public unsafe override void Decode(BinaryStreamBase stream, HistorianKey prevKey, HistorianValue prevValue, HistorianKey key, HistorianValue value, out bool isEndOfStream)
{
isEndOfStream = false;
uint code = stream.ReadUInt8();
byte b1;
byte b2;
byte b3;
//Compression Stages:
// Stage 1: Big Positive Float.
// Stage 2: Big Negative Float.
// Stage 3: Zero
// Stage 4: 32 bit
// Stage 5: Catch all
if (code < 0x80)
{
b1 = stream.ReadUInt8();
b2 = stream.ReadUInt8();
b3 = stream.ReadUInt8();
//If stage 1 (50% success)
key.Timestamp = prevKey.Timestamp;
key.PointID = prevKey.PointID + 1 + ((code >> 4) & 0x7);
key.EntryNumber = 0;
value.Value1 = (4u << 28) | (code & 0xF) << 24 | (uint)b1 << 16 | (uint)b2 << 8 | (uint)b3 << 0;
value.Value2 = 0;
value.Value3 = 0;
return;
}
if (code < 0xC0)
{
b1 = stream.ReadUInt8();
b2 = stream.ReadUInt8();
b3 = stream.ReadUInt8();
//If stage 2 (16% success)
key.Timestamp = prevKey.Timestamp;
key.PointID = prevKey.PointID + 1 + ((code >> 4) & 0x3);
key.EntryNumber = 0;
value.Value1 = (12u << 28) | (code & 0xF) << 24 | (uint)b1 << 16 | (uint)b2 << 8 | (uint)b3 << 0;
value.Value2 = 0;
value.Value3 = 0;
return;
}
if (code < 0xD0)
{
//If stage 3 (28% success)
key.Timestamp = prevKey.Timestamp;
key.PointID = prevKey.PointID + 1 + (code & 0xF);
key.EntryNumber = 0;
value.Value1 = 0;
value.Value2 = 0;
value.Value3 = 0;
return;
}
if (code < 0xE0)
{
//If stage 4 (3% success)
key.Timestamp = prevKey.Timestamp;
key.PointID = prevKey.PointID + 1 + (code & 0xF);
key.EntryNumber = 0;
value.Value1 = stream.ReadUInt32();
value.Value2 = 0;
value.Value3 = 0;
return;
}
//Stage 5: 2%
//Stage 5: Catch All
if ((code & 16) != 0) //T is set
{
key.Timestamp = prevKey.Timestamp + stream.Read7BitUInt64();
key.PointID = stream.Read7BitUInt64();
}
else
{
key.Timestamp = prevKey.Timestamp;
key.PointID = prevKey.PointID + stream.Read7BitUInt64();
}
if ((code & 8) != 0) //E is set)
{
key.EntryNumber = stream.Read7BitUInt64();
}
else
{
key.EntryNumber = 0;
}
if ((code & 4) != 0) //V1 is set)
{
value.Value1 = stream.ReadUInt64();
}
else
{
value.Value1 = stream.ReadUInt32();
}
if ((code & 2) != 0) //V2 is set)
{
value.Value2 = stream.Read7BitUInt64();
}
else
{
value.Value2 = 0;
}
if ((code & 1) != 0) //V3 is set)
{
value.Value3 = stream.Read7BitUInt64();
}
else
{
value.Value3 = 0;
}
}
public override void Decode(BinaryStreamBase stream, HistorianKey prevKey, HistorianValue prevValue, HistorianKey key, HistorianValue value, out bool isEndOfStream)
{
isEndOfStream = false;
byte code = stream.ReadUInt8();
if (code == 255)
{
isEndOfStream = true;
return;
}
if (code < 128)
{
if (code < 64)
{
key.Timestamp = prevKey.Timestamp;
key.PointID = prevKey.PointID ^ code;
key.EntryNumber = 0;
value.Value1 = 0;
value.Value2 = 0;
value.Value3 = 0;
}
else
{
key.Timestamp = prevKey.Timestamp;
key.PointID = prevKey.PointID ^ code ^ 64;
key.EntryNumber = 0;
value.Value1 = stream.ReadUInt32();
value.Value2 = 0;
value.Value3 = 0;
}
return;
}
if ((code & 64) != 0) //T is set
{
key.Timestamp = prevKey.Timestamp ^ stream.Read7BitUInt64();
}
else
{
key.Timestamp = prevKey.Timestamp;
}
key.PointID = prevKey.PointID ^ stream.Read7BitUInt64();
if ((code & 32) != 0) //E is set)
{
key.EntryNumber = stream.Read7BitUInt64();
}
else
{
key.EntryNumber = 0;
}
if ((code & 16) != 0) //V1 High is set)
{
value.Value1 = stream.ReadUInt64();
}
else if ((code & 8) != 0) //V1 low is set)
{
value.Value1 = stream.ReadUInt32();
}
else
{
value.Value1 = 0;
}
if ((code & 4) != 0) //V2 is set)
{
value.Value2 = stream.ReadUInt64();
}
else
{
value.Value2 = 0;
}
if ((code & 2) != 0) //V1 High is set)
{
value.Value3 = stream.ReadUInt64();
}
else if ((code & 1) != 0) //V1 low is set)
{
value.Value3 = stream.ReadUInt32();
}
else
{
value.Value3 = 0;
}
return;
}