/// <summary>
/// Create a new <see cref="AcroFieldCommonInformation"/>.
/// </summary>
public AcroFieldCommonInformation(IndirectReference?parent, string partialName, string alternateName, string mappingName)
{
Parent = parent;
PartialName = partialName;
AlternateName = alternateName;
MappingName = mappingName;
}
public bool MoveNext()
{
if (isDisposed)
{
throw new ObjectDisposedException(nameof(PdfTokenScanner));
}
// Read until we find object-number generation obj, e.g. "69 420 obj".
int tokensRead = 0;
while (coreTokenScanner.MoveNext() && !Equals(coreTokenScanner.CurrentToken, OperatorToken.StartObject))
{
if (coreTokenScanner.CurrentToken is CommentToken)
{
continue;
}
tokensRead++;
previousTokens[0] = previousTokens[1];
previousTokenPositions[0] = previousTokenPositions[1];
previousTokens[1] = coreTokenScanner.CurrentToken;
previousTokenPositions[1] = coreTokenScanner.CurrentTokenStart;
}
// We only read partial tokens.
if (tokensRead < 2)
{
return(false);
}
var startPosition = previousTokenPositions[0];
var objectNumber = previousTokens[0] as NumericToken;
var generation = previousTokens[1] as NumericToken;
if (objectNumber == null || generation == null)
{
// Handle case where the scanner correctly reads most of an object token but includes too much of the first token
// specifically %%EOF1 0 obj where scanning starts from 'F'.
if (generation != null && previousTokens[0] is OperatorToken op)
{
var match = EndsWithNumberRegex.Match(op.Data);
if (match.Success && int.TryParse(match.Value, NumberStyles.Any, CultureInfo.InvariantCulture, out var number))
{
startPosition = previousTokenPositions[0] + match.Index;
objectNumber = new NumericToken(number);
}
else
{
return(false);
}
}
else
{
return(false);
}
}
// Read all tokens between obj and endobj.
while (coreTokenScanner.MoveNext() && !Equals(coreTokenScanner.CurrentToken, OperatorToken.EndObject))
{
if (coreTokenScanner.CurrentToken is CommentToken)
{
continue;
}
if (ReferenceEquals(coreTokenScanner.CurrentToken, OperatorToken.StartObject))
{
// This should never happen.
Debug.Assert(false, "Encountered a start object 'obj' operator before the end of the previous object.");
return(false);
}
if (ReferenceEquals(coreTokenScanner.CurrentToken, OperatorToken.StartStream))
{
var streamIdentifier = new IndirectReference(objectNumber.Long, generation.Int);
// Prevent an infinite loop where a stream's length references the stream or the stream's offset.
var getLengthFromFile = !(callingObject.HasValue && callingObject.Value.Equals(streamIdentifier));
var outerCallingObject = callingObject;
try
{
callingObject = streamIdentifier;
// Read stream: special case.
if (TryReadStream(coreTokenScanner.CurrentTokenStart, getLengthFromFile, out var stream))
{
readTokens.Clear();
readTokens.Add(stream);
}
}
finally
{
callingObject = outerCallingObject;
}
}
else
{
readTokens.Add(coreTokenScanner.CurrentToken);
}
previousTokens[0] = previousTokens[1];
previousTokenPositions[0] = previousTokenPositions[1];
previousTokens[1] = coreTokenScanner.CurrentToken;
previousTokenPositions[1] = coreTokenScanner.CurrentPosition;
}
if (!ReferenceEquals(coreTokenScanner.CurrentToken, OperatorToken.EndObject))
{
readTokens.Clear();
return(false);
}
var reference = new IndirectReference(objectNumber.Long, generation.Int);
IToken token;
if (readTokens.Count == 3 && readTokens[0] is NumericToken objNum &&
readTokens[1] is NumericToken genNum &&
ReferenceEquals(readTokens[2], OperatorToken.R))
{
// I have no idea if this can ever happen.
token = new IndirectReferenceToken(new IndirectReference(objNum.Long, genNum.Int));
}
/// <summary>
/// Writes a valid single section cross-reference (xref) table plus trailer dictionary to the output for the set of object offsets.
/// </summary>
/// <param name="objectOffsets">The byte offset from the start of the document for each object in the document.</param>
/// <param name="catalogToken">The object representing the catalog dictionary which is referenced from the trailer dictionary.</param>
/// <param name="outputStream">The output stream to write to.</param>
/// <param name="documentInformationReference">The object reference for the document information dictionary if present.</param>
internal static void WriteCrossReferenceTable(IReadOnlyDictionary <IndirectReference, long> objectOffsets,
ObjectToken catalogToken,
Stream outputStream,
IndirectReference?documentInformationReference)
{
if (objectOffsets.Count == 0)
{
throw new InvalidOperationException("Could not write empty cross reference table.");
}
WriteLineBreak(outputStream);
var position = outputStream.Position;
outputStream.Write(Xref, 0, Xref.Length);
WriteLineBreak(outputStream);
var min = objectOffsets.Min(x => x.Key.ObjectNumber);
var max = objectOffsets.Max(x => x.Key.ObjectNumber);
if (max - min != objectOffsets.Count - 1)
{
throw new NotSupportedException("Object numbers must form a contiguous range");
}
WriteLong(0, outputStream);
WriteWhitespace(outputStream);
// 1 extra for the free entry.
WriteLong(objectOffsets.Count + 1, outputStream);
WriteWhitespace(outputStream);
WriteLineBreak(outputStream);
WriteFirstXrefEmptyEntry(outputStream);
foreach (var keyValuePair in objectOffsets.OrderBy(x => x.Key.ObjectNumber))
{
/*
* nnnnnnnnnn ggggg n eol
* where:
* nnnnnnnnnn is a 10-digit byte offset
* ggggg is a 5-digit generation number
* n is a literal keyword identifying this as an in-use entry
* eol is a 2-character end-of-line sequence ('\r\n' or ' \n')
*/
var paddedOffset = OtherEncodings.StringAsLatin1Bytes(keyValuePair.Value.ToString("D10"));
outputStream.Write(paddedOffset, 0, paddedOffset.Length);
WriteWhitespace(outputStream);
var generation = OtherEncodings.StringAsLatin1Bytes(keyValuePair.Key.Generation.ToString("D5"));
outputStream.Write(generation, 0, generation.Length);
WriteWhitespace(outputStream);
outputStream.WriteByte(InUseEntry);
WriteWhitespace(outputStream);
WriteLineBreak(outputStream);
}
outputStream.Write(Trailer, 0, Trailer.Length);
WriteLineBreak(outputStream);
var identifier = new ArrayToken(new IToken[]
{
new HexToken(Guid.NewGuid().ToString("N").ToCharArray()),
new HexToken(Guid.NewGuid().ToString("N").ToCharArray())
});
var trailerDictionaryData = new Dictionary <NameToken, IToken>
{
// 1 for the free entry.
{ NameToken.Size, new NumericToken(objectOffsets.Count + 1) },
{ NameToken.Root, new IndirectReferenceToken(catalogToken.Number) },
{ NameToken.Id, identifier }
};
if (documentInformationReference.HasValue)
{
trailerDictionaryData[NameToken.Info] = new IndirectReferenceToken(documentInformationReference.Value);
}
var trailerDictionary = new DictionaryToken(trailerDictionaryData);
WriteDictionary(trailerDictionary, outputStream);
WriteLineBreak(outputStream);
outputStream.Write(StartXref, 0, StartXref.Length);
WriteLineBreak(outputStream);
WriteLong(position, outputStream);
WriteLineBreak(outputStream);
// Complete!
outputStream.Write(Eof, 0, Eof.Length);
}
/// <summary>
/// Writes a valid single section cross-reference (xref) table plus trailer dictionary to the output for the set of object offsets.
/// </summary>
/// <param name="objectOffsets">The byte offset from the start of the document for each object in the document.</param>
/// <param name="catalogToken">The object representing the catalog dictionary which is referenced from the trailer dictionary.</param>
/// <param name="outputStream">The output stream to write to.</param>
/// <param name="documentInformationReference">The object reference for the document information dictionary if present.</param>
internal static void WriteCrossReferenceTable(IReadOnlyDictionary <IndirectReference, long> objectOffsets,
IndirectReference catalogToken,
Stream outputStream,
IndirectReference?documentInformationReference)
{
if (objectOffsets.Count == 0)
{
throw new InvalidOperationException("Could not write empty cross reference table.");
}
WriteLineBreak(outputStream);
var position = outputStream.Position;
outputStream.Write(Xref, 0, Xref.Length);
WriteLineBreak(outputStream);
var sets = new List <XrefSeries>();
var orderedList = objectOffsets.OrderBy(x => x.Key.ObjectNumber).ToList();
long firstObjectNumber = 0;
long currentObjNum = 0;
var items = new List <XrefSeries.OffsetAndGeneration>
{
// Zero entry
null
};
foreach (var item in orderedList)
{
var step = item.Key.ObjectNumber - currentObjNum;
if (step == 1)
{
currentObjNum = item.Key.ObjectNumber;
items.Add(new XrefSeries.OffsetAndGeneration(item.Value, item.Key.Generation));
}
else
{
sets.Add(new XrefSeries(firstObjectNumber, items));
items = new List <XrefSeries.OffsetAndGeneration>
{
new XrefSeries.OffsetAndGeneration(item.Value, item.Key.Generation)
};
currentObjNum = item.Key.ObjectNumber;
firstObjectNumber = item.Key.ObjectNumber;
}
}
if (items.Count > 0)
{
sets.Add(new XrefSeries(firstObjectNumber, items));
}
foreach (var series in sets)
{
WriteLong(series.First, outputStream);
WriteWhitespace(outputStream);
WriteLong(series.Offsets.Count, outputStream);
WriteWhitespace(outputStream);
WriteLineBreak(outputStream);
foreach (var offset in series.Offsets)
{
if (offset != null)
{
/*
* nnnnnnnnnn ggggg n eol
* where:
* nnnnnnnnnn is a 10-digit byte offset
* ggggg is a 5-digit generation number
* n is a literal keyword identifying this as an in-use entry
* eol is a 2-character end-of-line sequence ('\r\n' or ' \n')
*/
var paddedOffset = OtherEncodings.StringAsLatin1Bytes(offset.Offset.ToString("D10", CultureInfo.InvariantCulture));
outputStream.Write(paddedOffset, 0, paddedOffset.Length);
WriteWhitespace(outputStream);
var generation = OtherEncodings.StringAsLatin1Bytes(offset.Generation.ToString("D5", CultureInfo.InvariantCulture));
outputStream.Write(generation, 0, generation.Length);
WriteWhitespace(outputStream);
outputStream.WriteByte(InUseEntry);
WriteWhitespace(outputStream);
WriteLineBreak(outputStream);
}
else
{
WriteFirstXrefEmptyEntry(outputStream);
}
}
}
outputStream.Write(Trailer, 0, Trailer.Length);
WriteLineBreak(outputStream);
var identifier = new ArrayToken(new IToken[]
{
new HexToken(Guid.NewGuid().ToString("N").ToCharArray()),
new HexToken(Guid.NewGuid().ToString("N").ToCharArray())
});
var trailerDictionaryData = new Dictionary <NameToken, IToken>
{
// 1 for the free entry.
{ NameToken.Size, new NumericToken(objectOffsets.Count + 1) },
{ NameToken.Root, new IndirectReferenceToken(catalogToken) },
{ NameToken.Id, identifier }
};
if (documentInformationReference.HasValue)
{
trailerDictionaryData[NameToken.Info] = new IndirectReferenceToken(documentInformationReference.Value);
}
var trailerDictionary = new DictionaryToken(trailerDictionaryData);
WriteDictionary(trailerDictionary, outputStream);
WriteLineBreak(outputStream);
outputStream.Write(StartXref, 0, StartXref.Length);
WriteLineBreak(outputStream);
WriteLong(position, outputStream);
WriteLineBreak(outputStream);
// Complete!
outputStream.Write(Eof, 0, Eof.Length);
}