refactor core/utils.go and add comments

cmd/pdu/account.go

@@ -19,15 +19,16 @@ package main
 import (
 	"errors"
 	"fmt"
-	"github.com/pdupub/go-pdu/crypto"
-	"github.com/spf13/cobra"
 	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
 
+	"github.com/pdupub/go-pdu/crypto"
+	"github.com/pdupub/go-pdu/crypto/utils"
+	"github.com/spf13/cobra"
+
 	"github.com/howeyc/gopass"
-	"github.com/pdupub/go-pdu/core"
 )
 
 const (
@@ -84,7 +85,7 @@ func generate() error {
 		return crypto.ErrSigTypeNotSupport
 	}
 
-	engine, err = core.SelectEngine(accCrypt)
+	engine, err = utils.SelectEngine(accCrypt)
 	if err != nil {
 		return err
 	}

cmd/pdu/utils.go

@@ -27,8 +27,8 @@ import (
 
 	"github.com/howeyc/gopass"
 	"github.com/mitchellh/go-homedir"
-	"github.com/pdupub/go-pdu/core"
 	"github.com/pdupub/go-pdu/crypto"
+	"github.com/pdupub/go-pdu/crypto/utils"
 	"github.com/pdupub/go-pdu/db"
 	"github.com/pdupub/go-pdu/db/bolt"
 	"github.com/pdupub/go-pdu/params"
@@ -121,7 +121,7 @@ func unlockKeyByCmd() (*crypto.PrivateKey, *crypto.PublicKey, error) {
 		return nil, nil, err
 	}
 
-	return core.DecryptKey(keyJson, string(passwd))
+	return utils.DecryptKey(keyJson, string(passwd))
 }
 
 func unlockKeyByFile(keyFile, passFile string) (*crypto.PrivateKey, *crypto.PublicKey, error) {
@@ -135,7 +135,7 @@ func unlockKeyByFile(keyFile, passFile string) (*crypto.PrivateKey, *crypto.Publ
 		return nil, nil, err
 	}
 
-	return core.DecryptKey(keyJson, strings.TrimSpace(string(passwd)))
+	return utils.DecryptKey(keyJson, strings.TrimSpace(string(passwd)))
 }
 
 func scanLine(input *string) {

core/auth.go

@@ -18,7 +18,9 @@ package core
 
 import (
 	"encoding/json"
+
 	"github.com/pdupub/go-pdu/crypto"
+	"github.com/pdupub/go-pdu/crypto/utils"
 )
 
 // Auth contain public key
@@ -35,7 +37,7 @@ func (a *Auth) UnmarshalJSON(input []byte) error {
 	}
 	a.Source = aMap["source"].(string)
 	a.SigType = aMap["sigType"].(string)
-	engine, err := SelectEngine(a.Source)
+	engine, err := utils.SelectEngine(a.Source)
 	if err != nil {
 		return err
 	}
@@ -49,7 +51,7 @@ func (a *Auth) UnmarshalJSON(input []byte) error {
 
 // MarshalJSON marshal public key to json
 func (a Auth) MarshalJSON() ([]byte, error) {
-	engine, err := SelectEngine(a.Source)
+	engine, err := utils.SelectEngine(a.Source)
 	if err != nil {
 		return nil, err
 	}

core/message.go

@@ -20,8 +20,10 @@ import (
 	"crypto/sha256"
 	"encoding/json"
 	"fmt"
+
 	"github.com/pdupub/go-pdu/common"
 	"github.com/pdupub/go-pdu/crypto"
+	"github.com/pdupub/go-pdu/crypto/utils"
 )
 
 // Message is valid msg in pdu
@@ -57,7 +59,7 @@ func CreateMsg(user *User, value *MsgValue, priKey *crypto.PrivateKey, refs ...*
 		Signature: nil,
 	}
 
-	engine, err := SelectEngine(priKey.Source)
+	engine, err := utils.SelectEngine(priKey.Source)
 	if err != nil {
 		return nil, err
 	}
@@ -79,7 +81,7 @@ func CreateMsg(user *User, value *MsgValue, priKey *crypto.PrivateKey, refs ...*
 func VerifyMsg(msg Message) (bool, error) {
 	signature := msg.Signature
 	msg.Signature = nil
-	engine, err := SelectEngine(signature.Source)
+	engine, err := utils.SelectEngine(signature.Source)
 	if err != nil {
 		return false, err
 	}

core/msg_value.go

@@ -18,8 +18,10 @@ package core
 
 import (
 	"encoding/json"
+
 	"github.com/pdupub/go-pdu/common"
 	"github.com/pdupub/go-pdu/crypto"
+	"github.com/pdupub/go-pdu/crypto/utils"
 )
 
 const (
@@ -62,7 +64,7 @@ func (mv *DOBMsgContent) SignByParent(user *User, privKey crypto.PrivateKey) err
 		return err
 	}
 	var signature *crypto.Signature
-	engine, err := SelectEngine(privKey.Source)
+	engine, err := utils.SelectEngine(privKey.Source)
 	if err != nil {
 		return err
 	}

core/universe.go

@@ -23,14 +23,20 @@ import (
 	"github.com/pdupub/go-pdu/dag"
 )
 
-// Universe contain many space time on different time line
+// Universe is the struct contain all the information can be received and validated.
+// It is built with two precreate users as root users. Any message should be validated before
+// add into msgD, which is a DAG used to store message. If new user create from valid message,
+// the user should add into userD, a DAG used to store all users. The universe contain at least
+// one spacetime, each spacetime base on one user msg as time line. validation of message mean
+// this message should be valid at least in one of spacetime in stD. Infomation in local universe
+// is only part of infomation in whole decentralized system.
 type Universe struct {
-	msgD  *dag.DAG // contain all messages valid in any universe (time proof)
-	userD *dag.DAG // contain all users valid in any universe (time proof) (strict)
-	stD   *dag.DAG // contain all space time, which is the origin thought of PDU (strict)
+	msgD  *dag.DAG // contain all messages valid in at least one spacetime
+	userD *dag.DAG // contain all users valid in at least one spacetime (strict)
+	stD   *dag.DAG // contain all spacetime, which could be diff by selecting (strict)
 }
 
-// NewUniverse create Universe from two user with diff gender
+// NewUniverse create Universe with two user with diff gender as root users
 func NewUniverse(Eve, Adam *User) (*Universe, error) {
 	if Eve.Gender() == Adam.Gender() {
 		return nil, ErrNotSupportYet
@@ -51,9 +57,9 @@ func NewUniverse(Eve, Adam *User) (*Universe, error) {
 	return &Universe{userD: userD}, nil
 }
 
-// AddMsg will check if the msg from valid user,
-// add new msg into Universe, and update time proof if
-// msg.SenderID is belong to time proof
+// AddMsg will check if the message from valid user, who is validated in at least one spacetime
+// (in stD). Then new message will be added into Universe and update time proof if msg.SenderID
+// is any spacetime based on.
 func (u *Universe) AddMsg(msg *Message) error {
 	if !u.CheckUserExist(msg.SenderID) {
 		return ErrUserNotExist
@@ -66,7 +72,6 @@ func (u *Universe) AddMsg(msg *Message) error {
 			return err
 		}
 	} else {
-
 		// check
 		if u.GetMsgByID(msg.ID()) != nil {
 			return ErrMsgAlreadyExist
@@ -98,7 +103,7 @@ func (u *Universe) AddMsg(msg *Message) error {
 	return nil
 }
 
-// GetSpaceTimeIDs get ids in this space time
+// GetSpaceTimeIDs get ids in of spacetime (list of msg.SenderID of each spacetime)
 func (u *Universe) GetSpaceTimeIDs() []common.Hash {
 	var ids []common.Hash
 	if u.stD != nil {
@@ -109,7 +114,8 @@ func (u *Universe) GetSpaceTimeIDs() []common.Hash {
 	return ids
 }
 
-// AddSpaceTime will get all messages save in Universe with same msg.SenderID
+// AddSpaceTime will add spacetime in Universe with msg.SenderID, and follow the
+// time sequence from ref.
 func (u *Universe) AddSpaceTime(msg *Message, ref *MsgReference) error {
 	if u.GetMsgByID(msg.ID()) == nil {
 		return ErrMsgNotFound
@@ -171,7 +177,7 @@ func (u *Universe) initializeSpaceTime(msgSpaceTime *Message, ref *MsgReference)
 	return nil
 }
 
-// CheckUserExist check if the user valid in this Universe
+// CheckUserExist check if the user valid in the Universe
 func (u Universe) CheckUserExist(userID common.Hash) bool {
 	if nil != u.GetUserByID(userID) {
 		return true
@@ -227,6 +233,9 @@ func (u Universe) GetMsgByID(msgID interface{}) *Message {
 	return nil
 }
 
+// initializeMsgD only run once to create u.msgD by initial message, and the DAG
+// will remove strict rule, so msgD can accept new message if at least one of
+// reference exist in whole universe.
 func (u *Universe) initializeMsgD(msg *Message) error {
 	// build msg dag
 	msgVertex, err := dag.NewVertex(msg.ID(), msg)

core/universe_test.go

@@ -26,6 +26,7 @@ import (
 	"github.com/pdupub/go-pdu/common/log"
 	"github.com/pdupub/go-pdu/core/rule"
 	"github.com/pdupub/go-pdu/crypto"
+	"github.com/pdupub/go-pdu/crypto/utils"
 )
 
 var (
@@ -40,7 +41,7 @@ var (
 )
 
 func TestNewUniverse(t *testing.T) {
-	universeEngine, _ = SelectEngine(crypto.ETH)
+	universeEngine, _ = utils.SelectEngine(crypto.ETH)
 
 	// Test 1: Create root users, Adam and Eve , create universe
 	// The gender of user relate to public key (random), so createRootUser

core/utils.go → crypto/utils/utils.go

@@ -14,15 +14,16 @@
 // You should have received a copy of the GNU Lesser General Public License
 // along with the PDU library. If not, see <http://www.gnu.org/licenses/>.
 
-package core
+package utils
 
 import (
 	"encoding/json"
+	"strings"
+
 	"github.com/pdupub/go-pdu/crypto"
 	"github.com/pdupub/go-pdu/crypto/bitcoin"
 	"github.com/pdupub/go-pdu/crypto/ethereum"
 	"github.com/pdupub/go-pdu/crypto/pdu"
-	"strings"
 )
 
 // SelectEngine return a new engine by source type

go.sum

@@ -40,6 +40,7 @@ github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f/go.mod h1:E3G3o1h8I7cfc
 github.com/cpuguy83/go-md2man v1.0.10/go.mod h1:SmD6nW6nTyfqj6ABTjUi3V3JVMnlJmwcJI5acqYI6dE=
 github.com/davecgh/go-spew v0.0.0-20171005155431-ecdeabc65495/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/deckarep/golang-set v1.7.1 h1:SCQV0S6gTtp6itiFrTqI+pfmJ4LN85S1YzhDf9rTHJQ=
 github.com/deckarep/golang-set v1.7.1/go.mod h1:93vsz/8Wt4joVM7c2AVqh+YRMiUSc14yDtF28KmMOgQ=
@@ -133,6 +134,7 @@ github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/9
 github.com/pierrec/lz4 v0.0.0-20190327172049-315a67e90e41/go.mod h1:3/3N9NVKO0jef7pBehbT1qWhCMrIgbYNnFAZCqQ5LRc=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/profile v1.2.1/go.mod h1:hJw3o1OdXxsrSjjVksARp5W95eeEaEfptyVZyv6JUPA=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_golang v0.9.1/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
 github.com/prometheus/client_golang v0.9.3/go.mod h1:/TN21ttK/J9q6uSwhBd54HahCDft0ttaMvbicHlPoso=
@@ -178,6 +180,7 @@ github.com/steakknife/hamming v0.0.0-20180906055917-c99c65617cd3/go.mod h1:hpGUW
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/templexxx/cpufeat v0.0.0-20180724012125-cef66df7f161/go.mod h1:wM7WEvslTq+iOEAMDLSzhVuOt5BRZ05WirO+b09GHQU=
 github.com/templexxx/xor v0.0.0-20181023030647-4e92f724b73b/go.mod h1:5XA7W9S6mni3h5uvOC75dA3m9CCCaS83lltmc0ukdi4=