[FAB-1984] Remove GetQueryResult from QSCC

In order to control access, all queries will need to go through
application chaincode. This change is in response to early
v1 feedback.

See marbles02 for an example of calling GetQueryResult from application chaincode.

In the future if there is capability to place ACL on peer APIs,
then it would be possible to expose GetQueryResult as a peer
API (or via QSCC).

Change-Id: I1613563caf823e45fdfebeaa133f4ec523716cec
Signed-off-by: denyeart <enyeart@us.ibm.com>

core/scc/qscc/querier.go

@@ -17,14 +17,11 @@ limitations under the License.
 package qscc
 
 import (
-	"bytes"
 	"fmt"
 	"strconv"
 
 	"github.com/op/go-logging"
-	"github.com/spf13/viper"
 
-	commonledger "github.com/hyperledger/fabric/common/ledger"
 	"github.com/hyperledger/fabric/core/chaincode/shim"
 	"github.com/hyperledger/fabric/core/ledger"
 	"github.com/hyperledger/fabric/core/peer"
@@ -37,7 +34,6 @@ import (
 // - GetBlockByNumber returns a block
 // - GetBlockByHash returns a block
 // - GetTransactionByID returns a transaction
-// - GetQueryResult returns result of a freeform query
 type LedgerQuerier struct {
 }
 
@@ -49,7 +45,6 @@ const (
 	GetBlockByNumber   string = "GetBlockByNumber"
 	GetBlockByHash     string = "GetBlockByHash"
 	GetTransactionByID string = "GetTransactionByID"
-	GetQueryResult     string = "GetQueryResult"
 )
 
 // Init is called once per chain when the chain is created.
@@ -68,11 +63,6 @@ func (e *LedgerQuerier) Init(stub shim.ChaincodeStubInterface) pb.Response {
 // # GetBlockByNumber: Return the block specified by block number in args[2]
 // # GetBlockByHash: Return the block specified by block hash in args[2]
 // # GetTransactionByID: Return the transaction specified by ID in args[2]
-// # GetQueryResult: Return the result of executing the specified native
-// query string in args[2]. Note that this only works if plugged in database
-// supports it. The result is a JSON array in a byte array. Note that error
-// may be returned together with a valid partial result as error might occur
-// during accummulating records from the ledger
 func (e *LedgerQuerier) Invoke(stub shim.ChaincodeStubInterface) pb.Response {
 	args := stub.GetArgs()
 
@@ -97,8 +87,6 @@ func (e *LedgerQuerier) Invoke(stub shim.ChaincodeStubInterface) pb.Response {
 	// TODO: Handle ACL
 
 	switch fname {
-	case GetQueryResult:
-		return getQueryResult(targetLedger, args[2])
 	case GetTransactionByID:
 		return getTransactionByID(targetLedger, args[2])
 	case GetBlockByNumber:
@@ -112,89 +100,6 @@ func (e *LedgerQuerier) Invoke(stub shim.ChaincodeStubInterface) pb.Response {
 	return shim.Error(fmt.Sprintf("Requested function %s not found.", fname))
 }
 
-// Execute the specified query string
-func getQueryResult(vledger ledger.PeerLedger, query []byte) (res pb.Response) {
-	if query == nil {
-		return shim.Error("Query string must not be nil.")
-	}
-	qstring := string(query)
-	var qexe ledger.QueryExecutor
-	var ri commonledger.ResultsIterator
-	var err error
-
-	// We install a recover() to gain control in 2 cases
-	// 1) bytes.Buffer panics, which happens when out of memory
-	// This is a safety measure beyond the config limit variable
-	// 2) plugin db driver might panic
-	// We recover by stopping the query and return the panic error.
-	defer func() {
-		if panicValue := recover(); panicValue != nil {
-			if qscclogger.IsEnabledFor(logging.DEBUG) {
-				qscclogger.Debugf("Recovering panic: %s", panicValue)
-			}
-			res = shim.Error(fmt.Sprintf("Error recovery: %s", panicValue))
-		}
-	}()
-
-	if qexe, err = vledger.NewQueryExecutor(); err != nil {
-		return shim.Error(err.Error())
-	}
-	if ri, err = qexe.ExecuteQuery(qstring); err != nil {
-		return shim.Error(err.Error())
-	}
-	defer ri.Close()
-
-	limit := viper.GetInt("ledger.state.couchDBConfig.queryLimit")
-
-	// buffer is a JSON array containing QueryRecords
-	var buffer bytes.Buffer
-	buffer.WriteString("[")
-
-	var qresult commonledger.QueryResult
-	bArrayMemberAlreadyWritten := false
-	qresult, err = ri.Next()
-	for r := 0; qresult != nil && err == nil && r < limit; r++ {
-		if qr, ok := qresult.(*ledger.QueryRecord); ok {
-			// Add a comma before array members, suppress it for the first array member
-			if bArrayMemberAlreadyWritten == true {
-				buffer.WriteString(",")
-			}
-			collectRecord(&buffer, qr)
-			bArrayMemberAlreadyWritten = true
-		}
-		qresult, err = ri.Next()
-	}
-
-	buffer.WriteString("]")
-
-	// Return what we have accummulated
-	ret := buffer.Bytes()
-	return shim.Success(ret)
-}
-
-// Append QueryRecord into buffer as a JSON record of the form {namespace, key, record}
-// type QueryRecord struct {
-// 	Namespace string
-// 	Key       string
-// 	Record    []byte
-// }
-func collectRecord(buffer *bytes.Buffer, rec *ledger.QueryRecord) {
-	buffer.WriteString("{\"Namespace\":")
-	buffer.WriteString("\"")
-	buffer.WriteString(rec.Namespace)
-	buffer.WriteString("\"")
-
-	buffer.WriteString(", \"Key\":")
-	buffer.WriteString("\"")
-	buffer.WriteString(rec.Key)
-	buffer.WriteString("\"")
-
-	buffer.WriteString(", \"Record\":")
-	// Record is a JSON object, so we write as-is
-	buffer.WriteString(string(rec.Record))
-	buffer.WriteString("}")
-}
-
 func getTransactionByID(vledger ledger.PeerLedger, tid []byte) pb.Response {
 	if tid == nil {
 		return shim.Error("Transaction ID must not be nil.")

core/scc/qscc/querier_test.go

@@ -117,18 +117,3 @@ func TestQueryGetBlockByHash(t *testing.T) {
 		t.Fatalf("qscc GetBlockByHash should have failed with invalid hash: 0")
 	}
 }
-
-func TestQueryGetQueryResult(t *testing.T) {
-	viper.Set("peer.fileSystemPath", "/var/hyperledger/test7/")
-	defer os.RemoveAll("/var/hyperledger/test7/")
-	peer.MockInitialize()
-	peer.MockCreateChain("mytestchainid7")
-
-	e := new(LedgerQuerier)
-	stub := shim.NewMockStub("LedgerQuerier", e)
-	qstring := "{\"selector\":{\"key\":\"value\"}}"
-	args := [][]byte{[]byte(GetQueryResult), []byte("mytestchainid7"), []byte(qstring)}
-	if res := stub.MockInvoke("1", args); res.Status == shim.OK {
-		t.Fatalf("qscc GetQueryResult should have failed with invalid query: abc")
-	}
-}