From 744c85b8fa616648cc969d4765c159590f2b28d2 Mon Sep 17 00:00:00 2001 From: Dev Ojha Date: Tue, 7 Sep 2021 10:37:02 -0400 Subject: [PATCH] perf: Improve the speed of coins.String() (#10076) ## Description Speedup coins.String() and coin.String() In my local benchmarks, this >2x improves the time for balances with 1 coin, and further improves speed for strings with many balances. I did not benchmark on the two coin usecase --- ### Author Checklist *All items are required. Please add a note to the item if the item is not applicable and please add links to any relevant follow up issues.* I have... - [x] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title - [x] added `!` to the type prefix if API or client breaking change - [x] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting)) - [x] provided a link to the relevant issue or specification - n/a - [x] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules) - [x] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing) - covered by existing - [ ] added a changelog entry to `CHANGELOG.md` - [x] included comments for [documenting Go code](https://blog.golang.org/godoc) - seems sufficiently clear - [x] updated the relevant documentation or specification - [x] reviewed "Files changed" and left comments if necessary - [ ] confirmed all CI checks have passed ### Reviewers Checklist *All items are required. Please add a note if the item is not applicable and please add your handle next to the items reviewed if you only reviewed selected items.* I have... - [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title - [ ] confirmed `!` in the type prefix if API or client breaking change - [ ] confirmed all author checklist items have been addressed - [ ] reviewed state machine logic - [ ] reviewed API design and naming - [ ] reviewed documentation is accurate - [ ] reviewed tests and test coverage - [ ] manually tested (if applicable) --- CHANGELOG.md | 1 + types/coin.go | 15 ++++++++++----- 2 files changed, 11 insertions(+), 5 deletions(-) diff --git a/CHANGELOG.md b/CHANGELOG.md index 6faf4a675..b2a0b6165 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -87,6 +87,7 @@ Ref: https://keepachangelog.com/en/1.0.0/ ### Improvements +* (types) [\#10076](https://github.com/cosmos/cosmos-sdk/pull/10076) Significantly speedup and lower allocations for `Coins.String()`. * (x/bank) [\#10022](https://github.com/cosmos/cosmos-sdk/pull/10022) `BankKeeper.SendCoins` now takes less execution time. * (deps) [\#9956](https://github.com/cosmos/cosmos-sdk/pull/9956) Bump Tendermint to [v0.34.12](https://github.com/tendermint/tendermint/releases/tag/v0.34.12). * (cli) [\#9856](https://github.com/cosmos/cosmos-sdk/pull/9856) Overwrite `--sequence` and `--account-number` flags with default flag values when used with `offline=false` in `sign-batch` command. diff --git a/types/coin.go b/types/coin.go index 3cfc58b7b..facdd56a2 100644 --- a/types/coin.go +++ b/types/coin.go @@ -34,7 +34,7 @@ func NewInt64Coin(denom string, amount int64) Coin { // String provides a human-readable representation of a coin func (coin Coin) String() string { - return fmt.Sprintf("%v%v", coin.Amount, coin.Denom) + return fmt.Sprintf("%v%s", coin.Amount, coin.Denom) } // Validate returns an error if the Coin has a negative amount or if @@ -185,13 +185,18 @@ func (coins Coins) MarshalJSON() ([]byte, error) { func (coins Coins) String() string { if len(coins) == 0 { return "" + } else if len(coins) == 1 { + return coins[0].String() } - out := "" - for _, coin := range coins { - out += fmt.Sprintf("%v,", coin.String()) + // Build the string with a string builder + var out strings.Builder + for _, coin := range coins[:len(coins)-1] { + out.WriteString(coin.String()) + out.WriteByte(',') } - return out[:len(out)-1] + out.WriteString(coins[len(coins)-1].String()) + return out.String() } // Validate checks that the Coins are sorted, have positive amount, with a valid and unique