From 3a288fbf42f810731d27ca06c7688ee47be35bc5 Mon Sep 17 00:00:00 2001
From: Selim Mustafaev <selim@fastmail.fm>
Date: Thu, 4 Jan 2024 15:44:45 +0300
Subject: [PATCH] Reopening leases file on every reading

---
 DataSources/DnsmasqSource.cpp | 18 +++---------------
 DataSources/DnsmasqSource.h   | 12 ------------
 main.cpp                      |  1 -
 3 files changed, 3 insertions(+), 28 deletions(-)

diff --git a/DataSources/DnsmasqSource.cpp b/DataSources/DnsmasqSource.cpp
index 561e6c4..840bfc9 100644
--- a/DataSources/DnsmasqSource.cpp
+++ b/DataSources/DnsmasqSource.cpp
@@ -3,33 +3,21 @@
 //
 
 #include "DnsmasqSource.h"
-#include <exception>
 #include <sstream>
-#include <iostream>
 #include <ranges>
-#include <array>
-#include <algorithm>
-
-namespace views = std::ranges::views;
 
 DnsmasqSource::DnsmasqSource() {
-    _leases.open("/var/lib/misc/dnsmasq.leases");
-    if(_leases.fail()) {
-        throw std::runtime_error("failed to open leases file");
-    }
 }
 
 std::vector<prometheus::Labels> DnsmasqSource::readLeases() {
-    _leases.clear();
-    _leases.seekg(0);
-
+    std::ifstream leases("/var/lib/misc/dnsmasq.leases");
     std::string line;
     std::vector<prometheus::Labels> result;
     auto labels = std::array{ "time", "mac", "ip", "host", "id" };
 
-    while(std::getline(_leases, line)) {
+    while(std::getline(leases, line)) {
         prometheus::Labels lineMap;
-        for(const auto [index, item]: std::views::split(line, ' ') | views::enumerate) {
+        for(const auto [index, item]: std::views::split(line, ' ') | std::views::enumerate) {
             lineMap[labels[index]] = std::string_view(item);
         }
         result.push_back(lineMap);
diff --git a/DataSources/DnsmasqSource.h b/DataSources/DnsmasqSource.h
index d2fc87e..5f34e04 100644
--- a/DataSources/DnsmasqSource.h
+++ b/DataSources/DnsmasqSource.h
@@ -10,18 +10,6 @@
 #include <vector>
 
 class DnsmasqSource {
-public:
-    enum LeaseField: int {
-        EXPIRY_TIME = 0,
-        MAC         = 1,
-        IP          = 2,
-        HOST        = 3,
-        ID          = 4
-    };
-
-private:
-    std::ifstream _leases;
-
 public:
     DnsmasqSource();
     std::vector<prometheus::Labels> readLeases();
diff --git a/main.cpp b/main.cpp
index 9db103d..80d5450 100644
--- a/main.cpp
+++ b/main.cpp
@@ -24,7 +24,6 @@ int main() {
         std::this_thread::sleep_for(std::chrono::seconds(1));
         for(const auto& leaseLabels: dnsmasq.readLeases()) {
             gouge.Add(leaseLabels).Set(1);
-            std::cout << "mac: " << leaseLabels.at("mac") << std::endl;
         }
     }