61 lines
1.6 KiB
C++
61 lines
1.6 KiB
C++
/////////////////////////////////////////////////////////////////////////////
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//
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// LUASNAP
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//
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// A lua interpreter that can be checkpointed (snapshotted). This makes it
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// possible to roll the entire interpreter back to a previously-snapshotted
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// state.
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//
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// To accomplish this, we take advantage of the 'allocf' parameter to
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// lua_newstate. This lets us hook the lua allocator, which in turn lets us
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// find every block of memory currently in use by lua. To snapshot, we 'memcpy'
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// every block of memory that lua is using into a buffer. To rollback, we just
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// 'memcpy' the data back.
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//
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// The current implementation is a proof-of-concept. It's quite wasteful of
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// memory, roughly doubling the amount of RAM that LUA uses. It's also not
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// super-fast, since it allocates tons of tiny blocks. But it totally
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// works, so it demonstrate that this method of snapshot and rollback is
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// feasible.
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//
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/////////////////////////////////////////////////////////////////////////////
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#ifndef LUASNAP_HPP
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#define LUASNAP_HPP
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#include "luastack.hpp"
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class LuaSnapData;
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class LuaSnap {
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private:
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lua_State *state_;
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LuaSnapData *data_;
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public:
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LuaSnap();
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~LuaSnap();
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// Get the lua intepreter.
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//
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lua_State *state() const { return state_; }
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// Return true if there's a saved snapshot.
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//
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bool have_snapshot() const;
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// snapshot the state of the lua interpreter.
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//
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// If there is already a snapshot, this panics.
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//
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void snapshot();
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// Rollback the lua intepreter to the snapshotted state.
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//
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// If there is no snapshot, this panics.
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//
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void rollback();
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};
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#endif // LUASNAP_HPP
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