1 files changed, 96 insertions, 0 deletions
diff --git a/metrics/metrics.go b/metrics/metrics.go
new file mode 100644
index 000000000..33004ee3b
--- /dev/null
+++ b/metrics/metrics.go
@@ -0,0 +1,96 @@
+// Package metrics provides general system and process level metrics collection.
+package metrics
+
+import (
+	"os"
+	"runtime"
+	"strings"
+	"time"
+
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
+	"github.com/rcrowley/go-metrics"
+)
+
+// MetricsEnabledFlag is the CLI flag name to use to enable metrics collections.
+var MetricsEnabledFlag = "metrics"
+
+// enabled is the flag specifying if metrics are enable or not.
+var enabled = false
+
+// Init enables or disables the metrics system. Since we need this to run before
+// any other code gets to create meters and timers, we'll actually do an ugly hack
+// and peek into the command line args for the metrics flag.
+func init() {
+	for _, arg := range os.Args {
+		if strings.TrimLeft(arg, "-") == MetricsEnabledFlag {
+			glog.V(logger.Info).Infof("Enabling metrics collection")
+			enabled = true
+		}
+	}
+}
+
+// NewMeter create a new metrics Meter, either a real one of a NOP stub depending
+// on the metrics flag.
+func NewMeter(name string) metrics.Meter {
+	if !enabled {
+		return new(metrics.NilMeter)
+	}
+	return metrics.GetOrRegisterMeter(name, metrics.DefaultRegistry)
+}
+
+// NewTimer create a new metrics Timer, either a real one of a NOP stub depending
+// on the metrics flag.
+func NewTimer(name string) metrics.Timer {
+	if !enabled {
+		return new(metrics.NilTimer)
+	}
+	return metrics.GetOrRegisterTimer(name, metrics.DefaultRegistry)
+}
+
+// CollectProcessMetrics periodically collects various metrics about the running
+// process.
+func CollectProcessMetrics(refresh time.Duration) {
+	// Short circuit if the metrics system is disabled
+	if !enabled {
+		return
+	}
+	// Create the various data collectors
+	memstats := make([]*runtime.MemStats, 2)
+	diskstats := make([]*DiskStats, 2)
+	for i := 0; i < len(memstats); i++ {
+		memstats[i] = new(runtime.MemStats)
+		diskstats[i] = new(DiskStats)
+	}
+	// Define the various metrics to collect
+	memAllocs := metrics.GetOrRegisterMeter("system/memory/allocs", metrics.DefaultRegistry)
+	memFrees := metrics.GetOrRegisterMeter("system/memory/frees", metrics.DefaultRegistry)
+	memInuse := metrics.GetOrRegisterMeter("system/memory/inuse", metrics.DefaultRegistry)
+	memPauses := metrics.GetOrRegisterMeter("system/memory/pauses", metrics.DefaultRegistry)
+
+	var diskReads, diskReadBytes, diskWrites, diskWriteBytes metrics.Meter
+	if err := ReadDiskStats(diskstats[0]); err == nil {
+		diskReads = metrics.GetOrRegisterMeter("system/disk/readcount", metrics.DefaultRegistry)
+		diskReadBytes = metrics.GetOrRegisterMeter("system/disk/readdata", metrics.DefaultRegistry)
+		diskWrites = metrics.GetOrRegisterMeter("system/disk/writecount", metrics.DefaultRegistry)
+		diskWriteBytes = metrics.GetOrRegisterMeter("system/disk/writedata", metrics.DefaultRegistry)
+	} else {
+		glog.V(logger.Debug).Infof("failed to read disk metrics: %v", err)
+	}
+	// Iterate loading the different stats and updating the meters
+	for i := 1; ; i++ {
+		runtime.ReadMemStats(memstats[i%2])
+		memAllocs.Mark(int64(memstats[i%2].Mallocs - memstats[(i-1)%2].Mallocs))
+		memFrees.Mark(int64(memstats[i%2].Frees - memstats[(i-1)%2].Frees))
+		memInuse.Mark(int64(memstats[i%2].Alloc - memstats[(i-1)%2].Alloc))
+		memPauses.Mark(int64(memstats[i%2].PauseTotalNs - memstats[(i-1)%2].PauseTotalNs))
+
+		if ReadDiskStats(diskstats[i%2]) == nil {
+			diskReads.Mark(int64(diskstats[i%2].ReadCount - diskstats[(i-1)%2].ReadCount))
+			diskReadBytes.Mark(int64(diskstats[i%2].ReadBytes - diskstats[(i-1)%2].ReadBytes))
+			diskWrites.Mark(int64(diskstats[i%2].WriteCount - diskstats[(i-1)%2].WriteCount))
+			diskWriteBytes.Mark(int64(diskstats[i%2].WriteBytes - diskstats[(i-1)%2].WriteBytes))
+		}
+		time.Sleep(refresh)
+	}
+}