network plugin: Use a global buffer and fill it as much as possible.

This should lessen network load, hopefully.

diff --git a/src/network.c b/src/network.c
index 11c9718..cf2a017 100644 (file)
--- a/src/network.c
+++ b/src/network.c
@@ -1,6 +1,6 @@
 /**
  * collectd - src/network.c
- * Copyright (C) 2005,2006  Florian octo Forster
+ * Copyright (C) 2005-2007  Florian octo Forster
  *
  * 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
@@ -57,7 +57,7 @@
 # endif
 #endif /* !IP_ADD_MEMBERSHIP */
 
-#define BUFF_SIZE 4096
+#define BUFF_SIZE 1024
 
 /*
  * Private data types
@@ -157,6 +157,12 @@ static int listen_sockets_num = 0;
 static pthread_t listen_thread = 0;
 static int listen_loop = 0;
 
+static char         send_buffer[BUFF_SIZE];
+static char        *send_buffer_ptr;
+static int          send_buffer_fill;
+static value_list_t send_buffer_vl = VALUE_LIST_INIT;
+static char         send_buffer_type[DATA_MAX_NAME_LEN];
+
 /*
  * Private functions
  */
@@ -225,9 +231,6 @@ static int write_part_string (char **ret_buffer, int *ret_buffer_len,
        part_string_t ps;
        int len;
 
-       if (str_len < 1)
-               return (-1);
-
        len = 4 + str_len + 1;
        if (*ret_buffer_len < len)
                return (-1);
@@ -238,7 +241,8 @@ static int write_part_string (char **ret_buffer, int *ret_buffer_len,
 
        ps.head->type = htons ((uint16_t) type);
        ps.head->length = htons ((uint16_t) str_len + 5);
-       memcpy (ps.value, str, str_len);
+       if (str_len > 0)
+               memcpy (ps.value, str, str_len);
        ps.value[str_len] = '\0';
        *ret_buffer = (void *) (ps.value + (str_len + 1));
 
@@ -868,135 +872,150 @@ static void *receive_thread (void *arg)
        return (network_receive () ? (void *) 1 : (void *) 0);
 } /* void *receive_thread */
 
-#if 0
-int network_send (char *type, char *inst, char *value)
+static void network_send_buffer (const char *buffer, int buffer_len)
 {
-       char buf[BUFF_SIZE];
-       int buflen;
-
        sockent_t *se;
-
-       int ret;
        int status;
 
-       DBG ("type = %s, inst = %s, value = %s", type, inst, value);
-
-       assert (operating_mode == MODE_CLIENT);
-
-       buflen = snprintf (buf, BUFF_SIZE, "%s %s %s", type, inst, value);
-       if ((buflen >= BUFF_SIZE) || (buflen < 1))
-       {
-               syslog (LOG_WARNING, "network_send: snprintf failed..");
-               return (-1);
-       }
-       buf[buflen] = '\0';
-       buflen++;
-
-       if (socklist_head == NULL)
-               network_create_default_socket (0 /* listen == false */);
+       DBG ("buffer_len = %i", buffer_len);
 
-       ret = 0;
-       for (se = socklist_head; se != NULL; se = se->next)
+       for (se = sending_sockets; se != NULL; se = se->next)
        {
-               while (1)
+               while (42)
                {
-                       status = sendto (se->fd, buf, buflen, 0,
+                       status = sendto (se->fd, buffer, buffer_len, 0 /* no flags */,
                                        (struct sockaddr *) se->addr, se->addrlen);
-
-                       if (status == -1)
+                       if (status < 0)
                        {
                                if (errno == EINTR)
-                               {
-                                       DBG ("sendto was interrupted");
                                        continue;
-                               }
-                               else
-                               {
-                                       syslog (LOG_ERR, "sendto: %s", strerror (errno));
-                                       ret = -1;
-                                       break;
-                               }
+                               syslog (LOG_ERR, "network plugin: sendto failed: %s",
+                                               strerror (errno));
+                               break;
                        }
-                       else if (ret >= 0)
-                               ret++;
-                       break;
-               }
-       }
-
-       if (ret == 0)
-               syslog (LOG_WARNING, "Message wasn't sent to anybody..");
 
-       return (ret);
-} /* int network_send */
-#endif
+                       break;
+               } /* while (42) */
+       } /* for (sending_sockets) */
+} /* void network_send_buffer */
 
-static int network_write (const data_set_t *ds, const value_list_t *vl)
+static int add_to_buffer (char *buffer, int buffer_size,
+               value_list_t *vl_def, char *type_def,
+               const data_set_t *ds, const value_list_t *vl)
 {
-       char  buf[BUFF_SIZE];
-       char *buf_ptr;
-       int   buf_len;
+       if (strcmp (vl_def->host, vl->host) != 0)
+       {
+               if (write_part_string (&buffer, &buffer_size, TYPE_HOST,
+                                       vl->host, strlen (vl->host)) != 0)
+                       return (-1);
+               strcpy (vl_def->host, vl->host);
+               DBG ("host = %s", vl->host);
+       }
 
-       sockent_t *se;
+       if (vl_def->time != vl->time)
+       {
+               if (write_part_number (&buffer, &buffer_size, TYPE_TIME,
+                                       (uint64_t) vl->time))
+                       return (-1);
+               vl_def->time = vl->time;
+               DBG ("time = %u", (unsigned int) vl->time);
+       }
 
-       DBG ("time = %u; host = %s; "
-                       "plugin = %s; plugin_instance = %s; "
-                       "type = %s; type_instance = %s;",
-                       (unsigned int) vl->time, vl->host,
-                       vl->plugin, vl->plugin_instance,
-                       ds->type, vl->type_instance);
-
-       buf_len = sizeof (buf);
-       buf_ptr = buf;
-       if (write_part_string (&buf_ptr, &buf_len, TYPE_HOST,
-                               vl->host, strlen (vl->host)) != 0)
-               return (-1);
-       if (write_part_number (&buf_ptr, &buf_len, TYPE_TIME,
-                               (uint64_t) vl->time))
-               return (-1);
-       if (write_part_string (&buf_ptr, &buf_len, TYPE_PLUGIN,
-                               vl->plugin, strlen (vl->plugin)) != 0)
-               return (-1);
-       if (strlen (vl->plugin_instance) > 0)
-               if (write_part_string (&buf_ptr, &buf_len, TYPE_PLUGIN_INSTANCE,
+       if (strcmp (vl_def->plugin, vl->plugin) != 0)
+       {
+               if (write_part_string (&buffer, &buffer_size, TYPE_PLUGIN,
+                                       vl->plugin, strlen (vl->plugin)) != 0)
+                       return (-1);
+               strcpy (vl_def->plugin, vl->plugin);
+               DBG ("plugin = %s", vl->plugin);
+       }
+
+       if (strcmp (vl_def->plugin_instance, vl->plugin_instance) != 0)
+       {
+               if (write_part_string (&buffer, &buffer_size, TYPE_PLUGIN_INSTANCE,
                                        vl->plugin_instance,
                                        strlen (vl->plugin_instance)) != 0)
                        return (-1);
-       if (write_part_string (&buf_ptr, &buf_len, TYPE_TYPE,
-                               ds->type, strlen (ds->type)) != 0)
-               return (-1);
-       if (strlen (vl->type_instance) > 0)
-               if (write_part_string (&buf_ptr, &buf_len, TYPE_PLUGIN_INSTANCE,
+               strcpy (vl_def->plugin_instance, vl->plugin_instance);
+               DBG ("plugin_instance = %s", vl->plugin_instance);
+       }
+
+       if (strcmp (type_def, ds->type) != 0)
+       {
+               if (write_part_string (&buffer, &buffer_size, TYPE_TYPE,
+                                       ds->type, strlen (ds->type)) != 0)
+                       return (-1);
+               strcpy (type_def, ds->type);
+               DBG ("type = %s", ds->type);
+       }
+
+       if (strcmp (vl_def->type_instance, vl->type_instance) != 0)
+       {
+               if (write_part_string (&buffer, &buffer_size, TYPE_PLUGIN_INSTANCE,
                                        vl->type_instance,
                                        strlen (vl->type_instance)) != 0)
                        return (-1);
+               strcpy (vl_def->type_instance, vl->type_instance);
+               DBG ("type_instance = %s", vl->type_instance);
+       }
        
-       write_part_values (&buf_ptr, &buf_len, ds, vl);
+       if (write_part_values (&buffer, &buffer_size, ds, vl) != 0)
+               return (-1);
 
-       buf_len = sizeof (buf) - buf_len;
+       return (buffer_size);
+} /* int add_to_buffer */
 
-       for (se = sending_sockets; se != NULL; se = se->next)
+static void flush_buffer (void)
+{
+       network_send_buffer (send_buffer, send_buffer_fill);
+       send_buffer_ptr  = send_buffer;
+       send_buffer_fill = 0;
+       memset (&send_buffer_vl, '\0', sizeof (send_buffer_vl));
+       memset (send_buffer_type, '\0', sizeof (send_buffer_type));
+}
+
+static int network_write (const data_set_t *ds, const value_list_t *vl)
+{
+       int status;
+       /* TODO: lock buffer */
+       status = add_to_buffer (send_buffer_ptr,
+                       sizeof (send_buffer) - send_buffer_fill,
+                       &send_buffer_vl, send_buffer_type,
+                       ds, vl);
+       if (status >= 0)
        {
-               int status;
+               send_buffer_fill += status;
+               send_buffer_ptr  += status;
+       }
+       else
+       {
+               flush_buffer ();
 
-               while (42)
+               status = add_to_buffer (send_buffer_ptr,
+                               sizeof (send_buffer) - send_buffer_fill,
+                               &send_buffer_vl, send_buffer_type,
+                               ds, vl);
+
+               if (status >= 0)
                {
-                       status = sendto (se->fd, buf, buf_len, 0 /* no flags */,
-                                       (struct sockaddr *) se->addr, se->addrlen);
-                       if (status < 0)
-                       {
-                               if (errno == EINTR)
-                                       continue;
-                               syslog (LOG_ERR, "network: sendto failed: %s",
-                                               strerror (errno));
-                               break;
-                       }
+                       send_buffer_fill += status;
+                       send_buffer_ptr  += status;
+               }
+       }
 
-                       break;
-               } /* while (42) */
-       } /* for (sending_sockets) */
+       if (status < 0)
+       {
+               syslog (LOG_ERR, "network plugin: Unable to append to the "
+                               "buffer for some weird reason");
+       }
+       else if ((sizeof (send_buffer) - send_buffer_fill) < 15)
+       {
+               flush_buffer ();
+       }
+       /* TODO: unlock buffer */
 
-       return 0;
-}
+       return ((status < 0) ? -1 : 0);
+} /* int network_write */
 
 static int network_config (const char *key, const char *val)
 {
@@ -1060,6 +1079,11 @@ static int network_init (void)
 {
        plugin_register_shutdown ("network", network_shutdown);
 
+       send_buffer_ptr  = send_buffer;
+       send_buffer_fill = 0;
+       memset (&send_buffer_vl, '\0', sizeof (send_buffer_vl));
+       memset (send_buffer_type, '\0', sizeof (send_buffer_type));
+
        /* setup socket(s) and so on */
        if (sending_sockets != NULL)
                plugin_register_write ("network", network_write);