From f019c97ce8ee9700773d87ee2686877ac0a3d1f2 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 14 Apr 2021 23:53:47 +0300
Subject: [PATCH] connections: normalize weights, make config a bit more
 human-oriented

Current scheme requires people to calculate exact percentages for their
nodes. People are bad with pecentage calculations and it's really inconvenient
if you have more than 3-4 nodes. What I'd like to have is ability to specify
weights like weights, not percentages:
  .._0_WEIGHT=3
  .._1_WEIGHT=1
  .._2_WEIGHT=1

and let the gateway calculate things for me.
---
 README.md           | 2 +-
 connections/pool.go | 5 ++---
 settings.go         | 2 +-
 3 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index 6e214cc..8a394c5 100644
--- a/README.md
+++ b/README.md
@@ -80,5 +80,5 @@ HTTP_GW_WEB_MAX_REQUEST_BODY_SIZE=4194304  - maximum request body size, server r
 Peers preset:
 
 HTTP_GW_PEERS_<N>_ADDRESS = string
-HTTP_GW_PEERS_<N>_WEIGHT = 0..1 (float)
+HTTP_GW_PEERS_<N>_WEIGHT = float
 ```
diff --git a/connections/pool.go b/connections/pool.go
index 256acfa..f8b8f57 100644
--- a/connections/pool.go
+++ b/connections/pool.go
@@ -3,7 +3,6 @@ package connections
 import (
 	"context"
 	"crypto/ecdsa"
-	"math"
 	"math/rand"
 	"sync"
 	"time"
@@ -40,8 +39,8 @@ func (pb *PoolBuilder) Build(ctx context.Context, options *PoolBuilderOptions) (
 	for _, w := range pb.weights {
 		totalWeight += w
 	}
-	if math.Abs(totalWeight-1.0) >= 1e-4 {
-		return nil, errors.New("total weight must be equal to unity")
+	for i, w := range pb.weights {
+		pb.weights[i] = w / totalWeight
 	}
 	var cons = make([]*grpc.ClientConn, len(pb.addresses))
 	for i, address := range pb.addresses {
diff --git a/settings.go b/settings.go
index 32326cd..4e4dabb 100644
--- a/settings.go
+++ b/settings.go
@@ -183,7 +183,7 @@ func settings() *viper.Viper {
 		fmt.Println()
 
 		fmt.Printf("%s_%s_[N]_ADDRESS = string\n", Prefix, strings.ToUpper(cfgPeers))
-		fmt.Printf("%s_%s_[N]_WEIGHT = 0..1 (float)\n", Prefix, strings.ToUpper(cfgPeers))
+		fmt.Printf("%s_%s_[N]_WEIGHT = float\n", Prefix, strings.ToUpper(cfgPeers))
 
 		os.Exit(0)
 	case version != nil && *version: