Merge pull request #323 from stuartnelson3/dfly-devstat

Dragonfly devstat

Author: SuperQ

README.md

@@ -41,7 +41,7 @@ vmstat | Exposes statistics from `/proc/vmstat`. | Linux
 Name     | Description | OS
 ---------|-------------|----
 bonding | Exposes the number of configured and active slaves of Linux bonding interfaces. | Linux
-devstat | Exposes device statistics | FreeBSD
+devstat | Exposes device statistics | Dragonfly, FreeBSD
 gmond | Exposes statistics from Ganglia. | _any_
 interrupts | Exposes detailed interrupts statistics. | Linux, OpenBSD
 ipvs | Exposes IPVS status from `/proc/net/ip_vs` and stats from `/proc/net/ip_vs_stats`. | Linux

collector/devstat_dragonfly.go

@@ -0,0 +1,146 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !nodevstat
+
+package collector
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+/*
+#cgo LDFLAGS: -ldevstat
+#include <devstat.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct {
+	char		device[DEVSTAT_NAME_LEN];
+	int		unit;
+	uint64_t	bytes;
+	uint64_t	transfers;
+	uint64_t	blocks;
+} Stats;
+
+int _get_ndevs() {
+	struct statinfo current;
+	int num_devices;
+
+	current.dinfo = (struct devinfo *)calloc(1, sizeof(struct devinfo));
+	if (current.dinfo == NULL)
+		return -2;
+
+	checkversion();
+
+	if (getdevs(&current) == -1)
+		return -1;
+
+	return current.dinfo->numdevs;
+}
+
+Stats _get_stats(int i) {
+	struct statinfo current;
+	int num_devices;
+
+	current.dinfo = (struct devinfo *)calloc(1, sizeof(struct devinfo));
+	getdevs(&current);
+
+	num_devices = current.dinfo->numdevs;
+	Stats stats;
+
+	uint64_t total_bytes, total_transfers, total_blocks;
+	long double kb_per_transfer, transfers_per_second, mb_per_second, blocks_per_second, ms_per_transaction;
+
+	strcpy(stats.device, current.dinfo->devices[i].device_name);
+	stats.unit = current.dinfo->devices[i].unit_number;
+	compute_stats(&current.dinfo->devices[i],
+		NULL,
+		1.0,
+		&total_bytes,
+		&total_transfers,
+		&total_blocks,
+		&kb_per_transfer,
+		&transfers_per_second,
+		&mb_per_second,
+		&blocks_per_second,
+		&ms_per_transaction);
+
+	stats.bytes = total_bytes;
+	stats.transfers = total_transfers;
+	stats.blocks = total_blocks;
+
+        return stats;
+}
+*/
+import "C"
+
+const (
+	devstatSubsystem = "devstat"
+)
+
+type devstatCollector struct {
+	bytesDesc     *prometheus.Desc
+	transfersDesc *prometheus.Desc
+	blocksDesc    *prometheus.Desc
+}
+
+func init() {
+	Factories["devstat"] = NewDevstatCollector
+}
+
+// Takes a prometheus registry and returns a new Collector exposing
+// Device stats.
+func NewDevstatCollector() (Collector, error) {
+	return &devstatCollector{
+		bytesDesc: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, devstatSubsystem, "bytes_total"),
+			"The total number of bytes transferred for reads and writes on the device.",
+			[]string{"device"}, nil,
+		),
+		transfersDesc: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, devstatSubsystem, "transfers_total"),
+			"The total number of transactions completed.",
+			[]string{"device"}, nil,
+		),
+		blocksDesc: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, devstatSubsystem, "blocks_total"),
+			"The total number of bytes given in terms of the devices blocksize.",
+			[]string{"device"}, nil,
+		),
+	}, nil
+}
+
+func (c *devstatCollector) Update(ch chan<- prometheus.Metric) (err error) {
+	count := C._get_ndevs()
+	if count == -1 {
+		return errors.New("getdevs() failed")
+	}
+	if count == -2 {
+		return errors.New("calloc() failed")
+	}
+
+	for i := C.int(0); i < count; i++ {
+		stats := C._get_stats(i)
+		device := fmt.Sprintf("%s%d", C.GoString(&stats.device[0]), stats.unit)
+
+		ch <- prometheus.MustNewConstMetric(c.bytesDesc, prometheus.CounterValue, float64(stats.bytes), device)
+		ch <- prometheus.MustNewConstMetric(c.transfersDesc, prometheus.CounterValue, float64(stats.transfers), device)
+		ch <- prometheus.MustNewConstMetric(c.blocksDesc, prometheus.CounterValue, float64(stats.blocks), device)
+	}
+
+	return err
+}