btop/src/btop_linux.h
2021-05-13 03:11:29 +02:00

235 lines
7.1 KiB
C++

/* Copyright 2021 Aristocratos (jakob@qvantnet.com)
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
indent = tab
tab-size = 4
*/
#ifndef _btop_linux_included_
#define _btop_linux_included_
#include <string>
#include <vector>
#include <tuple>
#include <map>
#include <atomic>
#include <fstream>
#include <filesystem>
#include <ranges>
#include <unistd.h>
#include <btop_config.h>
#include <btop_globs.h>
#include <btop_tools.h>
namespace fs = std::filesystem;
using namespace std;
class Processes {
uint64_t tstamp;
long int clk_tck;
map<int, tuple<string, string, string>> cache;
map<string, unsigned> sorts = {
{"pid", 0},
{"name", 1},
{"command", 2},
{"user", 3},
{"cpu direct", 4},
{"cpu lazy", 5}
};
map<string, string> uid_user;
fs::file_time_type passwd_time;
map<int, uint64_t> cpu_times;
map<int, uint64_t> cpu_second;
unsigned counter = 0;
public:
atomic<bool> stop;
atomic<bool> running;
//* Collects process information from /proc and returns a vector of tuples
auto collect(string sorting="pid", bool reverse=false, string filter=""){
running.store(true);
int pid;
uint64_t cpu_t;
double cpu, cpu_s;
ifstream pread;
string pid_str, name, cmd, attr, user, instr, uid, status, tmpstr;
auto since_last = time_ms() - tstamp;
if (since_last < 1) since_last = 1;
auto uptime = system_uptime();
auto sortint = (sorts.contains(sorting)) ? sorts[sorting] : 5;
vector<string> pstat;
//? Return type! Values in tuple: pid, program, command, username, cpu%, cpu cumulative
vector<tuple<int, string, string, string, double, double>> procs;
//* Update uid_user map if /etc/passwd changed since last run
if (fs::last_write_time(fs::path("/etc/passwd")) != passwd_time) {
string r_uid, r_user;
passwd_time = fs::last_write_time(fs::path("/etc/passwd"));
uid_user.clear();
pread.clear();
ifstream pread("/etc/passwd");
while (true){
getline(pread, r_user, ':');
pread.ignore(numeric_limits<streamsize>::max(), ':');
getline(pread, r_uid, ':');
uid_user[r_uid] = r_user;
pread.ignore(numeric_limits<streamsize>::max(), '\n');
if (pread.eof()) break;
}
pread.close();
}
//* Iterate over all pid directories in /proc and get relevant values
for (auto& d: fs::directory_iterator("/proc")){
if (stop.load()) {
procs.clear();
running.store(false);
stop.store(false);
return procs;
}
pid_str = fs::path(d.path()).filename();
cpu = 0.0;
if (d.is_directory() && isdigit(pid_str[0])) {
pid = stoi(pid_str);
//* Get cpu usage
if (fs::is_regular_file((string)d.path() + "/stat")) {
pstat.clear();
ifstream pread((string)d.path() + "/stat");
while (getline(pread, instr, ' ')) pstat.push_back(instr);
pread.close();
//? Process utime + stime
cpu_t = stoull(pstat[13]) + stoull(pstat[14]);
if (!cpu_times.contains(pid)) cpu_times[pid] = cpu_t;
//? Cache process start time
if (!cpu_second.contains(pid)) cpu_second[pid] = stoull(pstat[21]);
//? Process cpu usage since last update, 100'000 because (100 percent * 1000 milliseconds) for correct conversion
cpu = static_cast<double>(100000 * (cpu_t - cpu_times[pid]) / since_last) / clk_tck;
//? Process cumulative cpu usage since process start
cpu_s = static_cast<double>((cpu_t / clk_tck) / (uptime - (cpu_second[pid] / clk_tck)));
cpu_times[pid] = cpu_t;
}
//* Cache program name, command and username
if (!cache.contains(pid)) {
if (fs::is_regular_file((string)d.path() + "/comm")) {
ifstream pread((string)d.path() + "/comm");
getline(pread, name);
pread.close();
}
if (fs::is_regular_file((string)d.path() + "/cmdline")) {
cmd.clear();
ifstream pread((string)d.path() + "/cmdline");
while(getline(pread, tmpstr, '\0')) cmd += tmpstr + " ";
pread.close();
if (!cmd.empty()) cmd.pop_back();
}
if (fs::exists((string)d.path() + "/status")) {
ifstream pread((string)d.path() + "/status");
status.clear();
while (!pread.eof()){
getline(pread, status, ':');
if (status == "Uid") {
pread.ignore();
getline(pread, uid, '\t');
break;
} else {
pread.ignore(numeric_limits<streamsize>::max(), '\n');
}
}
pread.close();
user = (uid_user.contains(uid)) ? uid_user.at(uid) : "";
}
cache[pid] = make_tuple(name, cmd, user);
}
// //* Match filter if applicable
if (!filter.empty() &&
pid_str.find(filter) == string::npos &&
get<0>(cache[pid]).find(filter) == string::npos &&
get<1>(cache[pid]).find(filter) == string::npos &&
get<2>(cache[pid]).find(filter) == string::npos
) continue;
//* Create tuple
procs.push_back(make_tuple(pid, get<0>(cache[pid]), get<1>(cache[pid]), get<2>(cache[pid]), cpu, cpu_s));
}
}
// auto st = time_ms();
//* Sort processes vector
ranges::sort(procs, [&sortint, &reverse](tuple<int, string, string, string, double, double>& a, tuple<int, string, string, string, double, double>& b) {
switch (sortint) {
case 0: return (reverse) ? get<0>(a) < get<0>(b) : get<0>(a) > get<0>(b); //? Pid
case 1: return (reverse) ? get<1>(a) < get<1>(b) : get<1>(a) > get<1>(b); //? Program
case 2: return (reverse) ? get<2>(a) < get<2>(b) : get<2>(a) > get<2>(b); //? Command
case 3: return (reverse) ? get<3>(a) < get<3>(b) : get<3>(a) > get<3>(b); //? User
case 4: return (reverse) ? get<4>(a) < get<4>(b) : get<4>(a) > get<4>(b); //? Cpu direct
case 5: return (reverse) ? get<5>(a) < get<5>(b) : get<5>(a) > get<5>(b); //? Cpu lazy
}
return false;
}
);
//* When using "cpu lazy" sorting, push processes with high cpu usage to the front regardless of cumulative usage
if (sortint == 5 && !reverse) {
double max = 10.0, target = 30.0;
for (size_t i = 0, offset = 0; i < procs.size(); i++) {
if (i <= 5 && get<4>(procs[i]) > max) max = get<4>(procs[i]);
else if (i == 6) target = (max > 30.0) ? max : 10.0;
if (i == offset && get<4>(procs[i]) > 30.0) offset++;
else if (get<4>(procs[i]) > target) rotate(procs.begin() + offset, procs.begin() + i, procs.begin() + i + 1);
}
}
// cout << "Sort took: " << time_ms() - st << "ms " << flush;
//* Clear all cached values at a regular interval
if (++counter >= 10000 || (filter.empty() && cache.size() > procs.size() + 100)) {
counter = 0;
cache.clear();
cpu_times.clear();
cpu_second.clear();
}
tstamp = time_ms();
running.store(false);
return procs;
}
Processes() {
clk_tck = sysconf(_SC_CLK_TCK);
tstamp = time_ms();
stop.store(false);
collect();
}
};
#endif