Remove Lua compaction filter from RocksDB main repo (#4971)

Summary:
as title. For people who continue to need Lua compaction filter, you
can copy the include/rocksdb/utilities/rocks_lua/lua_compaction_filter.h and
utilities/lua/rocks_lua_compaction_filter.cc to your own codebase.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4971

Differential Revision: D14047468

Pulled By: riversand963

fbshipit-source-id: 9ad1a6484a7c94e478f1e108127a3184e4069f70

1 files changed, 0 insertions, 189 deletions

diff --git a/include/rocksdb/utilities/lua/rocks_lua_compaction_filter.h b/include/rocksdb/utilities/lua/rocks_lua_compaction_filter.h
deleted file mode 100644
index c0154aae2..000000000
--- a/include/rocksdb/utilities/lua/rocks_lua_compaction_filter.h
+++ /dev/null
@@ -1,189 +0,0 @@
-//  Copyright (c) 2016, Facebook, Inc.  All rights reserved.
-//  This source code is licensed under both the GPLv2 (found in the
-//  COPYING file in the root directory) and Apache 2.0 License
-//  (found in the LICENSE.Apache file in the root directory).
-
-#pragma once
-
-#if defined(LUA) && !defined(ROCKSDB_LITE)
-// lua headers
-extern "C" {
-#include <lauxlib.h>
-#include <lua.h>
-#include <lualib.h>
-}
-
-#include <mutex>
-#include <string>
-#include <vector>
-
-#include "rocksdb/compaction_filter.h"
-#include "rocksdb/env.h"
-#include "rocksdb/slice.h"
-#include "rocksdb/utilities/lua/rocks_lua_custom_library.h"
-#include "rocksdb/utilities/lua/rocks_lua_util.h"
-
-namespace rocksdb {
-namespace lua {
-
-struct RocksLuaCompactionFilterOptions {
-  // The lua script in string that implements all necessary CompactionFilter
-  // virtual functions.  The specified lua_script must implement the following
-  // functions, which are Name and Filter, as described below.
-  //
-  // 0. The Name function simply returns a string representing the name of
-  //    the lua script.  If there's any erorr in the Name function, an
-  //    empty string will be used.
-  //    --- Example
-  //      function Name()
-  //        return "DefaultLuaCompactionFilter"
-  //      end
-  //
-  //
-  // 1. The script must contains a function called Filter, which implements
-  //    CompactionFilter::Filter() , takes three input arguments, and returns
-  //    three values as the following API:
-  //
-  //   function Filter(level, key, existing_value)
-  //     ...
-  //     return is_filtered, is_changed, new_value
-  //   end
-  //
-  //   Note that if ignore_value is set to true, then Filter should implement
-  //   the following API:
-  //
-  //   function Filter(level, key)
-  //     ...
-  //     return is_filtered
-  //   end
-  //
-  //   If there're any error in the Filter() function, then it will keep
-  //   the input key / value pair.
-  //
-  //   -- Input
-  //   The function must take three arguments (integer, string, string),
-  //   which map to "level", "key", and "existing_value" passed from
-  //   RocksDB.
-  //
-  //   -- Output
-  //   The function must return three values (boolean, boolean, string).
-  //     - is_filtered: if the first return value is true, then it indicates
-  //       the input key / value pair should be filtered.
-  //     - is_changed: if the second return value is true, then it indicates
-  //       the existing_value needs to be changed, and the resulting value
-  //       is stored in the third return value.
-  //     - new_value: if the second return value is true, then this third
-  //       return value stores the new value of the input key / value pair.
-  //
-  //   -- Examples
-  //     -- a filter that keeps all key-value pairs
-  //     function Filter(level, key, existing_value)
-  //       return false, false, ""
-  //     end
-  //
-  //     -- a filter that keeps all keys and change their values to "Rocks"
-  //     function Filter(level, key, existing_value)
-  //       return false, true, "Rocks"
-  //     end
-
-  std::string lua_script;
-
-  // If set to true, then existing_value will not be passed to the Filter
-  // function, and the Filter function only needs to return a single boolean
-  // flag indicating whether to filter out this key or not.
-  //
-  //   function Filter(level, key)
-  //     ...
-  //     return is_filtered
-  //   end
-  bool ignore_value = false;
-
-  // A boolean flag to determine whether to ignore snapshots.
-  bool ignore_snapshots = true;
-
-  // When specified a non-null pointer, the first "error_limit_per_filter"
-  // errors of each CompactionFilter that is lua related will be included
-  // in this log.
-  std::shared_ptr<Logger> error_log;
-
-  // The number of errors per CompactionFilter will be printed
-  // to error_log.
-  int error_limit_per_filter = 1;
-
-  // A string to luaL_reg array map that allows the Lua CompactionFilter
-  // to use custom C library.  The string will be used as the library
-  // name in Lua.
-  std::vector<std::shared_ptr<RocksLuaCustomLibrary>> libraries;
-
-  ///////////////////////////////////////////////////////////////////////////
-  //  NOT YET SUPPORTED
-  // The name of the Lua function in "lua_script" that implements
-  // CompactionFilter::FilterMergeOperand().  The function must take
-  // three input arguments (integer, string, string), which map to "level",
-  // "key", and "operand" passed from the RocksDB.  In addition, the
-  // function must return a single boolean value, indicating whether
-  // to filter the input key / operand.
-  //
-  // DEFAULT:  the default implementation always returns false.
-  // @see CompactionFilter::FilterMergeOperand
-};
-
-class RocksLuaCompactionFilterFactory : public CompactionFilterFactory {
- public:
-  explicit RocksLuaCompactionFilterFactory(
-      const RocksLuaCompactionFilterOptions opt);
-
-  virtual ~RocksLuaCompactionFilterFactory() {}
-
-  std::unique_ptr<CompactionFilter> CreateCompactionFilter(
-      const CompactionFilter::Context& context) override;
-
-  // Change the Lua script so that the next compaction after this
-  // function call will use the new Lua script.
-  void SetScript(const std::string& new_script);
-
-  // Obtain the current Lua script
-  std::string GetScript();
-
-  const char* Name() const override;
-
- private:
-  RocksLuaCompactionFilterOptions opt_;
-  std::string name_;
-  // A lock to protect "opt_" to make it dynamically changeable.
-  std::mutex opt_mutex_;
-};
-
-// A wrapper class that invokes Lua script to perform CompactionFilter
-// functions.
-class RocksLuaCompactionFilter : public rocksdb::CompactionFilter {
- public:
-  explicit RocksLuaCompactionFilter(const RocksLuaCompactionFilterOptions& opt)
-      : options_(opt),
-        lua_state_wrapper_(opt.lua_script, opt.libraries),
-        error_count_(0),
-        name_("") {}
-
-  virtual bool Filter(int level, const Slice& key, const Slice& existing_value,
-                      std::string* new_value,
-                      bool* value_changed) const override;
-  // Not yet supported
-  virtual bool FilterMergeOperand(int /*level*/, const Slice& /*key*/,
-                                  const Slice& /*operand*/) const override {
-    return false;
-  }
-  virtual bool IgnoreSnapshots() const override;
-  virtual const char* Name() const override;
-
- protected:
-  void LogLuaError(const char* format, ...) const;
-
-  RocksLuaCompactionFilterOptions options_;
-  LuaStateWrapper lua_state_wrapper_;
-  mutable int error_count_;
-  mutable std::string name_;
-};
-
-}  // namespace lua
-}  // namespace rocksdb
-#endif  // defined(LUA) && !defined(ROCKSDB_LITE)