public static unsafe double GetValueFromBuffer([NotNull] Agent agent, [NotNull] ScriptObject arrayBuffer, long byteIndex, [NotNull] TypeDescription description, bool isTypedArray, OrderType order, bool isLittleEndian)
{
//https://tc39.github.io/ecma262/#sec-getvaluefrombuffer
Debug.Assert(!IsDetachedBuffer(arrayBuffer));
var block = arrayBuffer.ArrayBuffer.Data;
Debug.Assert(byteIndex + description.Size <= block.LongLength);
byte *rawBytes = stackalloc byte[8];
if (SharedArrayBufferIntrinsics.IsSharedArrayBuffer(arrayBuffer))
{
//Let execution be the [[CandidateExecution]] field of the surrounding agent's Agent Record.
//Let eventList be the [[EventList]] field of the element in execution.[[EventLists]] whose [[AgentSignifier]] is AgentSignifier().
//If isTypedArray is true and type is "Int8", "Uint8", "Int16", "Uint16", "Int32", or "Uint32", let noTear be true; otherwise let noTear be false.
//Let rawValue be a List of length elementSize of nondeterministically chosen byte values.
//NOTE: In implementations, rawValue is the result of a non-atomic or atomic read instruction on the underlying hardware. The nondeterminism is a semantic prescription of the memory model to describe observable behaviour of hardware with weak consistency.
//Let readEvent be ReadSharedMemory{ [[Order]]: order, [[NoTear]]: noTear, [[Block]]: block, [[ByteIndex]]: byteIndex, [[ElementSize]]: elementSize }.
//Append readEvent to eventList.
//Append Chosen Value Record { [[Event]]: readEvent, [[ChosenValue]]: rawValue } to execution.[[ChosenValues]].
throw new NotImplementedException();
}
else
{
for (var i = 0u; i < description.Size; i++)
{
rawBytes[i] = block[byteIndex + i];
}
}
return(RawBytesToNumber(description, rawBytes, isLittleEndian));
}
public static unsafe void SetValueInBuffer([NotNull] Agent agent, [NotNull] ScriptObject arrayBuffer, long byteIndex, [NotNull] TypeDescription description, double value, bool isTypedArray, OrderType order, bool isLittleEndian)
{
//https://tc39.github.io/ecma262/#sec-setvalueinbuffer
Debug.Assert(!IsDetachedBuffer(arrayBuffer));
var block = arrayBuffer.ArrayBuffer.Data;
Debug.Assert(byteIndex + description.Size <= block.LongLength);
byte *rawBytes = stackalloc byte[8];
NumberToRawBytes(description, value, isLittleEndian, rawBytes);
if (SharedArrayBufferIntrinsics.IsSharedArrayBuffer(arrayBuffer))
{
//Let execution be the [[CandidateExecution]] field of the surrounding agent's Agent Record.
//Let eventList be the [[EventList]] field of the element in execution.[[EventLists]] whose [[AgentSignifier]] is AgentSignifier().
//If isTypedArray is true and type is "Int8", "Uint8", "Int16", "Uint16", "Int32", or "Uint32", let noTear be true; otherwise let noTear be false.
//Append WriteSharedMemory{ [[Order]]: order, [[NoTear]]: noTear, [[Block]]: block, [[ByteIndex]]: byteIndex, [[ElementSize]]: elementSize, [[Payload]]: rawBytes } to eventList.
throw new NotImplementedException();
}
else
{
for (var i = 0u; i < description.Size; i++)
{
block[byteIndex + i] = rawBytes[i];
}
}
}
private static ScriptValue Slice([NotNull] ScriptArguments arg)
{
//https://tc39.github.io/ecma262/#sec-arraybuffer.prototype.slice
var obj = arg.ThisValue.AsObject(arg.Agent);
if (obj.SpecialObjectType != SpecialObjectType.ArrayBuffer)
{
throw arg.Agent.CreateTypeError();
}
if (SharedArrayBufferIntrinsics.IsSharedArrayBuffer(obj))
{
throw arg.Agent.CreateTypeError();
}
if (IsDetachedBuffer(obj))
{
throw arg.Agent.CreateTypeError();
}
var length = obj.ArrayBuffer.Data.LongLength;
var relativeStart = (long)arg.Agent.ToInteger(arg[0]);
var first = relativeStart < 0 ? Math.Max(length + relativeStart, 0) : Math.Min(relativeStart, length);
var relativeEnd = arg[1] == ScriptValue.Undefined ? length : (long)arg.Agent.ToInteger(arg[1]);
var final = relativeEnd < 0 ? Math.Max(length + relativeEnd, 0) : Math.Min(relativeEnd, length);
var newLength = Math.Max(final - first, 0);
var constructor = arg.Agent.SpeciesConstructor(obj, arg.Function.Realm.ArrayBuffer);
var newObject = Agent.Construct(constructor, new ScriptValue[]
{
newLength
}).AsObject(arg.Agent);
if (newObject.SpecialObjectType != SpecialObjectType.ArrayBuffer)
{
throw arg.Agent.CreateTypeError();
}
if (SharedArrayBufferIntrinsics.IsSharedArrayBuffer(newObject))
{
throw arg.Agent.CreateTypeError();
}
if (IsDetachedBuffer(newObject))
{
throw arg.Agent.CreateTypeError();
}
if (newObject == obj)
{
throw arg.Agent.CreateTypeError();
}
if (newObject.ArrayBuffer.Data.LongLength < newLength)
{
throw arg.Agent.CreateTypeError();
}
//NOTE: Side-effects of the above steps may have detached O.
if (IsDetachedBuffer(obj))
{
throw arg.Agent.CreateTypeError();
}
var fromBuffer = obj.ArrayBuffer.Data;
var toBuffer = newObject.ArrayBuffer.Data;
Array.Copy(fromBuffer, first, toBuffer, 0, newLength);
return(newObject);
}
