add patches for reducing overhead of mpd plugin; rel 2

[packages/polybar.git] / polybar-mpd-overhead.patch

From b1b5cd6bbb1e0dea35e7b86429ff3e04fd67db9f Mon Sep 17 00:00:00 2001
From: Jan Palus <atler@pld-linux.org>
Date: Wed, 23 Dec 2020 23:31:20 +0100
Subject: [PATCH 1/5] feat(mpd): split noidle into noidle and recv_idle

---
 include/adapters/mpd.hpp |  3 ++-
 src/adapters/mpd.cpp     | 15 ++++++++++++---
 src/modules/mpd.cpp      |  3 ++-
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/include/adapters/mpd.hpp b/include/adapters/mpd.hpp
index 2a152b01c..2e9b438e8 100644
--- a/include/adapters/mpd.hpp
+++ b/include/adapters/mpd.hpp
@@ -91,7 +91,8 @@ namespace mpd {
 
     int get_fd();
     void idle();
-    int noidle();
+    bool noidle();
+    int recv_idle();
 
     unique_ptr<mpdstatus> get_status();
     unique_ptr<mpdstatus> get_status_safe();
diff --git a/src/adapters/mpd.cpp b/src/adapters/mpd.cpp
index 4a5438ad5..083427a9c 100644
--- a/src/adapters/mpd.cpp
+++ b/src/adapters/mpd.cpp
@@ -201,12 +201,21 @@ namespace mpd {
     }
   }
 
-  int mpdconnection::noidle() {
+  bool mpdconnection::noidle() {
+    check_connection(m_connection.get());
+    bool success = true;
+    if (m_idle) {
+      success = mpd_send_noidle(m_connection.get());
+    }
+    return success;
+  }
+
+  int mpdconnection::recv_idle() {
     check_connection(m_connection.get());
     int flags = 0;
-    if (m_idle && mpd_send_noidle(m_connection.get())) {
-      m_idle = false;
+    if (m_idle) {
       flags = mpd_recv_idle(m_connection.get(), true);
+      m_idle = false;
       mpd_response_finish(m_connection.get());
       check_errors(m_connection.get());
     }
diff --git a/src/modules/mpd.cpp b/src/modules/mpd.cpp
index ea867f281..1ba33c81c 100644
--- a/src/modules/mpd.cpp
+++ b/src/modules/mpd.cpp
@@ -182,7 +182,8 @@ namespace modules {
       m_mpd->idle();
 
       int idle_flags = 0;
-      if ((idle_flags = m_mpd->noidle()) != 0) {
+      m_mpd->noidle();
+      if ((idle_flags = m_mpd->recv_idle()) != 0) {
         // Update status on every event
         m_status->update(idle_flags, m_mpd.get());
         return true;

From 1e2d86354cf3553df202e3fddc848ee54b2ff872 Mon Sep 17 00:00:00 2001
From: Jan Palus <atler@pld-linux.org>
Date: Fri, 25 Dec 2020 01:15:30 +0100
Subject: [PATCH 2/5] feat(mpd): reduce wakeups/network traffic when not
 tracking time

---
 include/adapters/mpd.hpp |  1 +
 src/adapters/mpd.cpp     | 15 +++++++++++++++
 src/modules/mpd.cpp      | 16 ++++++++++++----
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/include/adapters/mpd.hpp b/include/adapters/mpd.hpp
index 2e9b438e8..7f5a43e1b 100644
--- a/include/adapters/mpd.hpp
+++ b/include/adapters/mpd.hpp
@@ -93,6 +93,7 @@ namespace mpd {
     void idle();
     bool noidle();
     int recv_idle();
+    int try_recv_idle(int timeout);
 
     unique_ptr<mpdstatus> get_status();
     unique_ptr<mpdstatus> get_status_safe();
diff --git a/src/adapters/mpd.cpp b/src/adapters/mpd.cpp
index 083427a9c..76f824115 100644
--- a/src/adapters/mpd.cpp
+++ b/src/adapters/mpd.cpp
@@ -1,5 +1,6 @@
 #include <cassert>
 #include <csignal>
+#include <poll.h>
 #include <thread>
 #include <utility>
 
@@ -222,6 +223,20 @@ namespace mpd {
     return flags;
   }
 
+  int mpdconnection::try_recv_idle(int timeout) {
+    struct pollfd pfd = { m_fd, POLLIN, 0 };
+
+    int poll_ret = poll(&pfd, 1, timeout);
+
+    if (poll_ret > 0) {
+      return recv_idle();
+    } else if (poll_ret == 0) {
+      return 0;
+    } else {
+      throw mpd_exception("poll() returned error: "s + std::strerror(errno));
+    }
+  }
+
   unique_ptr<mpdstatus> mpdconnection::get_status() {
     check_prerequisites();
     auto status = make_unique<mpdstatus>(this);
diff --git a/src/modules/mpd.cpp b/src/modules/mpd.cpp
index 1ba33c81c..9c53378b8 100644
--- a/src/modules/mpd.cpp
+++ b/src/modules/mpd.cpp
@@ -178,12 +178,20 @@ namespace modules {
       m_status = m_mpd->get_status_safe();
     }
 
+    bool track_time = (m_label_time || m_bar_progress) && m_status->match_state(mpdstate::PLAYING);
     try {
       m_mpd->idle();
 
-      int idle_flags = 0;
-      m_mpd->noidle();
-      if ((idle_flags = m_mpd->recv_idle()) != 0) {
+      int idle_flags;
+
+      if (track_time) {
+        m_mpd->noidle();
+        idle_flags = m_mpd->recv_idle();
+      } else {
+        idle_flags = m_mpd->try_recv_idle(2000);
+      }
+
+      if (idle_flags != 0) {
         // Update status on every event
         m_status->update(idle_flags, m_mpd.get());
         return true;
@@ -194,7 +202,7 @@ namespace modules {
       return def;
     }
 
-    if ((m_label_time || m_bar_progress) && m_status->match_state(mpdstate::PLAYING)) {
+    if (track_time) {
       auto now = chrono::system_clock::now();
       auto diff = now - m_lastsync;
 

From 139dca02ae02615cd331d8061ac7c0cae661be25 Mon Sep 17 00:00:00 2001
From: Jan Palus <atler@pld-linux.org>
Date: Fri, 25 Dec 2020 01:23:34 +0100
Subject: [PATCH 3/5] feat(mpd): subscribe only to relevant event types

---
 src/adapters/mpd.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/adapters/mpd.cpp b/src/adapters/mpd.cpp
index 76f824115..b4567e7f2 100644
--- a/src/adapters/mpd.cpp
+++ b/src/adapters/mpd.cpp
@@ -196,7 +196,7 @@ namespace mpd {
   void mpdconnection::idle() {
     check_connection(m_connection.get());
     if (!m_idle) {
-      mpd_send_idle(m_connection.get());
+      mpd_send_idle_mask(m_connection.get(), (mpd_idle) (MPD_IDLE_PLAYER | MPD_IDLE_OPTIONS));
       check_errors(m_connection.get());
       m_idle = true;
     }

From 00eeb73637ff1928c9621fe6008628f04a1cf655 Mon Sep 17 00:00:00 2001
From: Jan Palus <atler@pld-linux.org>
Date: Fri, 25 Dec 2020 01:31:04 +0100
Subject: [PATCH 4/5] feat(mpd): minor optimization of happy code path

---
 src/modules/mpd.cpp | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/src/modules/mpd.cpp b/src/modules/mpd.cpp
index 9c53378b8..702fbebf6 100644
--- a/src/modules/mpd.cpp
+++ b/src/modules/mpd.cpp
@@ -149,13 +149,7 @@ namespace modules {
   }
 
   bool mpd_module::has_event() {
-    bool def = false;
-
-    if (!connected() && m_statebroadcasted == mpd::connection_state::CONNECTED) {
-      def = true;
-    } else if (connected() && m_statebroadcasted == mpd::connection_state::DISCONNECTED) {
-      def = true;
-    }
+    bool def = (m_statebroadcasted == (connected() ? mpd::connection_state::DISCONNECTED : mpd::connection_state::CONNECTED));
 
     try {
       if (!m_mpd) {

From b073db3569d887a1567a387c3ea71989ffede0cc Mon Sep 17 00:00:00 2001
From: Jan Palus <atler@pld-linux.org>
Date: Fri, 25 Dec 2020 12:30:10 +0100
Subject: [PATCH 5/5] feat(mpd): slightly modify delay calculation between
 connection attempts

wait 0.5s more on each attempt and cap it at 5s
---
 include/modules/mpd.hpp | 2 +-
 src/modules/mpd.cpp     | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/modules/mpd.hpp b/include/modules/mpd.hpp
index 04afc97e7..ed591fe42 100644
--- a/include/modules/mpd.hpp
+++ b/include/modules/mpd.hpp
@@ -90,7 +90,7 @@ namespace modules {
     chrono::system_clock::time_point m_lastsync{};
     float m_synctime{1.0f};
 
-    int m_quick_attempts{0};
+    int m_connect_attempts{0};
 
     // This flag is used to let thru a broadcast once every time
     // the connection state changes
diff --git a/src/modules/mpd.cpp b/src/modules/mpd.cpp
index 702fbebf6..3394f42a9 100644
--- a/src/modules/mpd.cpp
+++ b/src/modules/mpd.cpp
@@ -141,10 +141,10 @@ namespace modules {
 
   void mpd_module::idle() {
     if (connected()) {
-      m_quick_attempts = 0;
+      m_connect_attempts = 0;
       sleep(80ms);
     } else {
-      sleep(m_quick_attempts++ < 5 ? 0.5s : 2s);
+      sleep(++m_connect_attempts < 10 ? m_connect_attempts * 0.5s : 5s);
     }
   }