public void ReadsEmptySection()
{
// Arrange
XRefSection section;
using (var pdfStream = new MemoryStream())
{
using (var sw = new StreamWriter(pdfStream, Encoding.ASCII, 128, true))
{
sw.WriteLine("xref");
sw.WriteLine("0 0");
sw.WriteLine("trailer");
}
pdfStream.Seek(0, SeekOrigin.Begin);
// Act
using (var reader = new PdfReader(pdfStream))
{
section = XRefSection.FromReader(reader);
}
}
// Assert
Assert.NotNull(section);
Assert.NotNull(section.Entries);
Assert.Equal(0, section.Entries.Count);
}
public void ReadsSimpleSection()
{
// Arrange
XRefSection section;
using (var pdfStream = new MemoryStream())
{
using (var sw = new StreamWriter(pdfStream, Encoding.ASCII, 128, true))
{
sw.WriteLine("xref");
sw.WriteLine("0 6");
sw.Write("0000000003 65535 f\r\n");
sw.Write("0000000017 00000 n\r\n");
sw.Write("0000000081 00000 n\r\n");
sw.Write("0000000000 00007 f\r\n");
sw.Write("0000000331 00000 n\r\n");
sw.Write("0000000409 00000 n\r\n");
sw.WriteLine("trailer");
}
pdfStream.Seek(0, SeekOrigin.Begin);
// Act
using (var reader = new PdfReader(pdfStream))
{
section = XRefSection.FromReader(reader);
}
}
// Assert
Assert.NotNull(section);
Assert.NotNull(section.Entries);
Assert.Equal(6, section.Entries.Count);
Assert.Equal(PdfObjectId.Zero, section.Entries[0].ObjectId);
Assert.Equal(3, (section.Entries[0] as PdfFreeObjectReference).NextFreeObjectNumber);
Assert.Equal(new PdfObjectId(1), section.Entries[1].ObjectId);
Assert.Equal(17, (section.Entries[1] as PdfObjectReference).Position);
Assert.Equal(new PdfObjectId(2), section.Entries[2].ObjectId);
Assert.Equal(81, (section.Entries[2] as PdfObjectReference).Position);
Assert.Equal(new PdfObjectId(3, 7), section.Entries[3].ObjectId);
Assert.Equal(0, (section.Entries[3] as PdfFreeObjectReference).NextFreeObjectNumber);
Assert.Equal(new PdfObjectId(4), section.Entries[4].ObjectId);
Assert.Equal(331, (section.Entries[4] as PdfObjectReference).Position);
Assert.Equal(new PdfObjectId(5), section.Entries[5].ObjectId);
Assert.Equal(409, (section.Entries[5] as PdfObjectReference).Position);
}
public void ReadsSubSections()
{
// Arrange
XRefSection section;
using (var pdfStream = new MemoryStream())
{
using (var sw = new StreamWriter(pdfStream, Encoding.ASCII, 128, true))
{
sw.WriteLine("xref");
sw.WriteLine("0 1");
sw.Write("0000000000 65535 f\r\n");
sw.WriteLine("3 1");
sw.Write("0000025325 00000 n\r\n");
sw.WriteLine("23 2");
sw.Write("0000025518 00002 n\r\n");
sw.Write("0000025635 00000 n\r\n");
sw.WriteLine("30 1");
sw.Write("0000025777 00000 n\r\n");
sw.WriteLine("trailer");
}
pdfStream.Seek(0, SeekOrigin.Begin);
// Act
using (var reader = new PdfReader(pdfStream))
{
section = XRefSection.FromReader(reader);
}
}
// Assert
Assert.NotNull(section);
Assert.NotNull(section.Entries);
Assert.Equal(5, section.Entries.Count);
Assert.Equal(PdfObjectId.Zero, section.Entries[0].ObjectId);
Assert.Equal(0, (section.Entries[0] as PdfFreeObjectReference).NextFreeObjectNumber);
Assert.Equal(new PdfObjectId(3), section.Entries[3].ObjectId);
Assert.Equal(25325, (section.Entries[3] as PdfObjectReference).Position);
Assert.Equal(new PdfObjectId(23, 2), section.Entries[23].ObjectId);
Assert.Equal(25518, (section.Entries[23] as PdfObjectReference).Position);
Assert.Equal(new PdfObjectId(24), section.Entries[24].ObjectId);
Assert.Equal(25635, (section.Entries[24] as PdfObjectReference).Position);
Assert.Equal(new PdfObjectId(30), section.Entries[30].ObjectId);
Assert.Equal(25777, (section.Entries[30] as PdfObjectReference).Position);
}
/// <summary>
/// Creates a new instance of the PdfDocument class from the IO stream.
/// </summary>
/// <param name="stream">The <see cref="Stream"/> on which to open the PdfDocument.</param>
/// <returns></returns>
public static PdfDocument Open(Stream stream)
{
if (stream == null)
{
throw new ArgumentNullException(nameof(stream));
}
if (!stream.CanRead)
{
throw new ArgumentException("Cannot read stream", nameof(stream));
}
var document = new PdfDocument(stream);
using (var reader = new PdfReader(stream))
{
// Check header
document.pdfVersion = PdfVersion.FromReader(reader);
// Check trailer
reader.Position = reader.GetXRefPosition();
// Read Cross-Reference Table
IPdfTrailer trailer;
IXRefSection xrefSection;
char fisrtChar;
do
{
fisrtChar = reader.Peek();
if (fisrtChar == XRefSection.StartKeyword[0])
{
// Cross-Reference Section
xrefSection = XRefSection.FromReader(reader);
trailer = PdfTrailer.FromReader(reader);
}
else if (char.IsDigit(fisrtChar))
{
// Cross-Reference Stream
var xrefStream = XRefStream.FromReader(reader);
trailer = xrefStream;
xrefSection = xrefStream;
}
else
{
throw new FormatException("Invalid Cross-Reference section.");
}
if (document.xrefTable == null)
{
// Initialize document's Cross-Reference Table
document.xrefTable = new XRefTable(xrefSection, trailer.Size);
}
else
{
// Register section
document.xrefTable.AddSection(xrefSection);
}
// Keep instance of last trailer
if (document.trailer == null)
{
document.trailer = trailer;
}
// Seek to previous trailer
if (trailer.Prev.HasValue)
{
reader.Position = trailer.Prev.Value;
}
}while (trailer.Prev != null);
}
return(document);
}
