public static List <ImageSelfDefiningField> GetAllSDFs(byte[] sdfData)
{
List <ImageSelfDefiningField> sdfList = new List <ImageSelfDefiningField>();
// Container info
byte[] beginCodes = new byte[4] {
0x70, 0x8C, 0x8E, 0x91
};
byte[] endCodes = new byte[4] {
0x71, 0x8D, 0x8F, 0x93
};
List <Container> activeContainers = new List <Container>();
for (int i = 0; i < sdfData.Length;)
{
// Check the first byte of the code. If it's 0xFE, this is an extended format SDF and will have two byte codes and lengths instead of one
bool isExtended = sdfData[i] == 0xFE;
// Get the ID, length, introducer, and data bytes
byte[] idArray = isExtended ? new byte[2] {
0xFE, sdfData[i + 1]
} : new byte[1] {
sdfData[i]
};
byte id = idArray.Last();
int length = isExtended ? GetNumericValue <ushort>(new[] { sdfData[i + 2], sdfData[i + 3] })
: GetNumericValue <byte>(new[] { sdfData[i + 1] });
byte[] data = new byte[length];
Array.ConstrainedCopy(sdfData, i + (isExtended ? 4 : 2), data, 0, length);
// Create an instance of the lookup type
Type iSDFType = typeof(ImageSelfDefiningFields.UNKNOWN);
if (Lookups.ImageSelfDefiningFields.ContainsKey(id))
{
iSDFType = Lookups.ImageSelfDefiningFields[id];
}
ImageSelfDefiningField sdf = (ImageSelfDefiningField)Activator.CreateInstance(iSDFType, idArray, data);
// If this is a begin tag, add a new container to our active list
if (beginCodes.Contains(id))
{
activeContainers.Add(new Container());
}
// Sync active containers
sdf.Containers = new List <Container>(activeContainers);
// Add this field to all containers
foreach (Container c in activeContainers)
{
c.Structures.Add(sdf);
}
// If this is the last structure in a container, close it up and parse any specific container data
if (endCodes.Contains(id))
{
Container c = activeContainers.Last();
activeContainers.Remove(c);
}
sdfList.Add(sdf);
// Go to next block
i += (isExtended ? 4 : 2) + length;
}
return(sdfList);
}
// This method can be overridden if it is complicated to parse
protected override string GetOffsetDescriptions()
{
StringBuilder sb = new StringBuilder();
if (Offsets.Count == 0)
{
sb.AppendLine("Not yet implemented...");
sb.AppendLine();
sb.AppendLine("Raw data:");
sb.AppendLine(DataHex);
sb.AppendLine();
sb.AppendLine("Raw data (EBCDIC):");
sb.Append(DataEBCDIC);
return(sb.ToString());
}
// If this is a repeating group identifier, loop through each subsection of offsets
int skip = IsRepeatingGroup ? RepeatingGroupStart : Offsets[0].StartingIndex;
int sectionLength = RepeatingGroupLength;
do
{
for (int i = 0; i < Offsets.Count; i++)
{
// If we are past the data length, break out of the loop
if (skip > Data.Length)
{
break;
}
// Get the length of the current repeating group if it is retrieved in each section (if there is not a fixed length)
if (IsRepeatingGroup && RepeatingGroupLength == 0 && i == 0)
{
int rgOffsetLength = Offsets[i + 1].StartingIndex;
sectionLength = GetNumericValueFromData <int>(skip, rgOffsetLength);
}
// Calculate section of bytes to take from data
int nextOffsetIdx = i == Offsets.Count - 1 ? 0 : Offsets[i + 1].StartingIndex;
int take = (nextOffsetIdx == 0 ? sectionLength : nextOffsetIdx) - Offsets[i].StartingIndex;
byte[] sectionedData = GetSectionedData(skip, take);
// Build description by data type
switch (Offsets[i].DataType)
{
// For special sub sectioned data types, call the static parser
case Lookups.DataTypes.IMAGESDFS:
if (i > 0)
{
sb.AppendLine();
}
sb.AppendLine(ImageSelfDefiningField.GetAllDescriptions(sectionedData));
break;
// For Triplets, parse them all at once
case Lookups.DataTypes.TRIPS:
sb.AppendLine();
foreach (Triplet t in Triplets)
{
sb.AppendLine(t.GetFullDescription());
}
break;
// Everything else
default:
sb.Append(GetSingleOffsetDescription(Offsets[i], sectionedData));
break;
}
// Increment the skip value so we take the correct offset of data next iteration
skip += take;
}
sb.AppendLine();
} while (skip < Data.Length);
return(sb.ToString().Trim());
}
