src/utils/SkBitSet: simplify

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2265623002

Review-Url: https://codereview.chromium.org/2265623002

1 files changed, 21 insertions, 42 deletions

diff --git a/src/utils/SkBitSet.h b/src/utils/SkBitSet.h
index 1e35c9120f..a8585a20b9 100644
--- a/src/utils/SkBitSet.h
+++ b/src/utils/SkBitSet.h
@@ -5,42 +5,30 @@
  * found in the LICENSE file.
  */
 
-
 #ifndef SkBitSet_DEFINED
 #define SkBitSet_DEFINED
 
-#include "SkTypes.h"
 #include "SkTDArray.h"
+#include "SkTemplates.h"
 
 class SkBitSet {
 public:
-    /** NumberOfBits must be greater than zero.
-     */
-    explicit SkBitSet(int numberOfBits);
+    explicit SkBitSet(int numberOfBits) {
+        SkASSERT(numberOfBits > 0);
+        fDwordCount = (numberOfBits + 31) / 32;  // Round up size to 32-bit boundary.
+        fBitData.reset((uint32_t*)sk_calloc_throw(fDwordCount * sizeof(uint32_t)));
+    }
+
     SkBitSet(const SkBitSet&) = delete;
-    SkBitSet(SkBitSet&&);
     SkBitSet& operator=(const SkBitSet&) = delete;
-    SkBitSet& operator=(SkBitSet&& rhs);
-
-    bool operator==(const SkBitSet& rhs);
-    bool operator!=(const SkBitSet& rhs);
 
-    /** Clear all data.
-     */
-    void clearAll();
-
-    /** Set the value of the index-th bit.
-     */
-    void setBit(int index, bool value) {
+    /** Set the value of the index-th bit to true.  */
+    void set(int index) {
         uint32_t mask = 1 << (index & 31);
         uint32_t* chunk = this->internalGet(index);
-        if (value) {
-            *chunk |= mask;
-        } else {
-            *chunk &= ~mask;
-        }
+        SkASSERT(chunk);
+        *chunk |= mask;
     }
-    void set(int index) { this->setBit(index, true); }
 
     template<typename T>
     void setAll(T* array, int len) {
@@ -50,21 +38,13 @@ public:
         }
     }
 
-    /** Test if bit index is set.
-     */
-    bool isBitSet(int index) const {
+    bool has(int index) const {
+        const uint32_t* chunk = this->internalGet(index);
         uint32_t mask = 1 << (index & 31);
-        return SkToBool(*this->internalGet(index) & mask);
+        return chunk && SkToBool(*chunk & mask);
     }
-    bool has(int index) const { return this->isBitSet(index); }
 
-    /** Or bits from source.  false is returned if this doesn't have the same
-     *  bit count as source.
-     */
-    bool orBits(const SkBitSet& source);
-
-    /** Export indices of set bits to T array.
-     */
+    /** Export indices of set bits to T array. */
     template<typename T>
     void exportTo(SkTDArray<T>* array) const {
         static_assert(std::is_integral<T>::value, "T is integral");
@@ -84,16 +64,15 @@ public:
     }
 
 private:
-    SkAutoFree fBitData;
-    // Dword (32-bit) count of the bitset.
-    size_t fDwordCount;
-    size_t fBitCount;
+    std::unique_ptr<uint32_t, SkFunctionWrapper<void, void, sk_free>> fBitData;
+    size_t fDwordCount;  // Dword (32-bit) count of the bitset.
 
     uint32_t* internalGet(int index) const {
-        SkASSERT((size_t)index < fBitCount);
         size_t internalIndex = index / 32;
-        SkASSERT(internalIndex < fDwordCount);
-        return reinterpret_cast<uint32_t*>(fBitData.get()) + internalIndex;
+        if (internalIndex >= fDwordCount) {
+            return nullptr;
+        }
+        return fBitData.get() + internalIndex;
     }
 };