add find()

git-svn-id: http://skia.googlecode.com/svn/trunk@1243 2bbb7eff-a529-9590-31e7-b0007b416f81

include/core/SkPtrRecorder.h

@@ -28,6 +28,12 @@
  */
 class SkPtrSet : public SkRefCnt {
 public:
+    /**
+     *  Search for the specified ptr in the set. If it is found, return its
+     *  32bit ID [1..N], or if not found, return 0. Always returns 0 for NULL.
+     */
+    uint32_t find(void*) const;
+
     /**
      *  Add the specified ptr to the set, returning a unique 32bit ID for it
      *  [1...N]. Duplicate ptrs will return the same ID.

src/core/SkPtrRecorder.cpp

@@ -15,6 +15,22 @@ int SkPtrSet::Cmp(const Pair& a, const Pair& b) {
     return (char*)a.fPtr - (char*)b.fPtr;
 }
 
+uint32_t SkPtrSet::find(void* ptr) const {
+    if (NULL == ptr) {
+        return 0;
+    }
+    
+    int count = fList.count();
+    Pair pair;
+    pair.fPtr = ptr;
+    
+    int index = SkTSearch<Pair>(fList.begin(), count, pair, sizeof(pair), &Cmp);
+    if (index < 0) {
+        return 0;
+    }
+    return fList[index].fIndex;
+}
+
 uint32_t SkPtrSet::add(void* ptr) {
     if (NULL == ptr) {
         return 0;