core, core/state: move gas tracking out of core/state

The amount of gas available for tx execution was tracked in the
StateObject representing the coinbase account. This commit makes the gas
counter a separate type in package core, which avoids unintended
consequences of intertwining the counter with state logic.

3 files changed, 1 insertions, 80 deletions

diff --git a/core/state/errors.go b/core/state/errors.go
deleted file mode 100644
index a08ed2d23..000000000
--- a/core/state/errors.go
+++ /dev/null
@@ -1,39 +0,0 @@
-// Copyright 2014 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-package state
-
-import (
-	"fmt"
-	"math/big"
-)
-
-type GasLimitErr struct {
-	Message string
-	Is, Max *big.Int
-}
-
-func IsGasLimitErr(err error) bool {
-	_, ok := err.(*GasLimitErr)
-
-	return ok
-}
-func (err *GasLimitErr) Error() string {
-	return err.Message
-}
-func GasLimitError(is, max *big.Int) *GasLimitErr {
-	return &GasLimitErr{Message: fmt.Sprintf("GasLimit error. Max %s, transaction would take it to %s", max, is), Is: is, Max: max}
-}
diff --git a/core/state/state_object.go b/core/state/state_object.go
index 40af9ed9c..c06e3d227 100644
--- a/core/state/state_object.go
+++ b/core/state/state_object.go
@@ -75,11 +75,6 @@ type StateObject struct {
 	// Cached storage (flushed when updated)
 	storage Storage
 
-	// Total gas pool is the total amount of gas currently
-	// left if this object is the coinbase. Gas is directly
-	// purchased of the coinbase.
-	gasPool *big.Int
-
 	// Mark for deletion
 	// When an object is marked for deletion it will be delete from the trie
 	// during the "update" phase of the state transition
@@ -89,10 +84,9 @@ type StateObject struct {
 }
 
 func NewStateObject(address common.Address, db ethdb.Database) *StateObject {
-	object := &StateObject{db: db, address: address, balance: new(big.Int), gasPool: new(big.Int), dirty: true}
+	object := &StateObject{db: db, address: address, balance: new(big.Int), dirty: true}
 	object.trie, _ = trie.NewSecure(common.Hash{}, db)
 	object.storage = make(Storage)
-	object.gasPool = new(big.Int)
 	return object
 }
 
@@ -121,7 +115,6 @@ func NewStateObjectFromBytes(address common.Address, data []byte, db ethdb.Datab
 	object.codeHash = extobject.CodeHash
 	object.trie = trie
 	object.storage = make(map[string]common.Hash)
-	object.gasPool = new(big.Int)
 	object.code, _ = db.Get(extobject.CodeHash)
 	return object
 }
@@ -209,36 +202,9 @@ func (c *StateObject) St() Storage {
 	return c.storage
 }
 
-//
-// Gas setters and getters
-//
-
 // Return the gas back to the origin. Used by the Virtual machine or Closures
 func (c *StateObject) ReturnGas(gas, price *big.Int) {}
 
-func (self *StateObject) SetGasLimit(gasLimit *big.Int) {
-	self.gasPool = new(big.Int).Set(gasLimit)
-	self.dirty = true
-
-	if glog.V(logger.Core) {
-		glog.Infof("%x: gas (+ %v)", self.Address(), self.gasPool)
-	}
-}
-
-func (self *StateObject) SubGas(gas, price *big.Int) error {
-	if self.gasPool.Cmp(gas) < 0 {
-		return GasLimitError(self.gasPool, gas)
-	}
-	self.gasPool.Sub(self.gasPool, gas)
-	self.dirty = true
-	return nil
-}
-
-func (self *StateObject) AddGas(gas, price *big.Int) {
-	self.gasPool.Add(self.gasPool, gas)
-	self.dirty = true
-}
-
 func (self *StateObject) Copy() *StateObject {
 	stateObject := NewStateObject(self.Address(), self.db)
 	stateObject.balance.Set(self.balance)
@@ -248,7 +214,6 @@ func (self *StateObject) Copy() *StateObject {
 	stateObject.code = common.CopyBytes(self.code)
 	stateObject.initCode = common.CopyBytes(self.initCode)
 	stateObject.storage = self.storage.Copy()
-	stateObject.gasPool.Set(self.gasPool)
 	stateObject.remove = self.remove
 	stateObject.dirty = self.dirty
 	stateObject.deleted = self.deleted
diff --git a/core/state/state_test.go b/core/state/state_test.go
index 08fbc47fa..7ddbe11a1 100644
--- a/core/state/state_test.go
+++ b/core/state/state_test.go
@@ -138,7 +138,6 @@ func TestSnapshot2(t *testing.T) {
 	so0 := state.GetStateObject(stateobjaddr0)
 	so0.balance = big.NewInt(42)
 	so0.nonce = 43
-	so0.gasPool = big.NewInt(44)
 	so0.code = []byte{'c', 'a', 'f', 'e'}
 	so0.codeHash = so0.CodeHash()
 	so0.remove = true
@@ -150,7 +149,6 @@ func TestSnapshot2(t *testing.T) {
 	so1 := state.GetStateObject(stateobjaddr1)
 	so1.balance = big.NewInt(52)
 	so1.nonce = 53
-	so1.gasPool = big.NewInt(54)
 	so1.code = []byte{'c', 'a', 'f', 'e', '2'}
 	so1.codeHash = so1.CodeHash()
 	so1.remove = true
@@ -207,9 +205,6 @@ func compareStateObjects(so0, so1 *StateObject, t *testing.T) {
 		}
 	}
 
-	if so0.gasPool.Cmp(so1.gasPool) != 0 {
-		t.Fatalf("GasPool mismatch: have %v, want %v", so0.gasPool, so1.gasPool)
-	}
 	if so0.remove != so1.remove {
 		t.Fatalf("Remove mismatch: have %v, want %v", so0.remove, so1.remove)
 	}