From 8b3d1c2c91e1bf2ed4d579996ece6725db8c746d Mon Sep 17 00:00:00 2001
From: Rui Pinheiro <rui@ruipinheiro.eu>
Date: Sat, 22 Sep 2018 16:03:00 +0100
Subject: [PATCH] Implement address_range utility class

---
 Utilities/address_range.h     | 590 ++++++++++++++++++++++++++++++++++
 rpcs3/emucore.vcxproj         |   1 +
 rpcs3/emucore.vcxproj.filters |   3 +
 3 files changed, 594 insertions(+)
 create mode 100644 Utilities/address_range.h

diff --git a/Utilities/address_range.h b/Utilities/address_range.h
new file mode 100644
index 0000000000..064e81bf59
--- /dev/null
+++ b/Utilities/address_range.h
@@ -0,0 +1,590 @@
+#include "types.h"
+#include "StrFmt.h"
+#include <vector>
+
+
+namespace utils
+{
+	class address_range_vector;
+
+
+	/**
+	 * Constexprs
+	 */
+	constexpr inline u32 page_start(u32 addr)
+	{
+		return addr & ~4095u;
+	}
+
+	constexpr inline u32 next_page(u32 addr)
+	{
+		return page_start(addr + 4096u);
+	}
+
+	constexpr inline u32 page_end(u32 addr)
+	{
+		return next_page(addr) - 1;
+	}
+
+	constexpr inline u32 is_page_aligned(u32 addr)
+	{
+		return page_start(addr) == addr;
+	}
+
+
+	/**
+	 * Address Range utility class
+	 */
+	class address_range
+	{
+	public:
+		u32 start = UINT32_MAX; // First address in range
+		u32 end = 0; // Last address
+
+	private:
+		// Helper constexprs
+		static constexpr inline bool range_overlaps(u32 start1, u32 end1, u32 start2, u32 end2)
+		{
+			return (start1 <= end2 && start2 <= end1);
+		}
+
+		static constexpr inline bool address_overlaps(u32 address, u32 start, u32 end)
+		{
+			return (start <= address && address <= end);
+		}
+
+		static constexpr inline bool range_inside_range(u32 start1, u32 end1, u32 start2, u32 end2)
+		{
+			return (start1 >= start2 && end1 <= end2);
+		}
+
+		address_range(u32 _start, u32 _end) : start(_start), end(_end) {};
+
+	public:
+		// Constructors
+		address_range() = default;
+		address_range(const address_range &other) : start(other.start), end(other.end) {};
+
+		static inline address_range start_length(u32 _start, u32 _length)
+		{
+			return address_range(_start, _start + (_length - 1));
+		}
+
+		static inline address_range start_end(u32 _start, u32 _end)
+		{
+			return address_range(_start, _end);
+		}
+
+		// Length
+		u32 length() const
+		{
+			AUDIT(valid());
+			return end - start + 1;
+		}
+
+		void set_length(const u32 new_length)
+		{
+			end = start + new_length - 1;
+			ASSERT(valid());
+		}
+
+		u32 next_address() const
+		{
+			return end + 1;
+		}
+
+		u32 prev_address() const
+		{
+			return start - 1;
+		}
+
+		// Overlapping checks
+		bool overlaps(const address_range &other) const
+		{
+			AUDIT(valid() && other.valid());
+			return range_overlaps(start, end, other.start, other.end);
+		}
+
+		bool overlaps(const u32 addr) const
+		{
+			AUDIT(valid());
+			return address_overlaps(addr, start, end);
+		}
+
+		bool inside(const address_range &other) const
+		{
+			AUDIT(valid() && other.valid());
+			return range_inside_range(start, end, other.start, other.end);
+		}
+
+		inline bool inside(const address_range_vector &vec) const;
+		inline bool overlaps(const address_range_vector &vec) const;
+
+		bool touches(const address_range &other) const
+		{
+			AUDIT(valid() && other.valid());
+			// returns true if there is overlap, or if sections are side-by-side
+			return overlaps(other) || other.start == next_address() || other.end == prev_address();
+		}
+
+		// Utilities
+		s32 signed_distance(const address_range &other) const
+		{
+			if (touches(other))
+			{
+				return 0;
+			}
+
+			// other after this
+			if (other.start > end)
+			{
+				return (s32)(other.start - end - 1);
+			}
+
+			// this after other
+			AUDIT(start > other.end);
+			return -((s32)(start - other.end - 1));
+		}
+
+		u32 distance(const address_range &other) const
+		{
+			if (touches(other))
+			{
+				return 0;
+			}
+
+			// other after this
+			if (other.start > end)
+			{
+				return (other.start - end - 1);
+			}
+
+			// this after other
+			AUDIT(start > other.end);
+			return (start - other.end - 1);
+		}
+
+		address_range get_min_max(const address_range &other) const
+		{
+			return {
+				std::min(valid() ? start : UINT32_MAX, other.valid() ? other.start : UINT32_MAX),
+				std::max(valid() ? end : 0, other.valid() ? other.end : 0)
+			};
+		}
+
+		void set_min_max(const address_range &other)
+		{
+			const address_range _range = get_min_max(other);
+			start = _range.start;
+			end = _range.end;
+		}
+
+		bool is_page_range() const
+		{
+			return (valid() && start % 4096u == 0 && length() % 4096u == 0);
+		}
+
+		address_range to_page_range() const
+		{
+			AUDIT(valid());
+			return { page_start(start), page_end(end) };
+		}
+
+		void page_align()
+		{
+			AUDIT(valid());
+			start = page_start(start);
+			end = page_end(end);
+			AUDIT(is_page_range());
+		}
+
+		address_range get_intersect(const address_range &clamp) const
+		{
+			if (!valid() || !clamp.valid())
+			{
+				return {};
+			}
+
+			return { std::max(start, clamp.start), std::min(end, clamp.end) };
+		}
+
+		void intersect(const address_range &clamp)
+		{
+			if (!clamp.valid())
+			{
+				invalidate();
+			}
+			else
+			{
+				start = std::max(start, clamp.start);
+				end = std::min(end, clamp.end);
+			}
+		}
+
+		// Validity
+		bool valid() const
+		{
+			return (start <= end);
+		}
+
+		void invalidate()
+		{
+			start = UINT32_MAX;
+			end = 0;
+		}
+
+		// Comparison Operators
+		bool operator ==(const address_range &other) const
+		{
+			return (start == other.start && end == other.end);
+		}
+
+		bool operator !=(const address_range &other) const
+		{
+			return (start != other.start || end != other.end);
+		}
+
+		/**
+		 * Debug
+		 */
+		std::string str() const
+		{
+			return fmt::format("{0x%x->0x%x}", start, end);
+		}
+	};
+
+	static inline address_range page_for(u32 addr)
+	{
+		return address_range::start_end(page_start(addr), page_end(addr));
+	}
+
+
+	/**
+	 * Address Range Vector utility class
+	 *
+	 * Collection of address_range objects. Allows for merging and removing ranges from the set.
+	 */
+	class address_range_vector
+	{
+	public:
+		using vector_type = typename std::vector<address_range>;
+		using iterator = typename vector_type::iterator;
+		using const_iterator = typename vector_type::const_iterator;
+		using size_type = typename vector_type::size_type;
+
+	private:
+		vector_type data;
+
+	public:
+		// Wrapped functions
+		inline void reserve(size_t nr) { data.reserve(nr); }
+		inline void clear() { data.clear(); }
+		inline size_type size() const { return data.size(); }
+		inline bool empty() const { return data.empty(); }
+		inline address_range& operator[](size_type n) { return data[n]; }
+		inline const address_range& operator[](size_type n) const { return data[n]; }
+		inline iterator begin() { return data.begin(); }
+		inline const_iterator begin() const { return data.begin(); }
+		inline iterator end() { return data.end(); }
+		inline const_iterator end() const { return data.end(); }
+
+		// Search for ranges that touch new_range. If found, merge instead of adding new_range.
+		// When adding a new range, re-use invalid ranges whenever possible
+		void merge(const address_range &new_range)
+		{
+			// Note the case where we have
+			//   AAAA  BBBB
+			//      CCCC
+			// If we have data={A,B}, and new_range=C, we have to merge A with C, then B with A and invalidate B
+
+			if (!new_range.valid())
+			{
+				return;
+			}
+
+			address_range *found = nullptr;
+			address_range *invalid = nullptr;
+
+			for (auto &existing : data)
+			{
+				if (!existing.valid())
+				{
+					invalid = &existing;
+					continue;
+				}
+
+				// range1 overlaps, is immediately before, or is immediately after range2
+				if (existing.touches(new_range))
+				{
+					if (found != nullptr)
+					{
+						// Already found a match, merge and invalidate "existing"
+						found->set_min_max(existing);
+						existing.invalidate();
+					}
+					else
+					{
+						// First match, merge "new_range"
+						existing.set_min_max(new_range);
+						found = &existing;
+					}
+				}
+			}
+
+			if (found != nullptr)
+			{
+				return;
+			}
+
+			if (invalid != nullptr)
+			{
+				*invalid = new_range;
+			}
+			else
+			{
+				data.push_back(new_range);
+			}
+
+			AUDIT(check_consistency());
+		}
+
+		void merge(const address_range_vector &other)
+		{
+			for (const address_range &new_range : other)
+			{
+				merge(new_range);
+			}
+		}
+
+		// Exclude a given range from data
+		void exclude(const address_range &exclusion)
+		{
+			// Note the case where we have
+			//    AAAAAAA
+			//      EEE
+			// where data={A} and exclusion=E.
+			// In this case, we need to reduce A to the head (before E starts), and then create a new address_range B for the tail (after E ends), i.e.
+			//    AA   BB
+			//      EEE
+
+			if (!exclusion.valid())
+			{
+				return;
+			}
+
+			address_range *invalid = nullptr; // try to re-use an invalid range instead of calling push_back
+
+			// We use index access because we might have to push_back within the loop, which could invalidate the iterators
+			size_type _size = data.size();
+			for (int n = 0; n < _size; ++n)
+			{
+				address_range &existing = data[n];
+
+				if (!existing.valid())
+				{
+					// Null
+					invalid = &existing;
+					continue;
+				}
+
+				if (!existing.overlaps(exclusion))
+				{
+					// No overlap, skip
+					continue;
+				}
+
+				const bool head_excluded = exclusion.overlaps(existing.start); // This section has its start inside excluded range
+				const bool tail_excluded = exclusion.overlaps(existing.end); // This section has its end inside excluded range
+
+				if (head_excluded && tail_excluded)
+				{
+					// Cannot be salvaged, fully excluded
+					existing.invalidate();
+					invalid = &existing;
+				}
+				else if (head_excluded)
+				{
+					// Head overlaps, truncate head
+					existing.start = exclusion.next_address();
+				}
+				else if (tail_excluded)
+				{
+					// Tail overlaps, truncate tail
+					existing.end = exclusion.prev_address();
+				}
+				else
+				{
+					// Section sits in the middle (see comment above function header)
+					AUDIT(exclusion.inside(existing));
+					const auto tail_end = existing.end;
+
+					// Head
+					existing.end = exclusion.prev_address();
+
+					// Tail
+					if (invalid != nullptr)
+					{
+						invalid->start = exclusion.next_address();
+						invalid->end = tail_end;
+						invalid = nullptr;
+					}
+					else
+					{
+						// IMPORTANT: adding to data invalidates "existing". This must be done last!
+						data.push_back(address_range::start_end(exclusion.next_address(), tail_end));
+					}
+				}
+			}
+			AUDIT(check_consistency());
+			AUDIT(!overlaps(exclusion));
+		}
+
+		void exclude(const address_range_vector &other)
+		{
+			for (const address_range &exclusion : other)
+			{
+				exclude(exclusion);
+			}
+		}
+
+		// Checks the consistency of this vector.
+		// Will fail if ranges within the vector overlap our touch each-other
+		bool check_consistency() const
+		{
+			size_t _size = data.size();
+
+			for (int i = 0; i < _size; ++i)
+			{
+				const auto &r1 = data[i];
+				if (!r1.valid())
+				{
+					continue;
+				}
+
+				for (int j = i + 1; j < _size; ++j)
+				{
+					const auto &r2 = data[j];
+					if (!r2.valid())
+					{
+						continue;
+					}
+
+					if (r1.touches(r2))
+					{
+						return false;
+					}
+				}
+			}
+			return true;
+		}
+
+		// Test for overlap with a given range
+		bool overlaps(const address_range &range) const
+		{
+			for (const address_range &current : data)
+			{
+				if (!current.valid())
+				{
+					continue;
+				}
+
+				if (current.overlaps(range))
+				{
+					return true;
+				}
+			}
+
+			return false;
+		}
+
+		// Test for overlap with a given address_range vector
+		bool overlaps(const address_range_vector &other) const
+		{
+			for (const address_range &rng1 : data)
+			{
+				if (!rng1.valid())
+				{
+					continue;
+				}
+
+				for (const address_range &rng2 : other.data)
+				{
+					if (!rng2.valid())
+					{
+						continue;
+					}
+
+					if (rng1.overlaps(rng2))
+					{
+						return true;
+					}
+				}
+			}
+			return false;
+		}
+
+		// Test if a given range is fully contained inside this vector
+		bool contains(const address_range &range) const
+		{
+			for (const address_range &cur : *this)
+			{
+				if (!cur.valid())
+				{
+					continue;
+				}
+
+				if (range.inside(cur))
+				{
+					return true;
+				}
+			}
+			return false;
+		}
+
+		// Test if all ranges in this vector are full contained inside a specific range
+		bool inside(const address_range &range) const
+		{
+			for (const address_range &cur : *this)
+			{
+				if (!cur.valid())
+				{
+					continue;
+				}
+
+				if (!cur.inside(range))
+				{
+					return false;
+				}
+			}
+			return true;
+		}
+	};
+
+
+	// These declarations must be done after address_range_vector has been defined
+	bool address_range::inside(const address_range_vector &vec) const
+	{
+		return vec.contains(*this);
+	}
+
+	bool address_range::overlaps(const address_range_vector &vec) const
+	{
+		return vec.overlaps(*this);
+	}
+
+}; // namespace utils
+
+
+namespace std {
+	static_assert(sizeof(size_t) >= 2 * sizeof(u32), "size_t must be at least twice the size of u32");
+
+	template <>
+	struct hash<utils::address_range>
+	{
+		std::size_t operator()(const utils::address_range& k) const
+		{
+			// we can guarantee a unique hash since our type is 64 bits and size_t as well
+			return (size_t{ k.start } << 32) | size_t{ k.end };
+		}
+	};
+};
\ No newline at end of file
diff --git a/rpcs3/emucore.vcxproj b/rpcs3/emucore.vcxproj
index c076f62a8e..fe6489dab8 100644
--- a/rpcs3/emucore.vcxproj
+++ b/rpcs3/emucore.vcxproj
@@ -346,6 +346,7 @@
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\3rdparty\stblib\stb_image.h" />
+    <ClInclude Include="..\Utilities\address_range.h" />
     <ClInclude Include="..\Utilities\Atomic.h" />
     <ClInclude Include="..\Utilities\AtomicPtr.h" />
     <ClInclude Include="..\Utilities\BEType.h" />
diff --git a/rpcs3/emucore.vcxproj.filters b/rpcs3/emucore.vcxproj.filters
index 82d37b991e..c8c8aa801c 100644
--- a/rpcs3/emucore.vcxproj.filters
+++ b/rpcs3/emucore.vcxproj.filters
@@ -1441,5 +1441,8 @@
     <ClInclude Include="..\Utilities\date_time.h">
       <Filter>Utilities</Filter>
     </ClInclude>
+    <ClInclude Include="..\Utilities\address_range.h">
+      <Filter>Utilities</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>
\ No newline at end of file