1 files changed, 111 insertions, 0 deletions
diff --git a/src/plugins/utils/UniqueProcess.cpp b/src/plugins/utils/UniqueProcess.cpp
new file mode 100644
index 0000000..d2025f5
--- /dev/null
+++ b/src/plugins/utils/UniqueProcess.cpp
@@ -0,0 +1,111 @@
+#include "../../../plugins/utils/UniqueProcess.hpp"
+#include "../../../include/Storage.hpp"
+#include <stdio.h>
+#include <limits.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+
+namespace QuickMedia {
+    bool is_quickmedia_instance_already_running(const char *sock_file_dir, const char *plugin_name) {
+        char sock_file[PATH_MAX];
+        snprintf(sock_file, sizeof(sock_file), "%s/quickmedia.%s.sock", sock_file_dir, plugin_name);
+
+        std::string resolved_path;
+        if(file_get_content(sock_file, resolved_path) != 0)
+            return false;
+        
+        resolved_path.resize(108); // sizeof(addr.sun_path) is 108
+
+        int fd = socket(AF_UNIX, SOCK_STREAM, 0);
+        if(fd == -1) {
+            fprintf(stderr, "Error: failed to create unix domain socket, error: %s\n", strerror(errno));
+            return true;
+        }
+
+        fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_NONBLOCK);
+
+        struct sockaddr_un addr;
+        memset(&addr, 0, sizeof(addr));
+        addr.sun_family = AF_UNIX;
+        strcpy(addr.sun_path, resolved_path.c_str());
+
+        bool running = connect(fd, (struct sockaddr*)&addr, sizeof(addr)) == 0;
+        int err = errno;
+        if(err == EAGAIN)
+            running = true;
+        else if(err == ENOENT)
+            running = false;
+        close(fd);
+        return running;
+    }
+
+    bool set_quickmedia_instance_unique(const char *sock_file_dir, const char *plugin_name) {
+        char socket_file[] = "/tmp/quickmedia.XXXXXX";
+        int tmp_file_fd = mkstemp(socket_file);
+        if(tmp_file_fd == -1) {
+            fprintf(stderr, "Error: failed to create temporary file for unix domain socket, error: %s\n", strerror(errno));
+            return false;
+        }
+        unlink(socket_file);
+        close(tmp_file_fd);
+
+        int fd = socket(AF_UNIX, SOCK_STREAM, 0);
+        if(fd == -1) {
+            fprintf(stderr, "Error: failed to create unix domain socket, error: %s\n", strerror(errno));
+            return false;
+        }
+
+        struct sockaddr_un addr;
+        memset(&addr, 0, sizeof(addr));
+        addr.sun_family = AF_UNIX;
+        strcpy(addr.sun_path, socket_file);
+
+        if(bind(fd, (struct sockaddr*)&addr, sizeof(addr)) == -1) {
+            fprintf(stderr, "Error: failed to bind unix domain socket, error: %s\n", strerror(errno));
+            unlink(socket_file);
+            close(fd);
+            return false;
+        }
+
+        if(listen(fd, 0) == -1) {
+            fprintf(stderr, "Error: failed to listen to unix domain socket, error: %s\n", strerror(errno));
+            unlink(socket_file);
+            close(fd);
+            return false;
+        }
+
+        char sock_file[PATH_MAX];
+        snprintf(sock_file, sizeof(sock_file), "%s/quickmedia.%s.sock", sock_file_dir, plugin_name);
+        bool success = file_overwrite(sock_file, socket_file) == 0;
+        if(!success) {
+            fprintf(stderr, "Error: failed to create %s unix domain socket link file\n", sock_file);
+            unlink(socket_file);
+            close(fd);
+        }
+        return success;
+    }
+
+    void remove_quickmedia_instance_lock(const char *sock_file_dir, const char *plugin_name) {
+        char sock_file[PATH_MAX];
+        snprintf(sock_file, sizeof(sock_file), "%s/quickmedia.%s.sock", sock_file_dir, plugin_name);
+
+        std::string resolved_path;
+        if(file_get_content(sock_file, resolved_path) != 0) {
+            unlink(sock_file);
+            return;
+        }
+        
+        resolved_path.resize(108); // sizeof(addr.sun_path) is 108
+
+        if(resolved_path.size() < 4 || memcmp(resolved_path.data(), "/tmp", 4) != 0) {
+            unlink(sock_file);
+            return;
+        }
+        
+        unlink(sock_file);
+        unlink(resolved_path.c_str());
+    }
+}
+\ No newline at end of file