In particular, this should reduce intermediate string creation by using
template strings and reduce variable lookup times by removing unneeded
variables and caching `this.current` in more places.
With PR 10675 having fixed the completely broken `disableRange=true` setting in the Firefox version of PDF.js, I couldn't help but noticing that loading progress is never reported properly in that case.
Currently loading progress is only reported for the `rangeProgress` chrome-event, which obviously isn't dispatched with `disableRange=true` set. However, the `progressiveRead` chrome-event includes loading progress as well, but this information isn't being used in any way.
Furthermore, the `PDFDataRangeTransport.onDataProgress` method wasn't able to handle "complete" loading information, and neither was `PDFDataTransportStream._onProgress` since that method would only ever attempt to report it through a RangeReader (which won't exist when `disableRange=true` is set).
Note how at https://mozilla.github.io/pdf.js/api/ it's being described as API docs, however `src/core/annotation.js` is not part of the public API.
Furthermore, given that the code residing in the `src/core/` folder is run in a worker-thread, it's not even accessible on the main-thread (since `postMessage` is being used to transfer the data).
Hence the different API methods simply returns a "proxy" to the underlying data, but not actually the same objects and data structures as in the worker-thread itself; thus it doesn't make a whole lot of sense to expose this in API docs as far as I'm concerned.
Finally, the patch fixes a small JSDoc related typo in `src/display/api.js` when referring to the `TextStyle` typedef.
The `moz-chunked-arraybuffer` responseType is a non-standard property, which has been subsumed by the Fetch API, and it's in the process of being removed from Firefox; please see https://bugzilla.mozilla.org/show_bug.cgi?id=1120171 and https://bugzilla.mozilla.org/show_bug.cgi?id=1411865
*Please note:* Rather than waiting for both `Fetch` *and* `ReadableStream` to be available in e.g. a Firefox ESR version (which is probably going to be 68 at the earliest), let's just decide that PDF.js release `2.1.266` will be the last one with `moz-chunked-arraybuffer` support and land this patch (since nothing should outright break without it anyway).
Note how `XRef.fetchUncompressed`, which is used *a lot* for most PDF documents, is calling the `makeSubStream` method without providing a `length` argument.
In practice this results in the `makeSubStream` method, on the `ChunkedStream` instance, calling the `ensureRange` method with `NaN` as the end position, thus resulting in no data being requested despite it possibly being necessary.
This may be quite bad, since in this particular case it will lead to a new `ChunkedStream` being created *and* also a new `Parser`/`Lexer` instance. Given that it's quite possible that even the very first `Parser.getObj` call could throw `MissingDataException`, this could thus lead to wasted time/resources (since re-parsing is necessary once the data finally arrives).
You obviously need to be very careful to not have `ChunkedStream.makeSubStream` accidentally requesting the *entire* file, hence its `this.end` property is of no use here, but it should be possible to at least check that the `start` of the data is present before any potentially expensive parsing occurs.
This transform resulted in an incorrectly positioned object when the
bounding box's upper-left corner did not start at (0,0), because
the translation was not reverted. This patch adds the missing transform.
The test file (tiling-pattern-box.pdf) is based on the PDF from #2825.
All but the first cube (including the PDF data) have been removed.
To trigger the bug that is fixed by this commit, I changed the BBox of
the first pattern from "[ 0 0 596 842]" to "[90 0 596 842]". Without
this patch, the dashed vertical line that intersects the corners at A
and E would disappear.
The new test file (tiling-pattern-large-steps.pdf) was manually created,
to have the following characteristics:
- Large xstep and ystep (90000)
- Page width is 4000 (which is larger than MAX_PATTERN_SIZE)
- Visually, the page consists of a red rectangle with a black border,
surrounded by a 50 unit white padding.
- Before patch: blurry; After patch: sharp
Fixes#6496Fixes#5698Fixes#1434Fixes#2825
Without this some fonts may incorrectly end up with matching `hash`es, thus breaking rendering since we'll not actually try to load/parse some of the fonts.
Note that `PartialEvaluator.preEvaluateFont` will return an empty string when no hash was computed. This will complete short-circuit the `fontAlias` comparison in `PartialEvaluator.loadFont`, since fonts which are totally different will then match if their `hash`es are empty.
Currently if trying to set `disableRange=true` in the built-in PDF Viewer in Firefox, either through `about:config` or via the URL hash, the PDF document will never load. It appears that this has been broken for a couple of years, without anyone noticing.
Obviously it's not a good idea to set `disableRange=true`, however it seems that this bug affects the PDF Viewer in Firefox even with default settings:
- In the case where `initialData` already contains the *entire* file, we're forced to dispatch a range request to re-fetch already available data just so that file loading may complete.
- (In the case where the data arrives, via streaming, before being specifically requested through `requestDataRange`, we're also forced to re-fetch data unnecessarily.) *This part was removed, to reduce the scope/risk of the patch somewhat.*
In the cases outlined above, we're having to re-fetch already available data thus potentially delaying loading/rendering of PDF files in Firefox (and wasting resources in the process).
This function is currently called with the `OperatorList` instance as its argument, hence I cannot think of any good reason for not just moving it into the `OperatorList` properly. (This will also help with other planned changes regarding the `ImageCache` functionality.)
By transfering `ArrayBuffer`s you can avoid having two copies of the same data, i.e. one copy on each of the worker/main-thread, for data that's used only *once* on the worker-thread.
Note how the code in [`PDFImage.createMask`](80135378ca/src/core/image.js (L284-L285)) goes to great lengths to actually enable tranfering of the image data. However in [`PartialEvaluator.buildPaintImageXObject`](80135378ca/src/core/evaluator.js (L336)) the `cached` property is always set to `true`, which disqualifies the image data from being transfered; see [`getTransfers`](80135378ca/src/core/operator_list.js (L552-L554)).
For most ImageMask data this patch won't matter, since images found in the `/Resources -> /XObject` dictionary will always be indexed by name. However for *inline* images which contains ImageMask data, where only "small" images are cached (in both `parser.js` and `evaluator.js`), the current code will result in some unnecessary memory usage.
This will further help reduce the amount of image data that's currently being held alive, by explicitly removing the `src` attribute.
Please note that this is mostly relevant for browsers which do not support `URL.createObjectURL`, or where `disableCreateObjectURL` was manually set by the user, since `blob:` URLs will be revoked (see the previous patch).
However, using `about:memory` (in Firefox) it does seem that this may also be generally helpful, given that calling `URL.revokeObjectURL` won't invalidate the image data itself (as far as I can tell).
Natively supported JPEG images are sent as-is, using a `blob:` or possibly a `data` URL, to the main-thread for loading/decoding.
However there's currently no attempt at releasing these resources, which are held alive by `blob:` URLs, which seems unfortunately given that images can be arbitrarily large.
As mentioned in https://developer.mozilla.org/en-US/docs/Web/API/URL/createObjectURL the lifetime of these URLs are tied to the document, hence they are not being removed when a page is cleaned-up/destroyed (e.g. when being removed from the `PDFPageViewBuffer` in the viewer).
This is easy to test with the help of `about:memory` (in Firefox), which clearly shows the number of `blob:` URLs becomming arbitrarily large *without* this patch. With this patch however the `blob:` URLs are immediately release upon clean-up as expected, and the memory consumption should thus be considerably reduced for long documents with (simple) JPEG images.
Note how `PDFDocumentProxy.destroy` is a nothing more than an alias for `PDFDocumentLoadingTask.destroy`. While removing the latter method would be a breaking API change, there's still room for at least some clean-up here.
The main changes in this patch are:
- Stop providing a `PDFDocumentLoadingTask` instance *separately* when creating a `PDFDocumentProxy`, since the loadingTask is already available through the `WorkerTransport` instance.
- Stop tracking the `PDFDocumentProxy` instance on the `WorkerTransport`, since that property is completely unused.
- Simplify the 'Multiple `getDocument` instances' unit-tests by only destroying *once*, rather than twice, for each document.
For Type3 fonts text-selection is often not that great, and there's a couple of heuristics used to try and improve things. This patch simple extends those heuristics a bit, and fixes a pre-existing "naive" array comparison, but this all feels a bit brittle to say the least.
The existing Type3 test-coverage isn't that great in general, and in particular Type3 `text` tests are few and far between, hence why this patch adds *two* different new `text` tests.
Notable changes:
- Remove the `return this;` from the `MurmurHash3_64.update` method, since it's completely unused and doesn't make a lot of sense.
- Remove the loop(s) from the `MurmurHash3_64.hexdigest` method, since creating a temporary array and then looping over it is wasteful given how simple this can be written with modern JavaScript.
Given that the function is (purposely) independent of the verbosity level and that its message is worded to only apply on the main-thread, there's no reason to duplicate this across the built `pdf.js`/`pdf.worker.js` files.
Currently for every single parsed/rendered page there's no less than *four* `Date.now()` calls being made on the worker-side. This seems totally unnecessary, since the result of these calls are, by default, not used for anything *unless* the verbosity level is set to `INFO`.
