Differential D4834 Diff 15386 src/script/scriptcache.h

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src/script/scriptcache.h

	// Copyright (c) 2017 - The Bitcoin Developers			// Copyright (c) 2017 - The Bitcoin Developers
	// Distributed under the MIT software license, see the accompanying			// Distributed under the MIT software license, see the accompanying
	// file COPYING or http://www.opensource.org/licenses/mit-license.php.			// file COPYING or http://www.opensource.org/licenses/mit-license.php.

	#ifndef BITCOIN_SCRIPT_SCRIPTCACHE_H			#ifndef BITCOIN_SCRIPT_SCRIPTCACHE_H
	#define BITCOIN_SCRIPT_SCRIPTCACHE_H			#define BITCOIN_SCRIPT_SCRIPTCACHE_H

	#include <uint256.h>			#include <array>

	#include <cstdint>			#include <cstdint>

	class CTransaction;			class CTransaction;

				/**
				* The script cache is a map using a key/value element.
				* The key is slightly shorter than a power-of-two size to make room for
				* the value.
				*/
				class ScriptCacheKey {
				std::array<uint8_t, 30> data;

				public:
				ScriptCacheKey() = default;
				ScriptCacheKey(const ScriptCacheKey &rhs) = default;
				ScriptCacheKey(const CTransaction &tx, uint32_t flags);

				bool operator==(const ScriptCacheKey &rhs) const {
				return rhs.data == data;
				}

				friend class ScriptCacheHasher;
				};

	// DoS prevention: limit cache size to 32MB (over 1000000 entries on 64-bit			// DoS prevention: limit cache size to 32MB (over 1000000 entries on 64-bit
	// systems). Due to how we count cache size, actual memory usage is slightly			// systems). Due to how we count cache size, actual memory usage is slightly
	// more (~32.25 MB)			// more (~32.25 MB)
	static const unsigned int DEFAULT_MAX_SCRIPT_CACHE_SIZE = 32;			static const unsigned int DEFAULT_MAX_SCRIPT_CACHE_SIZE = 32;
	// Maximum sig cache size allowed			// Maximum sig cache size allowed
	static const int64_t MAX_MAX_SCRIPT_CACHE_SIZE = 16384;			static const int64_t MAX_MAX_SCRIPT_CACHE_SIZE = 16384;

	/** Initializes the script-execution cache */			/** Initializes the script-execution cache */
	void InitScriptExecutionCache();			void InitScriptExecutionCache();

	/** Compute the cache key for a given transaction and flags. */			/** Check if a given key is in the cache, and if so, return its values.
	uint256 GetScriptCacheKey(const CTransaction &tx, uint32_t flags);			* (if not found nSigChecksRet may or may not be set to an arbitrary value)
				*/
				deadalnixUnsubmitted Not Done Inline Actions format \o/ I won't block for this if this is isolated, but make sure you pay attention to this kind of details as to avoid needless rounds of review. deadalnix: format \o/ I won't block for this if this is isolated, but make sure you pay attention to this…
	/** Check if a given key is in the cache. */			bool IsKeyInScriptCache(ScriptCacheKey key, bool erase, int &nSigChecksRet);
	bool IsKeyInScriptCache(uint256 key, bool erase);
				constexpr int SCRIPT_CACHE_MAX_SIGCHECKS = UINT16_MAX;
	/** Add an entry in the cache. */
	void AddKeyInScriptCache(uint256 key);			/**
				* Add an entry in the cache. The sigchecks count must be in the range
				* 0-SCRIPT_CACHE_MAX_SIGCHECKS inclusive, otherwise a cache entry must not
				* be added (if successfully added, it would be corrupt data, and possibly
				* lead to consensus failure when the cache is consulted during block
				* validation).
				*/
				void AddKeyInScriptCache(ScriptCacheKey key, int nSigChecks);

	#endif // BITCOIN_SCRIPT_SCRIPTCACHE_H			#endif // BITCOIN_SCRIPT_SCRIPTCACHE_H