Unpacker Class

Unpacker Class

Implements deserializing feature of MsgPack.

Inheritance Hierarchy

SystemObject
MsgPackUnpacker

Namespace: MsgPack
Assembly: MsgPack (in MsgPack.dll) Version: 0.6.0

Syntax

C++

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public abstract class Unpacker : IEnumerable<MessagePackObject>, 
	IEnumerable, IDisposable

Public MustInherit Class Unpacker
	Implements IEnumerable(Of MessagePackObject), IEnumerable, 
	IDisposable

public ref class Unpacker abstract : IEnumerable<MessagePackObject>, 
	IEnumerable, IDisposable

[<AbstractClassAttribute>]
type Unpacker =  
    class
        interface IEnumerable<MessagePackObject>
        interface IEnumerable
        interface IDisposable
    end

The Unpacker type exposes the following members.

Constructors

	Name	Description
	Unpacker	Initializes a new instance of the Unpacker class.

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Properties

	Name	Description
	Data	Obsolete. Gets a last unpacked data.
	IsArrayHeader	Gets a value indicating whether this instance is positioned to array header.
	IsCollectionHeader	Gets a value indicating whether this instance is positioned to array or map header.
	IsMapHeader	Gets a value indicating whether this instance is positioned to map header.
	ItemsCount	Gets the items count for current array or map.
	LastReadData	Gets a last unpacked data.
	UnderlyingStream	Gets the underlying stream to handle direct API.

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Methods

	Name	Description
	Create(Stream)	Creates the new Unpacker from specified stream.
	Create(Stream, Boolean)	Creates the new Unpacker from specified stream.
	Dispose	Releases all managed resources.
	Dispose(Boolean)	Releases unmanaged and optionally managed resources.
	EndReadSubtree	Ends the read subtree.
	GetEnumerator	Gets IEnumeratorT to enumerate MessagePackObject from source stream.
	Read	Reads next Message Pack entry.
	ReadArrayLength	Reads next array length value from current stream.
	ReadBinary	Reads next byte array value from current stream.
	ReadBoolean	Reads next Boolean value from current stream.
	ReadByte	Reads next Byte value from current stream.
	ReadCore	Reads next Message Pack entry.
	ReadDouble	Reads next Double value from current stream.
	ReadInt16	Reads next Int16 value from current stream.
	ReadInt32	Reads next Int32 value from current stream.
	ReadInt64	Reads next Int64 value from current stream.
	ReadItem	Gets a current item or collection as single MessagePackObject from the stream.
	ReadItemData	Gets a current item or collection as single MessagePackObject from the stream.
	ReadMapLength	Reads next map length value from current stream.
	ReadMessagePackExtendedTypeObject	Reads next MessagePackExtendedTypeObject value from current stream.
	ReadNullableBoolean	Reads next nullable Boolean value from current stream.
	ReadNullableByte	Reads next nullable Byte value from current stream.
	ReadNullableDouble	Reads next nullable Double value from current stream.
	ReadNullableInt16	Reads next nullable Int16 value from current stream.
	ReadNullableInt32	Reads next nullable Int32 value from current stream.
	ReadNullableInt64	Reads next nullable Int64 value from current stream.
	ReadNullableMessagePackExtendedTypeObject	Reads next nullable MessagePackExtendedTypeObject value from current stream.
	ReadNullableSByte	Reads next nullable SByte value from current stream.
	ReadNullableSingle	Reads next nullable Single value from current stream.
	ReadNullableUInt16	Reads next nullable UInt16 value from current stream.
	ReadNullableUInt32	Reads next nullable UInt32 value from current stream.
	ReadNullableUInt64	Reads next nullable UInt64 value from current stream.
	ReadObject	Reads next value from current stream.
	ReadSByte	Reads next SByte value from current stream.
	ReadSingle	Reads next Single value from current stream.
	ReadString	Reads next utf-8 encoded string value from current stream.
	ReadSubtree	Starts unpacking of current subtree.
	ReadSubtreeCore	Starts unpacking of current subtree.
	ReadUInt16	Reads next UInt16 value from current stream.
	ReadUInt32	Reads next UInt32 value from current stream.
	ReadUInt64	Reads next UInt64 value from current stream.
	Skip	Skips the subtree where the root is the current entry, and returns skipped byte length.
	SkipCore	Skips the subtree where the root is the current entry, and returns skipped byte length.
	UnpackSubtree	Unpacks current subtree and returns subtree root as array or map.
	UnpackSubtreeData	Unpacks current subtree and returns subtree root as array or map.

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Extension Methods

	Name	Description
	UnpackT	Overloaded. Unpacks specified type value with the default context. (Defined by PackerUnpackerExtensions.)
	UnpackT(SerializationContext)	Overloaded. Unpacks specified type value with the specified context. (Defined by PackerUnpackerExtensions.)

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Remarks

Unpacker implements three mode, that is 'Streaming', 'Enumerating', 'Skipping', and 'Subtree'.

Streaming
When the Read is called, unpacker go into 'Streaming' mode. In this mode, unpacker unpacks individual entries as MessagePackObject via Data property. If the underlying stream is ended unexpectedly, then Read returns false, and Data will be null. Note that if the underlying stream is feeded, that is the Length is expanded and its Position is not forwarded, subsequent Read invocation will success, and Data is set as complete entry which reflects feeded binary.
If the reading of the entry is completed, that is the Data is not null, unpacker can transit other mode.
Enumerating
When the GetEnumerator is called and the enumeration is started, unpacker go into 'Enumerating' mode. In this mode, unpacker unpacks individual entries as MessagePackObject via Current property. If the underlying stream is ended unexpectedly, enumeration is interrupted. The interrupted unpacker cannot be resume.
Once the enumeration is completed gracefully, unpacker can transit other mode.

Skipping

When the Skip is called, unpacker go into 'Skipping' mode. In this mode, unpacker scans the subtree where the root is current item, then returns skipped byte length. If the underlying stream is ended unexpectedly, it returns null. Note that if the underlying stream is feeded, that is the Length is expanded and its Position is not forwarded, subsequent Skip invocation will success, and returns length as complete entry which reflects feeded binary.

Note
If the underlying Stream is cannot be seeked (that is, CanSeek is false), DO NOT use this method. You can buffering the content via MemoryStream instead, for example.

If the skipping of the subtree is completed, that is the return value is not null, unpacker can transit other mode.

Subtree

When the ReadSubtree is called, unpacker go into 'Subtree' mode. In this mode, any operation for this unpacker instance is invalid. Instead of use this instance itself, you can use subtree unpacker returned from ReadSubtree. The subtree unpacker is the instance which scope is limited to the subtree where the root is the current entry when ReadSubtree is called. The subtree unpacker also have its own mode and state.

Note
Dispose of the subtree unpacker must be called to indicate subtree unpacking is gracefully completed. When the extra entries are remained in the subtree, these will be skipped on the disposal process.

Once the subtree unpacking is completed gracefully, that is, Dispose on the subtree unpacker called, the parant unpacker can transit other mode.

Reference

MsgPack Namespace

MsgPackUnpacking