internal Reader(IInputStream stream, Files.File file)
{
this.parser = new FileParser(stream, file);
}
protected override void WriteIncremental(
)
{
// 1. Original content (head, body and previous trailer).
FileParser parser = file.Reader.Parser;
stream.Write(parser.Stream);
// 2. Body update (modified indirect objects insertion).
int xrefSize = file.IndirectObjects.Count;
StringBuilder xrefBuilder = new StringBuilder(XRefChunk);
{
/*
* NOTE: Incremental xref table comprises multiple sections
* each one composed by multiple subsections; this update
* adds a new section.
*/
StringBuilder xrefSubBuilder = new StringBuilder(); // Xref-table subsection builder.
int xrefSubCount = 0; // Xref-table subsection counter.
int prevKey = 0; // Previous-entry object number.
foreach (
KeyValuePair <int, PdfIndirectObject> indirectObjectEntry
in file.IndirectObjects.ModifiedObjects
)
{
// Is the object in the current subsection?
/*
* NOTE: To belong to the current subsection, the object entry MUST be contiguous with the
* previous (condition 1) or the iteration has to have been just started (condition 2).
*/
if (indirectObjectEntry.Key - prevKey == 1 ||
prevKey == 0) // Current subsection continues.
{
xrefSubCount++;
}
else // Current subsection terminates.
{
// End current subsection!
AppendXRefSubsection(
xrefBuilder,
prevKey - xrefSubCount + 1,
xrefSubCount,
xrefSubBuilder
);
// Begin next subsection!
xrefSubBuilder.Length = 0;
xrefSubCount = 1;
}
prevKey = indirectObjectEntry.Key;
// Current entry insertion.
if (indirectObjectEntry.Value.IsInUse()) // In-use entry.
{
// Add in-use entry!
AppendXRefEntry(
xrefSubBuilder,
indirectObjectEntry.Value.Reference,
stream.Length
);
// Add in-use entry content!
indirectObjectEntry.Value.WriteTo(stream, file);
}
else // Free entry.
{
// Add free entry!
/*
* NOTE: We purposely neglect the linked list of free entries (see IndirectObjects.remove(int)),
* so that this entry links directly back to object number 0, having a generation number of 65535
* (not reusable) [PDF:1.6:3.4.3].
*/
AppendXRefEntry(
xrefSubBuilder,
indirectObjectEntry.Value.Reference,
0
);
}
}
// End last subsection!
AppendXRefSubsection(
xrefBuilder,
prevKey - xrefSubCount + 1,
xrefSubCount,
xrefSubBuilder
);
}
// 3. XRef-table last section.
long startxref = stream.Length;
stream.Write(xrefBuilder.ToString());
// 4. Trailer.
WriteTrailer(startxref, xrefSize, parser);
}
public ObjectEntry(PdfDataObject dataObject, FileParser parser)
: this(parser)
{
this.dataObject = dataObject;
this.offset = -1; // Undefined -- to set on stream serialization.
}
public ObjectEntry(int offset, FileParser parser)
: this(parser)
{
this.dataObject = null;
this.offset = offset;
}
private ObjectEntry(FileParser parser)
{
this.parser = parser;
}
internal Reader(IInputStream stream, Files.File file, string password = null, System.IO.Stream keyStoreInputStream = null)
{
this.parser = new FileParser(stream, file, password, keyStoreInputStream);
}
protected override void WriteIncremental()
{
// 1. Original content (header, body and previous trailer).
FileParser parser = file.Reader.Parser;
stream.Write(parser.Stream);
// 2. Body update (modified indirect objects insertion).
XRefEntry xrefStreamEntry;
{
// Create the xref stream!
/*
* NOTE: Incremental xref information structure comprises multiple sections; this update adds
* a new section.
*/
XRefStream xrefStream = new XRefStream(file);
// 2.1. Indirect objects.
IndirectObjects indirectObjects = file.IndirectObjects;
// 2.1.1. Modified indirect objects serialization.
XRefEntry prevFreeEntry = null;
/*
* NOTE: Any uncompressed indirect object will be compressed.
*/
ObjectStream objectStream = null;
/*
* NOTE: Any previously-compressed indirect object will have its original object stream
* updated through a new extension object stream.
*/
IDictionary <int, ObjectStream> extensionObjectStreams = new Dictionary <int, ObjectStream>();
int indirectObjectsPrecompressCount = indirectObjects.Count;
foreach (PdfIndirectObject indirectObject in new List <PdfIndirectObject>(indirectObjects.ModifiedObjects.Values))
{
if (indirectObject.IsCompressible())
{
if (objectStream == null ||
objectStream.Count >= ObjectStreamMaxEntryCount)
{
file.Register(objectStream = new ObjectStream());
}
indirectObject.Compress(objectStream);
}
prevFreeEntry = AddXRefEntry(
indirectObject,
xrefStream,
prevFreeEntry,
extensionObjectStreams
);
}
// 2.1.2. Additional object streams serialization.
for (int index = indirectObjectsPrecompressCount, limit = indirectObjects.Count; index < limit; index++)
{
prevFreeEntry = AddXRefEntry(
indirectObjects[index],
xrefStream,
prevFreeEntry,
null
);
}
if (prevFreeEntry != null)
{
prevFreeEntry.Offset = 0; // Links back to the first free object. NOTE: The first entry in the table (object number 0) is always free.
}
// 2.2. XRef stream.
UpdateTrailer(xrefStream.Header, stream);
xrefStream.Header[PdfName.Prev] = PdfInteger.Get((int)parser.RetrieveXRefOffset());
AddXRefEntry(
/*
* NOTE: This xref stream indirect object is purposely temporary (i.e. not registered into
* the file's indirect objects collection).
*/
new PdfIndirectObject(
file,
xrefStream,
xrefStreamEntry = new XRefEntry(indirectObjects.Count, 0, (int)stream.Length, XRefEntry.UsageEnum.InUse)
),
xrefStream,
null,
null
);
}
// 3. Tail.
WriteTail(xrefStreamEntry.Offset);
}