unixsock plugin: Add filtering regexen to the LISTVAL command.

diff --git a/src/collectd-unixsock.pod b/src/collectd-unixsock.pod
index 40626d3..9fefccd 100644 (file)
--- a/src/collectd-unixsock.pod
+++ b/src/collectd-unixsock.pod
@@ -61,7 +61,7 @@ Example:
   <- | 1 Value found
   <- | value=1.260000e+00
 
-=item B<LISTVAL>
+=item B<LISTVAL> [I<OptionList>]
 
 Returns a list of the values available in the value cache together with the
 time of the last update, so that querying applications can issue a B<GETVAL>
@@ -80,6 +80,28 @@ Example:
   <- | 1182204284 myhost/cpu-0/cpu-user
   ...
 
+Valid options are B<host>, B<plugin>, B<plugin_instance>, B<type> and
+B<type_instance>. Each option takes a regular expression as its argument. If at
+least one regular expression is supplied, only values where each appropriate
+part of the identifier satisfies the given regular expression are returned.
+
+Example:
+  -> | LISTVAL plugin_instance="^$"
+  <- | 5 Matching values
+  <- | 1300311250.802 myhost/load/load
+  <- | 1300311250.802 myhost/memory/memory-buffered
+  <- | 1300311250.802 myhost/memory/memory-cached
+  <- | 1300311250.804 myhost/memory/memory-free
+  <- | 1300311250.802 myhost/memory/memory-used
+
+Regular expressions follow the I<Extended Regular Expression> syntax (ERE)
+described in L<regex(7)> and will match case-sensitive. It is recommended to
+enclose the regular expression in double quotes. Please note that you will
+need to escape the backslash and double quote characters in this case. To
+request all values from hosts with the German top level domain ".de", for
+example, use:
+  LISTVAL host="\\.de$"
+
 =item B<PUTVAL> I<Identifier> [I<OptionList>] I<Valuelist>
 
 Submits one or more values (identified by I<Identifier>, see below) to the

diff --git a/src/utils_cmd_listval.c b/src/utils_cmd_listval.c
index ef66af5..078a527 100644 (file)
--- a/src/utils_cmd_listval.c
+++ b/src/utils_cmd_listval.c
@@ -1,6 +1,6 @@
 /**
  * collectd - src/utils_cms_listval.c
- * Copyright (C) 2008  Florian octo Forster
+ * Copyright (C) 2008-2011  Florian 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
@@ -16,18 +16,21 @@
  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  *
  * Author:
- *   Florian octo Forster <octo at verplant.org>
+ *   Florian "octo" Forster <octo at collectd.org>
  **/
 
 #include "collectd.h"
 #include "common.h"
 #include "plugin.h"
 
+#include <regex.h>
+
 #include "utils_cmd_listval.h"
 #include "utils_cache.h"
 #include "utils_parse_option.h"
 
-#define free_everything_and_return(status) do { \
+/* Not very nice, but oh so handy ... */
+#define FREE_EVERYTHING_AND_RETURN(status) do { \
     size_t j; \
     for (j = 0; j < number; j++) { \
       sfree(names[j]); \
@@ -35,6 +38,11 @@
     } \
     sfree(names); \
     sfree(times); \
+    if (have_re_host)            { regfree (&re_host);            } \
+    if (have_re_plugin)          { regfree (&re_plugin);          } \
+    if (have_re_plugin_instance) { regfree (&re_plugin_instance); } \
+    if (have_re_type)            { regfree (&re_type);            } \
+    if (have_re_type_instance)   { regfree (&re_type_instance);   } \
     return (status); \
   } while (0)
 
@@ -42,8 +50,8 @@
   if (fprintf (fh, __VA_ARGS__) < 0) { \
     char errbuf[1024]; \
     WARNING ("handle_listval: failed to write to socket #%i: %s", \
-       fileno (fh), sstrerror (errno, errbuf, sizeof (errbuf))); \
-    free_everything_and_return (-1); \
+        fileno (fh), sstrerror (errno, errbuf, sizeof (errbuf))); \
+    FREE_EVERYTHING_AND_RETURN (-1); \
   }
 
 int handle_listval (FILE *fh, char *buffer)
@@ -55,6 +63,17 @@ int handle_listval (FILE *fh, char *buffer)
   size_t i;
   int status;
 
+  regex_t re_host;
+  regex_t re_plugin;
+  regex_t re_plugin_instance;
+  regex_t re_type;
+  regex_t re_type_instance;
+  _Bool have_re_host = 0;
+  _Bool have_re_plugin = 0;
+  _Bool have_re_plugin_instance = 0;
+  _Bool have_re_type = 0;
+  _Bool have_re_type_instance = 0;
+
   DEBUG ("utils_cmd_listval: handle_listval (fh = %p, buffer = %s);",
       (void *) fh, buffer);
 
@@ -63,37 +82,179 @@ int handle_listval (FILE *fh, char *buffer)
   if (status != 0)
   {
     print_to_socket (fh, "-1 Cannot parse command.\n");
-    free_everything_and_return (-1);
+    FREE_EVERYTHING_AND_RETURN (-1);
   }
   assert (command != NULL);
 
   if (strcasecmp ("LISTVAL", command) != 0)
   {
     print_to_socket (fh, "-1 Unexpected command: `%s'.\n", command);
-    free_everything_and_return (-1);
+    FREE_EVERYTHING_AND_RETURN (-1);
   }
 
-  if (*buffer != 0)
+  /* Parse the options which may still be contained in the buffer. Valid
+   * options are "host", "plugin", "plugin_instance", "type" and
+   * "type_instance"; each option takes a regular expression as argument which
+   * is used to filter the returned identifiers. */
+  while (*buffer != 0)
   {
-    print_to_socket (fh, "-1 Garbage after end of command: %s\n", buffer);
-    free_everything_and_return (-1);
-  }
+    char *opt_key;
+    char *opt_value;
+    regex_t *re;
+    _Bool *have_re;
+
+    opt_key = NULL;
+    opt_value = NULL;
+    status = parse_option (&buffer, &opt_key, &opt_value);
+    if (status != 0)
+    {
+      print_to_socket (fh, "-1 Parsing options failed.\n");
+      FREE_EVERYTHING_AND_RETURN (-1);
+    }
 
+    if (strcasecmp ("host", opt_key) == 0)
+    {
+      re = &re_host;
+      have_re = &have_re_host;
+    }
+    else if (strcasecmp ("plugin", opt_key) == 0)
+    {
+      re = &re_plugin;
+      have_re = &have_re_plugin;
+    }
+    else if (strcasecmp ("plugin_instance", opt_key) == 0)
+    {
+      re = &re_plugin_instance;
+      have_re = &have_re_plugin_instance;
+    }
+    else if (strcasecmp ("type", opt_key) == 0)
+    {
+      re = &re_type;
+      have_re = &have_re_type;
+    }
+    else if (strcasecmp ("type_instance", opt_key) == 0)
+    {
+      re = &re_type_instance;
+      have_re = &have_re_type_instance;
+    }
+    else
+    {
+      print_to_socket (fh, "-1 Unknown option: %s\n", opt_key);
+      FREE_EVERYTHING_AND_RETURN (-1);
+    }
+
+    /* Free a previous regular expression */
+    if (*have_re)
+    {
+      NOTICE ("listval command: More than one match for part \"%s\". "
+          "Only the last regular expression will be used to search "
+          "for matching value lists!",
+          opt_key);
+      regfree (re);
+      *have_re = 0;
+    }
+
+    /* Compile the regular expression. */
+    status = regcomp (re, opt_value, REG_EXTENDED | REG_NOSUB);
+    if (status != 0)
+    {
+      char errbuf[1024];
+      regerror (status, re, errbuf, sizeof (errbuf));
+      errbuf[sizeof (errbuf) - 1] = 0;
+      print_to_socket (fh, "-1 Compiling %s regex failed: %s\n",
+          opt_key, errbuf);
+      FREE_EVERYTHING_AND_RETURN (-1);
+    }
+    *have_re = 1;
+  } /* while (*buffer != 0) */
+
+  /* Get a list of values from the cache. */
   status = uc_get_names (&names, &times, &number);
   if (status != 0)
   {
     DEBUG ("command listval: uc_get_names failed with status %i", status);
     print_to_socket (fh, "-1 uc_get_names failed.\n");
-    free_everything_and_return (-1);
+    FREE_EVERYTHING_AND_RETURN (-1);
+  }
+
+  /* If no regex has been specified, take the easy way out. This will avoid a
+   * lot of pointless if-blocks. */
+  if (!have_re_host
+      && !have_re_plugin
+      && !have_re_plugin_instance
+      && !have_re_type
+      && !have_re_type_instance)
+  {
+    print_to_socket (fh, "%i Value%s found\n",
+        (int) number, (number == 1) ? "" : "s");
+    for (i = 0; i < number; i++)
+      print_to_socket (fh, "%.3f %s\n", CDTIME_T_TO_DOUBLE (times[i]),
+          names[i]);
   }
+  else /* At least one regular expression is present. */
+  {
+    char *matching_names[number];
+    cdtime_t matching_times[number];
+    size_t matching_number = 0;
+
+    /* We need to figure out how many values we're going to return for the
+     * status line first. We save all matched values in the above arrays to
+     * avoid doing the matching twice. */
+    for (i = 0; i < number; i++)
+    {
+      value_list_t vl = VALUE_LIST_INIT;
 
-  print_to_socket (fh, "%i Value%s found\n",
-      (int) number, (number == 1) ? "" : "s");
-  for (i = 0; i < number; i++)
-    print_to_socket (fh, "%.3f %s\n", CDTIME_T_TO_DOUBLE (times[i]),
-               names[i]);
+      status = parse_identifier_vl (names[i], &vl);
+      if (status != 0)
+        continue;
+
+      /* If a regex exists and doesn't match, ignore this value and continue
+       * with the next one. */
+      if (have_re_host && (regexec (&re_host,
+              /* string = */ vl.host,
+              /* nmatch = */ 0,
+              /* pmatch = */ NULL,
+              /* flags  = */ 0) == REG_NOMATCH))
+        continue;
+      if (have_re_plugin && (regexec (&re_plugin,
+              /* string = */ vl.plugin,
+              /* nmatch = */ 0,
+              /* pmatch = */ NULL,
+              /* flags  = */ 0) == REG_NOMATCH))
+        continue;
+      if (have_re_plugin_instance && (regexec (&re_plugin_instance,
+              /* string = */ vl.plugin_instance,
+              /* nmatch = */ 0,
+              /* pmatch = */ NULL,
+              /* flags  = */ 0) == REG_NOMATCH))
+        continue;
+      if (have_re_type && (regexec (&re_type,
+              /* string = */ vl.type,
+              /* nmatch = */ 0,
+              /* pmatch = */ NULL,
+              /* flags  = */ 0) == REG_NOMATCH))
+        continue;
+      if (have_re_type_instance && (regexec (&re_type_instance,
+              /* string = */ vl.type_instance,
+              /* nmatch = */ 0,
+              /* pmatch = */ NULL,
+              /* flags  = */ 0) == REG_NOMATCH))
+        continue;
+
+      matching_names[matching_number] = names[i];
+      matching_times[matching_number] = times[i];
+      matching_number++;
+    }
+
+    print_to_socket (fh, "%zu Matching value%s\n",
+        matching_number, (matching_number == 1) ? "" : "s");
+    for (i = 0; i < matching_number; i++)
+      print_to_socket (fh, "%.3f %s\n",
+          CDTIME_T_TO_DOUBLE (matching_times[i]),
+          matching_names[i]);
+  }
 
-  free_everything_and_return (0);
+  FREE_EVERYTHING_AND_RETURN (0);
 } /* int handle_listval */
 
-/* vim: set sw=2 sts=2 ts=8 : */
+/* vim: set sw=2 sts=2 ts=8 et : */

diff --git a/src/utils_parse_option.c b/src/utils_parse_option.c
index 820f14f..6bb9d1f 100644 (file)
--- a/src/utils_parse_option.c
+++ b/src/utils_parse_option.c
@@ -127,7 +127,7 @@ int parse_option (char **ret_buffer, char **ret_key, char **ret_value)
 
   /* Look for the equal sign */
   buffer = key;
-  while (isalnum ((int) *buffer) || *buffer == '_')
+  while (isalnum ((int) *buffer) || (*buffer == '_'))
     buffer++;
   if ((*buffer != '=') || (buffer == key))
     return (1);