Move writing ICY Text to a separate async task

2 files changed, 36 insertions, 4 deletions

diff --git a/src/VLCInput.cpp b/src/VLCInput.cpp
index 70381fb..3a2e9ec 100644
--- a/src/VLCInput.cpp
+++ b/src/VLCInput.cpp
@@ -20,6 +20,7 @@
 #include <string>
 #include <cstring>
 #include <chrono>
+#include <functional>
 
 #include "VLCInput.h"
 
@@ -294,11 +295,39 @@ ssize_t VLCInput::read(uint8_t* buf, size_t length)
     return read;
 }
 
-void VLCInput::write_icy_text(const std::string& filename) const
+bool write_icy_to_file(const std::string& text, const std::string& filename)
 {
     FILE* fd = fopen(filename.c_str(), "wb");
-    fputs_unlocked(m_nowplaying.c_str(), fd);
-    fclose(fd);
+    if (fd) {
+        int ret = fputs(text.c_str(), fd);
+        fclose(fd);
+
+        return ret >= 0;
+    }
+
+    return false;
+}
+
+void VLCInput::write_icy_text(const std::string& filename)
+{
+    if (icy_text_written.valid()) {
+        auto status = icy_text_written.wait_for(std::chrono::microseconds(1));
+        if (status == std::future_status::ready) {
+            if (not icy_text_written.get()) {
+                fprintf(stderr, "Failed to write ICY Text to file!\n");
+            }
+        }
+    }
+
+    else {
+        if (m_nowplaying_previous != m_nowplaying) {
+            icy_text_written = std::async(std::launch::async,
+                    std::bind(write_icy_to_file, m_nowplaying, filename));
+
+        }
+
+        m_nowplaying_previous = m_nowplaying;
+    }
 }
 
 /* VLC up to version 2.1.0 used a different callback function signature.
diff --git a/src/VLCInput.h b/src/VLCInput.h
index 048c931..6b0a0f4 100644
--- a/src/VLCInput.h
+++ b/src/VLCInput.h
@@ -29,6 +29,7 @@
 #include <deque>
 #include <thread>
 #include <mutex>
+#include <future>
 
 #include <vlc/vlc.h>
 
@@ -67,7 +68,7 @@ class VLCInput
         /* Write the last received ICY-Text to the
          * file.
          */
-        void write_icy_text(const std::string& filename) const;
+        void write_icy_text(const std::string& filename);
 
         // Callbacks for VLC
 
@@ -102,7 +103,9 @@ class VLCInput
         unsigned m_channels;
         int m_rate;
 
+        std::future<bool> icy_text_written;
         std::string m_nowplaying;
+        std::string m_nowplaying_previous;
 
         // VLC pointers
         libvlc_instance_t     *m_vlc;