VmEnvironment RebuildEnvironment(
object[] objects, int index, Composite composite, Func<int, object> reader)
{
var result = new VmEnvironment ();
objects [index] = result;
result.Frame = (VmEnvFrame)reader (composite.Elements [0]);
result.Next = (VmEnvironment)reader (composite.Elements [1]);
result.Uses = (int)(long)reader (composite.Elements [2]);
return result;
}
int SerializeEnvironment(VmEnvironment env, object obj)
{
var composite = new Composite {
Kind = ObjectTypes.Environment,
Elements = new int[3]
};
var result = SerializeOneHashed (composite, obj);
composite.Elements [0] = Serialize (env.Frame);
composite.Elements [1] = Serialize (env.Next);
composite.Elements [2] = SerializeOne (env.Uses);
return result;
}
static Value GetFromEnvironment(VmEnvironment env, int frameNumber, int varIndex)
{
return FindFrame (env, frameNumber).Values [varIndex];
}
static void HandleNewFrame(Vm vm)
{
var instruction = vm.CurrentInstruction ();
var args = (string[])instruction.Arguments;
var frame = new VmEnvFrame () {
VarNames = args,
Values = new Value[args.Length],
IntroducedAtProgramCounter = vm.programCounter
};
var newEnv = new VmEnvironment () {
Frame = frame,
Next = vm.currentEnvironment
};
vm.currentEnvironment = newEnv;
vm.IncrementCells (args.Length * 3 + 5);
vm.programCounter++;
}
void DeserializeState(byte[] serializedState)
{
using (var ms = new MemoryStream(serializedState)) {
Serialization.Utils.DeserializeWithMd5CheckSum (ms, str => {
var version = Serialization.Utils.ReadInt (str);
if (version > Shovel.Api.Version) {
throw new Exceptions.VersionNotSupportedException ();
}
var stackIndex = Serialization.Utils.ReadInt (str);
var envIndex = Serialization.Utils.ReadInt (str);
this.programCounter = Serialization.Utils.ReadInt (str);
var bytes = new byte[32];
str.Read (bytes, 0, 32);
var actualBytecodeMd5 = Encoding.UTF8.GetString (bytes);
if (actualBytecodeMd5 != Utils.GetBytecodeMd5 (this.bytecode)) {
throw new Exceptions.BytecodeDoesntMatchState ();
}
// Read and ignore the source MD5.
str.Read (bytes, 0, 32);
// Read the number of ticks executed so far.
this.executedTicks = Serialization.Utils.ReadLong (ms);
// Read the number of used cells.
this.usedCells = Serialization.Utils.ReadInt (ms);
var ser = new Serialization.VmStateSerializer ();
ser.Deserialize (str, version, reader => {
this.stack = new Stack ((Value[])reader (stackIndex));
this.currentEnvironment = (VmEnvironment)reader (envIndex);
}
);
return null;
});
}
}
static VmEnvFrame FindFrame(VmEnvironment env, int frameNumber)
{
while (env != null && frameNumber > 0) {
env = env.Next;
frameNumber --;
}
if (env == null) {
Utils.Panic ();
}
return env.Frame;
}
int CountCellsEnvironment(VmEnvironment env, HashSet<object> visited)
{
var sum = 3;
visited.Add (env);
sum += CountCellsImpl (env.Frame, visited);
sum += CountCellsImpl (env.Next, visited);
return sum;
}
void ApplyReturnAddress(ReturnAddress returnAddress)
{
this.programCounter = returnAddress.ProgramCounter;
this.currentEnvironment = returnAddress.Environment;
}
static void SetInEnvironment(
VmEnvironment env, int frameNumber, int varIndex, Value value)
{
FindFrame (env, frameNumber).Values [varIndex] = value;
}
void ApplyReturnAddress(ReturnAddress returnAddress)
{
this.programCounter = returnAddress.ProgramCounter;
this.currentEnvironment = returnAddress.Environment;
this.currentEnvironment.DecreaseUsesLocally ();
}
static VmEnvironment FreshFrame(Vm vm, Instruction instruction)
{
var args = (string[])instruction.Arguments;
var frame = new VmEnvFrame () {
VarNames = args,
Values = new Value[args.Length],
IntroducedAtProgramCounter = vm.programCounter
};
var result = new VmEnvironment () {
Frame = frame,
};
vm.IncrementCells (args.Length * 3 + 5);
instruction.Cache = result;
return result;
}
