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// Copyright (c) 2011-present, 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
/*
* This macro is used for 32 bit OS. In 32 bit OS, the result number is a
negative number if we use reinterpret_cast<jlong>(pointer).
* For example, jlong ptr = reinterpret_cast<jlong>(pointer), ptr is a negative
number in 32 bit OS.
* If we check ptr using ptr > 0, it fails. For example, the following code is
not correct.
* if (jblock_cache_handle > 0) {
std::shared_ptr<ROCKSDB_NAMESPACE::Cache> *pCache =
reinterpret_cast<std::shared_ptr<ROCKSDB_NAMESPACE::Cache> *>(
jblock_cache_handle);
options.block_cache = *pCache;
}
* But the result number is positive number if we do
reinterpret_cast<size_t>(pointer) first and then cast it to jlong. size_t is 4
bytes long in 32 bit OS and 8 bytes long in 64 bit OS.
static_cast<jlong>(reinterpret_cast<size_t>(_pointer)) is also working in 64
bit OS.
*
* We don't need an opposite cast because it works from jlong to c++ pointer in
both 32 bit and 64 bit OS.
* For example, the following code is working in both 32 bit and 64 bit OS.
jblock_cache_handle is jlong.
* std::shared_ptr<ROCKSDB_NAMESPACE::Cache> *pCache =
reinterpret_cast<std::shared_ptr<ROCKSDB_NAMESPACE::Cache> *>(
jblock_cache_handle);
*/
#define GET_CPLUSPLUS_POINTER(_pointer) \
static_cast<jlong>(reinterpret_cast<size_t>(_pointer))
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