move ashmem switching logic to SkDiscardableMemory::Create

R=scroggo@google.com, reed@google.com

Author: halcanary@google.com

Review URL: https://codereview.chromium.org/293283002

git-svn-id: http://skia.googlecode.com/svn/trunk@14882 2bbb7eff-a529-9590-31e7-b0007b416f81

2 files changed, 21 insertions, 15 deletions

diff --git a/src/ports/SkDiscardableMemory_ashmem.cpp b/src/ports/SkDiscardableMemory_ashmem.cpp
index e5e5f53969..88261543fd 100644
--- a/src/ports/SkDiscardableMemory_ashmem.cpp
+++ b/src/ports/SkDiscardableMemory_ashmem.cpp
@@ -8,6 +8,7 @@
 #include <unistd.h>
 #include <sys/mman.h>
 #include "SkDiscardableMemory.h"
+#include "SkDiscardableMemoryPool.h"
 #include "SkTypes.h"
 #include "android/ashmem.h"
 
@@ -24,6 +25,8 @@ public:
     virtual bool lock() SK_OVERRIDE;
     virtual void* data() SK_OVERRIDE;
     virtual void unlock() SK_OVERRIDE;
+    static SkAshmemDiscardableMemory* Create(size_t bytes);
+
 private:
     bool         fLocked;
     int          fFd;
@@ -86,10 +89,8 @@ void SkAshmemDiscardableMemory::unlock() {
     }
     fLocked = false;
 }
-}  // namespace
-////////////////////////////////////////////////////////////////////////////////
 
-SkDiscardableMemory* SkDiscardableMemory::Create(size_t bytes) {
+SkAshmemDiscardableMemory* SkAshmemDiscardableMemory::Create(size_t bytes) {
     // ashmem likes lengths on page boundaries.
     const size_t mask = getpagesize() - 1;
     size_t size = (bytes + mask) & ~mask;
@@ -111,3 +112,18 @@ SkDiscardableMemory* SkDiscardableMemory::Create(size_t bytes) {
 
     return SkNEW_ARGS(SkAshmemDiscardableMemory, (fd, addr, size));
 }
+}  // namespace
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SK_ASHMEM_MINIMUM_MEMORY_SIZE
+// number taken from android/graphics/BitmapFactory.cpp
+#define SK_ASHMEM_MINIMUM_MEMORY_SIZE (32 * 1024)
+#endif  // SK_ASHMEM_MINIMUM_MEMORY_SIZE
+SkDiscardableMemory* SkDiscardableMemory::Create(size_t bytes) {
+    if (bytes < SK_ASHMEM_MINIMUM_MEMORY_SIZE) {
+        return SkGetGlobalDiscardableMemoryPool()->create(bytes);
+    } else {
+        return SkAshmemDiscardableMemory::Create(bytes);
+    }
+}
+
diff --git a/tests/ImageDecodingTest.cpp b/tests/ImageDecodingTest.cpp
index d5dd11ac85..7f9ff3042e 100644
--- a/tests/ImageDecodingTest.cpp
+++ b/tests/ImageDecodingTest.cpp
@@ -491,18 +491,8 @@ static SkPixelRef* install_pixel_ref(SkBitmap* bitmap,
     SkASSERT(stream->unique());
     SkColorType colorType = bitmap->colorType();
     SkDecodingImageGenerator::Options opts(sampleSize, ditherImage, colorType);
-    SkAutoTDelete<SkImageGenerator> gen(
-        SkDecodingImageGenerator::Create(stream, opts));
-    SkImageInfo info;
-    if ((NULL == gen.get()) || !gen->getInfo(&info)) {
-        return NULL;
-    }
-    SkDiscardableMemory::Factory* factory = NULL;
-    if (info.getSafeSize(info.minRowBytes()) < (32 * 1024)) {
-        // only use ashmem for large images, since mmaps come at a price
-        factory = SkGetGlobalDiscardableMemoryPool();
-    }
-    if (SkInstallDiscardablePixelRef(gen.detach(), bitmap, factory)) {
+    if (SkInstallDiscardablePixelRef(
+                SkDecodingImageGenerator::Create(stream, opts), bitmap)) {
         return bitmap->pixelRef();
     }
     return NULL;