This function only has a single call-site (if we ignore the unit-tests), where the colors are split into separate parameters.
Given that all the color components are modified in the exact same way, it seems easier (and shorter) to pass the colors as-is to `applyOpacity` and have it use `Array.prototype.map()` instead.
This obviously won't matter in practice, however it seems more "correct" to only extract the necessary number of color components rather than slicing off excess ones at the end.
Looking at the very similar `CssFontInfo.prototype.#readString` and `SystemFontInfo.prototype.#readString` methods they decode using the data as-is, but the `FontInfo.prototype.#readString` method for some reason copies the data into a new `Uint8Array` first; fixes yet another bug/inefficiency in PR 20197.
This is a little bit shorter, and it should be fine considering that in the API there are no `typeof` checks when invoking user-provided callbacks (see e.g. `onPassword` and `onProgress`).
The cache has been added in #3312 in 2013 and a lot of things changed since.
Having too many cached accelerated canvases can lead to have to move their data from the GPU to the RAM
which is costly.
So this patch:
- removes all the cached canvases;
- destroys the useless canvases in order to free their associated memory asap;
- slightly rewrite canvas.js::_scaleImage to avoid too much canvas creation.
This code already isn't used (or even bundled) in the Firefox PDF Viewer, and it also slightly reduces the number of import maps that need to be maintained.
Currently we have no less than three different, but very similar, factories for reading built-in CMap files, standard font files, and wasm files on the main-thread.[1]
These factories were added at different points in time, since I cannot imagine that we'd add essentially three copies of the same code otherwise.
Nowadays these factories are often not even used[2], since worker-thread fetching is used whenever possible to improve performance. In particular, they will *only* be used when either:
- The PDF.js library runs in Node.js environments.
- The user manually sets `useWorkerFetch = false` when calling `getDocument`.
- The user provides custom `CMapReaderFactory`, `StandardFontDataFactory`, and/or `WasmFactory` instances when calling `getDocument`.
By replacing these factories with *a single* new `BinaryDataFactory` factory/option the number of `getDocument` options are thus reduced, which cannot hurt.
This also reduces the total bundle-size of the Firefox PDF Viewer a little bit, and it slightly reduces the number of import maps that need to be maintained.
*Please note:* For users that provide custom `CMapReaderFactory`, `StandardFontDataFactory`, and `WasmFactory` instances when calling `getDocument` this will be a breaking change, however it's unlikely that (many) such users exist.
(The *internal* format data-format of `CMapReaderFactory` was changed in PR 18951, and there hasn't been a single question/complaint about it in well over a year.)
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[1] Any new functionality could easily lead to more such factories being added in the future, which wouldn't be great.
[2] Note that the Firefox PDF Viewer no longer use these factories, since it "forcibly" sets `useWorkerFetch = true` during building.
Trying to resolve the same `objId` more than once would be a bug elsewhere in the code-base, since that should never happen, hence update the `resolve` method to prevent that.
The `BaseCMapReaderFactory`, `BaseStandardFontDataFactory`, and `BaseWasmFactory` classes are all very similar, and the only difference is really in their respective `fetch` methods.
By have the worker-thread "compute" the complete `filename` it's possible to simplify the `BaseCMapReaderFactory.prototype.fetch` method, which will allow future improvements to all of these classes.
A couple of things to note:
- This code is unused, and it's not even bundled, in the Firefox PDF Viewer.
- In browsers it's unused by default, and worker-thread fetching will always be used when possible since that's more efficient.
*Please note:* For users that provide a custom `CMapReaderFactory` instance when calling `getDocument` this could be a breaking change, however it's unlikely that any such users exist.
(The *internal* format of this data was changed previously in PR 18951, and there hasn't been a single question/complaint about it in well over a year.)
The WebGPU feature hasn't been released yet but it's interesting to see how
we can use it in order to speed up the rendering of some objects.
This patch allows to render mesh patterns using WebGPU.
I didn't see any significant performance improvement on my machine (mac M2)
but it may be different on other platforms.
Given that we "forcibly" set `useWorkerFetch = true` for the MOZCENTRAL build-target there's a small amount of dead code as a result, which we can thus remove during building.
Given that these classes are only used from the "FetchBinaryData" message handler, the `name`/`filename` parameters should never actually be missing and if they are that's a bug elsewhere in the code-base.
Furthermore a missing `name`/`filename` parameter would result in a "nonsense" URL and the actual data fetching would then fail instead, hence keeping this old validation code just doesn't seem necessary.
Providing one of these parameters is necessary when calling `getDocument`, since otherwise there's nothing to actually load. However, we currently don't enforce that properly and if there's more than one of these parameters provided the behaviour isn't well defined.[1]
The new behaviour is thus, in order:
1. Use the `data` parameter, since the PDF is already available and no additional loading is necessary.
2. Use the `range` parameter, for custom PDF loading (e.g. the Firefox PDF Viewer).
3. Use the `url` parameter, and have the PDF.js library load the PDF with a suitable `networkStream`.
4. Throw an error, since there's no way to load the PDF.
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[1] E.g. if both `data` and `range` is provided, we'd load the document directly (since it's available) and also initialize a pointless `PDFDataTransportStream` instance.
After the changes in PR 20197 the code in the `TranslatedFont.prototype.send` method is not all that readable[1] given how it handles e.g. the `charProcOperatorList` data used with Type3 fonts.
Since this is the only spot where `Font.prototype.exportData` is used, it seems much simpler to move the `compileFontInfo` call there and *directly* return the intended data rather than messing with it after the fact.
Finally, while it doesn't really matter, the patch flips the order of the `charProcOperatorList` and `extra` properties throughout the code-base since the former is used with Type3 fonts while the latter (effectively) requires that debugging is enabled.
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[1] I had to re-read it twice, also looking at all the involved methods, in order to convince myself that it's actually correct.
The commit message for the patch in PR 20427 is pretty non-descriptive, being only a single line, however there's a bit more context in https://github.com/mozilla/pdf.js/pull/20427#issue-3597370951 but unfortunately the details there don't really make sense.
Note that the PR only changed main-thread code, but all the links are to worker-thread code!?
The `FontFaceObject` class is only used on the main-thread, and when encountering a broken font we fallback to the built-in font renderer; see 820b70eb25/src/display/font_loader.js (L135-L143)
Hence the `FontFaceObject` class *only* needs a way to set the `disableFontFace` property, however nowhere on the main-thread do we ever update the `bbox` of a font.
This is an old API-parameter that is now unused within the PDF.js project itself, and its description says that it's (partly) being used for "range requests operations".
Note that the `length` API-parameter is used to set the *initial* `contentLength` in various `BasePDFStreamReader` implementations, however it's always overridden by the "Content-Length" header (sent by the server) when that one exists *and* is a valid number. While we currently fallback to the keep the initial `contentLength` otherwise, note however how in that case range requests will always be *disabled* and thus the only spot in the code-base [where `fullReader.contentLength` is necessary](873378b718/src/core/worker.js (L230-L236)) cannot actually be reached.
Hence the only possible reason to use the `length` API-parameter would be for improved progress reporting[1] during streaming of PDF data in rare cases where the "Content-Length" header is missing/invalid, but the user *somehow* has information from another source about the correct `length` of the PDF document.
That situation feels very much like an edge-case, but it's obviously impossible to know if someone is depending on it. However, please note that there's a work-around available for users affected by this removal:
- Implement a `PDFDataRangeTransport` instance together with custom data-fetching[2], since in that case its `length`-parameter will always be used as-is.
Finally, updates various `BasePDFStreamReader` implementations to only set the `_isRangeSupported` field once the headers are available (since previously we'd just overwrite the "initial" value anyway).
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[1] I.e. to avoid the "indeterminate" loadingBar being displayed in the viewer.
[2] This is what e.g. the Firefox PDF Viewer uses.
Currently the `bbox`, `fontMatrix`, and `defaultVMetrics` getters duplicate almost the same code, which we can avoid by adding a new helper method (similar to existing ones for reading numbers and strings).
The added `assert` in the new helper method also caught a bug in how the `defaultVMetrics` length was compiled.
On the worker-thread only the static `write` methods are actually used, and on the main-thread only class instances are being created.
Hence this, after PR 20197, leads to a bunch of dead code in both of the *built* `pdf.mjs` and `pdf.worker.js` files.
This patch reduces the size of the `gulp mozcentral` output by `21 419` bytes, i.e. `21` kilo-bytes, which I believe is way too large of a saving to not do this.
(I can't even remember the last time we managed to reduce build-size this much with a single patch.)
The purpose of PR 11844 was to reduce memory usage once fonts have been attached to the DOM, since the font-data can be quite large in many cases.
Unfortunately the new `clearData` method added in PR 20197 doesn't actually remove *anything*, it just replaces the font-data with zeros which doesn't help when the underlying `ArrayBuffer` itself isn't modified.
The method does include a commented-out `resize` call[1], but uncommenting that just breaks rendering completely.
To address this regression, without having to make large or possibly complex changes, this patch simply changes the `clearData` method to replace the internal buffer/view with its contents *before* the font-data.
While this does lead to a data copy, the size of this data is usually orders of magnitude smaller than the font-data that we're removing.
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[1] Slightly off-topic, but I don't think that patches should include commented-out code since there's a very real risk that those things never get found/fixed.
At the very least such cases should be clearly marked with `// TODO: ...` comments, and should possibly also have an issue filed about fixing the TODO.
The `PagesMapper` class currently makes up one third of the `src/display/display_utils.js` file size, and since its introduction it's grown (a fair bit) in size.
Note that the intention with files such as `src/display/display_utils.js` was to have somewhere to place functionality too small/simple to deserve its own file.
