Merge PR: Cache codeanalysis (#5)

* op bitmap cache

* op bitmap cache

* remove useless code

* add verify code

core/vm/analysis.go

@@ -16,6 +16,11 @@
 
 package vm
 
+import (
+	"github.com/ethereum/go-ethereum/common"
+	lru "github.com/hashicorp/golang-lru"
+)
+
 const (
 	set2BitsMask = uint16(0b1100_0000_0000_0000)
 	set3BitsMask = uint16(0b1110_0000_0000_0000)
@@ -25,6 +30,10 @@ const (
 	set7BitsMask = uint16(0b1111_1110_0000_0000)
 )
 
+const codeBitmapCacheSize = 10000
+
+var codeBitmapCache, _ = lru.NewARC(codeBitmapCacheSize)
+
 // bitvec is a bit vector which maps bytes in a program.
 // An unset bit means the byte is an opcode, a set bit means
 // it's data (i.e. argument of PUSHxx).
@@ -122,3 +131,17 @@ func codeBitmapInternal(code, bits bitvec) bitvec {
 	}
 	return bits
 }
+
+func codeBitmapWithCache(code []byte, codeHash common.Hash) bitvec {
+	if (codeHash == emptyCodeHash || codeHash == common.Hash{}) {
+		return nil
+	}
+
+	if val, ok := codeBitmapCache.Get(codeHash); ok {
+		return val.(bitvec)
+	} else {
+		val := codeBitmap(code)
+		codeBitmapCache.Add(codeHash, val)
+		return val
+	}
+}

core/vm/contract.go

@@ -106,13 +106,13 @@ func (c *Contract) isCode(udest uint64) bool {
 	// Do we have a contract hash already?
 	// If we do have a hash, that means it's a 'regular' contract. For regular
 	// contracts ( not temporary initcode), we store the analysis in a map
-	if c.CodeHash != (common.Hash{}) {
+	if c.CodeHash != (common.Hash{}) && c.CodeHash != emptyCodeHash {
 		// Does parent context have the analysis?
 		analysis, exist := c.jumpdests[c.CodeHash]
 		if !exist {
 			// Do the analysis and save in parent context
 			// We do not need to store it in c.analysis
-			analysis = codeBitmap(c.Code)
+			analysis = codeBitmapWithCache(c.Code, c.CodeHash)
 			c.jumpdests[c.CodeHash] = analysis
 		}
 		// Also stash it in current contract for faster access