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author | MarcoFalke <falke.marco@gmail.com> | 2020-05-21 06:53:30 -0400 |
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committer | MarcoFalke <falke.marco@gmail.com> | 2020-05-21 06:53:39 -0400 |
commit | 25ad2c623af30056ffb36dcd203a52edda2b170f (patch) | |
tree | 94fabc7fa4df3d58fb1f2f1fc204ffc8db93bd0e /src/util/ref.h | |
parent | 97b21b302a117dc8ef8334a5f3c94f6a6b9eeff0 (diff) | |
parent | b3f7f375efb9a9ca9a7a4f2caf41fe3df2262520 (diff) | |
download | bitcoin-25ad2c623af30056ffb36dcd203a52edda2b170f.tar.xz |
Merge #18740: Remove g_rpc_node global
b3f7f375efb9a9ca9a7a4f2caf41fe3df2262520 refactor: Remove g_rpc_node global (Russell Yanofsky)
ccb5059ee89f6e8dc31ba5b82830b384890bb65e scripted-diff: Remove g_rpc_node references (Russell Yanofsky)
6fca33b2edc09ed62dab2323c780b31585de1750 refactor: Pass NodeContext to RPC and REST methods through util::Ref (Russell Yanofsky)
691c817b340d10e806dc3b1834d2a8fcc5e681fd Add util::Ref class as temporary alternative for c++17 std::any (Russell Yanofsky)
Pull request description:
This PR removes the `g_rpc_node` global, to get same benefits we see removing other globals and make RPC code more testable, modular, and reusable.
This uses a hybrid of the approaches suggested in #17548. Instead of using `std::any`, which isn't available in c++11, or `void*`, which isn't type safe, it uses a small new `util::Ref` helper class, which acts like a simplified `std::any` that only holds references, not values.
Motivation for writing this was to provide an simpler alternative to #18647 by Harris Brakmić (brakmic) which avoids some shortcomings of that PR (https://github.com/bitcoin/bitcoin/pull/18647#issuecomment-617878826)
ACKs for top commit:
MarcoFalke:
re-ACK b3f7f375ef, only change is adding back const and more tests 🚾
ajtowns:
ACK b3f7f375efb9a9ca9a7a4f2caf41fe3df2262520
Tree-SHA512: 56292268a001bdbe34d641db1180c215351503966ff451e55cc96c9137f1d262225d7d7733de9c9da7ce7d7a4b34213a98c2476266b58c89dbbb0f3cb5aa5d70
Diffstat (limited to 'src/util/ref.h')
-rw-r--r-- | src/util/ref.h | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/src/util/ref.h b/src/util/ref.h new file mode 100644 index 0000000000..9685ea9fec --- /dev/null +++ b/src/util/ref.h @@ -0,0 +1,38 @@ +// Copyright (c) 2020 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#ifndef BITCOIN_UTIL_REF_H +#define BITCOIN_UTIL_REF_H + +#include <util/check.h> + +#include <typeindex> + +namespace util { + +/** + * Type-safe dynamic reference. + * + * This implements a small subset of the functionality in C++17's std::any + * class, and can be dropped when the project updates to C++17 + * (https://github.com/bitcoin/bitcoin/issues/16684) + */ +class Ref +{ +public: + Ref() = default; + template<typename T> Ref(T& value) { Set(value); } + template<typename T> T& Get() const { CHECK_NONFATAL(Has<T>()); return *static_cast<T*>(m_value); } + template<typename T> void Set(T& value) { m_value = &value; m_type = std::type_index(typeid(T)); } + template<typename T> bool Has() const { return m_value && m_type == std::type_index(typeid(T)); } + void Clear() { m_value = nullptr; m_type = std::type_index(typeid(void)); } + +private: + void* m_value = nullptr; + std::type_index m_type = std::type_index(typeid(void)); +}; + +} // namespace util + +#endif // BITCOIN_UTIL_REF_H |