using System; using System.Collections.Generic; using System.Text; namespace Capnp { /// <summary> /// Provides deep-copy functionality to re-serialize an existing deserializer state into another serializer state. /// </summary> public static class Reserializing { /// <summary> /// Performs a deep copy of an existing deserializer state into another serializer state. /// This implementation does not analyze the source object graph and therefore cannot detect multiple references to the same object. /// Such cases will result in object duplication. /// </summary> /// <param name="from">source state</param> /// <param name="to">target state</param> /// <exception cref="ArgumentNullException"><paramref name="to"/> is null.</exception> /// <exception cref="InvalidOperationException">Target state was already set to a different object type than the source state.</exception> /// <exception cref="DeserializationException">Security violation due to amplification attack or stack overflow DoS attack, /// or illegal pointer detected during deserialization.</exception> public static void DeepCopy(DeserializerState from, SerializerState to) { if (to == null) throw new ArgumentNullException(nameof(to)); var ds = to.Rewrap<DynamicSerializerState>(); IReadOnlyList<DeserializerState> items; switch (from.Kind) { case ObjectKind.Struct: ds.SetStruct(from.StructDataCount, from.StructPtrCount); ds.Allocate(); from.StructDataSection.CopyTo(ds.StructDataSection); for (int i = 0; i < from.StructPtrCount; i++) { DeepCopy(from.StructReadPointer(i), ds.BuildPointer(i)); } break; case ObjectKind.ListOfBits: ds.SetListOfValues(1, from.ListElementCount); from.RawData.CopyTo(ds.RawData); break; case ObjectKind.ListOfBytes: ds.SetListOfValues(8, from.ListElementCount); from.RawData.CopyTo(ds.RawData); break; case ObjectKind.ListOfEmpty: ds.SetListOfValues(0, from.ListElementCount); break; case ObjectKind.ListOfInts: ds.SetListOfValues(32, from.ListElementCount); from.RawData.CopyTo(ds.RawData); break; case ObjectKind.ListOfLongs: ds.SetListOfValues(64, from.ListElementCount); from.RawData.CopyTo(ds.RawData); break; case ObjectKind.ListOfShorts: ds.SetListOfValues(16, from.ListElementCount); from.RawData.CopyTo(ds.RawData); break; case ObjectKind.ListOfPointers: ds.SetListOfPointers(from.ListElementCount); items = (IReadOnlyList<DeserializerState>)from.RequireList(); for (int i = 0; i < from.ListElementCount; i++) { DeepCopy(items[i], ds.BuildPointer(i)); } break; case ObjectKind.ListOfStructs: ds.SetListOfStructs(from.ListElementCount, from.StructDataCount, from.StructPtrCount); items = (IReadOnlyList<DeserializerState>)from.RequireList(); for (int i = 0; i < from.ListElementCount; i++) { DeepCopy(items[i], ds.ListBuildStruct(i)); } break; case ObjectKind.Capability: ds.SetCapability(from.CapabilityIndex); break; } to.InheritFrom(ds); } } }