1 //===-- CommandHistory.cpp --------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include <inttypes.h>
11 
12 #include "lldb/Host/StringConvert.h"
13 #include "lldb/Interpreter/CommandHistory.h"
14 
15 using namespace lldb;
16 using namespace lldb_private;
17 
18 CommandHistory::CommandHistory() : m_mutex(), m_history() {}
19 
20 CommandHistory::~CommandHistory() {}
21 
22 size_t CommandHistory::GetSize() const {
23   std::lock_guard<std::recursive_mutex> guard(m_mutex);
24   return m_history.size();
25 }
26 
27 bool CommandHistory::IsEmpty() const {
28   std::lock_guard<std::recursive_mutex> guard(m_mutex);
29   return m_history.empty();
30 }
31 
32 llvm::Optional<llvm::StringRef>
33 CommandHistory::FindString(llvm::StringRef input_str) const {
34   std::lock_guard<std::recursive_mutex> guard(m_mutex);
35   if (input_str.size() < 2)
36     return llvm::None;
37 
38   if (input_str[0] != g_repeat_char)
39     return llvm::None;
40 
41   if (input_str[1] == g_repeat_char) {
42     if (m_history.empty())
43       return llvm::None;
44     return m_history.back();
45   }
46 
47   input_str = input_str.drop_front();
48 
49   size_t idx = 0;
50   if (input_str.front() == '-') {
51     if (input_str.drop_front(2).getAsInteger(0, idx))
52       return llvm::None;
53     if (idx > m_history.size())
54       return llvm::None;
55     idx = m_history.size() - idx;
56     return m_history[idx];
57 
58   } else {
59     if (input_str.drop_front().getAsInteger(0, idx))
60       return llvm::None;
61     if (idx > m_history.size())
62       return llvm::None;
63     if (idx >= m_history.size())
64       return llvm::None;
65     return m_history[idx];
66   }
67 }
68 
69 llvm::StringRef CommandHistory::GetStringAtIndex(size_t idx) const {
70   std::lock_guard<std::recursive_mutex> guard(m_mutex);
71   if (idx < m_history.size())
72     return m_history[idx];
73   return "";
74 }
75 
76 llvm::StringRef CommandHistory::operator[](size_t idx) const {
77   return GetStringAtIndex(idx);
78 }
79 
80 llvm::StringRef CommandHistory::GetRecentmostString() const {
81   std::lock_guard<std::recursive_mutex> guard(m_mutex);
82   if (m_history.empty())
83     return "";
84   return m_history.back();
85 }
86 
87 void CommandHistory::AppendString(llvm::StringRef str, bool reject_if_dupe) {
88   std::lock_guard<std::recursive_mutex> guard(m_mutex);
89   if (reject_if_dupe) {
90     if (!m_history.empty()) {
91       if (str == m_history.back())
92         return;
93     }
94   }
95   m_history.push_back(str);
96 }
97 
98 void CommandHistory::Clear() {
99   std::lock_guard<std::recursive_mutex> guard(m_mutex);
100   m_history.clear();
101 }
102 
103 void CommandHistory::Dump(Stream &stream, size_t start_idx,
104                           size_t stop_idx) const {
105   std::lock_guard<std::recursive_mutex> guard(m_mutex);
106   stop_idx = std::min(stop_idx + 1, m_history.size());
107   for (size_t counter = start_idx; counter < stop_idx; counter++) {
108     const std::string hist_item = m_history[counter];
109     if (!hist_item.empty()) {
110       stream.Indent();
111       stream.Printf("%4" PRIu64 ": %s\n", (uint64_t)counter, hist_item.c_str());
112     }
113   }
114 }
115