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author | anastasy888 <anastasy888@yandex-team.ru> | 2022-02-10 16:45:55 +0300 |
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committer | Daniil Cherednik <dcherednik@yandex-team.ru> | 2022-02-10 16:45:55 +0300 |
commit | 3a7a498715ef1b66f5054455421b845e45e3a653 (patch) | |
tree | 1a2c5ffcf89eb53ecd79dbc9bc0a195c27404d0c /contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/internal/graphcycles.h | |
parent | 49f765d71da452ea93138a25559dfa68dd76c7f3 (diff) | |
download | ydb-3a7a498715ef1b66f5054455421b845e45e3a653.tar.gz |
Restoring authorship annotation for <anastasy888@yandex-team.ru>. Commit 2 of 2.
Diffstat (limited to 'contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/internal/graphcycles.h')
-rw-r--r-- | contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/internal/graphcycles.h | 270 |
1 files changed, 135 insertions, 135 deletions
diff --git a/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/internal/graphcycles.h b/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/internal/graphcycles.h index 954550875c..eaf130bc29 100644 --- a/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/internal/graphcycles.h +++ b/contrib/restricted/abseil-cpp-tstring/y_absl/synchronization/internal/graphcycles.h @@ -1,141 +1,141 @@ -// Copyright 2017 The Abseil Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// https://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. -// - -#ifndef ABSL_SYNCHRONIZATION_INTERNAL_GRAPHCYCLES_H_ -#define ABSL_SYNCHRONIZATION_INTERNAL_GRAPHCYCLES_H_ - -// GraphCycles detects the introduction of a cycle into a directed -// graph that is being built up incrementally. -// -// Nodes are identified by small integers. It is not possible to -// record multiple edges with the same (source, destination) pair; -// requests to add an edge where one already exists are silently -// ignored. -// -// It is also not possible to introduce a cycle; an attempt to insert -// an edge that would introduce a cycle fails and returns false. -// -// GraphCycles uses no internal locking; calls into it should be -// serialized externally. - -// Performance considerations: -// Works well on sparse graphs, poorly on dense graphs. -// Extra information is maintained incrementally to detect cycles quickly. -// InsertEdge() is very fast when the edge already exists, and reasonably fast -// otherwise. -// FindPath() is linear in the size of the graph. -// The current implementation uses O(|V|+|E|) space. - -#include <cstdint> - +// Copyright 2017 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. +// + +#ifndef ABSL_SYNCHRONIZATION_INTERNAL_GRAPHCYCLES_H_ +#define ABSL_SYNCHRONIZATION_INTERNAL_GRAPHCYCLES_H_ + +// GraphCycles detects the introduction of a cycle into a directed +// graph that is being built up incrementally. +// +// Nodes are identified by small integers. It is not possible to +// record multiple edges with the same (source, destination) pair; +// requests to add an edge where one already exists are silently +// ignored. +// +// It is also not possible to introduce a cycle; an attempt to insert +// an edge that would introduce a cycle fails and returns false. +// +// GraphCycles uses no internal locking; calls into it should be +// serialized externally. + +// Performance considerations: +// Works well on sparse graphs, poorly on dense graphs. +// Extra information is maintained incrementally to detect cycles quickly. +// InsertEdge() is very fast when the edge already exists, and reasonably fast +// otherwise. +// FindPath() is linear in the size of the graph. +// The current implementation uses O(|V|+|E|) space. + +#include <cstdint> + #include "y_absl/base/config.h" namespace y_absl { ABSL_NAMESPACE_BEGIN -namespace synchronization_internal { - -// Opaque identifier for a graph node. -struct GraphId { - uint64_t handle; - - bool operator==(const GraphId& x) const { return handle == x.handle; } - bool operator!=(const GraphId& x) const { return handle != x.handle; } -}; - -// Return an invalid graph id that will never be assigned by GraphCycles. -inline GraphId InvalidGraphId() { - return GraphId{0}; -} - -class GraphCycles { - public: - GraphCycles(); - ~GraphCycles(); - - // Return the id to use for ptr, assigning one if necessary. - // Subsequent calls with the same ptr value will return the same id - // until Remove(). - GraphId GetId(void* ptr); - - // Remove "ptr" from the graph. Its corresponding node and all - // edges to and from it are removed. - void RemoveNode(void* ptr); - - // Return the pointer associated with id, or nullptr if id is not - // currently in the graph. - void* Ptr(GraphId id); - - // Attempt to insert an edge from source_node to dest_node. If the - // edge would introduce a cycle, return false without making any - // changes. Otherwise add the edge and return true. - bool InsertEdge(GraphId source_node, GraphId dest_node); - - // Remove any edge that exists from source_node to dest_node. - void RemoveEdge(GraphId source_node, GraphId dest_node); - - // Return whether node exists in the graph. - bool HasNode(GraphId node); - - // Return whether there is an edge directly from source_node to dest_node. - bool HasEdge(GraphId source_node, GraphId dest_node) const; - - // Return whether dest_node is reachable from source_node - // by following edges. - bool IsReachable(GraphId source_node, GraphId dest_node) const; - - // Find a path from "source" to "dest". If such a path exists, - // place the nodes on the path in the array path[], and return - // the number of nodes on the path. If the path is longer than - // max_path_len nodes, only the first max_path_len nodes are placed - // in path[]. The client should compare the return value with - // max_path_len" to see when this occurs. If no path exists, return - // 0. Any valid path stored in path[] will start with "source" and - // end with "dest". There is no guarantee that the path is the - // shortest, but no node will appear twice in the path, except the - // source and destination node if they are identical; therefore, the - // return value is at most one greater than the number of nodes in - // the graph. - int FindPath(GraphId source, GraphId dest, int max_path_len, - GraphId path[]) const; - - // Update the stack trace recorded for id with the current stack - // trace if the last time it was updated had a smaller priority - // than the priority passed on this call. - // - // *get_stack_trace is called to get the stack trace. - void UpdateStackTrace(GraphId id, int priority, - int (*get_stack_trace)(void**, int)); - - // Set *ptr to the beginning of the array that holds the recorded - // stack trace for id and return the depth of the stack trace. - int GetStackTrace(GraphId id, void*** ptr); - - // Check internal invariants. Crashes on failure, returns true on success. - // Expensive: should only be called from graphcycles_test.cc. - bool CheckInvariants() const; - - // ---------------------------------------------------- - struct Rep; - private: - Rep *rep_; // opaque representation - GraphCycles(const GraphCycles&) = delete; - GraphCycles& operator=(const GraphCycles&) = delete; -}; - -} // namespace synchronization_internal +namespace synchronization_internal { + +// Opaque identifier for a graph node. +struct GraphId { + uint64_t handle; + + bool operator==(const GraphId& x) const { return handle == x.handle; } + bool operator!=(const GraphId& x) const { return handle != x.handle; } +}; + +// Return an invalid graph id that will never be assigned by GraphCycles. +inline GraphId InvalidGraphId() { + return GraphId{0}; +} + +class GraphCycles { + public: + GraphCycles(); + ~GraphCycles(); + + // Return the id to use for ptr, assigning one if necessary. + // Subsequent calls with the same ptr value will return the same id + // until Remove(). + GraphId GetId(void* ptr); + + // Remove "ptr" from the graph. Its corresponding node and all + // edges to and from it are removed. + void RemoveNode(void* ptr); + + // Return the pointer associated with id, or nullptr if id is not + // currently in the graph. + void* Ptr(GraphId id); + + // Attempt to insert an edge from source_node to dest_node. If the + // edge would introduce a cycle, return false without making any + // changes. Otherwise add the edge and return true. + bool InsertEdge(GraphId source_node, GraphId dest_node); + + // Remove any edge that exists from source_node to dest_node. + void RemoveEdge(GraphId source_node, GraphId dest_node); + + // Return whether node exists in the graph. + bool HasNode(GraphId node); + + // Return whether there is an edge directly from source_node to dest_node. + bool HasEdge(GraphId source_node, GraphId dest_node) const; + + // Return whether dest_node is reachable from source_node + // by following edges. + bool IsReachable(GraphId source_node, GraphId dest_node) const; + + // Find a path from "source" to "dest". If such a path exists, + // place the nodes on the path in the array path[], and return + // the number of nodes on the path. If the path is longer than + // max_path_len nodes, only the first max_path_len nodes are placed + // in path[]. The client should compare the return value with + // max_path_len" to see when this occurs. If no path exists, return + // 0. Any valid path stored in path[] will start with "source" and + // end with "dest". There is no guarantee that the path is the + // shortest, but no node will appear twice in the path, except the + // source and destination node if they are identical; therefore, the + // return value is at most one greater than the number of nodes in + // the graph. + int FindPath(GraphId source, GraphId dest, int max_path_len, + GraphId path[]) const; + + // Update the stack trace recorded for id with the current stack + // trace if the last time it was updated had a smaller priority + // than the priority passed on this call. + // + // *get_stack_trace is called to get the stack trace. + void UpdateStackTrace(GraphId id, int priority, + int (*get_stack_trace)(void**, int)); + + // Set *ptr to the beginning of the array that holds the recorded + // stack trace for id and return the depth of the stack trace. + int GetStackTrace(GraphId id, void*** ptr); + + // Check internal invariants. Crashes on failure, returns true on success. + // Expensive: should only be called from graphcycles_test.cc. + bool CheckInvariants() const; + + // ---------------------------------------------------- + struct Rep; + private: + Rep *rep_; // opaque representation + GraphCycles(const GraphCycles&) = delete; + GraphCycles& operator=(const GraphCycles&) = delete; +}; + +} // namespace synchronization_internal ABSL_NAMESPACE_END } // namespace y_absl - -#endif + +#endif |