FAB-11521 Have chaincode store return hash on save

Rather than require the user to compute the hash of the chaincode, it
makes more sense to return it to them on install.  Instead of requiring
a lookup, this CR simply adds it as a return value from the persisting
to the store.

Makes #Done FAB-11521

Change-Id: I8846ac7385440fe401ea2603b1e8632f212039e0
Signed-off-by: Jason Yellick <jyellick@us.ibm.com>

core/chaincode/persistence/persistence.go

@@ -71,25 +71,26 @@ type Store struct {
 
 // Save persists chaincode install package bytes with the given name
 // and version
-func (s *Store) Save(name, version string, ccInstallPkg []byte) error {
+func (s *Store) Save(name, version string, ccInstallPkg []byte) ([]byte, error) {
 	metadataJSON, err := toJSON(name, version)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
-	hashString := hex.EncodeToString(util.ComputeSHA256(ccInstallPkg))
+	hash := util.ComputeSHA256(ccInstallPkg)
+	hashString := hex.EncodeToString(hash)
 	metadataPath := filepath.Join(s.Path, hashString+".json")
 	if _, err := s.ReadWriter.Stat(metadataPath); err == nil {
-		return errors.Errorf("chaincode metadata already exists at %s", metadataPath)
+		return nil, errors.Errorf("chaincode metadata already exists at %s", metadataPath)
 	}
 
 	ccInstallPkgPath := filepath.Join(s.Path, hashString+".bin")
 	if _, err := s.ReadWriter.Stat(ccInstallPkgPath); err == nil {
-		return errors.Errorf("ChaincodeInstallPackage already exists at %s", ccInstallPkgPath)
+		return nil, errors.Errorf("ChaincodeInstallPackage already exists at %s", ccInstallPkgPath)
 	}
 
 	if err := s.ReadWriter.WriteFile(metadataPath, metadataJSON, 0600); err != nil {
-		return errors.Wrapf(err, "error writing metadata file to %s", metadataPath)
+		return nil, errors.Wrapf(err, "error writing metadata file to %s", metadataPath)
 	}
 
 	if err := s.ReadWriter.WriteFile(ccInstallPkgPath, ccInstallPkg, 0600); err != nil {
@@ -100,10 +101,10 @@ func (s *Store) Save(name, version string, ccInstallPkg []byte) error {
 		if err2 := s.ReadWriter.Remove(metadataPath); err2 != nil {
 			logger.Errorf("error removing metadata file at %s: %s", metadataPath, err2)
 		}
-		return err
+		return nil, err
 	}
 
-	return nil
+	return hash, nil
 }
 
 // Load loads a persisted chaincode install package bytes with the given hash

core/chaincode/persistence/persistence_test.go

@@ -120,8 +120,9 @@ var _ = Describe("Persistence", func() {
 		})
 
 		It("saves successfully", func() {
-			err := store.Save("testcc", "1.0", pkgBytes)
+			hash, err := store.Save("testcc", "1.0", pkgBytes)
 			Expect(err).NotTo(HaveOccurred())
+			Expect(hash).To(Equal(util.ComputeSHA256([]byte("testpkg"))))
 		})
 
 		Context("when the metadata file already exists", func() {
@@ -130,8 +131,9 @@ var _ = Describe("Persistence", func() {
 			})
 
 			It("returns an error", func() {
-				err := store.Save("testcc", "1.0", pkgBytes)
+				hash, err := store.Save("testcc", "1.0", pkgBytes)
 				Expect(err).To(HaveOccurred())
+				Expect(hash).To(BeNil())
 				Expect(err.Error()).To(Equal("chaincode metadata already exists at " + hashString + ".json"))
 			})
 		})
@@ -143,7 +145,8 @@ var _ = Describe("Persistence", func() {
 			})
 
 			It("returns an error", func() {
-				err := store.Save("testcc", "1.0", pkgBytes)
+				hash, err := store.Save("testcc", "1.0", pkgBytes)
+				Expect(hash).To(BeNil())
 				Expect(err).To(HaveOccurred())
 				Expect(err.Error()).To(Equal("ChaincodeInstallPackage already exists at " + hashString + ".bin"))
 			})
@@ -156,7 +159,8 @@ var _ = Describe("Persistence", func() {
 			})
 
 			It("returns an error", func() {
-				err := store.Save("testcc", "1.0", pkgBytes)
+				hash, err := store.Save("testcc", "1.0", pkgBytes)
+				Expect(hash).To(BeNil())
 				Expect(err).To(HaveOccurred())
 				Expect(err.Error()).To(ContainSubstring("error writing metadata file"))
 			})
@@ -169,7 +173,8 @@ var _ = Describe("Persistence", func() {
 			})
 
 			It("returns an error", func() {
-				err := store.Save("testcc", "1.0", pkgBytes)
+				hash, err := store.Save("testcc", "1.0", pkgBytes)
+				Expect(hash).To(BeNil())
 				Expect(err).To(HaveOccurred())
 				Expect(err.Error()).To(ContainSubstring("error writing chaincode install package"))
 			})
@@ -183,7 +188,8 @@ var _ = Describe("Persistence", func() {
 			})
 
 			It("returns an error", func() {
-				err := store.Save("testcc", "1.0", pkgBytes)
+				hash, err := store.Save("testcc", "1.0", pkgBytes)
+				Expect(hash).To(BeNil())
 				Expect(err).To(HaveOccurred())
 				Expect(err.Error()).To(ContainSubstring("error writing chaincode install package"))
 			})