Forgot the most important parts of the last commit

src/plugin.c

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+/*
+ * $Id: $
+ * Simple plug-in api for output, transcode, and scanning plug-ins
+ *
+ * Copyright (C) 2006 Ron Pedde (ron@pedde.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <errno.h>
+#include <pthread.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "err.h"
+#include "os.h"
+#include "plugin.h"
+
+typedef struct tag_pluginentry {
+    void *phandle;
+    int type;
+    char *versionstring;
+    struct tag_pluginentry *next;
+} PLUGIN_ENTRY;
+
+/* Globals */
+static PLUGIN_ENTRY _plugin_list = { NULL, 0, NULL, NULL };
+
+static pthread_mutex_t _plugin_mutex = PTHREAD_MUTEX_INITIALIZER;
+static char* _plugin_error_list[] = {
+    "Success.",
+    "Could not load plugin: %s",
+    "Plugin missing required export: plugin_type/plugin_ver"
+};
+
+
+/* Forwards */
+void _plugin_lock(void);
+void _plugin_unlock(void);
+int _plugin_error(char **pe, int error, ...);
+
+/**
+ * lock the plugin_mutex
+ */
+void _plugin_lock(void) {
+    int err;
+
+    if((err=pthread_mutex_lock(&_plugin_mutex))) {
+        DPRINTF(E_FATAL,L_PLUG,"cannot lock plugin lock: %s\n",strerror(err));
+    }
+}
+
+/**
+ * unlock the plugin_mutex
+ */
+void _plugin_unlock(void) {
+    int err;
+
+    if((err=pthread_mutex_unlock(&_plugin_mutex))) {
+        DPRINTF(E_FATAL,L_PLUG,"cannot unlock plugin lock: %s\n",strerror(err));
+    }
+}
+
+/**
+ * return the error 
+ * 
+ * @param pe buffer to store the error string in
+ * @param error error to return
+ * @returns the specified error,to thelp with returns
+ */
+int _plugin_error(char **pe, int error, ...) {
+    va_list ap;
+    char errbuf[1024];
+
+    if(!pe)
+        return error;
+
+    va_start(ap, error);
+    vsnprintf(errbuf, sizeof(errbuf), _plugin_error_list[error], ap);
+    va_end(ap);
+
+    DPRINTF(E_SPAM,L_PLUG,"Raising error: %s\n",errbuf);
+
+    *pe = strdup(errbuf);
+    return error;
+}
+
+/**
+ * load a specified plugin.
+ *
+ * @param pe pointer to error string returned (if error)
+ * @param plugin path to plugin to load
+ *
+ * return PLUGIN_E_SUCCESS, or not, with pe set
+ */
+int plugin_load(char **pe, char *path) {
+    PLUGIN_ENTRY *ppi;
+    void *phandle;
+    int (*type_func)(void);
+    char* (*ver_func)(void);
+
+    DPRINTF(E_DBG,L_PLUG,"Attempting to load plugin %s\n",path);
+    
+    phandle = os_loadlib(path);
+    if(!phandle) {
+        return _plugin_error(pe,PLUGIN_E_NOLOAD,strerror(errno));
+    }
+
+    ppi = (PLUGIN_ENTRY*)malloc(sizeof(PLUGIN_ENTRY));
+    memset(ppi,0x00,sizeof(PLUGIN_ENTRY));
+
+    ppi->phandle = phandle;
+
+    type_func = (int(*)(void)) os_libfunc(phandle,"plugin_type");
+    ver_func = (char*(*)(void)) os_libfunc(phandle,"plugin_ver");
+    
+    if((type_func == NULL) || (ver_func == NULL))
+        return _plugin_error(pe,PLUGIN_E_BADFUNCS);
+    
+    ppi->type = type_func();
+    ppi->versionstring = ver_func();
+    
+    DPRINTF(E_INF,L_PLUG,"Loaded plugin %s (%s)\n",path,ppi->versionstring);
+    
+    _plugin_lock();
+    
+    ppi->next = _plugin_list.next;
+    _plugin_list.next = ppi;
+    
+    _plugin_unlock();
+    
+    return PLUGIN_E_SUCCESS;
+}
+ 

src/plugin.h

@@ -0,0 +1,32 @@
+/*
+ * $Id: $
+ * Simple plug-in api for output, transcode, and scanning plug-ins
+ *
+ * Copyright (C) 2006 Ron Pedde (ron@pedde.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef _PLUGIN_H_
+#define _PLUGIN_H_
+
+extern int plugin_load(char **pe, char *path);
+
+#define PLUGIN_E_SUCCESS     0
+#define PLUGIN_E_NOLOAD      1
+#define PLUGIN_E_BADFUNCS    2
+
+
+#endif /* _PLUGIN_H_ */