- in charstring specs at page 21 (section 4.2): "Also, it may appear in the charstring as the difference from nominalWidthX" so the number we've on the stack doesn't have to be positive.
- currently this bug has probably no visible effect
- but when the font is loaded to be used with XFA, then the rendering is incorrect.
As can be seen in PR 13371, some of the `no-var` changes in the `PartialEvaluator.{getOperatorList, getTextContent}` methods caused errors in `gulp server`-mode.
However, there's a handful of instances of `var` in other methods which should be completely *safe* to convert since there's no strange scope-issues present in that code.
With modern JavaScript modules, where only *explicitly* exported properties are visible to the outside, the `QueueOptimizerClosure` should no longer be necessary.
Furthermore, to reduce the possibility of `NullOptimizer` and `QueueOptimizer` getting out of sync (note e.g. the inconsistency fixed in PR 10784), we now let the latter extend the former one.
This patch replaces the old structure with a abstract base-class, which the new RadialAxial/Mesh-shading classes then inherit from.[1]
The old `MeshClosure` can now be removed, since it's not necessary any more, and most of the functions inside of it are now instead methods on the new `MeshShading` class. This is particularly nice, in my opinion, since we previously were *manually* passing around a reference to the current `Mesh`-instance.
---
[1] If we want/need to, in the future, split e.g. the Mesh-handling into multiple classes that should now be easy to do.
Neither the `type` or the `cs` properties are used outside of the "constructors", and we can thus remove them.[1]
Note that a lot of this code is very old, and that it actually predates the main/worker-thread split before which the *same* file was used on both the main- *and* worker-threads.
---
[1] On the main-thread, a similar `type` property was removed in PR 12591.
- Right now, a glyph with an erroneous outline is replaced by an empty glyph
if the error is far enough from the start there's likely something to render
so the idea is to replace a command with args by an endchar when no args are
on the stack: this way OTS is likely happy (no remaining args on stack) and we
can draw something which is likely better than nothing.
First of all, by using `Dict.getArray` in the `Page.content` getter we remove the need to manually iterate through and fetch the sub-streams (when they exist) in the `Page.getContentStream` method.
Secondly, we can simplify the code in `Page.{getOperatorList, extractTextContent}` by letting `Page.getContentStream` ensure that `content` is available and returning a Promise instead.
Similar to the `get`/`getAsync` methods, this should be a *tiny* bit more efficient which cannot hurt considering that `getArray` is now used a lot more than when initially added.
This reverts commit 0ef9b5aafc, since it cases a lot of warnings (see below) *locally* with e.g. the document from issue 9627.
Strangely enough, this only occurs with `gulp server`-mode and the actual builds are apparently fine. It seems that this *may* be some unfortunate interaction with the old Babel-plugin that's used together with SystemJS.
```
Warning: getTextContent - ignoring ExtGState: "FormatError: ExtGState should be a dictionary.".
```
Rather than taking the risk that this could actually cover a more serious bug, and since I cannot immediately figure out what's wrong, it thus seem safest to revert this for now and we can (carefully) revisit this once SystemJS has been removed (see PR 12563).
This patch was tested using the PDF file from issue 2618, i.e. https://bug570667.bugzilla-attachments.gnome.org/attachment.cgi?id=226471, with the following manifest file:
```
[
{ "id": "issue2618",
"file": "../web/pdfs/issue2618.pdf",
"md5": "",
"rounds": 50,
"type": "eq"
}
]
```
which gave the following results when comparing this patch against the `master` branch:
```
-- Grouped By browser, stat --
browser | stat | Count | Baseline(ms) | Current(ms) | +/- | % | Result(P<.05)
------- | ------------ | ----- | ------------ | ----------- | --- | ---- | -------------
firefox | Overall | 50 | 3417 | 3426 | 9 | 0.27 |
firefox | Page Request | 50 | 1 | 1 | 0 | 5.41 |
firefox | Rendering | 50 | 3416 | 3426 | 9 | 0.27 |
```
Based on these results, there's no significant performance regression from using standard classes and this patch should thus be OK.
Previously, we set the base transformation and pattern matrix
directly to the main rendering ctx of the page, however doing this
caused the current transform to be lost. This would cause issues
with things like shear missing so the pattern was misaligned or when
stroke was used the scale of the line width or dash would be wrong.
Instead we should leave the current transform and use setTransfrom
on the pattern so it is applied correctly. For axial and radial shadings I had
to create a temporary canvas to draw the shading so I could in turn
use setTransform.
Fixes: #13325, #6769, #7847, #11018, #11597, #11473
The following already in the corpus are improved:
issue8078-page1
issue1877-page1
Compared to other data-structures, such as e.g. `Dict`s, we're purposely *not* caching Streams on the `XRef`-instance.[1]
The, somewhat unfortunate, effect of Streams not being cached is that repeatedly getting the *same* Stream-data requires re-parsing/re-initializing of a bunch of data; see `XRef.fetch` and related methods.
For the font-parsing in particular we're currently fetching the `toUnicode`-data, which is very often a Stream, in `PartialEvaluator.preEvaluateFont` and then *again* in `PartialEvaluator.extractDataStructures` soon afterwards.
By instead letting `PartialEvaluator.preEvaluateFont` export the "raw" `toUnicode`-data, we can avoid *some* unnecessary re-parsing/re-initializing when handling fonts.
*Please note:* In this particular case, given that `PartialEvaluator.preEvaluateFont` only accesses the "raw" `toUnicode` data, exporting a Stream should be safe.
---
[1] The reasons for this include:
- Streams, especially `DecodeStream`-instances, can become *very* large once read. Hence caching them really isn't a good idea simply because of the (potential) memory impact of doing so.
- Attempting to read from the *same* Stream-instance more than once won't work, unless it's `reset` in between, since using any method such as e.g. `getBytes` always starts at the current data position.
- Given that parsing, even in the worker-thread, is now fairly asynchronous it's generally impossible to assert that any one Stream-instance isn't being accessed "concurrently" by e.g. different `getOperatorList` calls. Hence `reset`-ing a cached Stream-instance isn't going to work in the general case.
Rather than re-fetching/re-parsing these properties immediately in `PartialEvaluator.translateFont`, we can simply export them instead. (Obviously the effect will be really tiny, but there is less parsing overall this way.)
*Please note:* While I don't have a document that this patches fixes, the current code is however not entirely correct as far as I can tell.
Looking at how the `Widths` array is parsed in `PartialEvaluator.extractWidths`, it's clear that the implementation in `PartialEvaluator.preEvaluateFont` is a bit too simplistic. In particular, by only wrapping the data into a TypedArray, there's no attempt to handle *indirect* objects which could potentially lead to colliding `hash`es being computed.
To hopefully help prevent any future bugs, make sure that composite/non-composite fonts cannot accidentally get matching `hash`es. Given the differences between those font types, that's very unlikely to be useful or even correct in general.
Without this some *composite* 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.
*Please note:* Given that the document, in the referenced issue, doesn't embed *any* of its fonts there's no guarantee that it renders correctly in all configurations even with this patch.
With modern JavaScript modules, where you explicitly list the properties that should be exported, it's no longer necessary to wrap *all* of the code within one file into a top-level closure.[1]
This patch reduces the size, of even the *built* `pdf.worker.js` file, since there's now a lot less unnecessary whitespace.
---
[1] For files which contain *different* functionality, some closures may however still make sense in order to separate the code.
It might be possible to remove some of those cases later, e.g. once private class fields becomes generally available/usable in browsers.
*My apologies for breaking this; thankfully PR 13303 hasn't reach mozilla-central yet.*
It's (obviously) necessary to initialize a `PredictorStream`-instance fully, since otherwise breakage may occur if there's errors during the actual stream parsing.
To reproduce this issue, try opening the PDF document from issue 13051 locally and observe the following message in the console:
```
Warning: Invalid stream: "ReferenceError: this hasn't been initialised - super() hasn't been called"
```
It shouldn't be possible for the `getBytes`-call to throw a `MissingDataException`, since all resources are loaded *before* e.g. font-parsing ever starts; see f0817015bd/src/core/object_loader.js (L111-L126)
Furthermore, even if we'd *somehow* re-throw a `MissingDataException` here that still won't help considering where the `Type1Font`-instance is created. Note how in the `Font`-constructor we simply catch any errors and fallback to a standard font, which means that a `MissingDataException` would just lead to rendering errors anyway; see f0817015bd/src/core/fonts.js (L648-L691)
All-in-all, it's not possible for a `MissingDataException` to be thrown in `getHeaderBlock` and this code-path can thus be removed.
Obviously the `Font`-class is still *very* large, given particularly how TrueType fonts are handled, however this patch-series at least improves things by moving a number of functions/classes into their own files.
As a follow-up it might make sense to try and re-factor/extract the TrueType parsing into its own file, since all of this code is quite old, however that's probably best left for another time.
For e.g. `gulp mozcentral`, the *built* `pdf.worker.js` files decreases from `1 620 332` to `1 617 466` bytes with this patch-series.
These changes were made automatically, using `gulp lint --fix`.
Given the large size of this patch, the manual fixes are done separately in the next commit.
These changes were made *mostly* automatically, using `gulp lint --fix`, with the following manual changes:
```diff
diff --git a/src/core/fonts_utils.js b/src/core/fonts_utils.js
index f88ce4a8c..c4b3f3808 100644
--- a/src/core/fonts_utils.js
+++ b/src/core/fonts_utils.js
@@ -167,8 +167,8 @@ function type1FontGlyphMapping(properties, builtInEncoding,
glyphNames) {
}
// Lastly, merge in the differences.
- let differences = properties.differences,
- glyphsUnicodeMap;
+ const differences = properties.differences;
+ let glyphsUnicodeMap;
if (differences) {
for (charCode in differences) {
const glyphName = differences[charCode];
```
- `FontFlags`, is used in both `src/core/fonts.js` and `src/core/evaluator.js`.
- `getFontType`, same as the above.
- `MacStandardGlyphOrdering`, is a fairly large data-structure and `src/core/fonts.js` is already a *very* large file.
- `recoverGlyphName`, a dependency of `type1FontGlyphMapping`; please see below.
- `SEAC_ANALYSIS_ENABLED`, is used by both `Type1Font`, `CFFFont`, and unit-tests; please see below.
- `type1FontGlyphMapping`, is used by both `Type1Font` and `CFFFont` which a later patch will move to their own files.
This is done automatically with `gulp lint --fix` and the following
manual changes:
```diff
diff --git a/src/core/function.js b/src/core/function.js
index 878001057..b7e3e6ccf 100644
--- a/src/core/function.js
+++ b/src/core/function.js
@@ -131,7 +131,7 @@ function toNumberArray(arr) {
return arr;
}
-var PDFFunction = (function PDFFunctionClosure() {
+const PDFFunction = (function PDFFunctionClosure() {
const CONSTRUCT_SAMPLED = 0;
const CONSTRUCT_INTERPOLATED = 2;
const CONSTRUCT_STICHED = 3;
@@ -484,7 +484,9 @@ var PDFFunction = (function PDFFunctionClosure() {
// clip to domain
const v = clip(src[srcOffset], domain[0], domain[1]);
// calculate which bound the value is in
- for (var i = 0, ii = bounds.length; i < ii; ++i) {
+ const length = bounds.length;
+ let i;
+ for (i = 0; i < length; ++i) {
if (v < bounds[i]) {
break;
}
@@ -673,23 +675,21 @@ const PostScriptStack = (function PostScriptStackClosure() {
roll(n, p) {
const stack = this.stack;
const l = stack.length - n;
- let r = stack.length - 1,
- c = l + (p - Math.floor(p / n) * n),
- i,
- j,
- t;
- for (i = l, j = r; i < j; i++, j--) {
- t = stack[i];
+ const r = stack.length - 1;
+ const c = l + (p - Math.floor(p / n) * n);
+
+ for (let i = l, j = r; i < j; i++, j--) {
+ const t = stack[i];
stack[i] = stack[j];
stack[j] = t;
}
- for (i = l, j = c - 1; i < j; i++, j--) {
- t = stack[i];
+ for (let i = l, j = c - 1; i < j; i++, j--) {
+ const t = stack[i];
stack[i] = stack[j];
stack[j] = t;
}
- for (i = c, j = r; i < j; i++, j--) {
- t = stack[i];
+ for (let i = c, j = r; i < j; i++, j--) {
+ const t = stack[i];
stack[i] = stack[j];
stack[j] = t;
}
@@ -939,7 +939,7 @@ class PostScriptEvaluator {
// We can compile most of such programs, and at the same moment, we can
// optimize some expressions using basic math properties. Keeping track of
// min/max values will allow us to avoid extra Math.min/Math.max calls.
-var PostScriptCompiler = (function PostScriptCompilerClosure() {
+const PostScriptCompiler = (function PostScriptCompilerClosure() {
class AstNode {
constructor(type) {
this.type = type;
```
Given that the `bytesToString(BaseStream.getBytes(...))` pattern is somewhat common throughout the `src/core/` code, it cannot hurt to add a new `BaseStream`-method which handles that case internally.
- Improve chunking in order to fix some bugs where the spaces aren't here:
* track the last position where a glyph has been drawn;
* when a new glyph (first glyph in a chunk) is added then compare its position with the last saved one and add a space or break:
- there are multiple ways to move the glyphs and to avoid to have to deal with all the different possibilities it's a way easier to just compare positions;
- and so there is now one function (i.e. "compareWithLastPosition") where all the job is done.
- Add some breaks in order to get lines;
- Remove the multiple whites spaces:
* some spaces were filled with several whites spaces and so it makes harder to find some sequences of words using the search tool;
* other pdf readers replace spaces by one white space.
Update src/core/evaluator.js
Co-authored-by: Jonas Jenwald <jonas.jenwald@gmail.com>
Co-authored-by: Jonas Jenwald <jonas.jenwald@gmail.com>
Looking at the `ChunkedStream` implementation, it's basically a "regular" `Stream` but with added functionality in order to deal with fetching/loading of missing data.
Hence, by letting `ChunkedStream` extend `Stream`, we can remove some duplicate methods from the `ChunkedStream` class.
For all of the other `DecodeStream`s we're not passing in a `Dict`-instance manually, but instead get it from the `stream`-parameter. Hence there's no particularly good reason, as far as I can tell, to not do the same thing in `Jbig2Stream`/`JpegStream`/`JpxStream` as well.
The way that `getBaseStreams` is currently handled has bothered me from time to time, especially how we're checking if the method exists before calling it.
By adding a dummy `BaseStream.getBaseStreams` method, and having the call-sites simply check the return value, we can improve some of the relevant code.
Note in particular how the `ObjectLoader._walk` method didn't actually check that the data in question is a Stream instance, and instead only checked the `currentNode` (which could be anything) for the existence of a `getBaseStreams` property.
By having an abstract base-class, it becomes a lot clearer exactly which methods/getters are expected to exist on all Stream instances.
Furthermore, since a number of the methods are *identical* for all Stream implementations, this reduces unnecessary code duplication in the `Stream`, `DecodeStream`, and `ChunkedStream` classes.
For e.g. `gulp mozcentral`, the *built* `pdf.worker.js` files decreases from `1 619 329` to `1 616 115` bytes with this patch-series.
