Merge pull request #13808 from brendandahl/pattern-cache-v2

Improve caching of shading patterns. (bug 1721949)
This commit is contained in:
Brendan Dahl 2021-07-28 11:17:16 -07:00 committed by GitHub
commit 4ad5c5d52a
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
4 changed files with 85 additions and 60 deletions

View File

@ -1315,20 +1315,17 @@ class PartialEvaluator {
}
parseShading({
keyObj,
shading,
resources,
localColorSpaceCache,
localShadingPatternCache,
matrix = null,
}) {
// Shadings and patterns may be referenced by the same name but the resource
// dictionary could be different so we can't use the name for the cache key.
let id = localShadingPatternCache.get(keyObj);
let id = localShadingPatternCache.get(shading);
if (!id) {
var shadingFill = Pattern.parseShading(
shading,
matrix,
this.xref,
resources,
this.handler,
@ -1337,7 +1334,7 @@ class PartialEvaluator {
);
const patternIR = shadingFill.getIR();
id = `pattern_${this.idFactory.createObjId()}`;
localShadingPatternCache.set(keyObj, id);
localShadingPatternCache.set(shading, id);
this.handler.send("obj", [id, this.pageIndex, "Pattern", patternIR]);
}
return id;
@ -1402,14 +1399,12 @@ class PartialEvaluator {
const shading = dict.get("Shading");
const matrix = dict.getArray("Matrix");
const objId = this.parseShading({
keyObj: pattern,
shading,
matrix,
resources,
localColorSpaceCache,
localShadingPatternCache,
});
operatorList.addOp(fn, ["Shading", objId]);
operatorList.addOp(fn, ["Shading", objId, matrix]);
return undefined;
}
throw new FormatError(`Unknown PatternType: ${typeNum}`);
@ -1942,7 +1937,6 @@ class PartialEvaluator {
throw new FormatError("No shading object found");
}
const patternId = self.parseShading({
keyObj: shading,
shading,
resources,
localColorSpaceCache,

View File

@ -44,7 +44,6 @@ class Pattern {
static parseShading(
shading,
matrix,
xref,
res,
handler,
@ -60,7 +59,6 @@ class Pattern {
case ShadingType.RADIAL:
return new RadialAxialShading(
dict,
matrix,
xref,
res,
pdfFunctionFactory,
@ -72,7 +70,6 @@ class Pattern {
case ShadingType.TENSOR_PATCH_MESH:
return new MeshShading(
shading,
matrix,
xref,
res,
pdfFunctionFactory,
@ -115,16 +112,8 @@ class BaseShading {
// Radial and axial shading have very similar implementations
// If needed, the implementations can be broken into two classes.
class RadialAxialShading extends BaseShading {
constructor(
dict,
matrix,
xref,
resources,
pdfFunctionFactory,
localColorSpaceCache
) {
constructor(dict, xref, resources, pdfFunctionFactory, localColorSpaceCache) {
super();
this.matrix = matrix;
this.coordsArr = dict.getArray("Coords");
this.shadingType = dict.get("ShadingType");
const cs = ColorSpace.parse({
@ -244,17 +233,7 @@ class RadialAxialShading extends BaseShading {
unreachable(`getPattern type unknown: ${shadingType}`);
}
return [
"RadialAxial",
type,
this.bbox,
this.colorStops,
p0,
p1,
r0,
r1,
this.matrix,
];
return ["RadialAxial", type, this.bbox, this.colorStops, p0, p1, r0, r1];
}
}
@ -418,7 +397,6 @@ class MeshShading extends BaseShading {
constructor(
stream,
matrix,
xref,
resources,
pdfFunctionFactory,
@ -429,7 +407,6 @@ class MeshShading extends BaseShading {
throw new FormatError("Mesh data is not a stream");
}
const dict = stream.dict;
this.matrix = matrix;
this.shadingType = dict.get("ShadingType");
const bbox = dict.getArray("BBox");
if (Array.isArray(bbox) && bbox.length === 4) {
@ -942,7 +919,6 @@ class MeshShading extends BaseShading {
this.colors,
this.figures,
this.bounds,
this.matrix,
this.bbox,
this.background,
];

View File

@ -37,6 +37,10 @@ const MIN_FONT_SIZE = 16;
const MAX_FONT_SIZE = 100;
const MAX_GROUP_SIZE = 4096;
// This value comes from sampling a few PDFs that re-use patterns, there doesn't
// seem to be any that benefit from caching more than 2 patterns.
const MAX_CACHED_CANVAS_PATTERNS = 2;
// Defines the time the `executeOperatorList`-method is going to be executing
// before it stops and shedules a continue of execution.
const EXECUTION_TIME = 15; // ms
@ -231,6 +235,46 @@ class CachedCanvases {
}
}
/**
* Least recently used cache implemented with a JS Map. JS Map keys are ordered
* by last insertion.
*/
class LRUCache {
constructor(maxSize = 0) {
this._cache = new Map();
this._maxSize = maxSize;
}
has(key) {
return this._cache.has(key);
}
get(key) {
if (this._cache.has(key)) {
// Delete and set the value so it's moved to the end of the map iteration.
const value = this._cache.get(key);
this._cache.delete(key);
this._cache.set(key, value);
}
return this._cache.get(key);
}
set(key, value) {
if (this._maxSize <= 0) {
return;
}
if (this._cache.size + 1 > this._maxSize) {
// Delete the least recently used.
this._cache.delete(this._cache.keys().next().value);
}
this._cache.set(key, value);
}
clear() {
this._cache.clear();
}
}
function compileType3Glyph(imgData) {
const POINT_TO_PROCESS_LIMIT = 1000;
const POINT_TYPES = new Uint8Array([
@ -866,6 +910,7 @@ class CanvasGraphics {
this.markedContentStack = [];
this.optionalContentConfig = optionalContentConfig;
this.cachedCanvases = new CachedCanvases(this.canvasFactory);
this.cachedCanvasPatterns = new LRUCache(MAX_CACHED_CANVAS_PATTERNS);
this.cachedPatterns = new Map();
if (canvasCtx) {
// NOTE: if mozCurrentTransform is polyfilled, then the current state of
@ -1017,6 +1062,7 @@ class CanvasGraphics {
}
this.cachedCanvases.clear();
this.cachedCanvasPatterns.clear();
this.cachedPatterns.clear();
if (this.imageLayer) {
@ -2125,7 +2171,7 @@ class CanvasGraphics {
baseTransform
);
} else {
pattern = this._getPattern(IR[1]);
pattern = this._getPattern(IR[1], IR[2]);
}
return pattern;
}
@ -2152,12 +2198,20 @@ class CanvasGraphics {
this.current.patternFill = false;
}
_getPattern(objId) {
_getPattern(objId, matrix = null) {
let pattern;
if (this.cachedPatterns.has(objId)) {
return this.cachedPatterns.get(objId);
pattern = this.cachedPatterns.get(objId);
} else {
pattern = getShadingPattern(
this.objs.get(objId),
this.cachedCanvasPatterns
);
this.cachedPatterns.set(objId, pattern);
}
if (matrix) {
pattern.matrix = matrix;
}
const pattern = getShadingPattern(this.objs.get(objId));
this.cachedPatterns.set(objId, pattern);
return pattern;
}

View File

@ -46,7 +46,7 @@ class BaseShadingPattern {
}
class RadialAxialShadingPattern extends BaseShadingPattern {
constructor(IR) {
constructor(IR, cachedCanvasPatterns) {
super();
this._type = IR[1];
this._bbox = IR[2];
@ -55,8 +55,8 @@ class RadialAxialShadingPattern extends BaseShadingPattern {
this._p1 = IR[5];
this._r0 = IR[6];
this._r1 = IR[7];
this._matrix = IR[8];
this._patternCache = null;
this.matrix = null;
this.cachedCanvasPatterns = cachedCanvasPatterns;
}
_createGradient(ctx) {
@ -87,10 +87,10 @@ class RadialAxialShadingPattern extends BaseShadingPattern {
getPattern(ctx, owner, inverse, shadingFill = false) {
let pattern;
if (this._patternCache) {
pattern = this._patternCache;
} else {
if (!shadingFill) {
if (!shadingFill) {
if (this.cachedCanvasPatterns.has(this)) {
pattern = this.cachedCanvasPatterns.get(this);
} else {
const tmpCanvas = owner.cachedCanvases.getCanvas(
"pattern",
owner.ctx.canvas.width,
@ -104,8 +104,8 @@ class RadialAxialShadingPattern extends BaseShadingPattern {
tmpCtx.rect(0, 0, tmpCtx.canvas.width, tmpCtx.canvas.height);
tmpCtx.setTransform.apply(tmpCtx, owner.baseTransform);
if (this._matrix) {
tmpCtx.transform.apply(tmpCtx, this._matrix);
if (this.matrix) {
tmpCtx.transform.apply(tmpCtx, this.matrix);
}
applyBoundingBox(tmpCtx, this._bbox);
@ -113,11 +113,12 @@ class RadialAxialShadingPattern extends BaseShadingPattern {
tmpCtx.fill();
pattern = ctx.createPattern(tmpCanvas.canvas, "repeat");
} else {
applyBoundingBox(ctx, this._bbox);
pattern = this._createGradient(ctx);
this.cachedCanvasPatterns.set(this, pattern);
}
this._patternCache = pattern;
} else {
// Don't bother caching gradients, they are quick to rebuild.
applyBoundingBox(ctx, this._bbox);
pattern = this._createGradient(ctx);
}
if (!shadingFill) {
const domMatrix = new DOMMatrix(inverse);
@ -305,9 +306,9 @@ class MeshShadingPattern extends BaseShadingPattern {
this._colors = IR[3];
this._figures = IR[4];
this._bounds = IR[5];
this._matrix = IR[6];
this._bbox = IR[7];
this._background = IR[8];
this.matrix = null;
}
_createMeshCanvas(combinedScale, backgroundColor, cachedCanvases) {
@ -389,8 +390,8 @@ class MeshShadingPattern extends BaseShadingPattern {
} else {
// Obtain scale from matrix and current transformation matrix.
scale = Util.singularValueDecompose2dScale(owner.baseTransform);
if (this._matrix) {
const matrixScale = Util.singularValueDecompose2dScale(this._matrix);
if (this.matrix) {
const matrixScale = Util.singularValueDecompose2dScale(this.matrix);
scale = [scale[0] * matrixScale[0], scale[1] * matrixScale[1]];
}
}
@ -405,8 +406,8 @@ class MeshShadingPattern extends BaseShadingPattern {
if (!shadingFill) {
ctx.setTransform.apply(ctx, owner.baseTransform);
if (this._matrix) {
ctx.transform.apply(ctx, this._matrix);
if (this.matrix) {
ctx.transform.apply(ctx, this.matrix);
}
}
@ -426,10 +427,10 @@ class DummyShadingPattern extends BaseShadingPattern {
}
}
function getShadingPattern(IR) {
function getShadingPattern(IR, cachedCanvasPatterns) {
switch (IR[0]) {
case "RadialAxial":
return new RadialAxialShadingPattern(IR);
return new RadialAxialShadingPattern(IR, cachedCanvasPatterns);
case "Mesh":
return new MeshShadingPattern(IR);
case "Dummy":