protected override void EmitRead(ProtoBuf.Compiler.CompilerContext ctx, ProtoBuf.Compiler.Local valueFrom)
{
Type listType;
#if NO_GENERICS
listType = typeof(BasicList);
#else
listType = ctx.MapType(typeof(System.Collections.Generic.List<>)).MakeGenericType(itemType);
#endif
Type expected = ExpectedType;
using (Compiler.Local oldArr = AppendToCollection ? ctx.GetLocalWithValue(expected, valueFrom) : null)
using (Compiler.Local newArr = new Compiler.Local(ctx, expected))
using (Compiler.Local list = new Compiler.Local(ctx, listType))
{
ctx.EmitCtor(listType);
ctx.StoreValue(list);
ListDecorator.EmitReadList(ctx, list, Tail, listType.GetMethod("Add"), packedWireType, false);
// leave this "using" here, as it can share the "FieldNumber" local with EmitReadList
using(Compiler.Local oldLen = AppendToCollection ? new ProtoBuf.Compiler.Local(ctx, ctx.MapType(typeof(int))) : null) {
Type[] copyToArrayInt32Args = new Type[] { ctx.MapType(typeof(Array)), ctx.MapType(typeof(int)) };
if (AppendToCollection)
{
ctx.LoadLength(oldArr, true);
ctx.CopyValue();
ctx.StoreValue(oldLen);
ctx.LoadAddress(list, listType);
ctx.LoadValue(listType.GetProperty("Count"));
ctx.Add();
ctx.CreateArray(itemType, null); // length is on the stack
ctx.StoreValue(newArr);
ctx.LoadValue(oldLen);
Compiler.CodeLabel nothingToCopy = ctx.DefineLabel();
ctx.BranchIfFalse(nothingToCopy, true);
ctx.LoadValue(oldArr);
ctx.LoadValue(newArr);
ctx.LoadValue(0); // index in target
ctx.EmitCall(expected.GetMethod("CopyTo", copyToArrayInt32Args));
ctx.MarkLabel(nothingToCopy);
ctx.LoadValue(list);
ctx.LoadValue(newArr);
ctx.LoadValue(oldLen);
}
else
{
ctx.LoadAddress(list, listType);
ctx.LoadValue(listType.GetProperty("Count"));
ctx.CreateArray(itemType, null);
ctx.StoreValue(newArr);
ctx.LoadAddress(list, listType);
ctx.LoadValue(newArr);
ctx.LoadValue(0);
}
copyToArrayInt32Args[0] = expected; // // prefer: CopyTo(T[], int)
MethodInfo copyTo = listType.GetMethod("CopyTo", copyToArrayInt32Args);
if (copyTo == null)
{ // fallback: CopyTo(Array, int)
copyToArrayInt32Args[1] = ctx.MapType(typeof(Array));
copyTo = listType.GetMethod("CopyTo", copyToArrayInt32Args);
}
ctx.EmitCall(copyTo);
}
ctx.LoadValue(newArr);
}
}