Currently if `RenderTask.cancel` is called *immediately* after rendering was started, then by the time that `InternalRenderTask.initializeGraphics` is called rendering will already have been cancelled.
However, we're still inserting the canvas into the `canvasInRendering` map, thus breaking any future attempts at re-rendering using the same canvas. Considering that `InternalRenderTask.cancel` always removes the canvas from the map, I cannot imagine that we'd ever want to re-add it *after* rendering was cancelled (it was likely just a simple oversight in PR 8519).
Fixes 9456.
This wasn't included in PR 9245, since all the API options were still global at that time.
Writing the unit-tests also uncovered an issue with `getOperatorList` not starting the "Page Request" timer.
Incomplete path operators, in particular, can result in fairly chaotic rendering artifacts, as can be observed on page four of the referenced PDF file.
The initial (naive) solution that was attempted, was to simply throw a `FormatError` as soon as any invalid (i.e. too short) operator was found and rely on the existing `ignoreErrors` code-paths. However, doing so would have caused regressions in some files; see the existing `issue2391-1` test-case, which was promoted to an `eq` test to help prevent future bugs.
Hence this patch, which adds special handling for invalid path operators since those may cause quite bad rendering artifacts.
You could, in all fairness, argue that the patch is a handwavy solution and I wouldn't object. However, given that this only concerns *corrupt* PDF files, the way that PDF viewers (PDF.js included) try to gracefully deal with those could probably be described as a best-effort solution anyway.
This patch also adjusts the existing `warn`/`info` messages to print the command name according to the PDF specification, rather than an internal PDF.js enumeration value. The former should be much more useful for debugging purposes.
Fixes https://bugzilla.mozilla.org/show_bug.cgi?id=1443140.
This patch avoids choosing a (possible) 'trailer' dictionary that `XRef.parse` and/or the `Catalog` constructor/methods will reject anyway.
Since `XRef.indexObjects` is already parsing the entire PDF file, the extra dictionary look-ups added here shouldn't matter much. Besides, this is a fallback code-path that only applies to corrupt PDF files anyway.
Note that the `Catalog` constructor, and some of its methods, are already enforcing that the 'Root' dictionary is valid/well-formed. However, by doing additional validation already in `XRef.parse` there's a slightly larger chance that corrupt PDF files could be successfully parsed/rendered.
With the current code line-breaks are accepted not just after an operator, but after a decimal point as well. When looking at this again, the latter case seems prone to cause false positives and might also interfere with subsequent patches.
Hence this is code is adjusted to actually do what the original commit message says, and nothing more.
Please note that the standalone `pdf.image_decoders.js` file will be including the complete `src/shared/util.js` file, despite only using parts of it.[1] This was done *purposely*, to not negatively impact the readability/maintainability of the core PDF.js code.
Furthermore, to ensure that the compatibility is the same in the regular PDF.js library *and* in the the standalone image decoders, `src/shared/compatibility.js` was included as well.
To (hopefully) prevent future complaints about the size of the built `pdf.image_decoders.js` file, a few existing async-related polyfills are being skipped (since all of the image decoders are completely synchronous).
Obviously this required adding a couple of pre-processor statements, but given that these are all limited to "compatibility" code, I think this might be OK!?
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[1] However, please note that previous commits moved `PageViewport` and `MessageHandler` out of `src/shared/util.js` which reduced its size.
The purpose of this patch is to hopefully provide *slightly* better user ergonomics, if/when the PDF.js image decoders are used standalone.
This implementation is (basically) reverting the changes in PR 9386, in conjunction with code from the `parse` method found at https://github.com/notmasteryet/jpgjs/blob/master/src/pdfjs.js
Obviously it's still not possible to render non-embedded fonts as paths, but in this way the rest of the page will at least be allowed to continue rendering.
*Please note:* Including the 14 standard fonts in PDF.js probably wouldn't be *that* difficult to implement. (I'm not a lawyer, but the fonts from PDFium could probably be used given their BSD license.)
However, the main blocker ought to be the total size of the necessary font data, since I cannot imagine people being OK with shipping ~5 MB of (additional) font data with Firefox. (Based on the reactions when the CMap files were added, and those are only ~1 MB in size.)
Since `ColorSpace` now depends on the native clamping of `Uint8ClampedArray`, this patch adds non-production/test-only `assert`s to enforce that the expected TypedArray is used for the output.
These `assert`s are purposely *not* included in PRODUCTION builds since that would break rendering completely, as opposed to "only" displaying some weird colours, when a `Uint8Array` was used. Furthermore, these are mostly added to help catch explicit developer errors when working with the `ColorSpace` and `PDFImage` code.
Since the tests (currently) run with the `pdf.worker.js` file built, i.e. with `PRODUCTION = true` set, there's no simple way to add e.g. `assert` calls for both non-production *and* test-only builds without also affecting PRODUCTION builds.
The built-in image decoders are already using `Uint8ClampedArray` when returning data, and this patch simply extends that to the rest of the image/colorspace code.
As far as I can tell, the only reason for using manual clamping/rounding in the first place was because TypedArrays used to be polyfilled (using regular arrays). And trying to polyfill the native clamping/rounding would probably have been had too much overhead, but given that TypedArray support is required in PDF.js version `2.0` that's no longer a concern.
*Please note:* Because of different rounding behaviour, basically `Math.round` in `Uint8ClampedArray` respectively `Math.floor` in the old code, there will be very slight movement in quite a few existing test-cases. However, the changes should be imperceivable to the naked eye, given that the absolute difference is *at most* `1` for each RGB component when comparing `master` and this patch (see also the updated expectation values in the unit-tests).
The built-in image decoders are already returning data as `Uint8ClampedArray`, and subsequently the JPEG/JBIG2/JPX streams are as well. However, for general streams we obviously don't want to force the use of `Uint8ClampedArray` unless an "Image" is actually being decoded.
Hence this patch, which adds a parameter that allows the caller of the `getBytes`/`peekBytes` methods to force a `Uint8ClampedArray` (rather than a `Uint8Array`) to be returned.
Not only is the `Util.loadScript` helper function unused on the Worker side, even trying to use it there would throw an Error (since `document` isn't defined/available in Workers).
Hence this helper function is moved, and its code modernized slightly by having it return a Promise rather than needing a callback function.
Finally, to reduced code duplication, the "new" loadScript function is exported and used in the viewer.
The various classes have `this._errored` and `this._reason` properties, where the first one is a boolean indicating if an error was encountered and the second one contains the actual `Error` (or `null` initially).
In practice this means that errors are basically tracked *twice*, rather than just once. This kind of double-bookkeeping is generally a bad idea, since it's quite easy for the properties to (accidentally) get into an inconsistent state whenever the relevant code is modified.
Rather than using a separate boolean, we can just as well check the "error" property directly (since `null` is falsy).
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Somewhat unrelated to this patch, but `src/display/node_stream.js` is currently *not* handling errors in a consistent or even correct way; compared with `src/display/network.js` and `src/display/fetch_stream.js`.
Obviously using the `createResponseStatusError` utility function, from `src/display/network_utils.js`, might not make much sense in a Node.js environment. However at the *very* least it seems that `MissingPDFException`, or `UnknownErrorException` when one cannot tell that the PDF file is "missing", should be manually thrown.
As is, the API (i.e. `getDocument`) is not returning the *expected* errors when loading fails in Node.js environments (as evident from the `pending` API unit-test).
Since the old comment mentions a now unsupported browser, let's update it such that someone won't accidentally conclude that the code in question can be removed.
This special handling was added in PR 8567, but was made redundant in PR 8721 which stopped sending everything but the kitchen sink to the Worker side.
Since `PDFPageProxy` already provide getters for all the data returned by `GetPage` (in the Worker), there isn't any compelling reason for accessing the `pageInfo` directly on `PDFPageProxy`.
The patch also changes the `GetPage` handler, in `src/core/worker.js`, to use modern JavaScript features.
Since `PDFDocumentProxy` already provide getters for all the data returned by `GetDoc` (in the Worker), there isn't any compelling reason for accessing the `pdfInfo` directly on `PDFDocumentProxy`.
After PR 8617 the `PDFManagerReady` message handler function, in `src/display/api.js`, is now a no-op. Hence it seems completely unnecessary to keep sending this message from `src/core/worker.js`.
With native typed array support now being mandatory in PDF.js, since version 2.0, this probably isn't a huge problem even though the current code seems wrong (it was changed in PR 6571).
Note how in the `!(data instanceof Uint8Array)` case we're currently attempting to send `handler.send('test', 'main', false);` to the main-thread, which doesn't really make any sense since the signature of the method reads `send(actionName, data, transfers) {`.
Hence the data that's *actually* being sent here is `'main'`, with `false` as the transferList, which just seems weird. On the main-thread, this means that we're in this case checking `data && data.supportTypedArray`, where `data` contains the string `'main'` rather than being falsy. Since a string doesn't have a `supportTypedArray` property, that check still fails as expected but it doesn't seem great nonetheless.
Since all the built-in PDF.js image decoders now return their data as `Uint8ClampedArray`, for consistency `JpegDecode` on the main-thread should be doing the same thing; follow-up to PR 8778.
The signature of the `PDFWorker.fromPort` method, in addition to the `PDFWorker` constructor, was changed in PR 9480.
Hence it's probably a good idea to add a bit more validation to `PDFWorker.fromPort`, to ensure that it won't fail silently for an API consumer that updates to version 2.0 of the PDF.js library.
With version 2.0, native support for typed arrays is now a requirement for using the PDF.js library; see PR 9094 where the old polyfills were removed.
Hence the `isTypedArraysPresent` check, when setting up fake workers, no longer serves any purpose here and can thus be removed.
There's no good reason, as far as I can tell, to duplicate the functionality of the `LoopbackPort` in the unit-tests. The only difference between the implementations is that `LoopbackPort` mimics the (native) structured cloning, however that shouldn't matter here since the tests are only sending "simple" data (strings respectively arrays with numbers).
Furthermore the patch also changes `LoopbackPort` to default to using "structured cloning" and deferred invocation of the listeners, since native typed array support is now a requirement for using the PDF.js library.
The `MessageHandler` itself, and its assorted helper functions, are currently the single largest[1] piece of code in the `src/shared/util.js` file. By moving this code into its own file, `src/shared/util.js` thus becomes smaller and more manageable.
