From cbc164a271b21b4a5e74eabc741a0e6766b27f8f Mon Sep 17 00:00:00 2001
From: "mergify[bot]" <37929162+mergify[bot]@users.noreply.github.com>
Date: Thu, 16 Sep 2021 15:06:21 +0200
Subject: [PATCH] perf: Speedup coins.AmountOf() by removing many regex calls
 (backport #10021) (#10166)

* perf: Speedup coins.AmountOf() by removing many regex calls (#10021)

(cherry picked from commit ed35bfdf52ec18af497fc04787cdb509562af95e)

# Conflicts:
#	CHANGELOG.md

* fix conflict

* fix changelog

Co-authored-by: Dev Ojha <ValarDragon@users.noreply.github.com>
Co-authored-by: Robert Zaremba <robert@zaremba.ch>
---
 CHANGELOG.md  |  3 +++
 types/coin.go | 10 ++++++++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index cfe08c13ccf6..50ae73502d60 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -37,6 +37,9 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ## [Unreleased]
 
+### Improvements
+* (types) [\#10021](https://github.com/cosmos/cosmos-sdk/pull/10021) Speedup coins.AmountOf(), by removing many intermittent regex calls.
+
 ### Bug Fixes
 
 * (x/genutil) [#10104](https://github.com/cosmos/cosmos-sdk/pull/10104) Ensure the `init` command reads the `--home` flag value correctly.
diff --git a/types/coin.go b/types/coin.go
index 3cfc58b7b3bb..e8fe7a5f8781 100644
--- a/types/coin.go
+++ b/types/coin.go
@@ -517,7 +517,12 @@ func (coins Coins) Empty() bool {
 // AmountOf returns the amount of a denom from coins
 func (coins Coins) AmountOf(denom string) Int {
 	mustValidateDenom(denom)
+	return coins.AmountOfNoDenomValidation(denom)
+}
 
+// AmountOfNoDenomValidation returns the amount of a denom from coins
+// without validating the denomination.
+func (coins Coins) AmountOfNoDenomValidation(denom string) Int {
 	switch len(coins) {
 	case 0:
 		return ZeroInt()
@@ -530,15 +535,16 @@ func (coins Coins) AmountOf(denom string) Int {
 		return ZeroInt()
 
 	default:
+		// Binary search the amount of coins remaining
 		midIdx := len(coins) / 2 // 2:1, 3:1, 4:2
 		coin := coins[midIdx]
 		switch {
 		case denom < coin.Denom:
-			return coins[:midIdx].AmountOf(denom)
+			return coins[:midIdx].AmountOfNoDenomValidation(denom)
 		case denom == coin.Denom:
 			return coin.Amount
 		default:
-			return coins[midIdx+1:].AmountOf(denom)
+			return coins[midIdx+1:].AmountOfNoDenomValidation(denom)
 		}
 	}
 }