private PacketDefinition(IFieldReader reader)
{
m_TypeName = reader.ReadString();
m_Version = reader.ReadInt32();
int fieldCount = reader.ReadInt32();
for (int i = 0; i < fieldCount; i++)
{
string fieldName = reader.ReadString();
FieldType fieldType = (FieldType)reader.ReadInt32();
m_Fields.Add(new FieldDefinition(fieldName, fieldType));
}
// Handle the possiblity that a Packet aggregates lower level packets
int subPacketCount = reader.ReadInt32();
m_SubPackets = new List <PacketDefinition>();
for (int i = 0; i < subPacketCount; i++)
{
// We need to call the static ReadPacketDefinition(reader) in order to
// read and process the cacheable, version, and dynamic name fields which
// also exist for each subPacket definition. Fixed as part of Case #165
PacketDefinition subPacket = ReadPacketDefinition(reader);
m_SubPackets.Add(subPacket);
}
}
/// <summary>
/// Returns a PacketDefinition from the stream (including nested PacketDefinition
/// objects for cases in which an IPacket is subclassed and has serialized state
/// at multiple levels).
/// </summary>
/// <param name="reader">Stream to read data from</param>
/// <returns>PacketDefinition (including nested definitions for subclassed packets)</returns>
public static PacketDefinition ReadPacketDefinition(IFieldReader reader)
{
bool cachedPacket = reader.ReadBool();
int nestingDepth = reader.ReadInt32();
if (nestingDepth < 1)
{
throw new GibraltarException(string.Format(CultureInfo.InvariantCulture, "While reading the definition of the next packet, the number of types in the definition was read as {0} which is less than 1.", nestingDepth));
}
string dynamicTypeName = reader.ReadString();
PacketDefinition[] definitions = new PacketDefinition[nestingDepth];
for (int i = 0; i < nestingDepth; i++)
{
definitions[i] = new PacketDefinition(reader);
if (i > 0)
{
definitions[i].m_BasePacket = definitions[i - 1];
}
}
PacketDefinition topLevelDefinition = definitions[nestingDepth - 1];
topLevelDefinition.m_IsCachable = cachedPacket;
topLevelDefinition.m_DynamicTypeName = dynamicTypeName;
return(topLevelDefinition);
}
public void SetField(string fieldName, object value)
{
if (string.IsNullOrEmpty(fieldName))
{
throw new ArgumentNullException(nameof(fieldName));
}
if (m_ReadOnly)
{
throw new InvalidOperationException("The packet has been deserialized and is read-only");
}
//find the field index for the field name
FieldDefinition fieldDefinition = m_Definition.Fields[fieldName];
int fieldIndex = m_Definition.Fields.IndexOf(fieldDefinition);
//now we need to check the value for sanity.
if (value != null)
{
FieldType valueType = PacketDefinition.GetSerializableType(value.GetType());
if (fieldDefinition.IsCompatible(valueType) == false)
{
throw new ArgumentException("The provided value's type doesn't match the definition for the field.", nameof(value));
}
}
//now that we know we're of the right type, store it away.
m_Values[fieldIndex] = value;
}
/// <summary>
/// Create a storage summary instance referencing a particualr PacketDefinition
/// </summary>
public PacketTypeStorageSummary(PacketDefinition packetDefinition)
{
QualifiedTypeName = packetDefinition.QualifiedTypeName;
TypeName = packetDefinition.TypeName;
PacketCount = packetDefinition.PacketCount;
PacketSize = packetDefinition.PacketSize;
}
/// <summary>
/// Read and return the next IPacket from the stream
/// </summary>
public IPacket ReadPacket(Stream packetStream)
{
m_Reader.ReplaceStream(packetStream);
PacketDefinition definition;
int typeIndex = (int)m_Reader.ReadUInt32();
if (typeIndex >= m_cachedTypes.Count)
{
definition = PacketDefinition.ReadPacketDefinition(m_Reader);
if (string.IsNullOrEmpty(definition.TypeName))
{
//we're hosed... we won't be able to parse this packet.
throw new GibraltarSerializationException("The type name of the definition is null, which can't be correct. The packet stream is corrupted.", true);
}
m_cachedTypes.Add(definition);
m_cachedTypes.Commit();
}
else
{
definition = m_cachedTypes[typeIndex];
}
definition.PacketCount++;
definition.PacketSize += packetStream.Length;
IPacketFactory factory = m_PacketFactory.GetPacketFactory(definition.TypeName);
IPacket packet = factory.CreatePacket(definition, m_Reader);
return(packet);
}
public PacketDefinition(string typeName, int version, bool canHaveRequiredPackets)
{
m_TypeName = typeName;
m_Version = version;
m_BasePacket = null;
m_CanHaveRequiredPackets = canHaveRequiredPackets;
m_SubPackets = new List <PacketDefinition>();
}
/// <summary>
/// Read and return the next IPacket from the stream
/// </summary>
public IPacket Read()
{
#if ADD_GUARD_BYTES
byte[] preamble = new byte[4];
m_Stream.Read(preamble, 0, 4);
//now compare it against the preamble.
CompareArrays(preamble, PacketWriter.s_PreambleGuardPattern);
#endif
int packetSize = (int)m_Reader.ReadUInt64();
//if the packet size is less than one, that's obviously wrong
if (packetSize < 1)
{
throw new GibraltarSerializationException("The size of the next packet is smaller than 1 byte or negative, which can't be correct. The packet stream is corrupted.", true);
}
// TODO: There's got to be a more efficient way to get this done
byte[] buffer = new byte[packetSize];
m_Stream.Read(buffer, 0, packetSize);
IFieldReader bufferReader = new FieldReader(new MemoryStream(buffer), m_Reader.Strings, m_MajorVersion, m_MinorVersion);
PacketDefinition definition;
int typeIndex = (int)bufferReader.ReadUInt32();
if (typeIndex >= m_cachedTypes.Count)
{
definition = PacketDefinition.ReadPacketDefinition(bufferReader);
if (string.IsNullOrEmpty(definition.TypeName))
{
//we're hosed... we won't be able to parse this packet.
throw new GibraltarSerializationException("The type name of the definition is null, which can't be correct. The packet stream is corrupted.", true);
}
m_cachedTypes.Add(definition);
m_cachedTypes.Commit();
}
else
{
definition = m_cachedTypes[typeIndex];
}
IPacketFactory factory = m_PacketFactory.GetPacketFactory(definition.TypeName);
IPacket packet = factory.CreatePacket(definition, bufferReader);
//we used to populate a packet cache here, but a cached packet should be read just once - it shouldn't be in the stream
//(and I changed PacketWriter to enforce that)
#if ADD_GUARD_BYTES
byte[] postamble = new byte[4];
m_Stream.Read(postamble, 0, 4);
//now compare it against the preamble.
CompareArrays(postamble, PacketWriter.s_PostambleGuardPattern);
#endif
return(packet);
}
/// <summary>
/// Write an object to the stream as its serializable type
/// </summary>
/// <param name="value">The object (or boxed integral value) to write.</param>
public void Write(object value)
{
//but what type are we going to use?
FieldType serializedType = PacketDefinition.GetSerializableType(value.GetType());
Write((Int32)serializedType); // cast to Int32 to match ReadFieldType()
Write(value, serializedType);
}
/// <summary>
/// Compare this PacketDefinition to another to verify that they are equivalent
/// for purposes of order-dependant field deserialization.
/// </summary>
public bool Equals(PacketDefinition other)
{
// Verify that base packets are equivalent
if (BasePacket == null)
{
if (other.BasePacket != null)
{
return(false);
}
}
else
{
if (other.BasePacket == null)
{
return(false);
}
if (!BasePacket.Equals(other.BasePacket))
{
return(false);
}
}
// Verify that basic characteristics are equivalent
if (TypeName != other.TypeName)
{
return(false);
}
if (Version != other.Version)
{
return(false);
}
if (Fields.Count != other.Fields.Count)
{
return(false);
}
// Verify that all fields are equivalent
for (int i = 0; i < Fields.Count; i++)
{
if (Fields[i].Name != other.Fields[i].Name)
{
return(false);
}
if (Fields[i].FieldType != other.Fields[i].FieldType)
{
return(false);
}
}
return(true);
}
/// <summary>
/// Write the data needed to serialize the state of the packet
/// </summary>
/// <param name="packet">Object to be serialized, must implement IPacket</param>
public void Write(IPacket packet)
{
//Before we do anything - is this a cached packet that's already been written out?
ICachedPacket cachedPacket = packet as ICachedPacket;
if (cachedPacket != null)
{
//it is cacheable - is it in the cache?
if (m_PacketCache.Contains(cachedPacket))
{
//good to go, we're done.
return;
}
}
//First, we need to find out if there are any packets this guy depends on. If there are,
//they have to be serialized out first. They may have been - they could be cached.
//to do this, we'll need to get the definition.
PacketDefinition previewDefinition;
int previewTypeIndex = m_CachedTypes.IndexOf(packet);
if (previewTypeIndex < 0)
{
//we're going to get the definition, BUT we're not going to cache it yet.
//This is because we recurse on our self if there are required packets, and if one of those
//packets is our same type, IT has to write out the definition so that it's on the stream
//before the packet itself.
previewDefinition = PacketDefinition.CreatePacketDefinition(packet);
}
else
{
previewDefinition = m_CachedTypes[previewTypeIndex];
}
Dictionary <IPacket, IPacket> requiredPackets = previewDefinition.GetRequiredPackets(packet);
foreach (IPacket requiredPacket in requiredPackets.Values)
{
Write(requiredPacket); //this will handle if it's a cached packet and shouldn't be written out.
}
//Begin our "transactional" phase
try
{
// This routine is written to either write a complete packet, or to write nothing.
// As we build up the packet, we will write to a MemoryStream. Only after we've
// built up the complete packet will we write it to the actual stream.
m_Buffer.SetLength(0);
m_Buffer.Position = 0;
// The first time a packet type is written, we send along a packet definition
PacketDefinition definition;
int typeIndex = m_CachedTypes.IndexOf(packet);
if (typeIndex < 0)
{
// Record that we've seen this type so we don't bother sending the PacketDefinition again
definition = PacketDefinition.CreatePacketDefinition(packet);
typeIndex = m_CachedTypes.Count;
m_CachedTypes.Add(definition);
// Each packet always starts with a packet type index. And the first time a new
// index is used, it is followed by the packet definition.
m_BufferWriter.Write((UInt32)typeIndex);
definition.WriteDefinition(m_BufferWriter);
}
else
{
// If this type has been written before, just send the type index
m_BufferWriter.Write((UInt32)typeIndex);
definition = m_CachedTypes[typeIndex];
}
// if it's cacheable then we need to add it to our packet cache before we write it out
if (definition.IsCachable)
{
// In the case of an ICachedPacket, we need to add it to the cache.
// we'd have already bailed if it was in there.
// Note: Use previous cast for efficiency, but we must recast here *if* packet gets reassigned above
// Currently it does not get reassigned, so cachedPacket which we cast packet into above is still valid.
m_PacketCache.AddOrGet(cachedPacket);
}
//Finally, and it really is a long journey, we ask the definition to write out
//the individual fields for the packet
definition.WriteFields(packet, m_BufferWriter);
}
catch (Exception ex)
{
GC.KeepAlive(ex);
Rollback();
throw;
}
#if ADD_GUARD_BYTES
m_Stream.Write(s_PreambleGuardPattern, 0, s_PreambleGuardPattern.Length);
#endif
// Write the data to the stream preceded by the length of this packet
// NOTE: The logic below is careful to ensure that the length and payload is written in one call
// This is necessary to ensure that the GZipStream writes the whole packet in edge cases
// of writing the very last packet as an application is exiting.
var payloadLength = (int)m_Buffer.Position; // get the actual length of the payload
MemoryStream encodedLength = FieldWriter.WriteLength(payloadLength);
var lengthLength = (int)encodedLength.Length;
var packetBytes = new byte[lengthLength + payloadLength];
encodedLength.Position = 0; // reset the position in preparation to read the data back
encodedLength.Read(packetBytes, 0, lengthLength);
m_Buffer.Position = 0; // reset the position in preparation to read the data back
m_Buffer.Read(packetBytes, lengthLength, payloadLength);
m_Stream.Write(packetBytes, 0, packetBytes.Length);
#if ADD_GUARD_BYTES
m_Stream.Write(s_PostambleGuardPattern, 0, s_PostambleGuardPattern.Length);
#endif
Commit();
}
/// <summary>
/// Read back the field values for the current packet.
/// </summary>
/// <param name="definition">The definition that was used to persist the packet.</param>
/// <param name="packet">The serialized packet to read data from</param>
void IPacket.ReadFields(PacketDefinition definition, SerializedPacket packet)
{
throw new System.NotImplementedException();
}
/// <summary>
/// Read any packet based solely on its PacketDefinition
/// </summary>
/// <param name="definition">PacketDefinition describing the next packet in the stream</param>
/// <param name="reader">Data stream to be read</param>
public GenericPacket(PacketDefinition definition, IFieldReader reader)
{
if (definition.BasePacket != null)
{
m_BasePacket = new GenericPacket(definition.BasePacket, reader);
}
m_Definition = definition;
m_FieldValues = new object[definition.Fields.Count];
for (int index = 0; index < definition.Fields.Count; index++)
{
switch (definition.Fields[index].FieldType)
{
case FieldType.Bool:
m_FieldValues[index] = reader.ReadBool();
break;
case FieldType.BoolArray:
m_FieldValues[index] = reader.ReadBoolArray();
break;
case FieldType.String:
m_FieldValues[index] = reader.ReadString();
break;
case FieldType.StringArray:
m_FieldValues[index] = reader.ReadStringArray();
break;
case FieldType.Int32:
m_FieldValues[index] = reader.ReadInt32();
break;
case FieldType.Int32Array:
m_FieldValues[index] = reader.ReadInt32Array();
break;
case FieldType.Int64:
m_FieldValues[index] = reader.ReadInt64();
break;
case FieldType.Int64Array:
m_FieldValues[index] = reader.ReadInt64Array();
break;
case FieldType.UInt32:
m_FieldValues[index] = reader.ReadUInt32();
break;
case FieldType.UInt32Array:
m_FieldValues[index] = reader.ReadUInt32Array();
break;
case FieldType.UInt64:
m_FieldValues[index] = reader.ReadUInt64();
break;
case FieldType.UInt64Array:
m_FieldValues[index] = reader.ReadUInt64Array();
break;
case FieldType.Double:
m_FieldValues[index] = reader.ReadDouble();
break;
case FieldType.DoubleArray:
m_FieldValues[index] = reader.ReadDoubleArray();
break;
case FieldType.TimeSpan:
m_FieldValues[index] = reader.ReadTimeSpan();
break;
case FieldType.TimeSpanArray:
m_FieldValues[index] = reader.ReadTimeSpanArray();
break;
case FieldType.DateTime:
m_FieldValues[index] = reader.ReadDateTime();
break;
case FieldType.DateTimeArray:
m_FieldValues[index] = reader.ReadDateTimeArray();
break;
case FieldType.Guid:
m_FieldValues[index] = reader.ReadGuid();
break;
case FieldType.GuidArray:
m_FieldValues[index] = reader.ReadGuidArray();
break;
case FieldType.DateTimeOffset:
m_FieldValues[index] = reader.ReadDateTimeOffset();
break;
case FieldType.DateTimeOffsetArray:
m_FieldValues[index] = reader.ReadDateTimeOffsetArray();
break;
default:
#if DEBUG
if (Debugger.IsAttached)
{
Debugger.Break();
}
#endif
throw new InvalidOperationException(string.Format("The field type {0} is unknown so we can't deserialize the packet ", definition.Fields[index].FieldType));
}
}
}
/// <summary>
/// Write out all of the fields for the current packet
/// </summary>
/// <param name="definition">The definition that was used to persist the packet.</param>
/// <param name="packet">The serialized packet to populate with data</param>
void IPacket.WriteFields(PacketDefinition definition, SerializedPacket packet)
{
if (m_BasePacket != null)
{
((IPacket)m_BasePacket).WriteFields(definition, packet);
}
for (int index = 0; index < m_Definition.Fields.Count; index++)
{
FieldDefinition fieldDefinition = m_Definition.Fields[index];
switch (fieldDefinition.FieldType)
{
case FieldType.Bool:
packet.SetField(fieldDefinition.Name, (bool)m_FieldValues[index]);
break;
case FieldType.BoolArray:
packet.SetField(fieldDefinition.Name, (bool[])m_FieldValues[index]);
break;
case FieldType.String:
packet.SetField(fieldDefinition.Name, (string)m_FieldValues[index]);
break;
case FieldType.StringArray:
packet.SetField(fieldDefinition.Name, (string[])m_FieldValues[index]);
break;
case FieldType.Int32:
packet.SetField(fieldDefinition.Name, (Int32)m_FieldValues[index]);
break;
case FieldType.Int32Array:
packet.SetField(fieldDefinition.Name, (Int32[])m_FieldValues[index]);
break;
case FieldType.Int64:
packet.SetField(fieldDefinition.Name, (Int64)m_FieldValues[index]);
break;
case FieldType.Int64Array:
packet.SetField(fieldDefinition.Name, (Int64[])m_FieldValues[index]);
break;
case FieldType.UInt32:
packet.SetField(fieldDefinition.Name, (UInt32)m_FieldValues[index]);
break;
case FieldType.UInt32Array:
packet.SetField(fieldDefinition.Name, (UInt32[])m_FieldValues[index]);
break;
case FieldType.UInt64:
packet.SetField(fieldDefinition.Name, (UInt64)m_FieldValues[index]);
break;
case FieldType.UInt64Array:
packet.SetField(fieldDefinition.Name, (UInt64[])m_FieldValues[index]);
break;
case FieldType.Double:
packet.SetField(fieldDefinition.Name, (double)m_FieldValues[index]);
break;
case FieldType.DoubleArray:
packet.SetField(fieldDefinition.Name, (double[])m_FieldValues[index]);
break;
case FieldType.TimeSpan:
packet.SetField(fieldDefinition.Name, (TimeSpan)m_FieldValues[index]);
break;
case FieldType.TimeSpanArray:
packet.SetField(fieldDefinition.Name, (TimeSpan[])m_FieldValues[index]);
break;
case FieldType.DateTime:
packet.SetField(fieldDefinition.Name, (DateTime)m_FieldValues[index]);
break;
case FieldType.DateTimeArray:
packet.SetField(fieldDefinition.Name, (DateTime[])m_FieldValues[index]);
break;
case FieldType.Guid:
packet.SetField(fieldDefinition.Name, (Guid)m_FieldValues[index]);
break;
case FieldType.GuidArray:
packet.SetField(fieldDefinition.Name, (Guid[])m_FieldValues[index]);
break;
case FieldType.DateTimeOffset:
packet.SetField(fieldDefinition.Name, (DateTimeOffset)m_FieldValues[index]);
break;
case FieldType.DateTimeOffsetArray:
packet.SetField(fieldDefinition.Name, (DateTimeOffset[])m_FieldValues[index]);
break;
default:
#if DEBUG
if (Debugger.IsAttached)
{
Debugger.Break();
}
#endif
throw new InvalidOperationException(string.Format("The field type {0} is unknown so we can't serialize the packet ", definition.Fields[index].FieldType));
}
}
}
/// <summary>
/// Create a new serailized packet for deserialization
/// </summary>
/// <param name="definition"></param>
/// <param name="values"></param>
internal SerializedPacket(PacketDefinition definition, object[] values)
{
m_Definition = definition;
m_Values = values;
m_ReadOnly = true;
}
public void Add(string fieldName, Type type)
{
Add(fieldName, PacketDefinition.GetSerializableType(type));
}
/// <summary>
/// Create a new serialized packet for serialization
/// </summary>
/// <param name="definition"></param>
internal SerializedPacket(PacketDefinition definition)
{
m_Definition = definition;
m_Values = new object[definition.Fields.Count];
m_ReadOnly = false;
}
/// <summary>
/// Create a PacketDefinition describing the fields and serialization version information for the
/// IPacket object passed by the caller.
/// </summary>
/// <param name="packet">IPacket object to generate a PacketDefinition for</param>
/// <returns>PacketDefinition describing fields to be serialized, including nested types</returns>
public static PacketDefinition CreatePacketDefinition(IPacket packet)
{
// These flags are used in the GetMethod call below. The key flag is DeclaredOnly
// which is needed because we want to support object hierarchies that implement
// IPacket at multiple levels. We accomplish this by called GetPacketDefinition
// at each level in the hierarchy that implements IPacket.
const BindingFlags flags = BindingFlags.DeclaredOnly |
BindingFlags.Instance |
BindingFlags.InvokeMethod |
BindingFlags.NonPublic;
// We iterate from the type we are passed down object hierarchy looking for
// IPacket implementations. Then, on the way back up, we link together
// the m_BasePacket fields to that the PacketDefinition we return includes
// a description of all the nested types.
Stack <PacketDefinition> stack = new Stack <PacketDefinition>();
Type type = packet.GetType();
// walk down the hierarchy till we get to a base object that no longer implements IPacket
while (typeof(IPacket).IsAssignableFrom(type))
{
// We push one PacketDefinition on the stack for each level in the hierarchy
PacketDefinition definition;
// Even though the current type implements IPacket, it may not have a GetPacketDefinition at this level
MethodInfo method = GetIPacketMethod(type, "GetPacketDefinition", flags, Type.EmptyTypes);
if (method != null)
{
definition = (PacketDefinition)method.Invoke(packet, new object[0]);
definition.m_WriteMethod = GetIPacketMethod(type, "WriteFields", flags, new Type[] { typeof(PacketDefinition), typeof(SerializedPacket) });
if (definition.m_WriteMethod == null)
{
throw new GibraltarSerializationException("The current packet implements part but not all of the IPacket interface. No Write Method could be found. Did you implement IPacket explicitly?");
}
if (definition.CanHaveRequiredPackets)
{
definition.m_GetRequiredPacketsMethod = GetIPacketMethod(type, "GetRequiredPackets", flags, Type.EmptyTypes);
if (definition.m_GetRequiredPacketsMethod == null)
{
throw new GibraltarSerializationException("The current packet implements part but not all of the IPacket interface. No GetRequiredPackets Method could be found. Did you implement IPacket explicitly?");
}
}
}
else
{
// If GetPacketDefinition isn't defined at this level,
// push an empty PacketDefinition on the stack as a placeholder
definition = new PacketDefinition(type.Name, -1, false);
}
// Push the PacketDefinition for this level on the stack
// then iterate down to the next deeper level in the object hierarchy
stack.Push(definition);
type = type.GetTypeInfo().BaseType;
}
// At this point the top of the stack contains the mostly deeply nested base type.
// While there are 2 or more elements on the stack, the deeper of the two
// should reference the top element as a base type
while (stack.Count >= 2)
{
// Pop off the deepest base type still in the stack
PacketDefinition basePacket = stack.Pop();
// The next element is now visible, so let's peek at it
PacketDefinition derivedPacket = stack.Peek();
// link the base type with its derived class
derivedPacket.m_BasePacket = basePacket;
}
// At this point there should be exactly one element in the stack
// which contains the return value for this method.
PacketDefinition packetDefinition = stack.Pop();
// Check if this is a DynamicPacket. If so, it should have a unique dynamic type.
// If the DynamicType field has not been assigned, assign a unique string.
IDynamicPacket dynamicPacket = packet as IDynamicPacket;
if (dynamicPacket != null)
{
if (dynamicPacket.DynamicTypeName == null)
{
dynamicPacket.DynamicTypeName = Guid.NewGuid().ToString();
}
packetDefinition.m_DynamicTypeName = dynamicPacket.DynamicTypeName;
}
// Record whether or not this is a cachable packet.
packetDefinition.m_IsCachable = packet is ICachedPacket;
return(packetDefinition);
}
