From d08c1c76c1347e3c3a401adb0a67b76e3316b48f Mon Sep 17 00:00:00 2001 From: Alex Vanin Date: Wed, 28 Oct 2020 16:05:53 +0300 Subject: [PATCH] [#122] Reduce precision from balance contract to Fixed8. Fixed8 won't overflow int64 for values less than 92 billion that is suitable for GAS. Signed-off-by: Alex Vanin --- pkg/services/accounting/morph/executor.go | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/pkg/services/accounting/morph/executor.go b/pkg/services/accounting/morph/executor.go index 33384f1b..f0409930 100644 --- a/pkg/services/accounting/morph/executor.go +++ b/pkg/services/accounting/morph/executor.go @@ -7,12 +7,15 @@ import ( "github.com/nspcc-dev/neofs-api-go/v2/accounting" "github.com/nspcc-dev/neofs-node/pkg/morph/client/balance/wrapper" accountingSvc "github.com/nspcc-dev/neofs-node/pkg/services/accounting" + "github.com/nspcc-dev/neofs-node/pkg/util/precision" ) type morphExecutor struct { client *wrapper.Wrapper } +const fixed8Precision = 8 + func NewExecutor(client *wrapper.Wrapper) accountingSvc.ServiceExecutor { return &morphExecutor{ client: client, @@ -25,14 +28,21 @@ func (s *morphExecutor) Balance(ctx context.Context, body *accounting.BalanceReq return nil, err } - precision, err := s.client.Decimals() + balancePrecision, err := s.client.Decimals() if err != nil { return nil, err } + // Convert amount to Fixed8 precision. This way it will definitely fit + // int64 value. + // Max Fixed8 decimal integer value that fit into int64: 92 233 720 368. + // Max Fixed12 decimal integer value that fit into int64: 9 223 372. + // Max Fixed16 decimal integer value that fit into int64: 922. + fixed8Amount := precision.Convert(balancePrecision, fixed8Precision, amount) + dec := new(accounting.Decimal) - dec.SetValue(amount) - dec.SetPrecision(precision) + dec.SetValue(fixed8Amount.Int64()) + dec.SetPrecision(fixed8Precision) res := new(accounting.BalanceResponseBody) res.SetBalance(dec)