From 46c4b699c8b5b537416d395852a3f44fd7a45f49 Mon Sep 17 00:00:00 2001
From: Marius van der Wijden <m.vanderwijden@live.de>
Date: Wed, 12 Feb 2020 11:33:17 +0100
Subject: [PATCH] accounts/abi/bind/backends: add support for historical state
(#20644)
---
accounts/abi/bind/backends/simulated.go | 40 +++++++++++++++++--------
1 file changed, 28 insertions(+), 12 deletions(-)
diff --git a/accounts/abi/bind/backends/simulated.go b/accounts/abi/bind/backends/simulated.go
index 0b2555c99..f7f3dec83 100644
--- a/accounts/abi/bind/backends/simulated.go
+++ b/accounts/abi/bind/backends/simulated.go
@@ -127,15 +127,28 @@ func (b *SimulatedBackend) rollback() {
b.pendingState, _ = state.New(b.pendingBlock.Root(), statedb.Database())
}
+// stateByBlockNumber retrieves a state by a given blocknumber.
+func (b *SimulatedBackend) stateByBlockNumber(ctx context.Context, blockNumber *big.Int) (*state.StateDB, error) {
+ if blockNumber == nil || blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) == 0 {
+ return b.blockchain.State()
+ }
+ block, err := b.BlockByNumber(ctx, blockNumber)
+ if err != nil {
+ return nil, err
+ }
+ return b.blockchain.StateAt(block.Hash())
+}
+
// CodeAt returns the code associated with a certain account in the blockchain.
func (b *SimulatedBackend) CodeAt(ctx context.Context, contract common.Address, blockNumber *big.Int) ([]byte, error) {
b.mu.Lock()
defer b.mu.Unlock()
- if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 {
- return nil, errBlockNumberUnsupported
+ statedb, err := b.stateByBlockNumber(ctx, blockNumber)
+ if err != nil {
+ return nil, err
}
- statedb, _ := b.blockchain.State()
+
return statedb.GetCode(contract), nil
}
@@ -144,10 +157,11 @@ func (b *SimulatedBackend) BalanceAt(ctx context.Context, contract common.Addres
b.mu.Lock()
defer b.mu.Unlock()
- if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 {
- return nil, errBlockNumberUnsupported
+ statedb, err := b.stateByBlockNumber(ctx, blockNumber)
+ if err != nil {
+ return nil, err
}
- statedb, _ := b.blockchain.State()
+
return statedb.GetBalance(contract), nil
}
@@ -156,10 +170,11 @@ func (b *SimulatedBackend) NonceAt(ctx context.Context, contract common.Address,
b.mu.Lock()
defer b.mu.Unlock()
- if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 {
- return 0, errBlockNumberUnsupported
+ statedb, err := b.stateByBlockNumber(ctx, blockNumber)
+ if err != nil {
+ return 0, err
}
- statedb, _ := b.blockchain.State()
+
return statedb.GetNonce(contract), nil
}
@@ -168,10 +183,11 @@ func (b *SimulatedBackend) StorageAt(ctx context.Context, contract common.Addres
b.mu.Lock()
defer b.mu.Unlock()
- if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 {
- return nil, errBlockNumberUnsupported
+ statedb, err := b.stateByBlockNumber(ctx, blockNumber)
+ if err != nil {
+ return nil, err
}
- statedb, _ := b.blockchain.State()
+
val := statedb.GetState(contract, key)
return val[:], nil
}
--
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