public static MobipocketRecord FromBinary(byte[] data, bool isTextRecord, TrailingEntryParser parser)
{
if (data == null)
{
throw new ArgumentNullException("data");
}
if (isTextRecord && parser == null)
{
throw new ArgumentException("parser cannot be null if isTextRecord is true");
}
var record = new MobipocketRecord {
Data = data, IsTextRecord = isTextRecord
};
if (isTextRecord)
{
try
{
record.TrailingEntries = parser.Parse(data);
}
catch (Exception e)
{
throw new Exception("cannot parse trailing entries for record", e);
}
}
return(record);
}
/// <summary>
/// Parses all text record
/// </summary>
private IEnumerable <MobipocketRecord> ParseTextMobipocketRecords()
{
int bytesUsed = 0;
var parser = new TrailingEntryParser(Header.TrailingEntries);
int previousOverlapSize = 0;
//skip first record as header, and process all text records
for (int recordIndex = 0; recordIndex < Header.TextRecordCount; recordIndex++)
{
//get current record
var record = _pdb.Records[recordIndex + 1];
//read record
var mobiRecord = MobipocketRecord.FromBinary(record.Data, true, parser);
//uncompress text
mobiRecord.Text = GetRecordText(mobiRecord, previousOverlapSize, ref bytesUsed);
//yield record
yield return(mobiRecord);
//save trailing entries
previousOverlapSize = mobiRecord.TrailingEntries.IsMultibyteCharacterOverlapping ?
mobiRecord.TrailingEntries.MultibyteCharacterOverlap.Length : 0;
}
if (bytesUsed != Header.TotalTextLength)
{
throw new Exception("text length doesn't match used characters");
}
}
//---------------------------------------------
//
// Private methods
//
//---------------------------------------------
#region Private methods
private IEnumerable <MobipocketRecord> ParseMobipocketRecords()
{
foreach (var record in ParseTextMobipocketRecords())
{
AddResource(MobipocketResourceTypes.Text, record.Text);
yield return(record);
}
for (int index = (int)Header.FirstNonTextRecord; index < _pdb.Records.Count; index++)
{
var data = _pdb.Records[index].Data;
var record = MobipocketRecord.FromBinary(data);
yield return(record);
if (record.IsFLISRecord)
{
AddResource(MobipocketResourceTypes.FLIS, data);
}
else if (record.IsFCISRecord)
{
AddResource(MobipocketResourceTypes.FCIS, data);
}
else if (record.IsEOFRecord)
{
AddResource(MobipocketResourceTypes.EOF, data);
}
else
{
try
{
using (var stream = new MemoryStream(record.Data))
using (var image = Image.FromStream(stream))
{
var format = image.RawFormat;
if (format.Equals(ImageFormat.Jpeg) ||
format.Equals(ImageFormat.Gif) ||
format.Equals(ImageFormat.Bmp))
{
AddResource(MobipocketResourceTypes.Image, data);
}
else
{
throw new NotSupportedException("image not supported");
}
}
}
catch
{
AddResource(MobipocketResourceTypes.Binary, data);
}
}
}
}
/// <summary>
/// Gets string value associated with palm database record using given compression schemes.
/// </summary>
/// <param name="record"></param>
/// <returns></returns>
private string GetRecordText(MobipocketRecord record, int previousOverlapSize, ref int bytesUsed)
{
if (record == null)
{
throw new ArgumentException("record");
}
//resulting data
byte[] resultData;
//decompress the text
switch (Compression)
{
case MobipocketCompression.NoCompression:
{
var segment = record.GetDataWithoutTrailingEntries();
resultData = new byte[segment.Count];
Array.Copy(segment.Array, segment.Offset, resultData, 0, segment.Count);
break;
}
case MobipocketCompression.LZ77:
resultData = GetLZ77DecodedText(record.GetDataWithoutTrailingEntries());
break;
case MobipocketCompression.Huffdic:
throw new NotSupportedException("huffdic compression not supported yet");
default:
throw new NotSupportedException();
}
//adjust bytes used
bytesUsed += resultData.Length;
//add Multibyte character overlap entry to text
if (record.TrailingEntries.IsMultibyteCharacterOverlapping)
{
//may be not the most proficient method
resultData = resultData.Concat(record.TrailingEntries.MultibyteCharacterOverlap).ToArray();
}
return(GetSystemEncoding().GetString(resultData, previousOverlapSize, resultData.Length - previousOverlapSize));
}
public static MobipocketRecord FromBinary(byte[] data, bool isTextRecord, TrailingEntryParser parser)
{
if (data == null)
throw new ArgumentNullException("data");
if (isTextRecord && parser == null)
throw new ArgumentException("parser cannot be null if isTextRecord is true");
var record = new MobipocketRecord { Data = data, IsTextRecord = isTextRecord };
if (isTextRecord)
{
try
{
record.TrailingEntries = parser.Parse(data);
}
catch (Exception e)
{
throw new Exception("cannot parse trailing entries for record", e);
}
}
return record;
}