Class | PDF::Reader::XRef |
In: |
lib/pdf/reader/xref.rb
|
Parent: | Object |
An internal PDF::Reader class that represents the XRef table in a PDF file as a hash-like object.
An Xref table is a map of object identifiers and byte offsets. Any time a particular object needs to be found, the Xref table is used to find where it is stored in the file.
Hash keys are object ids, values are either:
The class behaves much like a standard Ruby hash, including the use of the Enumerable mixin. The key difference is no []= method - the hash is read only.
trailer | [R] |
create a new Xref table based on the contents of the supplied io object
io - must be an IO object, generally either a file or a StringIO
returns the byte offset for the specified PDF object.
ref - a PDF::Reader::Reference object containing an object ID and revision number