mirror of
https://github.com/facebook/sapling.git
synced 2024-10-06 23:07:18 +03:00
bb1cccac89
Summary: Backing stores differentiate between individual tree objects and the root of a checkout. For example, Git and Mercurial roots are commit hashes. Allow EdenFS to track variable-width roots to better support arbitrary backing stores. Reviewed By: genevievehelsel Differential Revision: D28619584 fbshipit-source-id: d94f1ecd21a0c416c1b4933341c70deabf386496
84 lines
2.0 KiB
C++
84 lines
2.0 KiB
C++
/*
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* Copyright (c) Facebook, Inc. and its affiliates.
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*
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* This software may be used and distributed according to the terms of the
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* GNU General Public License version 2.
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*/
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#pragma once
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#include <string>
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#include "eden/fs/model/Hash.h"
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namespace facebook::eden {
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/**
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* Each BackingStore implementation defines the meaning of its root. For
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* example, for Mercurial, that's a 20-byte commit hash. Roots may have a
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* different representation than tree IDs, so allow the BackingStore to define
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* the semantics.
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*
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* RootId should generally be human-readable (e.g. hex strings) because it is
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* printed to logs with C escaping rules.
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*/
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class RootId {
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public:
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RootId() = default;
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explicit RootId(std::string id) : id_{std::move(id)} {}
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RootId(const RootId&) = default;
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RootId(RootId&&) = default;
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RootId& operator=(const RootId&) = default;
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RootId& operator=(RootId&&) = default;
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const std::string& value() const {
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return id_;
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}
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friend bool operator==(const RootId& lhs, const RootId& rhs) {
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return lhs.id_ == rhs.id_;
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}
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friend bool operator!=(const RootId& lhs, const RootId& rhs) {
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return lhs.id_ != rhs.id_;
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}
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friend bool operator<(const RootId& lhs, const RootId& rhs) {
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return lhs.id_ < rhs.id_;
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}
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private:
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std::string id_;
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};
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std::ostream& operator<<(std::ostream& os, const RootId& rootId);
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// Make folly::to<string>(RootId) work.
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void toAppend(const RootId&, std::string* result);
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/**
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* The meaning of a RootId is defined by the BackingStore implementation. Allow
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* it to also define how how root IDs are parsed and rendered at API boundaries
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* such as Thrift.
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*/
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class RootIdCodec {
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public:
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virtual ~RootIdCodec() = default;
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virtual RootId parseRootId(folly::StringPiece rootId) = 0;
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virtual std::string renderRootId(const RootId& rootId) = 0;
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};
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} // namespace facebook::eden
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namespace std {
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template <>
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struct hash<facebook::eden::RootId> {
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std::size_t operator()(const facebook::eden::RootId& rootId) const {
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return std::hash<std::string>{}(rootId.value());
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}
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};
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} // namespace std
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