1 //===--- MemoryTree.h - A special tree for components and sizes -*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_SUPPORT_MEMORYTREE_H 10 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_SUPPORT_MEMORYTREE_H 11 12 #include "Trace.h" 13 #include "llvm/ADT/DenseMap.h" 14 #include "llvm/ADT/StringRef.h" 15 #include "llvm/Support/Allocator.h" 16 #include <cstddef> 17 #include <string> 18 #include <vector> 19 20 namespace clang { 21 namespace clangd { 22 23 /// A tree that can be used to represent memory usage of nested components while 24 /// preserving the hierarchy. 25 /// Edges have associated names. An edge that might not be interesting to all 26 /// traversers or costly to copy (e.g. file names) can be marked as "detail". 27 /// Tree construction allows chosing between a detailed and brief mode, in brief 28 /// mode all "detail" edges are ignored and tree is constructed without any 29 /// string copies. 30 struct MemoryTree { 31 public: 32 /// If Alloc is nullptr, tree is in brief mode and will ignore detail edges. 33 MemoryTree(llvm::BumpPtrAllocator *DetailAlloc = nullptr) DetailAllocMemoryTree34 : DetailAlloc(DetailAlloc) {} 35 36 /// No copy of the \p Name. 37 /// Note that returned pointers are invalidated with subsequent calls to 38 /// child/detail. childMemoryTree39 MemoryTree &child(llvm::StringLiteral Name) { return createChild(Name); } 40 41 MemoryTree(const MemoryTree &) = delete; 42 MemoryTree &operator=(const MemoryTree &) = delete; 43 44 MemoryTree(MemoryTree &&) = default; 45 MemoryTree &operator=(MemoryTree &&) = default; 46 47 /// Makes a copy of the \p Name in detailed mode, returns current node 48 /// otherwise. 49 /// Note that returned pointers are invalidated with subsequent calls to 50 /// child/detail. detailMemoryTree51 MemoryTree &detail(llvm::StringRef Name) { 52 return DetailAlloc ? createChild(Name.copy(*DetailAlloc)) : *this; 53 } 54 55 /// Increases size of current node by \p Increment. addUsageMemoryTree56 void addUsage(size_t Increment) { Size += Increment; } 57 58 /// Returns edges to direct children of this node. 59 const llvm::DenseMap<llvm::StringRef, MemoryTree> &children() const; 60 61 /// Returns total number of bytes used by this sub-tree. Performs a traversal. 62 size_t total() const; 63 64 /// Returns total number of bytes used by this node only. selfMemoryTree65 size_t self() const { return Size; } 66 67 private: 68 /// Adds a child with an edge labeled as \p Name. Multiple calls to this 69 /// function returns the same node. 70 MemoryTree &createChild(llvm::StringRef Name); 71 72 /// Allocator to use for detailed edge names. 73 llvm::BumpPtrAllocator *DetailAlloc = nullptr; 74 75 /// Bytes owned by this component specifically. 76 size_t Size = 0; 77 78 /// Edges from current node to its children. Keys are the labels for edges. 79 llvm::DenseMap<llvm::StringRef, MemoryTree> Children; 80 }; 81 82 /// Records total memory usage of each node under \p Out. Labels are edges on 83 /// the path joined with ".", starting with \p RootName. 84 void record(const MemoryTree &MT, std::string RootName, 85 const trace::Metric &Out); 86 87 } // namespace clangd 88 } // namespace clang 89 90 #endif 91