perl plugin: Made global variables available to Perl plugins.

[collectd.git] / src / perl.c

diff --git a/src/perl.c b/src/perl.c
index 0d9474a..c0e99f5 100644 (file)
--- a/src/perl.c
+++ b/src/perl.c
@@ -154,6 +154,24 @@ struct {
        { "", 0 }
 };
 
+struct {
+       char  name[64];
+       char *var;
+} g_strings[] =
+{
+       { "Collectd::hostname_g", hostname_g },
+       { "", NULL }
+};
+
+struct {
+       char  name[64];
+       int  *var;
+} g_integers[] =
+{
+       { "Collectd::interval_g", &interval_g },
+       { "", NULL }
+};
+
 /*
  * Helper functions for data type conversion.
  */
@@ -1029,10 +1047,50 @@ static int perl_shutdown (void)
        return ret;
 } /* static void perl_shutdown (void) */
 
+/*
+ * Access functions for global variables.
+ *
+ * These functions implement the "magic" used to access
+ * the global variables from Perl.
+ */
+
+static int g_pv_get (pTHX_ SV *var, MAGIC *mg)
+{
+       char *pv = mg->mg_ptr;
+       sv_setpv (var, pv);
+       return 0;
+} /* static int g_pv_get (pTHX_ SV *, MAGIC *) */
+
+static int g_pv_set (pTHX_ SV *var, MAGIC *mg)
+{
+       char *pv = mg->mg_ptr;
+       strncpy (pv, SvPV_nolen (var), DATA_MAX_NAME_LEN);
+       pv[DATA_MAX_NAME_LEN - 1] = '\0';
+       return 0;
+} /* static int g_pv_set (pTHX_ SV *, MAGIC *) */
+
+static int g_iv_get (pTHX_ SV *var, MAGIC *mg)
+{
+       int *iv = (int *)mg->mg_ptr;
+       sv_setiv (var, *iv);
+       return 0;
+} /* static int g_iv_get (pTHX_ SV *, MAGIC *) */
+
+static int g_iv_set (pTHX_ SV *var, MAGIC *mg)
+{
+       int *iv = (int *)mg->mg_ptr;
+       *iv = (int)SvIV (var);
+       return 0;
+} /* static int g_iv_set (pTHX_ SV *, MAGIC *) */
+
+static MGVTBL g_pv_vtbl = { g_pv_get, g_pv_set, NULL, NULL, NULL };
+static MGVTBL g_iv_vtbl = { g_iv_get, g_iv_set, NULL, NULL, NULL };
+
 /* bootstrap the Collectd module */
 static void xs_init (pTHX)
 {
        HV   *stash = NULL;
+       SV   *tmp   = NULL;
        char *file  = __FILE__;
 
        int i = 0;
@@ -1051,6 +1109,25 @@ static void xs_init (pTHX)
        /* export "constants" */
        for (i = 0; '\0' != constants[i].name[0]; ++i)
                newCONSTSUB (stash, constants[i].name, newSViv (constants[i].value));
+
+       /* export global variables
+        * by adding "magic" to the SV's representing the globale variables
+        * perl is able to automagically call the get/set function when
+        * accessing any such variable (this is basically the same as using
+        * tie() in Perl) */
+       /* global strings */
+       for (i = 0; '\0' != g_strings[i].name[0]; ++i) {
+               tmp = get_sv (g_strings[i].name, 1);
+               sv_magicext (tmp, NULL, PERL_MAGIC_ext, &g_pv_vtbl,
+                               g_strings[i].var, 0);
+       }
+
+       /* global integers */
+       for (i = 0; '\0' != g_integers[i].name[0]; ++i) {
+               tmp = get_sv (g_integers[i].name, 1);
+               sv_magicext (tmp, NULL, PERL_MAGIC_ext, &g_iv_vtbl,
+                               (char *)g_integers[i].var, 0);
+       }
        return;
 } /* static void xs_init (pTHX) */