Dylan M. Taylor
7f0f352d21
* pdf inspection: count pending text clips and drop page content after reading - hayro-interpret: state_bytes counts the pending text-clip outlines a saved state copies, so MAX_SAVED_STATE_BYTES bounds them too. - plate-test structure: read each page through a ContentReader into a buffer dropped after the page, instead of page.operations(), which keeps every page's decoded content for as long as the document. * address review: cap page content read at the 256 MiB decode limit * fix the saved-state test: start the clip outline with a MoveTo
hayro-interpret
A crate for interpreting PDF files.
This crate provides an abstraction to interpret the content of a PDF file and render them
into an abstract [Device], which clients can implement as needed. This allows you, for
example, to render PDF files to bitmaps (which is what the hayro crate does), or other formats
such as SVG.
It should be noted that this crate is still very much in development. Therefore it currently lacks pretty much any documentation on how to use it. It's current API also only really makes it useful for rendering to PNG or SVG, though this will be improved upon in the future.
Examples
See the examples folder on the GitHub repository. Apart from that, you can also consult
the implementation of hayro and hayro-svg to get an idea on how to use this crate.
Safety
This crate forbids unsafe code via a crate-level attribute.
Cargo features
This crate has one optional feature:
embed-fonts: PDF processors are required to support 14 predefined fonts that do not need to be embedded into a PDF file. If you enable this feature, hayro will embed a (permissively-licensed) substitute for each font, so that you don't have to implement your custom font loading logic. This will add around ~240KB to your binary.
License
Licensed under either of
- Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
PdfCraft function limits
The PdfCraft patch rejects function construction after 64 nested functions or 10,000 total
function nodes, including repeated references, and detects cycles on the current path. Shared
children in different branches remain valid. Stitching functions reject empty or unresolved
child lists instead of silently truncating them. Calculator functions have a shared limit of 64
procedure levels and 10,000 parsed tokens (operators and procedure openings); evaluation has
its own 10,000-operator limit across selected branches. These are implementation resource
limits rather than PDF format limits. Rejection returns the existing None, and the optional
logging feature reports the reason and limit; no new interface warning is introduced.
Calculator integer division without an integer result is also rejected. Bit shifting discards bits beyond the 32-bit word and fills with zeroes, including logical right shifts of negative words; rotation accepts the full signed shift range without negating the minimum integer. Fixed-size operand and procedure-stack overflow errors propagate instead of truncating work. Normal function signatures and supported color/transfer-function behavior remain unchanged.