljava/util/UUID;
aload 2
iload 3
invokevirtual org.apache.cassandra.utils.UUIDSerializer.serialize:(Ljava/util/UUID;Lorg/apache/cassandra/io/util/DataOutputPlus;I)V
1: aload 2
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.sequenceNumber:I
invokeinterface org.apache.cassandra.io.util.DataOutputPlus.writeInt:(I)V
2: aload 2
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.version:Lorg/apache/cassandra/io/sstable/format/Version;
invokevirtual org.apache.cassandra.io.sstable.format.Version.toString:()Ljava/lang/String;
invokeinterface org.apache.cassandra.io.util.DataOutputPlus.writeUTF:(Ljava/lang/String;)V
3: iload 3
iconst_3
if_icmpge 5
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.format:Lorg/apache/cassandra/io/sstable/format/SSTableFormat$Type;
getstatic org.apache.cassandra.io.sstable.format.SSTableFormat$Type.LEGACY:Lorg/apache/cassandra/io/sstable/format/SSTableFormat$Type;
if_acmpeq 5
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.format:Lorg/apache/cassandra/io/sstable/format/SSTableFormat$Type;
getstatic org.apache.cassandra.io.sstable.format.SSTableFormat$Type.BIG:Lorg/apache/cassandra/io/sstable/format/SSTableFormat$Type;
if_acmpeq 5
4: new java.lang.UnsupportedOperationException
dup
ldc "Can't stream non-legacy sstables to nodes < 2.2"
invokespecial java.lang.UnsupportedOperationException.<init>:(Ljava/lang/String;)V
athrow
5: StackMap locals:
StackMap stack:
iload 3
iconst_3
if_icmplt 7
6: aload 2
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.format:Lorg/apache/cassandra/io/sstable/format/SSTableFormat$Type;
getfield org.apache.cassandra.io.sstable.format.SSTableFormat$Type.name:Ljava/lang/String;
invokeinterface org.apache.cassandra.io.util.DataOutputPlus.writeUTF:(Ljava/lang/String;)V
7: StackMap locals:
StackMap stack:
aload 2
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.estimatedKeys:J
invokeinterface org.apache.cassandra.io.util.DataOutputPlus.writeLong:(J)V
8: aload 2
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.sections:Ljava/util/List;
invokeinterface java.util.List.size:()I
invokeinterface org.apache.cassandra.io.util.DataOutputPlus.writeInt:(I)V
9: aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.sections:Ljava/util/List;
invokeinterface java.util.List.iterator:()Ljava/util/Iterator;
astore 5
goto 13
StackMap locals: org.apache.cassandra.streaming.messages.FileMessageHeader$FileMessageHeaderSerializer org.apache.cassandra.streaming.messages.FileMessageHeader org.apache.cassandra.io.util.DataOutputPlus int top java.util.Iterator
StackMap stack:
10: aload 5
invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
checkcast org.apache.cassandra.utils.Pair
astore 4
start local 4 11: aload 2
aload 4
getfield org.apache.cassandra.utils.Pair.left:Ljava/lang/Object;
checkcast java.lang.Long
invokevirtual java.lang.Long.longValue:()J
invokeinterface org.apache.cassandra.io.util.DataOutputPlus.writeLong:(J)V
12: aload 2
aload 4
getfield org.apache.cassandra.utils.Pair.right:Ljava/lang/Object;
checkcast java.lang.Long
invokevirtual java.lang.Long.longValue:()J
invokeinterface org.apache.cassandra.io.util.DataOutputPlus.writeLong:(J)V
end local 4 13: StackMap locals:
StackMap stack:
aload 5
invokeinterface java.util.Iterator.hasNext:()Z
ifne 10
14: aconst_null
astore 4
start local 4 15: aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.compressionMetadata:Lorg/apache/cassandra/io/compress/CompressionMetadata;
ifnull 17
16: new org.apache.cassandra.streaming.compress.CompressionInfo
dup
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.compressionMetadata:Lorg/apache/cassandra/io/compress/CompressionMetadata;
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.sections:Ljava/util/List;
invokevirtual org.apache.cassandra.io.compress.CompressionMetadata.getChunksForSections:(Ljava/util/Collection;)[Lorg/apache/cassandra/io/compress/CompressionMetadata$Chunk;
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.compressionMetadata:Lorg/apache/cassandra/io/compress/CompressionMetadata;
getfield org.apache.cassandra.io.compress.CompressionMetadata.parameters:Lorg/apache/cassandra/schema/CompressionParams;
invokespecial org.apache.cassandra.streaming.compress.CompressionInfo.<init>:([Lorg/apache/cassandra/io/compress/CompressionMetadata$Chunk;Lorg/apache/cassandra/schema/CompressionParams;)V
astore 4
17: StackMap locals: org.apache.cassandra.streaming.messages.FileMessageHeader$FileMessageHeaderSerializer org.apache.cassandra.streaming.messages.FileMessageHeader org.apache.cassandra.io.util.DataOutputPlus int org.apache.cassandra.streaming.compress.CompressionInfo
StackMap stack:
getstatic org.apache.cassandra.streaming.compress.CompressionInfo.serializer:Lorg/apache/cassandra/io/IVersionedSerializer;
aload 4
aload 2
iload 3
invokeinterface org.apache.cassandra.io.IVersionedSerializer.serialize:(Ljava/lang/Object;Lorg/apache/cassandra/io/util/DataOutputPlus;I)V
18: aload 2
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.repairedAt:J
invokeinterface org.apache.cassandra.io.util.DataOutputPlus.writeLong:(J)V
19: aload 2
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.sstableLevel:I
invokeinterface org.apache.cassandra.io.util.DataOutputPlus.writeInt:(I)V
20: iload 3
iconst_4
if_icmplt 22
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.version:Lorg/apache/cassandra/io/sstable/format/Version;
invokevirtual org.apache.cassandra.io.sstable.format.Version.storeRows:()Z
ifeq 22
21: getstatic org.apache.cassandra.db.SerializationHeader.serializer:Lorg/apache/cassandra/db/SerializationHeader$Serializer;
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.version:Lorg/apache/cassandra/io/sstable/format/Version;
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.header:Lorg/apache/cassandra/db/SerializationHeader$Component;
aload 2
invokevirtual org.apache.cassandra.db.SerializationHeader$Serializer.serialize:(Lorg/apache/cassandra/io/sstable/format/Version;Lorg/apache/cassandra/db/SerializationHeader$Component;Lorg/apache/cassandra/io/util/DataOutputPlus;)V
22: StackMap locals:
StackMap stack:
aload 4
areturn
end local 4 end local 3 end local 2 end local 1 end local 0 LocalVariableTable:
Start End Slot Name Signature
0 23 0 this Lorg/apache/cassandra/streaming/messages/FileMessageHeader$FileMessageHeaderSerializer;
0 23 1 header Lorg/apache/cassandra/streaming/messages/FileMessageHeader;
0 23 2 out Lorg/apache/cassandra/io/util/DataOutputPlus;
0 23 3 version I
11 13 4 section Lorg/apache/cassandra/utils/Pair<Ljava/lang/Long;Ljava/lang/Long;>;
15 23 4 compressionInfo Lorg/apache/cassandra/streaming/compress/CompressionInfo;
Exceptions:
throws java.io.IOException
MethodParameters:
Name Flags
header
out
version
public org.apache.cassandra.streaming.messages.FileMessageHeader deserialize(org.apache.cassandra.io.util.DataInputPlus, int);
descriptor: (Lorg/apache/cassandra/io/util/DataInputPlus;I)Lorg/apache/cassandra/streaming/messages/FileMessageHeader;
flags: (0x0001) ACC_PUBLIC
Code:
stack=14, locals=16, args_size=3
start local 0 start local 1 start local 2 0: getstatic org.apache.cassandra.utils.UUIDSerializer.serializer:Lorg/apache/cassandra/utils/UUIDSerializer;
aload 1
getstatic org.apache.cassandra.net.MessagingService.current_version:I
invokevirtual org.apache.cassandra.utils.UUIDSerializer.deserialize:(Lorg/apache/cassandra/io/util/DataInputPlus;I)Ljava/util/UUID;
astore 3
start local 3 1: aload 1
invokeinterface org.apache.cassandra.io.util.DataInputPlus.readInt:()I
istore 4
start local 4 2: invokestatic org.apache.cassandra.io.sstable.format.SSTableFormat$Type.current:()Lorg/apache/cassandra/io/sstable/format/SSTableFormat$Type;
getfield org.apache.cassandra.io.sstable.format.SSTableFormat$Type.info:Lorg/apache/cassandra/io/sstable/format/SSTableFormat;
aload 1
invokeinterface org.apache.cassandra.io.util.DataInputPlus.readUTF:()Ljava/lang/String;
invokeinterface org.apache.cassandra.io.sstable.format.SSTableFormat.getVersion:(Ljava/lang/String;)Lorg/apache/cassandra/io/sstable/format/Version;
astore 5
start local 5 3: getstatic org.apache.cassandra.io.sstable.format.SSTableFormat$Type.LEGACY:Lorg/apache/cassandra/io/sstable/format/SSTableFormat$Type;
astore 6
start local 6 4: iload 2
iconst_3
if_icmplt 6
5: aload 1
invokeinterface org.apache.cassandra.io.util.DataInputPlus.readUTF:()Ljava/lang/String;
invokestatic org.apache.cassandra.io.sstable.format.SSTableFormat$Type.validate:(Ljava/lang/String;)Lorg/apache/cassandra/io/sstable/format/SSTableFormat$Type;
astore 6
6: StackMap locals: org.apache.cassandra.streaming.messages.FileMessageHeader$FileMessageHeaderSerializer org.apache.cassandra.io.util.DataInputPlus int java.util.UUID int org.apache.cassandra.io.sstable.format.Version org.apache.cassandra.io.sstable.format.SSTableFormat$Type
StackMap stack:
aload 1
invokeinterface org.apache.cassandra.io.util.DataInputPlus.readLong:()J
lstore 7
start local 7 7: aload 1
invokeinterface org.apache.cassandra.io.util.DataInputPlus.readInt:()I
istore 9
start local 9 8: new java.util.ArrayList
dup
iload 9
invokespecial java.util.ArrayList.<init>:(I)V
astore 10
start local 10 9: iconst_0
istore 11
start local 11 10: goto 13
11: StackMap locals: org.apache.cassandra.streaming.messages.FileMessageHeader$FileMessageHeaderSerializer org.apache.cassandra.io.util.DataInputPlus int java.util.UUID int org.apache.cassandra.io.sstable.format.Version org.apache.cassandra.io.sstable.format.SSTableFormat$Type long int java.util.List int
StackMap stack:
aload 10
aload 1
invokeinterface org.apache.cassandra.io.util.DataInputPlus.readLong:()J
invokestatic java.lang.Long.valueOf:(J)Ljava/lang/Long;
aload 1
invokeinterface org.apache.cassandra.io.util.DataInputPlus.readLong:()J
invokestatic java.lang.Long.valueOf:(J)Ljava/lang/Long;
invokestatic org.apache.cassandra.utils.Pair.create:(Ljava/lang/Object;Ljava/lang/Object;)Lorg/apache/cassandra/utils/Pair;
invokeinterface java.util.List.add:(Ljava/lang/Object;)Z
pop
12: iinc 11 1
StackMap locals:
StackMap stack:
13: iload 11
iload 9
if_icmplt 11
end local 11 14: getstatic org.apache.cassandra.streaming.compress.CompressionInfo.serializer:Lorg/apache/cassandra/io/IVersionedSerializer;
aload 1
getstatic org.apache.cassandra.net.MessagingService.current_version:I
invokeinterface org.apache.cassandra.io.IVersionedSerializer.deserialize:(Lorg/apache/cassandra/io/util/DataInputPlus;I)Ljava/lang/Object;
checkcast org.apache.cassandra.streaming.compress.CompressionInfo
astore 11
start local 11 15: aload 1
invokeinterface org.apache.cassandra.io.util.DataInputPlus.readLong:()J
lstore 12
start local 12 16: aload 1
invokeinterface org.apache.cassandra.io.util.DataInputPlus.readInt:()I
istore 14
start local 14 17: iload 2
iconst_4
if_icmplt 19
aload 5
invokevirtual org.apache.cassandra.io.sstable.format.Version.storeRows:()Z
ifeq 19
18: getstatic org.apache.cassandra.db.SerializationHeader.serializer:Lorg/apache/cassandra/db/SerializationHeader$Serializer;
aload 5
aload 1
invokevirtual org.apache.cassandra.db.SerializationHeader$Serializer.deserialize:(Lorg/apache/cassandra/io/sstable/format/Version;Lorg/apache/cassandra/io/util/DataInputPlus;)Lorg/apache/cassandra/db/SerializationHeader$Component;
goto 20
19: StackMap locals: org.apache.cassandra.streaming.messages.FileMessageHeader$FileMessageHeaderSerializer org.apache.cassandra.io.util.DataInputPlus int java.util.UUID int org.apache.cassandra.io.sstable.format.Version org.apache.cassandra.io.sstable.format.SSTableFormat$Type long int java.util.List org.apache.cassandra.streaming.compress.CompressionInfo long int
StackMap stack:
aconst_null
20: StackMap locals:
StackMap stack: org.apache.cassandra.db.SerializationHeader$Component
astore 15
start local 15 21: new org.apache.cassandra.streaming.messages.FileMessageHeader
dup
aload 3
iload 4
aload 5
aload 6
lload 7
aload 10
aload 11
lload 12
iload 14
aload 15
invokespecial org.apache.cassandra.streaming.messages.FileMessageHeader.<init>:(Ljava/util/UUID;ILorg/apache/cassandra/io/sstable/format/Version;Lorg/apache/cassandra/io/sstable/format/SSTableFormat$Type;JLjava/util/List;Lorg/apache/cassandra/streaming/compress/CompressionInfo;JILorg/apache/cassandra/db/SerializationHeader$Component;)V
areturn
end local 15 end local 14 end local 12 end local 11 end local 10 end local 9 end local 7 end local 6 end local 5 end local 4 end local 3 end local 2 end local 1 end local 0 LocalVariableTable:
Start End Slot Name Signature
0 22 0 this Lorg/apache/cassandra/streaming/messages/FileMessageHeader$FileMessageHeaderSerializer;
0 22 1 in Lorg/apache/cassandra/io/util/DataInputPlus;
0 22 2 version I
1 22 3 cfId Ljava/util/UUID;
2 22 4 sequenceNumber I
3 22 5 sstableVersion Lorg/apache/cassandra/io/sstable/format/Version;
4 22 6 format Lorg/apache/cassandra/io/sstable/format/SSTableFormat$Type;
7 22 7 estimatedKeys J
8 22 9 count I
9 22 10 sections Ljava/util/List<Lorg/apache/cassandra/utils/Pair<Ljava/lang/Long;Ljava/lang/Long;>;>;
10 14 11 k I
15 22 11 compressionInfo Lorg/apache/cassandra/streaming/compress/CompressionInfo;
16 22 12 repairedAt J
17 22 14 sstableLevel I
21 22 15 header Lorg/apache/cassandra/db/SerializationHeader$Component;
Exceptions:
throws java.io.IOException
MethodParameters:
Name Flags
in
version
public long serializedSize(org.apache.cassandra.streaming.messages.FileMessageHeader, int);
descriptor: (Lorg/apache/cassandra/streaming/messages/FileMessageHeader;I)J
flags: (0x0001) ACC_PUBLIC
Code:
stack=5, locals=7, args_size=3
start local 0 start local 1 start local 2 0: getstatic org.apache.cassandra.utils.UUIDSerializer.serializer:Lorg/apache/cassandra/utils/UUIDSerializer;
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.cfId:Ljava/util/UUID;
iload 2
invokevirtual org.apache.cassandra.utils.UUIDSerializer.serializedSize:(Ljava/util/UUID;I)J
lstore 3
start local 3 1: lload 3
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.sequenceNumber:I
invokestatic org.apache.cassandra.db.TypeSizes.sizeof:(I)I
i2l
ladd
lstore 3
2: lload 3
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.version:Lorg/apache/cassandra/io/sstable/format/Version;
invokevirtual org.apache.cassandra.io.sstable.format.Version.toString:()Ljava/lang/String;
invokestatic org.apache.cassandra.db.TypeSizes.sizeof:(Ljava/lang/String;)I
i2l
ladd
lstore 3
3: iload 2
iconst_3
if_icmplt 5
4: lload 3
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.format:Lorg/apache/cassandra/io/sstable/format/SSTableFormat$Type;
getfield org.apache.cassandra.io.sstable.format.SSTableFormat$Type.name:Ljava/lang/String;
invokestatic org.apache.cassandra.db.TypeSizes.sizeof:(Ljava/lang/String;)I
i2l
ladd
lstore 3
5: StackMap locals: long
StackMap stack:
lload 3
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.estimatedKeys:J
invokestatic org.apache.cassandra.db.TypeSizes.sizeof:(J)I
i2l
ladd
lstore 3
6: lload 3
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.sections:Ljava/util/List;
invokeinterface java.util.List.size:()I
invokestatic org.apache.cassandra.db.TypeSizes.sizeof:(I)I
i2l
ladd
lstore 3
7: aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.sections:Ljava/util/List;
invokeinterface java.util.List.iterator:()Ljava/util/Iterator;
astore 6
goto 11
StackMap locals: org.apache.cassandra.streaming.messages.FileMessageHeader$FileMessageHeaderSerializer org.apache.cassandra.streaming.messages.FileMessageHeader int long top java.util.Iterator
StackMap stack:
8: aload 6
invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
checkcast org.apache.cassandra.utils.Pair
astore 5
start local 5 9: lload 3
aload 5
getfield org.apache.cassandra.utils.Pair.left:Ljava/lang/Object;
checkcast java.lang.Long
invokevirtual java.lang.Long.longValue:()J
invokestatic org.apache.cassandra.db.TypeSizes.sizeof:(J)I
i2l
ladd
lstore 3
10: lload 3
aload 5
getfield org.apache.cassandra.utils.Pair.right:Ljava/lang/Object;
checkcast java.lang.Long
invokevirtual java.lang.Long.longValue:()J
invokestatic org.apache.cassandra.db.TypeSizes.sizeof:(J)I
i2l
ladd
lstore 3
end local 5 11: StackMap locals:
StackMap stack:
aload 6
invokeinterface java.util.Iterator.hasNext:()Z
ifne 8
12: lload 3
getstatic org.apache.cassandra.streaming.compress.CompressionInfo.serializer:Lorg/apache/cassandra/io/IVersionedSerializer;
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.compressionInfo:Lorg/apache/cassandra/streaming/compress/CompressionInfo;
iload 2
invokeinterface org.apache.cassandra.io.IVersionedSerializer.serializedSize:(Ljava/lang/Object;I)J
ladd
lstore 3
13: lload 3
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.sstableLevel:I
invokestatic org.apache.cassandra.db.TypeSizes.sizeof:(I)I
i2l
ladd
lstore 3
14: iload 2
iconst_4
if_icmplt 16
15: lload 3
getstatic org.apache.cassandra.db.SerializationHeader.serializer:Lorg/apache/cassandra/db/SerializationHeader$Serializer;
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.version:Lorg/apache/cassandra/io/sstable/format/Version;
aload 1
getfield org.apache.cassandra.streaming.messages.FileMessageHeader.header:Lorg/apache/cassandra/db/SerializationHeader$Component;
invokevirtual org.apache.cassandra.db.SerializationHeader$Serializer.serializedSize:(Lorg/apache/cassandra/io/sstable/format/Version;Lorg/apache/cassandra/db/SerializationHeader$Component;)I
i2l
ladd
lstore 3
16: StackMap locals: org.apache.cassandra.streaming.messages.FileMessageHeader$FileMessageHeaderSerializer org.apache.cassandra.streaming.messages.FileMessageHeader int long
StackMap stack:
lload 3
lreturn
end local 3 end local 2 end local 1 end local 0 LocalVariableTable:
Start End Slot Name Signature
0 17 0 this Lorg/apache/cassandra/streaming/messages/FileMessageHeader$FileMessageHeaderSerializer;
0 17 1 header Lorg/apache/cassandra/streaming/messages/FileMessageHeader;
0 17 2 version I
1 17 3 size J
9 11 5 section Lorg/apache/cassandra/utils/Pair<Ljava/lang/Long;Ljava/lang/Long;>;
MethodParameters:
Name Flags
header
version
}
SourceFile: "FileMessageHeader.java"
NestHost: org.apache.cassandra.streaming.messages.FileMessageHeader
InnerClasses:
public Component = org.apache.cassandra.db.SerializationHeader$Component of org.apache.cassandra.db.SerializationHeader
public Serializer = org.apache.cassandra.db.SerializationHeader$Serializer of org.apache.cassandra.db.SerializationHeader
public Chunk = org.apache.cassandra.io.compress.CompressionMetadata$Chunk of org.apache.cassandra.io.compress.CompressionMetadata
public final Type = org.apache.cassandra.io.sstable.format.SSTableFormat$Type of org.apache.cassandra.io.sstable.format.SSTableFormat
FileMessageHeaderSerializer = org.apache.cassandra.streaming.messages.FileMessageHeader$FileMessageHeaderSerializer of org.apache.cassandra.streaming.messages.FileMessageHeader