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#include "history.h"
#include <sys/stat.h>
#include <fcntl.h>
#include <print>
#include <cstdio>
#include <unistd.h>
#include <fstream>
#include <iostream>
#include <sys/stat.h>
#include <optional>
#include "util/io.h"
#include "util/file.h"
using namespace std;
namespace ov4
{
void add_history(const std::string &s)
{
history_vec.push_back(s);
}
void clear_history()
{
history_vec.clear();
}
size_t get_last_index()
{
return history_vec.size() - 1;
}
string get_default_history_path()
{
return get_home_dir() + '/' + ".ccshell_history";
}
/*
* load history from file
*/
void load_history(const string &path)
{
history_vec.clear();
ifstream ifs(path);
if (!ifs.is_open())
{
loggerln("load_history: fail to open history");
return;
}
string tmp;
while (getline(ifs, tmp))
{
history_vec.push_back(tmp);
}
return;
}
/*
* atomically save history to file
*/
void save_history(const string &path)
{
/*
* C++ and C standard lib do not guarantee that write is atomic
* So if the program crashes, or computer shutdowns, it will leave a bad file
* Then reading it may lead to problems if we launch the shell again
* But unix guarantees rename(2) is atomic
* So we just write to a temp file, and rename it to replace the "real" history file
*/
string tmp_path = path + ".tmp";
// int fd = open(tmp_path.c_str(), (O_WRONLY | O_CREAT | O_TRUNC | O_NOFOLLOW), (S_IRUSR | S_IWUSR));
optional<T_unix_file_p> file_fp_optional;
try
{
file_fp_optional.emplace(tmp_path.c_str(), (O_WRONLY | O_CREAT | O_TRUNC | O_NOFOLLOW), (S_IRUSR | S_IWUSR));
}
catch(const T_error &e)
{
std::cerr << e.what() << endl;
switch (e.code)
{
case error_code::FILE_FAIL_TO_OPEN:
loggerln("save_history: fail to open() history");
break;
case error_code::FILE_POINTER_FAIL_TO_OPEN:
loggerln("save_history: fail to fdopen() history");
default:
;
}
return;
}
T_unix_file_p &file_fp = *file_fp_optional;
for (auto &c : history_vec)
{
println(file_fp.fp, "{}", c);
}
bool success_write = true;
if (fflush(file_fp.fp) != 0) success_write = false;
if (fsync(file_fp.fd) != 0) success_write = false;
if (file_fp.close() != 0) success_write = false;
if (!success_write)
{
loggerln("save_history: fail to write");
return;
}
// atomic rename (replace)
if (rename(tmp_path.c_str(), path.c_str()) != 0)
{
loggerln("save_history: fail to rename");
return;
}
}
}
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