Update vdir.[ch] from varnish-cache

src/vdir.c

 /*-
  * Copyright (c) 2013-2015 Varnish Software AS
+ * Copyright 2019 UPLEX - Nils Goroll Systemoptimierung
  * All rights reserved.
  *
  * Author: Poul-Henning Kamp <phk@FreeBSD.org>
+ * Author: Nils Goroll <nils.goroll@uplex.de>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -29,10 +33,13 @@
 #include "config.h"
 
 #include <stdlib.h>
+#include <stdio.h>
 
 #include "cache/cache.h"
 
 #include "vbm.h"
+#include "vcl.h"
+#include "vsb.h"
 
 #include "vdir.h"
 
@@ -45,6 +52,9 @@ vdir_expand(struct vdir *vd, unsigned n)
 	AN(vd->backend);
 	vd->weight = realloc(vd->weight, n * sizeof *vd->weight);
 	AN(vd->weight);
+	if (n > vd->healthy->nbits)
+		vbit_expand(vd->healthy, n);
+	AN(vd->healthy);
 	vd->l_backend = n;
 }
 
@@ -64,8 +74,8 @@ vdir_new(VRT_CTX, struct vdir **vdp, const char *vcl_name,
 	*vdp = vd;
 	AZ(pthread_rwlock_init(&vd->mtx, NULL));
 	vd->dir = VRT_AddDirector(ctx, m, priv, "%s", vcl_name);
-	vd->vbm = vbit_new(8);
-	AN(vd->vbm);
+	vd->healthy = vbit_new(8);
+	AN(vd->healthy);
 }
 
 void
@@ -82,7 +92,7 @@ vdir_delete(struct vdir **vdp)
 	free(vd->backend);
 	free(vd->weight);
 	AZ(pthread_rwlock_destroy(&vd->mtx));
-	vbit_destroy(vd->vbm);
+	vbit_destroy(vd->healthy);
 	FREE_OBJ(vd);
 }
 
@@ -116,7 +126,7 @@ vdir_add_backend(VRT_CTX, struct vdir *vd, VCL_BACKEND be, double weight)
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
 	CHECK_OBJ_NOTNULL(vd, VDIR_MAGIC);
 	if (be == NULL) {
-		VRT_fail(ctx, "%s: NULL backend cannot be added",
+		VRT_fail(ctx, "%s: None backend cannot be added",
 		    VRT_BACKEND_string(vd->dir));
 		return;
 	}
@@ -126,6 +136,7 @@ vdir_add_backend(VRT_CTX, struct vdir *vd, VCL_BACKEND be, double weight)
 		vdir_expand(vd, vd->l_backend + 16);
 	assert(vd->n_backend < vd->l_backend);
 	u = vd->n_backend++;
+	vd->backend[u] = NULL;
 	VRT_Assign_Backend(&vd->backend[u], be);
 	vd->weight[u] = weight;
 	vd->total_weight += weight;
@@ -140,7 +151,7 @@ vdir_remove_backend(VRT_CTX, struct vdir *vd, VCL_BACKEND be, unsigned *cur)
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
 	CHECK_OBJ_NOTNULL(vd, VDIR_MAGIC);
 	if (be == NULL) {
-		VRT_fail(ctx, "%s: NULL backend cannot be removed",
+		VRT_fail(ctx, "%s: None backend cannot be removed",
 		    VRT_BACKEND_string(vd->dir));
 		return;
 	}
@@ -176,7 +187,7 @@ vdir_any_healthy(VRT_CTX, struct vdir *vd, VCL_TIME *changed)
 	unsigned retval = 0;
 	VCL_BACKEND be;
 	unsigned u;
-	double c;
+	vtim_real c;
 
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
 	CHECK_OBJ_NOTNULL(vd, VDIR_MAGIC);
@@ -196,19 +207,152 @@ vdir_any_healthy(VRT_CTX, struct vdir *vd, VCL_TIME *changed)
 	return (retval);
 }
 
+void
+vdir_list(VRT_CTX, struct vdir *vd, struct vsb *vsb, int pflag, int jflag,
+    int weight)
+{
+	VCL_BACKEND be;
+	VCL_BOOL h;
+	unsigned u, nh;
+	double w;
+
+	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
+	CHECK_OBJ_NOTNULL(vd, VDIR_MAGIC);
+
+	if (pflag) {
+		if (jflag) {
+			VSB_cat(vsb, "{\n");
+			VSB_indent(vsb, 2);
+			if (weight)
+				VSB_printf(vsb, "\"total_weight\": %f,\n",
+				    vd->total_weight);
+			VSB_cat(vsb, "\"backends\": {\n");
+			VSB_indent(vsb, 2);
+		} else {
+			VSB_cat(vsb, "\n\n\tBackend\tWeight\tHealth\n");
+		}
+	}
+
+	vdir_rdlock(vd);
+	vdir_update_health(ctx, vd);
+	for (u = 0; pflag && u < vd->n_backend; u++) {
+		be = vd->backend[u];
+		CHECK_OBJ_NOTNULL(be, DIRECTOR_MAGIC);
+
+		h = vbit_test(vd->healthy, u);
+
+		w = h ? vd->weight[u] : 0.0;
+
+		if (jflag) {
+			if (u)
+				VSB_cat(vsb, ",\n");
+			VSB_printf(vsb, "\"%s\": {\n", be->vcl_name);
+			VSB_indent(vsb, 2);
+
+			if (weight)
+				VSB_printf(vsb, "\"weight\": %f,\n", w);
+
+			if (h)
+				VSB_cat(vsb, "\"health\": \"healthy\"\n");
+			else
+				VSB_cat(vsb, "\"health\": \"sick\"\n");
+
+			VSB_indent(vsb, -2);
+			VSB_cat(vsb, "}");
+		} else {
+			VSB_cat(vsb, "\t");
+			VSB_cat(vsb, be->vcl_name);
+			if (weight)
+				VSB_printf(vsb, "\t%6.2f%%\t",
+				    100 * w / vd->total_weight);
+			else
+				VSB_cat(vsb, "\t-\t");
+			VSB_cat(vsb, h ? "healthy" : "sick");
+			VSB_cat(vsb, "\n");
+		}
+	}
+	nh = vd->n_healthy;
+	u = vd->n_backend;
+	vdir_unlock(vd);
+
+	if (jflag && (pflag)) {
+		VSB_cat(vsb, "\n");
+		VSB_indent(vsb, -2);
+		VSB_cat(vsb, "}\n");
+		VSB_indent(vsb, -2);
+		VSB_cat(vsb, "},\n");
+	}
+
+	if (pflag)
+		return;
+
+	if (jflag)
+		VSB_printf(vsb, "[%u, %u, \"%s\"]", nh, u,
+		    nh ? "healthy" : "sick");
+	else
+		VSB_printf(vsb, "%u/%u\t%s", nh, u, nh ? "healthy" : "sick");
+}
+
+/*
+ * iterate backends and update
+ * - healthy bitmap
+ * - number of healthy backends
+ * - total_weight
+ * - last change time of the VCL_BACKEND
+ *
+ * must be called under the vdir lock (read or write).
+ *
+ * A write lock is required if consistency between the individual attributes is
+ * a must, e.g. when total_weight is required to be the exact sum of the weights
+ *
+ * The read lock is safe because add_backend expands the healthy bitmap and all
+ * other members are atomic and may be used if consistency is not required.
+ */
+void
+vdir_update_health(VRT_CTX, struct vdir *vd)
+{
+	VCL_TIME c, changed = 0;
+	VCL_BOOL h;
+	VCL_BACKEND be;
+	unsigned u, nh = 0;
+	double tw = 0.0;
+	struct vbitmap *healthy;
+
+	CHECK_OBJ_NOTNULL(vd, VDIR_MAGIC);
+	healthy = vd->healthy;
+	for (u = 0; u < vd->n_backend; u++) {
+		be = vd->backend[u];
+		CHECK_OBJ_NOTNULL(be, DIRECTOR_MAGIC);
+		c = 0;
+		h = VRT_Healthy(ctx, vd->backend[u], &c);
+		if (h) {
+			nh++;
+			tw += vd->weight[u];
+		}
+		if (c > changed)
+			changed = c;
+		if (h != vbit_test(healthy, u)) {
+			if (h)
+				vbit_set(healthy, u);
+			else
+				vbit_clr(healthy, u);
+		}
+	}
+	VRT_SetChanged(vd->dir, changed);
+	vd->total_weight = tw;
+	vd->n_healthy = nh;
+}
+
 static unsigned
-vdir_pick_by_weight(const struct vdir *vd, double w,
-    const struct vbitmap *blacklist)
+vdir_pick_by_weight(const struct vdir *vd, double w)
 {
+	const struct vbitmap *healthy = vd->healthy;
 	double a = 0.0;
-	VCL_BACKEND be = NULL;
 	unsigned u;
 
-	AN(blacklist);
+	AN(healthy);
 	for (u = 0; u < vd->n_backend; u++) {
-		be = vd->backend[u];
-		CHECK_OBJ_NOTNULL(be, DIRECTOR_MAGIC);
-		if (vbit_test(blacklist, u))
+		if (! vbit_test(healthy, u))
 			continue;
 		a += vd->weight[u];
 		if (w < a)
@@ -221,21 +365,14 @@ VCL_BACKEND
 vdir_pick_be(VRT_CTX, struct vdir *vd, double w)
 {
 	unsigned u;
-	double tw = 0.0;
 	VCL_BACKEND be = NULL;
 
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
 	CHECK_OBJ_NOTNULL(vd, VDIR_MAGIC);
 	vdir_wrlock(vd);
-	for (u = 0; u < vd->n_backend; u++) {
-		if (VRT_Healthy(ctx, vd->backend[u], NULL)) {
-			vbit_clr(vd->vbm, u);
-			tw += vd->weight[u];
-		} else
-			vbit_set(vd->vbm, u);
-	}
-	if (tw > 0.0) {
-		u = vdir_pick_by_weight(vd, w * tw, vd->vbm);
+	vdir_update_health(ctx, vd);
+	if (vd->total_weight > 0.0) {
+		u = vdir_pick_by_weight(vd, w * vd->total_weight);
 		assert(u < vd->n_backend);
 		be = vd->backend[u];
 		CHECK_OBJ_NOTNULL(be, DIRECTOR_MAGIC);

src/vdir.h

@@ -4,6 +4,8 @@
  *
  * Author: Poul-Henning Kamp <phk@FreeBSD.org>
  *
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -31,14 +33,15 @@ struct vbitmap;
 struct vdir {
 	unsigned				magic;
 #define VDIR_MAGIC				0x99f4b726
-	pthread_rwlock_t			mtx;
 	unsigned				n_backend;
 	unsigned				l_backend;
+	unsigned				n_healthy;
+	pthread_rwlock_t			mtx;
 	VCL_BACKEND				*backend;
 	double					*weight;
 	double					total_weight;
 	VCL_BACKEND				dir;
-	struct vbitmap				*vbm;
+	struct vbitmap				*healthy;
 };
 
 void vdir_new(VRT_CTX, struct vdir **vdp, const char *vcl_name,
@@ -50,4 +53,6 @@ void vdir_unlock(struct vdir *vd);
 void vdir_add_backend(VRT_CTX, struct vdir *, VCL_BACKEND, double weight);
 void vdir_remove_backend(VRT_CTX, struct vdir *, VCL_BACKEND, unsigned *cur);
 VCL_BOOL vdir_any_healthy(VRT_CTX, struct vdir *, VCL_TIME *);
+void vdir_list(VRT_CTX, struct vdir *, struct vsb *, int, int, int);
+void vdir_update_health(VRT_CTX, struct vdir *);
 VCL_BACKEND vdir_pick_be(VRT_CTX, struct vdir *, double w);