/// <summary> Decodes. </summary>
/// <remarks> 19.09.2020. </remarks>
/// <param name="m"> A byte[] to process. </param>
/// <param name="p"> [in,out] an int to process. </param>
/// <returns> A CompactInteger. </returns>
public static CompactInteger Decode(byte[] m, ref int p)
{
uint firstByte = m[p++];
var flag = firstByte & 0b00000011u;
CompactInteger number = 0u;
switch (flag)
{
case 0b00u:
{
number = firstByte >> 2;
break;
}
case 0b01u:
{
uint secondByte = m[p++];
number = ((firstByte & 0b11111100u) + secondByte * 256u) >> 2;
break;
}
case 0b10u:
{
number = firstByte;
var multiplier = 256u;
for (var i = 0; i < 3; ++i)
{
number += m[p++] * multiplier;
multiplier = multiplier << 8;
}
number = number >> 2;
break;
}
case 0b11:
{
var bytesCount = (firstByte >> 2) + 4u;
CompactInteger multiplier = 1u;
CompactInteger value = 0;
// we assured that there are m more bytes,
// no need to make checks in a loop
for (var i = 0; i < bytesCount; ++i)
{
value += multiplier * m[p++];
multiplier *= 256u;
}
return(value);
}
}
return(number);
}
private byte[] ExtractBytes(byte[] m, ref int p)
{
var value = CompactInteger.Decode(m, ref p);
var bytes = new byte[value];
for (var i = 0; i < value; i++)
{
bytes[i] = m[p++];
}
return(bytes);
}
private byte[] ExtractBytes(byte[] m, ref int p, Utils.HexStringFormat format = Utils.HexStringFormat.PREFIXED)
{
var value = CompactInteger.Decode(m, ref p);
byte[] bytes = new byte[(int)value];
for (int i = 0; i < value; i++)
{
bytes[i] = m[p++];
}
return(bytes);
}
private string ExtractString(byte[] m, ref int p)
{
var value = CompactInteger.Decode(m, ref p);
var s = string.Empty;
for (var i = 0; i < value; i++)
{
s += (char)m[p++];
}
return(s);
}
internal MetaData Parse(string origin, byte[] m)
{
var p = 0;
MetaData = new MetaData(origin)
{
Magic = Encoding.ASCII.GetString(new[] { m[p++], m[p++], m[p++], m[p++] }),
Version = "v" + BitConverter.ToInt16(new byte[] { m[p++], 0x00 }, 0)
};
var mlen = CompactInteger.Decode(m, ref p);
MetaData.Modules = new Module[mlen];
for (var modIndex = 0; modIndex < mlen; modIndex++)
{
var module = new Module
{
Name = ExtractString(m, ref p)
};
var hasStorage = m[p++];
if (hasStorage != 0)
{
module.Storage = new Storage();
module.Storage.Prefix = ExtractString(m, ref p);
var storageLen = CompactInteger.Decode(m, ref p);
module.Storage.Items = new Item[storageLen];
for (var i = 0; i < storageLen; i++)
{
var item = new Item();
item.Name = ExtractString(m, ref p);
item.Modifier = (Storage.Modifier)BitConverter.ToInt16(new byte[] { m[p++], 0x00 }, 0);
item.Type = (Storage.Type)BitConverter.ToInt16(new byte[] { m[p++], 0x00 }, 0);
item.Function = new Function
{
Hasher = (Storage.Hasher)(item.Type != Storage.Type.Plain
? BitConverter.ToInt16(new byte[] { m[p++], 0x00 }, 0)
: -1)
};
// default
item.Function.Key1 = null;
item.Function.Key2 = null;
item.Function.IsLinked = null;
item.Function.Key2Hasher = Storage.Hasher.None;
switch (item.Type)
{
case Storage.Type.Plain:
item.Function.Value = ExtractString(m, ref p);
break;
case Storage.Type.Map:
item.Function.Key1 = ExtractString(m, ref p);
item.Function.Value = ExtractString(m, ref p);
item.Function.IsLinked = m[p++] != 0;
break;
case Storage.Type.DoubleMap:
item.Function.Key1 = ExtractString(m, ref p);
item.Function.Key2 = ExtractString(m, ref p);
item.Function.Value = ExtractString(m, ref p);
item.Function.Key2Hasher = (Storage.Hasher)(item.Type != Storage.Type.Plain
? BitConverter.ToInt16(new byte[] { m[p++], 0x00 }, 0)
: -1);
break;
}
item.FallBack = Utils.Bytes2HexString(ExtractBytes(m, ref p));
var docLen = CompactInteger.Decode(m, ref p);
item.Documentations = new string[docLen];
for (var j = 0; j < docLen; j++)
{
item.Documentations[j] = ExtractString(m, ref p);
}
module.Storage.Items[i] = item;
}
}
var hasCalls = m[p++];
if (hasCalls != 0)
{
var callsLen = CompactInteger.Decode(m, ref p);
module.Calls = new Call[callsLen];
for (var i = 0; i < callsLen; i++)
{
var call = new Call();
call.Name = ExtractString(m, ref p);
var argsLen = CompactInteger.Decode(m, ref p);
call.Arguments = new Argument[argsLen];
for (var j = 0; j < argsLen; j++)
{
var argument = new Argument();
argument.Name = ExtractString(m, ref p);
argument.Type = ExtractString(m, ref p);
call.Arguments[j] = argument;
}
var docLen = CompactInteger.Decode(m, ref p);
call.Documentations = new string[docLen];
for (var j = 0; j < docLen; j++)
{
call.Documentations[j] = ExtractString(m, ref p);
}
module.Calls[i] = call;
}
}
var hasEvents = m[p++];
if (hasEvents != 0)
{
var eventsLen = CompactInteger.Decode(m, ref p);
module.Events = new Event[eventsLen];
for (var i = 0; i < eventsLen; i++)
{
var evnt = new Event
{
Name = ExtractString(m, ref p)
};
var argsLen = CompactInteger.Decode(m, ref p);
evnt.EventArgs = new string[argsLen];
for (var j = 0; j < argsLen; j++)
{
evnt.EventArgs[j] = ExtractString(m, ref p);
}
var docLen = CompactInteger.Decode(m, ref p);
evnt.Documentations = new string[docLen];
for (var j = 0; j < docLen; j++)
{
evnt.Documentations[j] = ExtractString(m, ref p);
}
module.Events[i] = evnt;
}
}
var conLen = CompactInteger.Decode(m, ref p);
module.Consts = new Const[conLen];
for (var i = 0; i < conLen; i++)
{
var cons = new Const
{
Name = ExtractString(m, ref p),
Type = ExtractString(m, ref p),
Value = Utils.Bytes2HexString(ExtractBytes(m, ref p))
};
var docLen = CompactInteger.Decode(m, ref p);
cons.Documentations = new string[docLen];
for (var j = 0; j < docLen; j++)
{
cons.Documentations[j] = ExtractString(m, ref p);
}
module.Consts[i] = cons;
}
var errLen = CompactInteger.Decode(m, ref p);
module.Errors = new Error[errLen];
for (var i = 0; i < errLen; i++)
{
var err = new Error
{
Name = ExtractString(m, ref p)
};
var docLen = CompactInteger.Decode(m, ref p);
err.Documentations = new string[docLen];
for (var j = 0; j < docLen; j++)
{
err.Documentations[j] = ExtractString(m, ref p);
}
module.Errors[i] = err;
}
module.Index = m[p++];
MetaData.Modules[modIndex] = module;
}
var eLen = CompactInteger.Decode(m, ref p);
for (var i = 0; i < eLen; i++)
{
var itmLen = CompactInteger.Decode(m, ref p);
MetaData.ExtrinsicExtensions = new string[itmLen];
for (var j = 0; j < itmLen; j++)
{
MetaData.ExtrinsicExtensions[j] = ExtractString(m, ref p);
}
}
return(MetaData);
}
