Pdf.Toolbox.Core.XRef

Cross reference

Documentation

data XRef

Cross reference

Constructors

XRefTable Int64

Offset

XRefStream Int64 (Stream Int64)

Offset and stream with content offset

Instances

Show XRef

data XRefEntry

Entry in cross reference

Constructors

XRefTableEntry TableEntry

XRefStreamEntry StreamEntry

Instances

Show XRefEntry

data TableEntry

Entry in cross reference table

Constructors

TableEntry

Fields

teOffset :: Int64

teGen :: Int

teIsFree :: Bool

Instances

Show TableEntry

data StreamEntry

Entry in cross reference stream

Constructors

StreamEntryFree Int Int

Object number and generation

StreamEntryUsed Int64 Int

Object offset (in bytes from the beginning of file) and generation

StreamEntryCompressed Int Int

Object number of object stream and index within the object stream

Instances

Show StreamEntry

lastXRef :: MonadIO m => RIS -> PdfE m XRef

Find the last cross reference

prevXRef :: MonadIO m => RIS -> XRef -> PdfE m (Maybe XRef)

Find prev cross reference

trailer :: MonadIO m => RIS -> XRef -> PdfE m Dict

Read trailer for the xref

lookupTableEntry

Arguments

:: MonadIO m

=> RIS

input stream to read from

-> Ref

indirect object to look for

-> PdfE m (Maybe TableEntry)

Read xref entry for the indirect object from xref table

RIS position should point to the begining of the next line after "xref" keyword

lookupStreamEntry

Arguments

:: MonadIO m

=> Stream IS

decoded xref stream content

-> Ref

indirect object

-> PdfE m (Maybe StreamEntry)

Read xref entry for the indirect object from xref stream

See pdf1.7 spec: 7.5.8 Cross-Reference Streams

isTable :: MonadIO m => IS -> PdfE m Bool

Check whether the stream starts with "xref" keyword. The keyword iyself is consumed