Make SkImage_Lazy cache its result from onMakeColorSpace

May sites will all onMakeColorSpace every frame, resulting repeatedly
re-created new SkImage_Lazy class instances, new cache keys, and
repeated cache misses.

Save the most recent result from onMakeColorSpace, to avoid this thrash.

Bug:741607
Change-Id: I34091327a17275722f82ed372eb0b341806a9ddc
Reviewed-on: https://skia-review.googlesource.com/23287
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>

1 files changed, 17 insertions, 1 deletions

diff --git a/src/image/SkImage_Lazy.cpp b/src/image/SkImage_Lazy.cpp
index 809ada01f6..e760d036a2 100644
--- a/src/image/SkImage_Lazy.cpp
+++ b/src/image/SkImage_Lazy.cpp
@@ -159,6 +159,12 @@ private:
 
     uint32_t getUniqueID(CachedFormat) const;
 
+    // Repeated calls to onMakeColorSpace will result in a proliferation of unique IDs and
+    // SkImage_Lazy instances. Cache the result of the last successful onMakeColorSpace call.
+    mutable SkMutex             fOnMakeColorSpaceMutex;
+    mutable sk_sp<SkColorSpace> fOnMakeColorSpaceTarget;
+    mutable sk_sp<SkImage>      fOnMakeColorSpaceResult;
+
     typedef SkImage_Base INHERITED;
 };
 
@@ -649,10 +655,20 @@ sk_sp<SkImage> SkImage_Lazy::onMakeSubset(const SkIRect& subset) const {
 sk_sp<SkImage> SkImage_Lazy::onMakeColorSpace(sk_sp<SkColorSpace> target,
                                               SkColorType targetColorType,
                                               SkTransferFunctionBehavior premulBehavior) const {
+    SkAutoExclusive autoAquire(fOnMakeColorSpaceMutex);
+    if (target && fOnMakeColorSpaceTarget &&
+        SkColorSpace::Equals(target.get(), fOnMakeColorSpaceTarget.get())) {
+        return fOnMakeColorSpaceResult;
+    }
     const SkIRect generatorSubset =
             SkIRect::MakeXYWH(fOrigin.x(), fOrigin.y(), fInfo.width(), fInfo.height());
     Validator validator(fSharedGenerator, &generatorSubset, target);
-    return validator ? sk_sp<SkImage>(new SkImage_Lazy(&validator)) : nullptr;
+    sk_sp<SkImage> result = validator ? sk_sp<SkImage>(new SkImage_Lazy(&validator)) : nullptr;
+    if (result) {
+        fOnMakeColorSpaceTarget = target;
+        fOnMakeColorSpaceResult = result;
+    }
+    return result;
 }
 
 sk_sp<SkImage> SkImage::MakeFromGenerator(std::unique_ptr<SkImageGenerator> generator,