@ -17,8 +17,10 @@
package backends
import (
"fmt"
"math/big"
"github.com/ethereum/go-ethereum"
"github.com/ethereum/go-ethereum/accounts/abi/bind"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core"
@ -79,58 +81,44 @@ func (b *SimulatedBackend) Rollback() {
b . pendingState , _ = state . New ( b . pendingBlock . Root ( ) , b . database )
}
// HasCode implements ContractVerifier.HasCode, checking whether there is any
// code associated with a certain account in the blockchain.
func ( b * SimulatedBackend ) Has Code( ctx context . Context , contract common . Address , pending bool ) ( bool , error ) {
if pending {
return len ( b . pendingState . GetCode ( contract ) ) > 0 , nil
// CodeAt implements ChainStateReader.CodeAt, returning the code associated with
// a certain account at a given block number in the blockchain.
func ( b * SimulatedBackend ) CodeAt ( ctx context . Context , contract common . Address , blockNumber * big . Int ) ( [ ] byte , error ) {
if blockNumber != nil && blockNumber . Cmp ( b . blockchain . CurrentBlock ( ) . Number ( ) ) != 0 {
return nil , fmt . Errorf ( "SimulatedBackend cannot access blocks other than the latest block" )
}
statedb , _ := b . blockchain . State ( )
return len ( statedb . GetCode ( contract ) ) > 0 , nil
return statedb . GetCode ( contract ) , nil
}
// ContractCall implements ContractCaller.ContractCall, executing the specified
// contract with the given input data.
func ( b * SimulatedBackend ) ContractCall ( ctx context . Context , contract common . Address , data [ ] byte , pending bool ) ( [ ] byte , error ) {
// Create a copy of the current state db to screw around with
var (
block * types . Block
statedb * state . StateDB
)
if pending {
block , statedb = b . pendingBlock , b . pendingState . Copy ( )
} else {
block = b . blockchain . CurrentBlock ( )
statedb , _ = b . blockchain . State ( )
}
// If there's no code to interact with, respond with an appropriate error
if code := statedb . GetCode ( contract ) ; len ( code ) == 0 {
return nil , bind . ErrNoCode
}
// Set infinite balance to the a fake caller account
from := statedb . GetOrNewStateObject ( common . Address { } )
from . SetBalance ( common . MaxBig )
// PendingCodeAt implements PendingStateReader.PendingCodeAt, returning the
// code associated with a certain account in the pending state of the blockchain.
func ( b * SimulatedBackend ) PendingCodeAt ( ctx context . Context , contract common . Address ) ( [ ] byte , error ) {
return b . pendingState . GetCode ( contract ) , nil
}
// Assemble the call invocation to measure the gas usage
msg := callmsg {
from : from ,
to : & contract ,
gasPrice : new ( big . Int ) ,
gasLimit : common . MaxBig ,
value : new ( big . Int ) ,
data : data ,
// CallContract executes a contract call.
func ( b * SimulatedBackend ) CallContract ( ctx context . Context , call ethereum . CallMsg , blockNumber * big . Int ) ( [ ] byte , error ) {
if blockNumber != nil && blockNumber . Cmp ( b . blockchain . CurrentBlock ( ) . Number ( ) ) != 0 {
return nil , fmt . Errorf ( "SimulatedBackend cannot access blocks other than the latest block" )
}
// Execute the call and return
vmenv := core . NewEnv ( statedb , chainConfig , b . blockchain , msg , block . Header ( ) , vm . Config { } )
gaspool := new ( core . GasPool ) . AddGas ( common . MaxBig )
state , err := b . blockchain . State ( )
if err != nil {
return nil , err
}
rval , _ , err := b . callContract ( ctx , call , b . blockchain . CurrentBlock ( ) , state )
return rval , err
}
out , _ , err := core . ApplyMessage ( vmenv , msg , gaspool )
return out , err
// PendingCallContract executes a contract call on the pending state.
func ( b * SimulatedBackend ) PendingCallContract ( ctx context . Context , call ethereum . CallMsg ) ( [ ] byte , error ) {
rval , _ , err := b . callContract ( ctx , call , b . pendingBlock , b . pendingState . Copy ( ) )
return rval , err
}
// PendingAccountNonce implements ContractTransactor.PendingAccountNonce , retrieving
// PendingNonceAt implements PendingStateReader.PendingNonceAt , retrieving
// the nonce currently pending for the account.
func ( b * SimulatedBackend ) PendingAccount Nonce ( ctx context . Context , account common . Address ) ( uint64 , error ) {
func ( b * SimulatedBackend ) PendingNonceAt ( ctx context . Context , account common . Address ) ( uint64 , error ) {
return b . pendingState . GetOrNewStateObject ( account ) . Nonce ( ) , nil
}
@ -140,45 +128,49 @@ func (b *SimulatedBackend) SuggestGasPrice(ctx context.Context) (*big.Int, error
return big . NewInt ( 1 ) , nil
}
// EstimateGasLimit implements ContractTransactor.EstimateGasLimit, executing the
// requested code against the currently pending block/state and returning the used
// gas.
func ( b * SimulatedBackend ) EstimateGasLimit ( ctx context . Context , sender common . Address , contract * common . Address , value * big . Int , data [ ] byte ) ( * big . Int , error ) {
// Create a copy of the currently pending state db to screw around with
var (
block = b . pendingBlock
statedb = b . pendingState . Copy ( )
)
// If there's no code to interact with, respond with an appropriate error
if contract != nil {
if code := statedb . GetCode ( * contract ) ; len ( code ) == 0 {
return nil , bind . ErrNoCode
// EstimateGas executes the requested code against the currently pending block/state and
// returns the used amount of gas.
func ( b * SimulatedBackend ) EstimateGas ( ctx context . Context , call ethereum . CallMsg ) ( * big . Int , error ) {
_ , gas , err := b . callContract ( ctx , call , b . pendingBlock , b . pendingState . Copy ( ) )
return gas , err
}
// callContract implemens common code between normal and pending contract calls.
// state is modified during execution, make sure to copy it if necessary.
func ( b * SimulatedBackend ) callContract ( ctx context . Context , call ethereum . CallMsg , block * types . Block , statedb * state . StateDB ) ( [ ] byte , * big . Int , error ) {
// Ensure message is initialized properly.
if call . GasPrice == nil {
call . GasPrice = big . NewInt ( 1 )
}
if call . Gas == nil || call . Gas . BitLen ( ) == 0 {
call . Gas = big . NewInt ( 50000000 )
}
// Set infinite balance to the a fake caller account
from := statedb . GetOrNewStateObject ( sender )
from . SetBalance ( common . MaxBig )
// Assemble the call invocation to measure the gas usage
msg := callmsg {
from : from ,
to : contract ,
gasPrice : new ( big . Int ) ,
gasLimit : common . MaxBig ,
value : value ,
data : data ,
if call . Value == nil {
call . Value = new ( big . Int )
}
// Execute the call and return
// Set infinite balance to the fake caller account.
from := statedb . GetOrNewStateObject ( call . From )
from . SetBalance ( common . MaxBig )
// Execute the call.
msg := callmsg { call }
vmenv := core . NewEnv ( statedb , chainConfig , b . blockchain , msg , block . Header ( ) , vm . Config { } )
gaspool := new ( core . GasPool ) . AddGas ( common . MaxBig )
_ , gas , _ , err := core . NewStateTransition ( vmenv , msg , gaspool ) . TransitionDb ( )
return gas , err
ret , gasUsed , _ , err := core . NewStateTransition ( vmenv , msg , gaspool ) . TransitionDb ( )
return ret , gasUsed , err
}
// SendTransaction implements ContractTransactor.SendTransaction, delegating the raw
// transaction injection to the remote node .
// SendTransaction updates the pending block to include the given transaction.
// It panics if the transaction is invalid .
func ( b * SimulatedBackend ) SendTransaction ( ctx context . Context , tx * types . Transaction ) error {
sender , err := tx . From ( )
if err != nil {
panic ( fmt . Errorf ( "invalid transaction: %v" , err ) )
}
nonce := b . pendingState . GetNonce ( sender )
if tx . Nonce ( ) != nonce {
panic ( fmt . Errorf ( "invalid transaction nonce: got %d, want %d" , tx . Nonce ( ) , nonce ) )
}
blocks , _ := core . GenerateChain ( nil , b . blockchain . CurrentBlock ( ) , b . database , 1 , func ( number int , block * core . BlockGen ) {
for _ , tx := range b . pendingBlock . Transactions ( ) {
block . AddTx ( tx )
@ -187,26 +179,20 @@ func (b *SimulatedBackend) SendTransaction(ctx context.Context, tx *types.Transa
} )
b . pendingBlock = blocks [ 0 ]
b . pendingState , _ = state . New ( b . pendingBlock . Root ( ) , b . database )
return nil
}
// callmsg implements core.Message to allow passing it as a transaction simulator.
type callmsg struct {
from * state . StateObject
to * common . Address
gasLimit * big . Int
gasPrice * big . Int
value * big . Int
data [ ] byte
ethereum . CallMsg
}
func ( m callmsg ) From ( ) ( common . Address , error ) { return m . from . Address ( ) , nil }
func ( m callmsg ) FromFrontier ( ) ( common . Address , error ) { return m . from . Address ( ) , nil }
func ( m callmsg ) From ( ) ( common . Address , error ) { return m . CallMsg . From , nil }
func ( m callmsg ) FromFrontier ( ) ( common . Address , error ) { return m . CallMsg . From , nil }
func ( m callmsg ) Nonce ( ) uint64 { return 0 }
func ( m callmsg ) CheckNonce ( ) bool { return false }
func ( m callmsg ) To ( ) * common . Address { return m . t o}
func ( m callmsg ) GasPrice ( ) * big . Int { return m . gasPrice }
func ( m callmsg ) Gas ( ) * big . Int { return m . gasLimit }
func ( m callmsg ) Value ( ) * big . Int { return m . v alue}
func ( m callmsg ) Data ( ) [ ] byte { return m . d ata}
func ( m callmsg ) To ( ) * common . Address { return m . CallMsg . T o}
func ( m callmsg ) GasPrice ( ) * big . Int { return m . CallMs g. G asPrice}
func ( m callmsg ) Gas ( ) * big . Int { return m . CallMsg . Gas }
func ( m callmsg ) Value ( ) * big . Int { return m . CallMsg . V alue}
func ( m callmsg ) Data ( ) [ ] byte { return m . CallMsg . D ata}
Felix Lange
8 years ago