From 9f5caf8feaa97da09b672260b134bd5bfab2dd08 Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Sun, 5 Jan 2020 11:12:48 -0800
Subject: [PATCH] total and target balances metrics (#4414)

---
 beacon-chain/blockchain/forkchoice/BUILD.bazel    |  1 +
 beacon-chain/blockchain/forkchoice/metrics.go     | 14 ++++++++++++++
 beacon-chain/core/epoch/precompute/attestation.go |  5 +++++
 3 files changed, 20 insertions(+)

diff --git a/beacon-chain/blockchain/forkchoice/BUILD.bazel b/beacon-chain/blockchain/forkchoice/BUILD.bazel
index 2965c1b66..3695a0446 100644
--- a/beacon-chain/blockchain/forkchoice/BUILD.bazel
+++ b/beacon-chain/blockchain/forkchoice/BUILD.bazel
@@ -15,6 +15,7 @@ go_library(
     deps = [
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/core/blocks:go_default_library",
+        "//beacon-chain/core/epoch/precompute:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/core/state:go_default_library",
         "//beacon-chain/db:go_default_library",
diff --git a/beacon-chain/blockchain/forkchoice/metrics.go b/beacon-chain/blockchain/forkchoice/metrics.go
index 01e1695d4..8d915f367 100644
--- a/beacon-chain/blockchain/forkchoice/metrics.go
+++ b/beacon-chain/blockchain/forkchoice/metrics.go
@@ -3,6 +3,7 @@ package forkchoice
 import (
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/epoch/precompute"
 	pb "github.com/prysmaticlabs/prysm/proto/beacon/p2p/v1"
 	"github.com/prysmaticlabs/prysm/shared/bytesutil"
 	"github.com/prysmaticlabs/prysm/shared/params"
@@ -61,6 +62,14 @@ var (
 		Name: "current_eth1_data_deposit_count",
 		Help: "The current eth1 deposit count in the last processed state eth1data field.",
 	})
+	totalEligibleBalances = promauto.NewGauge(prometheus.GaugeOpts{
+		Name: "total_eligible_balances",
+		Help: "The total amount of ether, in gwei, that has been used in voting attestation target of previous epoch",
+	})
+	totalVotedTargetBalances = promauto.NewGauge(prometheus.GaugeOpts{
+		Name: "total_voted_target_balances",
+		Help: "The total amount of ether, in gwei, that is eligible for voting of previous epoch",
+	})
 )
 
 func reportEpochMetrics(state *pb.BeaconState) {
@@ -144,4 +153,9 @@ func reportEpochMetrics(state *pb.BeaconState) {
 	if state.Eth1Data != nil {
 		currentEth1DataDepositCount.Set(float64(state.Eth1Data.DepositCount))
 	}
+
+	if precompute.Balances != nil {
+		totalEligibleBalances.Set(float64(precompute.Balances.PrevEpoch))
+		totalVotedTargetBalances.Set(float64(precompute.Balances.PrevEpochTargetAttesters))
+	}
 }
diff --git a/beacon-chain/core/epoch/precompute/attestation.go b/beacon-chain/core/epoch/precompute/attestation.go
index bd5d2fbc5..fdaf5e740 100644
--- a/beacon-chain/core/epoch/precompute/attestation.go
+++ b/beacon-chain/core/epoch/precompute/attestation.go
@@ -11,6 +11,10 @@ import (
 	"go.opencensus.io/trace"
 )
 
+// Balances stores balances such as prev/current total validator balances, attested balances and more.
+// It's used for metrics reporting.
+var Balances *Balance
+
 // ProcessAttestations process the attestations in state and update individual validator's pre computes,
 // it also tracks and updates epoch attesting balances.
 func ProcessAttestations(
@@ -48,6 +52,7 @@ func ProcessAttestations(
 	}
 
 	bp = UpdateBalance(vp, bp)
+	Balances = bp
 
 	return vp, bp, nil
 }