1 //===-- UniqueCStringMap.h --------------------------------------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 #ifndef liblldb_UniqueCStringMap_h_
10 #define liblldb_UniqueCStringMap_h_
15 #include "lldb/Utility/ConstString.h"
16 #include "lldb/Utility/RegularExpression.h"
18 namespace lldb_private {
20 // Templatized uniqued string map.
22 // This map is useful for mapping unique C string names to values of type T.
23 // Each "const char *" name added must be unique for a given
24 // C string value. ConstString::GetCString() can provide such strings.
25 // Any other string table that has guaranteed unique values can also be used.
26 template <typename T> class UniqueCStringMap {
29 Entry(ConstString cstr, const T &v) : cstring(cstr), value(v) {}
35 // Call this function multiple times to add a bunch of entries to this map,
36 // then later call UniqueCStringMap<T>::Sort() before doing any searches by
38 void Append(ConstString unique_cstr, const T &value) {
39 m_map.push_back(typename UniqueCStringMap<T>::Entry(unique_cstr, value));
42 void Append(const Entry &e) { m_map.push_back(e); }
44 void Clear() { m_map.clear(); }
46 // Get an entries by index in a variety of forms.
48 // The caller is responsible for ensuring that the collection does not change
49 // during while using the returned values.
50 bool GetValueAtIndex(uint32_t idx, T &value) const {
51 if (idx < m_map.size()) {
52 value = m_map[idx].value;
58 ConstString GetCStringAtIndexUnchecked(uint32_t idx) const {
59 return m_map[idx].cstring;
62 // Use this function if you have simple types in your map that you can easily
63 // copy when accessing values by index.
64 T GetValueAtIndexUnchecked(uint32_t idx) const { return m_map[idx].value; }
66 // Use this function if you have complex types in your map that you don't
67 // want to copy when accessing values by index.
68 const T &GetValueRefAtIndexUnchecked(uint32_t idx) const {
69 return m_map[idx].value;
72 ConstString GetCStringAtIndex(uint32_t idx) const {
73 return ((idx < m_map.size()) ? m_map[idx].cstring : ConstString());
76 // Find the value for the unique string in the map.
78 // Return the value for \a unique_cstr if one is found, return \a fail_value
79 // otherwise. This method works well for simple type
80 // T values and only if there is a sensible failure value that can
81 // be returned and that won't match any existing values.
82 T Find(ConstString unique_cstr, T fail_value) const {
83 auto pos = llvm::lower_bound(m_map, unique_cstr, Compare());
84 if (pos != m_map.end() && pos->cstring == unique_cstr)
89 // Get a pointer to the first entry that matches "name". nullptr will be
90 // returned if there is no entry that matches "name".
92 // The caller is responsible for ensuring that the collection does not change
93 // during while using the returned pointer.
94 const Entry *FindFirstValueForName(ConstString unique_cstr) const {
95 auto pos = llvm::lower_bound(m_map, unique_cstr, Compare());
96 if (pos != m_map.end() && pos->cstring == unique_cstr)
101 // Get a pointer to the next entry that matches "name" from a previously
102 // returned Entry pointer. nullptr will be returned if there is no subsequent
103 // entry that matches "name".
105 // The caller is responsible for ensuring that the collection does not change
106 // during while using the returned pointer.
107 const Entry *FindNextValueForName(const Entry *entry_ptr) const {
108 if (!m_map.empty()) {
109 const Entry *first_entry = &m_map[0];
110 const Entry *after_last_entry = first_entry + m_map.size();
111 const Entry *next_entry = entry_ptr + 1;
112 if (first_entry <= next_entry && next_entry < after_last_entry) {
113 if (next_entry->cstring == entry_ptr->cstring)
120 size_t GetValues(ConstString unique_cstr, std::vector<T> &values) const {
121 const size_t start_size = values.size();
123 for (const Entry &entry : llvm::make_range(std::equal_range(
124 m_map.begin(), m_map.end(), unique_cstr, Compare())))
125 values.push_back(entry.value);
127 return values.size() - start_size;
130 size_t GetValues(const RegularExpression ®ex,
131 std::vector<T> &values) const {
132 const size_t start_size = values.size();
134 const_iterator pos, end = m_map.end();
135 for (pos = m_map.begin(); pos != end; ++pos) {
136 if (regex.Execute(pos->cstring.GetCString()))
137 values.push_back(pos->value);
140 return values.size() - start_size;
143 // Get the total number of entries in this map.
144 size_t GetSize() const { return m_map.size(); }
146 // Returns true if this map is empty.
147 bool IsEmpty() const { return m_map.empty(); }
149 // Reserve memory for at least "n" entries in the map. This is useful to call
150 // when you know you will be adding a lot of entries using
151 // UniqueCStringMap::Append() (which should be followed by a call to
152 // UniqueCStringMap::Sort()) or to UniqueCStringMap::Insert().
153 void Reserve(size_t n) { m_map.reserve(n); }
155 // Sort the unsorted contents in this map. A typical code flow would be:
156 // size_t approximate_num_entries = ....
157 // UniqueCStringMap<uint32_t> my_map;
158 // my_map.Reserve (approximate_num_entries);
161 // my_map.Append (UniqueCStringMap::Entry(GetName(...), GetValue(...)));
164 void Sort() { llvm::sort(m_map.begin(), m_map.end(), Compare()); }
166 // Since we are using a vector to contain our items it will always double its
167 // memory consumption as things are added to the vector, so if you intend to
168 // keep a UniqueCStringMap around and have a lot of entries in the map, you
169 // will want to call this function to create a new vector and copy _only_ the
170 // exact size needed as part of the finalization of the string map.
172 if (m_map.size() < m_map.capacity()) {
173 collection temp(m_map.begin(), m_map.end());
180 bool operator()(const Entry &lhs, const Entry &rhs) {
181 return operator()(lhs.cstring, rhs.cstring);
184 bool operator()(const Entry &lhs, ConstString rhs) {
185 return operator()(lhs.cstring, rhs);
188 bool operator()(ConstString lhs, const Entry &rhs) {
189 return operator()(lhs, rhs.cstring);
192 // This is only for uniqueness, not lexicographical ordering, so we can
193 // just compare pointers. *However*, comparing pointers from different
194 // allocations is UB, so we need compare their integral values instead.
195 bool operator()(ConstString lhs, ConstString rhs) {
196 return uintptr_t(lhs.GetCString()) < uintptr_t(rhs.GetCString());
199 typedef std::vector<Entry> collection;
200 typedef typename collection::iterator iterator;
201 typedef typename collection::const_iterator const_iterator;
205 } // namespace lldb_private
207 #endif // liblldb_UniqueCStringMap_h_