Automated merge with http://bitbucket.org/lindenlab/viewer-development

1 files changed, 210 insertions, 0 deletions

diff --git a/indra/llcommon/llpredicate.h b/indra/llcommon/llpredicate.h
new file mode 100644
index 0000000000..a0e970a799
--- /dev/null
+++ b/indra/llcommon/llpredicate.h
@@ -0,0 +1,210 @@
+/** 
+ * @file llpredicate.h
+ * @brief abstraction for filtering objects by predicates, with arbitrary boolean expressions
+ *
+ * $LicenseInfo:firstyear=2008&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#ifndef LL_LLPREDICATE_H
+#define LL_LLPREDICATE_H
+
+#include "llerror.h"
+
+namespace LLPredicate
+{
+	template<typename ENUM> class Rule;
+
+	extern const U32 cPredicateFlagsFromEnum[5];
+
+	template<typename ENUM>
+	class Value
+	{
+	public:
+		typedef U32 predicate_flag_t;
+		static const S32 cMaxEnum = 5;
+
+		Value(ENUM e, bool predicate_value = true)
+		:	mPredicateFlags(predicate_value ? cPredicateFlagsFromEnum[e] : ~cPredicateFlagsFromEnum[e])
+		{
+			llassert(0 <= e && e < cMaxEnum);
+		}
+
+		Value()
+		:	mPredicateFlags(0xFFFFffff)
+		{}
+
+		Value operator!() const
+		{
+			Value new_value;
+			new_value.mPredicateFlags = ~mPredicateFlags;
+			return new_value;
+		}
+
+		Value operator &&(const Value other) const
+		{
+			Value new_value;
+			new_value.mPredicateFlags = mPredicateFlags & other.mPredicateFlags;
+			return new_value;
+		}
+
+		Value operator ||(const Value other) const
+		{
+			Value new_value;
+			new_value.mPredicateFlags = mPredicateFlags | other.mPredicateFlags;
+			return new_value;
+		}
+
+		void set(ENUM e, bool value = true)
+		{
+			llassert(0 <= e && e < cMaxEnum);
+			predicate_flag_t flags_to_modify;
+			predicate_flag_t mask = cPredicateFlagsFromEnum[e];
+			if (value)
+			{	// add predicate "e" to flags that don't contain it already
+				flags_to_modify = (mPredicateFlags & ~mask);
+				// clear flags not containing e
+				mPredicateFlags &= mask;
+				// add back flags shifted to contain e
+				mPredicateFlags |= flags_to_modify << (0x1 << e);
+			}
+			else
+			{	// remove predicate "e" from flags that contain it
+				flags_to_modify = (mPredicateFlags & mask);
+				// clear flags containing e
+				mPredicateFlags &= ~mask;
+				// add back flags shifted to not contain e
+				mPredicateFlags |= flags_to_modify >> (0x1 << e);
+			}
+		}
+
+		void forget(ENUM e)
+		{
+			set(e, true);
+			U32 flags_with_predicate = mPredicateFlags;
+			set(e, false);
+			// ambiguous value is result of adding and removing predicate at the same time!
+			mPredicateFlags |= flags_with_predicate;
+		}
+
+		bool allSet() const
+		{
+			return mPredicateFlags == ~0;
+		}
+
+		bool noneSet() const
+		{
+			return mPredicateFlags == 0;
+		}
+
+		bool someSet() const
+		{
+			return mPredicateFlags != 0;
+		}
+
+	private:
+		predicate_flag_t mPredicateFlags;
+	};
+
+	template<typename ENUM>
+	class Rule
+	{
+	public:
+		Rule(ENUM value)
+		:	mRule(value)
+		{}
+
+		Rule(const Value<ENUM> other)
+		:	mRule(other)
+		{}
+
+		Rule()
+		{}
+
+		void require(ENUM e)
+		{
+			mRule.set(e, require);
+		}
+
+		void allow(ENUM e)
+		{
+			mRule.forget(e);
+		}
+
+		bool check(const Value<ENUM> value) const
+		{
+			return (mRule && value).someSet();
+		}
+
+		bool requires(const Value<ENUM> value) const
+		{
+			return (mRule && value).someSet() && (!mRule && value).noneSet();
+		}
+
+		bool isAmbivalent(const Value<ENUM> value) const
+		{
+			return (mRule && value).someSet() && (!mRule && value).someSet();
+		}
+
+		bool acceptsAll() const
+		{
+			return mRule.allSet();
+		}
+
+		bool acceptsNone() const
+		{
+			return mRule.noneSet();
+		}
+
+		Rule operator!() const
+		{
+			Rule new_rule;
+			new_rule.mRule = !mRule;
+			return new_rule;
+		}
+
+		Rule operator &&(const Rule other) const
+		{
+			Rule new_rule;
+			new_rule.mRule = mRule && other.mRule;
+			return new_rule;
+		}
+
+		Rule operator ||(const Rule other) const
+		{
+			Rule new_rule;
+			new_rule.mRule = mRule || other.mRule;
+			return new_rule;
+		}
+
+	private:
+		Value<ENUM> mRule;
+	};
+}
+
+template<typename ENUM>
+LLPredicate::Value<ENUM> ll_make_predicate(ENUM e, bool predicate_value = true)
+{
+	 return LLPredicate::Value<ENUM>(e, predicate_value);
+}
+
+
+#endif // LL_LLPREDICATE_H