The text read and the rasterizer each opened pdf.js on their own: the text
read with bare options, the rasterizer through src/lib/documents/pdfjs.ts
with the standard font, CMap and wasm directories. The loader now serves
both, so a CID font with a predefined CMap is mapped to characters on the
text path too, and there is one set of options to keep in step.
The loader is typed with pdf.js' own declarations instead of a hand-written
shape. That drops isEvalSupported, which pdf.js 6 no longer has and which did
nothing. Only the render slice the DOM-typed declarations cannot describe
(the native canvas factory) keeps a named local type in the rasterizer.
The run joiner with its named steps moves into the loader as joinTextRuns,
and readPdfText is its one page walk; the second layout copy that mimicked
the previous library's tabs and blank lines is gone. extractPdfText keeps
its outcomes and page cap on top of it, and a failed read still says what
pdf.js threw (documents.local_extract.failed). A test draws a word in two
fonts into a real PDF and reads it back whole.
Refs #1277
Under Node, pdf.js runs its worker in the server process and keeps it on
a global, and whichever copy of pdf.js opens a document first owns that
global until a restart. The local text read went through pdf-parse, which
pins its own pdfjs-dist 5.4.296; the rasterizer uses the app's 6.4.299. A
text read first made every later rasterization fail with "The API version
does not match the Worker version" (thumbnails raster-failed, the vision
read of a scan 422), and a rasterization first made every later local text
read fail, which left the document out of the search index with nothing in
the logs.
src/lib/documents/pdfjs.ts is now the one place pdf.js is loaded and
opened, with one set of options (asset directories, no eval, no system
fonts). The text read walks the pages with getTextContent and lays the
text out the way pdf-parse did with the options it was called with: line
breaks, tabs between far-apart items, a blank line after each page, the
200-page cap. Text extracted from the PDF fixtures and from generated lab
tables, encrypted files and doctor reports is identical before and after.
A failed text read now emits documents.local_extract.failed with the
error pdf.js threw, and annotates the index event with it, instead of
returning a bare error.
The report tests read PDF text through the same reader. Two tests, one per
order, run a text read and a rasterization in one process; both failed
before this change.
Refs #1277
Marc-André Bombeck