/// <summary>
/// Reads a FITS header from a stream.
/// </summary>
/// <param name="s">Input stream.</param>
/// <param name="Length">Expected length of input stream.</param>
/// <returns>A list with all raw keyword records in the header.</returns>
static List <KeywordRecord> ReadHeader(Stream s, long Length)
{
List <KeywordRecord> Kwlist = new List <KeywordRecord>();
bool HeaderEnd = false;
while (!HeaderEnd & s.Position < Length)
{
int i;
byte[] Buffer = new byte[80];
for (i = 0; i < 36; i++)
{
s.Read(Buffer, 0, 80);
KeywordRecord kr = new KeywordRecord(Buffer);
Kwlist.Add(kr);
if (kr.Name.TrimEnd(' ') == "END")
{
HeaderEnd = true;
}
}
}
return(Kwlist);
}
/// <summary>
/// Reads a FITS header from a stream.
/// </summary>
/// <param name="stream">Input stream.</param>
/// <param name="Length">Expected length of the input stream.</param>
/// <returns>A tuple containing a list and a dictionary of the header records.</returns>
internal static Tuple <List <MetadataRecord>, HeaderTable> ReadHeaderFromStream(Stream stream, long Length)
{
/* Read the headers and create the ElevatedRecord entries. */
List <KeywordRecord> prirec = ReadHeader(stream, Length);
List <MetadataRecord> PrimaryHeader = new List <MetadataRecord>();
foreach (KeywordRecord kr in prirec)
{
if (kr.HasEqual)
{
PrimaryHeader.Add(KeywordRecord.Elevate(kr));
}
}
/* Give easy access to the metadata in the headers via the PrimaryTable. */
Dictionary <string, bool> Unique = new Dictionary <string, bool>();
HeaderTable PrimaryTable = new Dictionary <string, MetadataRecord>();
foreach (MetadataRecord ere in PrimaryHeader)
{
if (Unique.ContainsKey(ere.Name))
{
Unique[ere.Name] = false; continue;
}
Unique.Add(ere.Name, true);
PrimaryTable.Add(ere.Name, ere);
}
foreach (MetadataRecord ere in PrimaryHeader)
{
if (!Unique[ere.Name])
{
PrimaryTable.Remove(ere.Name);
}
}
return(new Tuple <List <MetadataRecord>, HeaderTable>(PrimaryHeader, PrimaryTable));
}
internal static MetadataRecord Elevate(KeywordRecord kwr)
{
MetadataRecord ev = new FITSMetadataRecord(kwr.Name.TrimEnd(' '), kwr.Data);
return(ev);
}
