Improvements/additions to SkImageCache/SkLazyPixelRef.
SkPurgeableImageCache:
New image cache that uses virtual memory to store the pixels. Combines
features of SkAshmemImageCache (which has been removed) with SkPurgeableMemoryBlock, which has android and Mac versions.
SkImageCache:
Modified the API. pinCache now returns a status out parameter which
states whether the pinned memory retained the old data. This allows
allocAndPinCache to only be used for allocations.
Add a new debug only interface to purge unpinned data.
Updates to documentation, clarifying behavior.
Changed CachedStatus to MemoryStatus
SkLruImageCache:
Implement the new function purgeAllUnpinnedCaches and change implementation
of pinCache for the new behavior.
SkLazyPixelRef:
Rewrite onLockPixels to account for the new behavior of pinCache.
BitmapFactoryTest:
Test the new SkPurgeableImageCache.
Write tests which directly test the SkImageCaches.
Create a larger bitmap, since some of the SkImageCaches are designed
to handle large bitmaps.
bench_ and render_pictures:
Consolidate lazy_decode_bitmap into one function.
Allow using a flag to specify using the purgeable image cache.
Clean up some #includes.
Review URL: https://codereview.chromium.org/12433020
git-svn-id: http://skia.googlecode.com/svn/trunk@8207 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/lazy/SkImageCache.h b/include/lazy/SkImageCache.h
index 6cd064b..bfd5269 100644
--- a/include/lazy/SkImageCache.h
+++ b/include/lazy/SkImageCache.h
@@ -22,22 +22,45 @@
* call to releaseCache and a call to throwAwayCache.
* @param bytes Number of bytes needed.
* @param ID Output parameter which must not be NULL. On success, ID will be set to a value
- * associated with that memory which can be used as a parameter to the other functions
- * in SkImageCache. On failure, ID is unchanged.
+ * associated with that memory which can be used as a parameter to the other functions
+ * in SkImageCache. On failure, ID is unchanged.
* @return Pointer to the newly allocated memory, or NULL. This memory is safe to use until
- * releaseCache is called with ID.
+ * releaseCache is called with ID.
*/
virtual void* allocAndPinCache(size_t bytes, intptr_t* ID) = 0;
/**
- * Re-request the memory associated with ID.
- * @param ID Unique ID for the memory block.
- * @return Pointer: If non-NULL, points to the previously allocated memory, in which case
- * this call must be balanced with a call to releaseCache. If NULL, the memory
- * has been reclaimed, so allocAndPinCache must be called again with a pointer to
- * the same ID.
+ * Output parameter for pinCache, stating whether the memory still contains the data it held
+ * when releaseCache was last called for the same ID.
*/
- virtual void* pinCache(intptr_t ID) = 0;
+ enum DataStatus {
+ /**
+ * The data has been purged, and therefore needs to be rewritten to the returned memory.
+ */
+ kUninitialized_DataStatus,
+
+ /**
+ * The memory still contains the data it held when releaseCache was last called with the
+ * same ID.
+ */
+ kRetained_DataStatus,
+ };
+
+ /**
+ * Re-request the memory associated with ID and pin it so that it will not be reclaimed until
+ * the next call to releaseCache with the same ID.
+ * @param ID Unique ID for the memory block.
+ * @param status Output parameter which must not be NULL. On success (i.e. the return value is
+ * not NULL), status will be set to one of two states representing the cached memory. If
+ * status is set to kRetained_DataStatus, the memory contains the same data it did
+ * before releaseCache was called with this ID. If status is set to
+ * kUninitialized_DataStatus, the memory is still pinned, but the previous data is no
+ * longer available. If the return value is NULL, status is unchanged.
+ * @return Pointer: If non-NULL, points to the previously allocated memory, in which case
+ * this call must be balanced with a call to releaseCache. If NULL, the memory
+ * has been reclaimed, and throwAwayCache MUST NOT be called.
+ */
+ virtual void* pinCache(intptr_t ID, DataStatus* status) = 0;
/**
* Inform the cache that it is safe to free the block of memory corresponding to ID. After
@@ -61,16 +84,42 @@
static const intptr_t UNINITIALIZED_ID = 0;
#ifdef SK_DEBUG
- enum CacheStatus {
- kPinned_CacheStatus,
- kUnpinned_CacheStatus,
- kThrownAway_CacheStatus,
+ /**
+ * Debug only status of a memory block.
+ */
+ enum MemoryStatus {
+ /**
+ * It is safe to use the pointer returned by the most recent of allocAndPinCache(ID) or
+ * pinCache(ID) with the same ID.
+ */
+ kPinned_MemoryStatus,
+
+ /**
+ * The pointer returned by the most recent call to allocAndPinCache(ID) or pinCache(ID) has
+ * since been released by releaseCache(ID). In order to reuse it, pinCache(ID) must be
+ * called again. Note that after calling releaseCache(ID), the status of that particular
+ * ID may not be kUnpinned_MemoryStatus, depending on the implementation, but it will not
+ * be kPinned_MemoryStatus.
+ */
+ kUnpinned_MemoryStatus,
+
+ /**
+ * The memory associated with ID has been thrown away. No calls should be made using the
+ * same ID.
+ */
+ kFreed_MemoryStatus,
};
/**
- * Debug only function to get the status of a particular block of memory.
+ * Debug only function to get the status of a particular block of memory. Safe to call after
+ * throwAwayCache has been called with this ID.
*/
- virtual CacheStatus getCacheStatus(intptr_t ID) const = 0;
+ virtual MemoryStatus getMemoryStatus(intptr_t ID) const = 0;
+
+ /**
+ * Debug only function to clear all unpinned caches.
+ */
+ virtual void purgeAllUnpinnedCaches() = 0;
#endif
};
#endif // SkImageCache_DEFINED