github.com/igggame/nebulas-go@v2.1.0+incompatible/nf/nvm/random.go (about) 1 package nvm 2 3 /* 4 #include "v8/lib/nvm_error.h" 5 */ 6 import "C" 7 8 import ( 9 "crypto/md5" 10 "encoding/binary" 11 "io" 12 "strconv" 13 "unsafe" 14 15 "math/rand" 16 17 "github.com/nebulasio/go-nebulas/util/logging" 18 "github.com/sirupsen/logrus" 19 ) 20 21 //GetTxRandomFunc return random 22 //export GetTxRandomFunc 23 func GetTxRandomFunc(handler unsafe.Pointer, gasCnt *C.size_t, result **C.char, exceptionInfo **C.char) int { 24 engine, _ := getEngineByStorageHandler(uint64(uintptr(handler))) 25 if engine == nil || engine.ctx.block == nil { 26 logging.VLog().Error("random.GetTxRandomFunc Unexpected error: failed to get engine") 27 return C.NVM_UNEXPECTED_ERR 28 } 29 // calculate Gas. 30 *gasCnt = C.size_t(GetTxRandomGasBase) 31 32 if engine.ctx.contextRand == nil { 33 logging.VLog().WithFields(logrus.Fields{ 34 "height": engine.ctx.block.Height(), 35 }).Error("ContextRand is nil") 36 *exceptionInfo = C.CString("random.GetTxRandomFunc(), contextRand is nil") 37 return C.NVM_EXCEPTION_ERR 38 } 39 40 if engine.ctx.contextRand.rand == nil { 41 bs := engine.ctx.block.RandomSeed() 42 if len(bs) == 0 { 43 logging.VLog().WithFields(logrus.Fields{ 44 "height": engine.ctx.block.Height(), 45 }).Error("block seed is nil") 46 *exceptionInfo = C.CString("random.GetTxRandomFunc(), randomSeed len is zero") 47 return C.NVM_EXCEPTION_ERR 48 } 49 50 txhash := engine.ctx.tx.Hash().String() 51 if len(txhash) == 0 { 52 logging.VLog().WithFields(logrus.Fields{ 53 "height": engine.ctx.block.Height(), 54 }).Error("transaction hash is nil") 55 *exceptionInfo = C.CString("random.GetTxRandomFunc(), randomSeed len is zero") 56 return C.NVM_EXCEPTION_ERR 57 } 58 59 m := md5.New() 60 io.WriteString(m, bs) 61 io.WriteString(m, txhash) 62 seed := int64(binary.BigEndian.Uint64(m.Sum(nil))) 63 engine.ctx.contextRand.rand = rand.New(rand.NewSource(seed)) 64 } 65 *result = C.CString(strconv.FormatFloat(engine.ctx.contextRand.rand.Float64(), 'f', -1, 64)) 66 return C.NVM_SUCCESS 67 }