1 //===-- CommandHistory.cpp ------------------------------------------------===//
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 #include <cinttypes>
10 #include <optional>
11 
12 #include "lldb/Interpreter/CommandHistory.h"
13 
14 using namespace lldb;
15 using namespace lldb_private;
16 
17 size_t CommandHistory::GetSize() const {
18   std::lock_guard<std::recursive_mutex> guard(m_mutex);
19   return m_history.size();
20 }
21 
22 bool CommandHistory::IsEmpty() const {
23   std::lock_guard<std::recursive_mutex> guard(m_mutex);
24   return m_history.empty();
25 }
26 
27 std::optional<llvm::StringRef>
28 CommandHistory::FindString(llvm::StringRef input_str) const {
29   std::lock_guard<std::recursive_mutex> guard(m_mutex);
30   if (input_str.size() < 2)
31     return std::nullopt;
32 
33   if (input_str[0] != g_repeat_char)
34     return std::nullopt;
35 
36   if (input_str[1] == g_repeat_char) {
37     if (m_history.empty())
38       return std::nullopt;
39     return llvm::StringRef(m_history.back());
40   }
41 
42   input_str = input_str.drop_front();
43 
44   size_t idx = 0;
45   if (input_str.front() == '-') {
46     if (input_str.drop_front(1).getAsInteger(0, idx))
47       return std::nullopt;
48     if (idx >= m_history.size())
49       return std::nullopt;
50     idx = m_history.size() - idx;
51   } else {
52     if (input_str.getAsInteger(0, idx))
53       return std::nullopt;
54     if (idx >= m_history.size())
55       return std::nullopt;
56   }
57 
58   return llvm::StringRef(m_history[idx]);
59 }
60 
61 llvm::StringRef CommandHistory::GetStringAtIndex(size_t idx) const {
62   std::lock_guard<std::recursive_mutex> guard(m_mutex);
63   if (idx < m_history.size())
64     return m_history[idx];
65   return "";
66 }
67 
68 llvm::StringRef CommandHistory::operator[](size_t idx) const {
69   return GetStringAtIndex(idx);
70 }
71 
72 llvm::StringRef CommandHistory::GetRecentmostString() const {
73   std::lock_guard<std::recursive_mutex> guard(m_mutex);
74   if (m_history.empty())
75     return "";
76   return m_history.back();
77 }
78 
79 void CommandHistory::AppendString(llvm::StringRef str, bool reject_if_dupe) {
80   std::lock_guard<std::recursive_mutex> guard(m_mutex);
81   if (reject_if_dupe) {
82     if (!m_history.empty()) {
83       if (str == m_history.back())
84         return;
85     }
86   }
87   m_history.push_back(std::string(str));
88 }
89 
90 void CommandHistory::Clear() {
91   std::lock_guard<std::recursive_mutex> guard(m_mutex);
92   m_history.clear();
93 }
94 
95 void CommandHistory::Dump(Stream &stream, size_t start_idx,
96                           size_t stop_idx) const {
97   std::lock_guard<std::recursive_mutex> guard(m_mutex);
98   stop_idx = std::min(stop_idx + 1, m_history.size());
99   for (size_t counter = start_idx; counter < stop_idx; counter++) {
100     const std::string hist_item = m_history[counter];
101     if (!hist_item.empty()) {
102       stream.Indent();
103       stream.Printf("%4" PRIu64 ": %s\n", (uint64_t)counter, hist_item.c_str());
104     }
105   }
106 }
107