Program memory cache

src/Targets/TargetMemoryCache.hpp

@@ -0,0 +1,72 @@
+#pragma once
+
+#include <cstdint>
+#include <map>
+
+#include "TargetMemory.hpp"
+
+namespace Targets
+{
+    class TargetMemoryCache
+    {
+    public:
+        TargetMemoryCache(const TargetMemoryDescriptor& memoryDescriptor);
+
+        /**
+         * Fetches data from the cache.
+         *
+         * @param startAddress
+         * @param bytes
+         *
+         * @return
+         */
+        TargetMemoryBuffer fetch(TargetMemoryAddress startAddress, TargetMemorySize bytes) const;
+
+        /**
+         * Checks if the cache currently holds data within the given address range.
+         *
+         * @param startAddress
+         * @param bytes
+         *
+         * @return
+         */
+        bool contains(TargetMemoryAddress startAddress, TargetMemorySize bytes) const;
+
+        /**
+         * Inserts data into the cache and performs any necessary bookkeeping.
+         *
+         * @param startAddress
+         * @param data
+         */
+        void insert(TargetMemoryAddress startAddress, const TargetMemoryBuffer& data);
+
+        /**
+         * Clears the cache.
+         */
+        void clear();
+
+    private:
+        const TargetMemoryDescriptor& memoryDescriptor;
+        TargetMemoryBuffer data;
+
+        /**
+         * A populated segment is just an address range in the cache that we know we've populated.
+         *
+         * populatedSegments::value_type::first = The start address (inclusive) of the populated range
+         * populatedSegments::value_type::second = The end address (inclusive) of the populated range
+         */
+        std::map<TargetMemoryAddress, TargetMemoryAddress> populatedSegments = {};
+
+        /**
+         * Finds the segment that intersects with the given address. Segments cannot overlap, so only one segment can
+         * intersect with the given address, at any given time.
+         *
+         * @param address
+         *
+         * @return
+         *  An iterator to the intersecting segment, or populatedSegments::end() if none is found.
+         */
+        using SegmentIt = decltype(TargetMemoryCache::populatedSegments)::const_iterator;
+        SegmentIt intersectingSegment(TargetMemoryAddress address) const;
+    };
+}