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+
+/*
+ * Copyright 2006 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#ifndef SkTSearch_DEFINED
+#define SkTSearch_DEFINED
+
+#include "SkTypes.h"
+
+/**
+ * All of the SkTSearch variants want to return the index (0...N-1) of the
+ * found element, or the bit-not of where to insert the element.
+ *
+ * At a simple level, if the return value is negative, it was not found.
+ *
+ * For clients that want to insert the new element if it was not found, use
+ * the following logic:
+ *
+ * int index = SkTSearch(...);
+ * if (index >= 0) {
+ * // found at index
+ * } else {
+ * index = ~index; // now we are positive
+ * // insert at index
+ * }
+ */
+
+
+// The most general form of SkTSearch takes an array of T and a key of type K. A functor, less, is
+// used to perform comparisons. It has two function operators:
+// bool operator() (const T& t, const K& k)
+// bool operator() (const K& t, const T& k)
+template <typename T, typename K, typename LESS>
+int SkTSearch(const T base[], int count, const K& key, size_t elemSize, LESS& less)
+{
+ SkASSERT(count >= 0);
+ if (count <= 0) {
+ return ~0;
+ }
+
+ SkASSERT(base != NULL); // base may be NULL if count is zero
+
+ int lo = 0;
+ int hi = count - 1;
+
+ while (lo < hi) {
+ int mid = lo + ((hi - lo) >> 1);
+ const T* elem = (const T*)((const char*)base + mid * elemSize);
+
+ if (less(*elem, key))
+ lo = mid + 1;
+ else
+ hi = mid;
+ }
+
+ const T* elem = (const T*)((const char*)base + hi * elemSize);
+ if (less(*elem, key)) {
+ hi += 1;
+ hi = ~hi;
+ } else if (less(key, *elem)) {
+ hi = ~hi;
+ }
+ return hi;
+}
+
+// Adapts a less-than function to a functor.
+template <typename T, bool (LESS)(const T&, const T&)> struct SkTLessFunctionToFunctorAdaptor {
+ bool operator()(const T& a, const T& b) { return LESS(a, b); }
+};
+
+// Specialization for case when T==K and the caller wants to use a function rather than functor.
+template <typename T, bool (LESS)(const T&, const T&)>
+int SkTSearch(const T base[], int count, const T& target, size_t elemSize) {
+ static SkTLessFunctionToFunctorAdaptor<T, LESS> functor;
+ return SkTSearch(base, count, target, elemSize, functor);
+}
+
+// Adapts operator < to a functor.
+template <typename T> struct SkTLessFunctor {
+ bool operator()(const T& a, const T& b) { return a < b; }
+};
+
+// Specialization for T==K, compare using op <.
+template <typename T>
+int SkTSearch(const T base[], int count, const T& target, size_t elemSize) {
+ static SkTLessFunctor<T> functor;
+ return SkTSearch(base, count, target, elemSize, functor);
+}
+
+// Similar to SkLessFunctionToFunctorAdaptor but makes the functor interface take T* rather than T.
+template <typename T, bool (LESS)(const T&, const T&)> struct SkTLessFunctionToPtrFunctorAdaptor {
+ bool operator() (const T* t, const T* k) { return LESS(*t, *k); }
+};
+
+// Specialization for case where domain is an array of T* and the key value is a T*, and you want
+// to compare the T objects, not the pointers.
+template <typename T, bool (LESS)(const T&, const T&)>
+int SkTSearch(T* base[], int count, T* target, size_t elemSize) {
+ static SkTLessFunctionToPtrFunctorAdaptor<T, LESS> functor;
+ return SkTSearch(base, count, target, elemSize, functor);
+}
+
+int SkStrSearch(const char*const* base, int count, const char target[],
+ size_t target_len, size_t elemSize);
+int SkStrSearch(const char*const* base, int count, const char target[],
+ size_t elemSize);
+
+/** Like SkStrSearch, but treats target as if it were all lower-case. Assumes that
+ base points to a table of lower-case strings.
+*/
+int SkStrLCSearch(const char*const* base, int count, const char target[],
+ size_t target_len, size_t elemSize);
+int SkStrLCSearch(const char*const* base, int count, const char target[],
+ size_t elemSize);
+
+/** Helper class to convert a string to lower-case, but only modifying the ascii
+ characters. This makes the routine very fast and never changes the string
+ length, but it is not suitable for linguistic purposes. Normally this is
+ used for buiding and searching string tables.
+*/
+class SkAutoAsciiToLC {
+public:
+ SkAutoAsciiToLC(const char str[], size_t len = (size_t)-1);
+ ~SkAutoAsciiToLC();
+
+ const char* lc() const { return fLC; }
+ size_t length() const { return fLength; }
+
+private:
+ char* fLC; // points to either the heap or fStorage
+ size_t fLength;
+ enum {
+ STORAGE = 64
+ };
+ char fStorage[STORAGE+1];
+};
+
+// Helper when calling qsort with a compare proc that has typed its arguments
+#define SkCastForQSort(compare) reinterpret_cast<int (*)(const void*, const void*)>(compare)
+
+#endif