Add the .create_stats() method.

.gitignore

@@ -32,6 +32,7 @@ Makefile.in
 /src/vcc_if.c
 /src/vcc_if.h
 /src/vmod_*rst
+/src/VSC_selector.*
 
 /src/tests/*.log
 /src/tests/*.trs

README.rst

@@ -26,6 +26,7 @@ CONTENTS
 * :ref:`obj_set`
 * :ref:`func_set.add`
 * :ref:`func_set.backend`
+* :ref:`func_set.create_stats`
 * :ref:`func_set.debug`
 * :ref:`func_set.element`
 * :ref:`func_set.hasprefix`
@@ -310,6 +311,25 @@ Example::
   }
 
 
+.. _func_set.create_stats:
+
+VOID xset.create_stats()
+------------------------
+
+Creates statistics counters for this object that are displayed by
+tools such as varnishstat(1).
+
+Example::
+
+  sub vcl_init {
+      new myset = selector.set();
+      set.add("foo");
+      set.add("bar");
+      set.add("baz");
+      set.create_stats();
+  }
+
+
 .. _func_set.debug:
 
 STRING xset.debug()
@@ -332,6 +352,11 @@ Example::
 
   std.log("Using VMOD selector version: " + selector.version());
 
+STATISTICS
+==========
+
+XXX ...
+
 REQUIREMENTS
 ============
 

configure.ac

@@ -39,6 +39,7 @@ m4_ifndef([VARNISH_PREREQ], AC_MSG_ERROR([Need varnish.m4 -- see README.rst]))
 
 VARNISH_PREREQ([6.0.0])
 VARNISH_VMODS([selector])
+VARNISH_COUNTERS([selector])
 
 VMOD_TESTS="$(cd $srcdir/src && echo tests/*.vtc)"
 AC_SUBST(VMOD_TESTS)

src/Makefile.am

@@ -12,10 +12,14 @@ libvmod_selector_la_SOURCES = \
 
 nodist_libvmod_selector_la_SOURCES = \
 	vcc_if.c \
-	vcc_if.h
+	vcc_if.h \
+	VSC_selector.c \
+	VSC_selector.h
 
 dist_man_MANS = vmod_selector.3
 
+@BUILD_VSC_SELECTOR@
+
 vmod_selector.c patricia.c: patricia.h
 
 vmod_selector.lo: $(nodist_libvmod_selector_la_SOURCES)
@@ -43,6 +47,7 @@ TESTS = @VMOD_TESTS@
 
 EXTRA_DIST = \
 	vmod_selector.vcc \
+	selector.vsc \
 	$(VMOD_TESTS)
 
 CLEANFILES = \
@@ -50,4 +55,6 @@ CLEANFILES = \
 	$(builddir)/vcc_if.h \
 	$(builddir)/vmod_selector.rst \
 	$(builddir)/vmod_selector.man.rst \
-	$(builddir)/vmod_selector.3
+	$(builddir)/vmod_selector.3 \
+	$(builddir)/VSC_selector.c \
+	$(builddir)/VSC_selector.h

src/patricia.c

@@ -364,3 +364,50 @@ PT_Dump(struct pt_y *root, char **strings)
 	VSB_finish(sb);
 	return (sb);
 }
+
+void
+pt_stats(const struct pt_y * const restrict y,
+	 char * const restrict * const restrict strings,
+	 struct pt_stats * const restrict stats, unsigned depth)
+{
+	if (y == NULL)
+		return;
+
+	CHECK_OBJ(y, PT_Y_MAGIC);
+	depth++;
+	stats->nodes++;
+
+	if (strings[y->idx][y->off + y->len] == '\0') {
+		if (depth < stats->dmin)
+			stats->dmin = depth;
+		if (depth > stats->dmax)
+			stats->dmax = depth;
+		stats->davg += (depth - stats->davg) / (stats->terms + 1.);
+		stats->terms++;
+	}
+
+	if (y->leaf[0] == NULL && y->leaf[1] == NULL) {
+		stats->leaves++;
+		return;
+	}
+
+	pt_stats(y->leaf[0], strings, stats, depth);
+	pt_stats(y->leaf[1], strings, stats, depth);
+}
+
+void
+PT_Stats(const struct pt_y * const restrict root,
+	 char * const restrict * const restrict strings,
+	 struct pt_stats * const restrict stats)
+{
+	CHECK_OBJ_NOTNULL(stats, PT_STATS_MAGIC);
+
+	stats->nodes = 0;
+	stats->leaves = 0;
+	stats->terms = 0;
+	stats->dmin = UINT64_MAX;
+	stats->dmax = 0;
+	stats->davg = 0.;
+
+	pt_stats(root, strings, stats, 0);
+}

src/patricia.h

@@ -45,6 +45,17 @@ struct match_data {
 	unsigned	max;
 };
 
+struct pt_stats {
+	unsigned	magic;
+#define PT_STATS_MAGIC 0xf1c1114e
+	uint64_t	nodes;
+	uint64_t	leaves;
+	uint64_t	terms;
+	uint64_t	dmin;
+	uint64_t	dmax;
+	double		davg;
+};
+
 void PT_Init(void);
 int PT_Inited(void);
 int PT_Insert(struct pt_y * * restrict root, unsigned idx,
@@ -56,5 +67,8 @@ int PT_Prefixes(const struct pt_y * const restrict root,
 		char * const restrict * const restrict strings,
 		const char * const restrict subject,
 		struct match_data * const restrict match);
+void PT_Stats(const struct pt_y * const restrict root,
+	      char * const restrict * const restrict strings,
+	      struct pt_stats * const restrict stats);
 void PT_Free(struct pt_y *y);
 struct vsb * PT_Dump(struct pt_y *root, char **strings);

src/selector.vsc

+..
+	This is *NOT* a RST file but the syntax has been chosen so
+	that it may become an RST file at some later date.
+
+.. varnish_vsc_begin::  selector
+	:oneliner:      VMOD selector set object stats
+	:order:         90
+
+.. varnish_vsc:: elements
+	:type:  gauge
+	:oneliner:      Elements
+
+	Number of elements (strings) in the set.
+
+.. varnish_vsc:: nodes
+	:type:  gauge
+	:oneliner:      Nodes
+
+	Total number of nodes in the internal data structure.
+
+.. varnish_vsc:: leaves
+	:type:  gauge
+	:oneliner:      Leaf nodes
+
+	Number of leaf nodes in the internal data structure.
+
+.. varnish_vsc:: dmin
+	:type:  gauge
+	:oneliner:      Minimum terminating node depth
+
+	Minimum depth of a node in the internal data structure at
+	which an element of the set may be found.
+
+.. varnish_vsc:: dmax
+	:type:  gauge
+	:oneliner:      Maximum terminating node depth
+
+	Maximum depth of a node in the internal data structure at
+	which an element of the set may be found.
+
+.. varnish_vsc:: davg
+	:type:  gauge
+	:oneliner:      Average terminating node depth
+
+	Average depth of nodes in the internal data structure at which
+	an element of the set may be found, rounded to the nearest integer.
+
+.. varnish_vsc_end::    selector

src/tests/stats.vtc

+# looks like -*- vcl -*-
+
+varnishtest ".create_stats() method"
+
+varnish v1 -vcl {
+	import ${vmod_selector};
+	backend b { .host = "${bad_ip}"; }
+
+	sub vcl_init {
+		new s = selector.set();
+		s.add("foo");
+		s.add("bar");
+		s.add("baz");
+		s.add("quux");
+		s.create_stats();
+	}
+} -start
+
+varnish v1 -vsc SELECTOR.*
+
+varnish v1 -expect SELECTOR.vcl1.s.elements == 4
+varnish v1 -expect SELECTOR.vcl1.s.nodes > 0
+varnish v1 -expect SELECTOR.vcl1.s.leaves <= 4
+varnish v1 -expect SELECTOR.vcl1.s.dmin > 0
+varnish v1 -expect SELECTOR.vcl1.s.dmax > 0
+varnish v1 -expect SELECTOR.vcl1.s.davg > 0
+
+varnish v1 -vcl {
+	import ${vmod_selector};
+	backend b { .host = "${bad_ip}"; }
+
+	sub vcl_init {
+		new p = selector.set();
+		p.add("foo");
+		p.add("foobar");
+		p.add("foobarbaz");
+		p.add("foobarbazquux");
+		p.create_stats();
+
+		# No .create_stats() call.
+		new n = selector.set();
+		n.add("foo");
+		n.add("bar");
+		n.add("baz");
+		n.add("quux");
+	}
+}
+
+# Stats for vc1.s and vcl2.p appear, but not for vcl2.n.
+varnish v1 -vsc SELECTOR.*
+
+varnish v1 -expect SELECTOR.vcl2.p.elements == 4
+varnish v1 -expect SELECTOR.vcl2.p.nodes > 0
+varnish v1 -expect SELECTOR.vcl2.p.leaves <= 4
+varnish v1 -expect SELECTOR.vcl2.p.dmin > 0
+varnish v1 -expect SELECTOR.vcl2.p.dmax > 0
+varnish v1 -expect SELECTOR.vcl2.p.davg > 0
+
+# When vcl1 is set to cold, stats for vcl2.p but not vcl1.s appear.
+varnish v1 -cliok "vcl.state vcl1 cold"
+varnish v1 -vsc SELECTOR.*
+
+# When vcl1 is set back to warm, stats for vcl2.p and vcl1.s appear.
+varnish v1 -cliok "vcl.state vcl1 warm"
+varnish v1 -vsc SELECTOR.*
+varnish v1 -expect SELECTOR.vcl1.s.elements == 4
+varnish v1 -expect SELECTOR.vcl1.s.nodes > 0
+varnish v1 -expect SELECTOR.vcl1.s.leaves <= 4
+varnish v1 -expect SELECTOR.vcl1.s.dmin > 0
+varnish v1 -expect SELECTOR.vcl1.s.dmax > 0
+varnish v1 -expect SELECTOR.vcl1.s.davg > 0
+
+# The same 100 words from /usr/share/dict/words as in match.vtc
+varnish v1 -vcl {
+	import ${vmod_selector};
+	backend b { .host = "${bad_ip}"; }
+
+	sub vcl_init {
+		new words = selector.set();
+		words.add("trustee's");
+		words.add("Marc");
+		words.add("remover's");
+		words.add("brutishly");
+		words.add("Blythe");
+		words.add("tastier");
+		words.add("backed");
+		words.add("rain");
+		words.add("banality");
+		words.add("unstrung");
+		words.add("barnyards");
+		words.add("paperweight");
+		words.add("Kazan's");
+		words.add("fanfares");
+		words.add("Donny's");
+		words.add("faze");
+		words.add("redefinition");
+		words.add("Schulz");
+		words.add("Lanai's");
+		words.add("bastions");
+		words.add("kicker's");
+		words.add("Denny");
+		words.add("disgraced");
+		words.add("downswings");
+		words.add("pullback's");
+		words.add("Gregorio's");
+		words.add("spillways");
+		words.add("puller");
+		words.add("basilica's");
+		words.add("serviced");
+		words.add("insistently");
+		words.add("Frisian's");
+		words.add("question");
+		words.add("mien");
+		words.add("rockier");
+		words.add("indivisible");
+		words.add("megahertzes");
+		words.add("Oldfield's");
+		words.add("accusatory");
+		words.add("Mabel");
+		words.add("magnetize");
+		words.add("Philly");
+		words.add("Katheryn's");
+		words.add("policewoman's");
+		words.add("ashcan");
+		words.add("deviousness's");
+		words.add("suspends");
+		words.add("furnishings");
+		words.add("compiler's");
+		words.add("Claudio");
+		words.add("zestfully");
+		words.add("laughter's");
+		words.add("Manuel");
+		words.add("palatal's");
+		words.add("eminent");
+		words.add("strongboxes");
+		words.add("pinafores");
+		words.add("Glendale");
+		words.add("dethronement");
+		words.add("chlorinate");
+		words.add("Souths");
+		words.add("tilting");
+		words.add("trenched");
+		words.add("run");
+		words.add("initialized");
+		words.add("breakfast");
+		words.add("winning's");
+		words.add("mediates");
+		words.add("triads");
+		words.add("verdict");
+		words.add("Irish");
+		words.add("Jeremy");
+		words.add("handouts");
+		words.add("Billie's");
+		words.add("romanticist's");
+		words.add("descanting");
+		words.add("bidders");
+		words.add("play");
+		words.add("navigability's");
+		words.add("leapfrogging");
+		words.add("Libby");
+		words.add("smelter's");
+		words.add("hermit's");
+		words.add("Tabatha's");
+		words.add("churlish");
+		words.add("spuriousness's");
+		words.add("Salish's");
+		words.add("Curry");
+		words.add("hula");
+		words.add("ruse's");
+		words.add("bureaucratic");
+		words.add("Moseley");
+		words.add("confluence");
+		words.add("inseams");
+		words.add("producers");
+		words.add("cozier");
+		words.add("augur's");
+		words.add("electrode's");
+		words.add("disposition");
+		words.add("Rena's");
+		words.create_stats();
+	}
+}
+
+varnish v1 -expect SELECTOR.vcl3.words.elements == 100
+varnish v1 -expect SELECTOR.vcl3.words.nodes > 0
+varnish v1 -expect SELECTOR.vcl3.words.leaves <= 100
+varnish v1 -expect SELECTOR.vcl3.words.dmin > 0
+varnish v1 -expect SELECTOR.vcl3.words.dmax > 0
+varnish v1 -expect SELECTOR.vcl3.words.davg > 0
+
+varnish v1 -cliok "vcl.state vcl1 cold"
+varnish v1 -cli "vcl.discard vcl1"
+
+# No stats for vcl1 appear after discard.
+varnish v1 -vsc SELECTOR.vc1.*
+
+# The same for vcl2 after discard.
+varnish v1 -cli "vcl.discard vcl2"
+varnish v1 -vsc SELECTOR.vc2.*

src/vmod_selector.c

@@ -43,6 +43,7 @@
 
 #include "vcc_if.h"
 #include "patricia.h"
+#include "VSC_selector.h"
 
 #define VFAIL(ctx, fmt, ...) \
 	VRT_fail((ctx), "vmod selector failure: " fmt, __VA_ARGS__)
@@ -89,17 +90,67 @@ struct vmod_selector_set {
 	VCL_BOOL	case_sensitive;
 };
 
+struct vsc_entry {
+	unsigned		magic;
+#define VMOD_SELECTOR_VSC_MAGIC 0x4b99b64a
+	VSLIST_ENTRY(vsc_entry)	list;
+	struct vsc_seg		*vsc_seg;
+};
+
+VSLIST_HEAD(vsc_head, vsc_entry);
+
 /* Event function */
 
 int
 event(VRT_CTX, struct vmod_priv *priv, enum vcl_event_e e)
 {
-        (void) ctx;
-        (void) priv;
+	struct vsc_head *vsc_head;
+	struct vsc_entry *vsc_entry;
 
-        if (e == VCL_EVENT_LOAD && !PT_Inited())
-		PT_Init();
-        return 0;
+	ASSERT_CLI();
+	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
+	AN(priv);
+
+	if (priv->priv == NULL) {
+		vsc_head = malloc(sizeof(*vsc_head));
+		AN(vsc_head);
+		priv->priv = vsc_head;
+		VSLIST_INIT(vsc_head);
+	}
+	else
+		vsc_head = priv->priv;
+
+	switch(e) {
+	case VCL_EVENT_LOAD:
+		if (!PT_Inited())
+			PT_Init();
+		break;
+	case VCL_EVENT_DISCARD:
+		while (!VSLIST_EMPTY(vsc_head)) {
+			vsc_entry = VSLIST_FIRST(vsc_head);
+			CHECK_OBJ_NOTNULL(vsc_entry, VMOD_SELECTOR_VSC_MAGIC);
+			VSC_selector_Destroy(&vsc_entry->vsc_seg);
+			VSLIST_REMOVE_HEAD(vsc_head, list);
+			FREE_OBJ(vsc_entry);
+		}
+		free(vsc_head);
+		break;
+	case VCL_EVENT_WARM:
+		VSLIST_FOREACH(vsc_entry, vsc_head, list) {
+			CHECK_OBJ_NOTNULL(vsc_entry, VMOD_SELECTOR_VSC_MAGIC);
+			VRT_VSC_Reveal(vsc_entry->vsc_seg);
+		}
+		break;
+	case VCL_EVENT_COLD:
+		VSLIST_FOREACH(vsc_entry, vsc_head, list) {
+			CHECK_OBJ_NOTNULL(vsc_entry, VMOD_SELECTOR_VSC_MAGIC);
+			VRT_VSC_Hide(vsc_entry->vsc_seg);
+		}
+		break;
+	default:
+		WRONG("illegal event enum");
+	}
+	return 0;
 }
 
 /* Object regex */
@@ -695,6 +746,59 @@ vmod_set_debug(VRT_CTX, struct vmod_selector_set *set)
 	return output;
 }
 
+VCL_VOID
+vmod_set_create_stats(VRT_CTX, struct vmod_selector_set *set,
+		      struct vmod_priv *priv)
+{
+	struct pt_stats stats = { .magic = PT_STATS_MAGIC };
+	struct VSC_selector *vsc;
+	struct vsc_seg *vsc_seg;
+	struct vsc_head *vsc_head;
+	struct vsc_entry *vsc_entry;
+
+	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
+	CHECK_OBJ_NOTNULL(set, VMOD_SELECTOR_SET_MAGIC);
+	if ((ctx->method & VCL_MET_INIT) == 0) {
+		VFAIL(ctx, "%s.add() may only be called in vcl_init",
+		      set->vcl_name);
+		return;
+	}
+
+	AN(priv);
+	AN(priv->priv);
+	vsc_head = priv->priv;
+
+	if (set->nmembers == 0)
+		memset(&stats, 0, sizeof(stats));
+	else {
+		char **members = set->members;
+		if (!set->case_sensitive)
+			members = set->lomembers;
+		AN(members);
+		PT_Stats(set->origo, members, &stats);
+		assert(stats.terms == set->nmembers);
+		assert(stats.leaves <= stats.terms);
+		assert(stats.terms <= stats.nodes);
+		assert(stats.dmin <= stats.dmax);
+		assert(stats.dmin <= stats.davg);
+		assert(stats.davg <= stats.dmax);
+	}
+
+	vsc = VSC_selector_New(NULL, &vsc_seg, "%s.%s", VCL_Name(ctx->vcl),
+			       set->vcl_name);
+	vsc->elements = set->nmembers;
+	vsc->nodes = stats.nodes;
+	vsc->leaves = stats.leaves;
+	vsc->dmin = stats.dmin;
+	vsc->dmax = stats.dmax;
+	vsc->davg = (uint64_t)(stats.davg + 0.5);
+
+	ALLOC_OBJ(vsc_entry, VMOD_SELECTOR_VSC_MAGIC);
+	AN(vsc_entry);
+	vsc_entry->vsc_seg = vsc_seg;
+	VSLIST_INSERT_HEAD(vsc_head, vsc_entry, list);
+}
+
 VCL_STRING
 vmod_version(VRT_CTX)
 {

src/vmod_selector.vcc

@@ -177,6 +177,21 @@ Example::
      # ...
   }
 
+$Method VOID .create_stats(PRIV_VCL)
+
+Creates statistics counters for this object that are displayed by
+tools such as varnishstat(1).
+
+Example::
+
+  sub vcl_init {
+      new myset = selector.set();
+      set.add("foo");
+      set.add("bar");
+      set.add("baz");
+      set.create_stats();
+  }
+
 $Method STRING .debug()
 
 Intentionally not documented.
@@ -189,6 +204,11 @@ Example::
 
   std.log("Using VMOD selector version: " + selector.version());
 
+STATISTICS
+==========
+
+XXX ...
+
 REQUIREMENTS
 ============