Merge pull request #942 from dolthub/andy/feature-version

Andy/feature version

bats/status.bats

@@ -9,6 +9,14 @@ teardown() {
     teardown_common
 }
 
+@test "dolt version --feature" {
+    # bump this test with feature version bumps
+    run dolt version --feature
+    [ "$status" -ne 0 ]
+    [[ "$output" =~ "dolt version" ]] || false
+    [[ "$output" =~ "the current head does not have a feature version" ]] || false
+}
+
 @test "no changes" {
     dolt status
     run dolt status

go/cmd/dolt/cli/command.go

@@ -24,6 +24,7 @@ import (
 	"github.com/dolthub/dolt/go/libraries/doltcore/env"
 	"github.com/dolthub/dolt/go/libraries/events"
 	"github.com/dolthub/dolt/go/libraries/utils/filesys"
+	"github.com/dolthub/dolt/go/store/nbs"
 )
 
 func isHelp(str string) bool {
@@ -193,6 +194,10 @@ func CheckEnvIsValid(dEnv *env.DoltEnv) bool {
 	} else if dEnv.DBLoadError != nil {
 		PrintErrln(color.RedString("Failed to load database."))
 		PrintErrln(dEnv.DBLoadError.Error())
+		if dEnv.DBLoadError == nbs.ErrUnreadableManifest {
+			PrintErrln("\tyou might need to upgrade your Dolt client")
+			PrintErrln("\tvisit https://github.com/dolthub/dolt/releases/latest/")
+		}
 		return false
 	}
 

go/cmd/dolt/commands/version.go

@@ -17,10 +17,16 @@ package commands
 import (
 	"context"
 
-	"github.com/dolthub/dolt/go/libraries/utils/filesys"
+	"github.com/dolthub/dolt/go/cmd/dolt/errhand"
 
 	"github.com/dolthub/dolt/go/cmd/dolt/cli"
 	"github.com/dolthub/dolt/go/libraries/doltcore/env"
+	"github.com/dolthub/dolt/go/libraries/utils/argparser"
+	"github.com/dolthub/dolt/go/libraries/utils/filesys"
+)
+
+const (
+	featureVersionFlag = "feature"
 )
 
 type VersionCmd struct {
@@ -48,10 +54,38 @@ func (cmd VersionCmd) CreateMarkdown(fs filesys.Filesys, path, commandStr string
 	return nil
 }
 
+func (cmd VersionCmd) createArgParser() *argparser.ArgParser {
+	ap := argparser.NewArgParser()
+	ap.SupportsFlag(featureVersionFlag, "f", "query the feature version of this repository.")
+	return ap
+}
+
 // Version displays the version of the running dolt client
 // Exec executes the command
 func (cmd VersionCmd) Exec(ctx context.Context, commandStr string, args []string, dEnv *env.DoltEnv) int {
 	cli.Println("dolt version", cmd.VersionStr)
 
-	return 0
+	usage := func() {}
+	ap := cmd.createArgParser()
+	apr := cli.ParseArgs(ap, args, usage)
+
+	var verr errhand.VerboseError
+	if apr.Contains(featureVersionFlag) {
+		wr, err := dEnv.WorkingRoot(ctx)
+		if err != nil {
+			verr = errhand.BuildDError("could not read working root").AddCause(err).Build()
+			return HandleVErrAndExitCode(verr, usage)
+		}
+
+		fv, ok, err := wr.GetFeatureVersion(ctx)
+		if err != nil {
+			verr = errhand.BuildDError("error reading feature version").AddCause(err).Build()
+		} else if !ok {
+			verr = errhand.BuildDError("the current head does not have a feature version").Build()
+		} else {
+			cli.Println("feature version:", fv)
+		}
+	}
+
+	return HandleVErrAndExitCode(verr, usage)
 }

go/libraries/doltcore/doltdb/doltdb.go

@@ -45,9 +45,13 @@ const (
 	MasterBranch     = "master"
 	CommitStructName = "Commit"
 
+	FeatureVersion featureVersion = 0
+
 	defaultChunksPerTF = 256 * 1024
 )
 
+type featureVersion int64
+
 // LocalDirDoltDB stores the db in the current directory
 var LocalDirDoltDB = "file://./" + dbfactory.DoltDataDir
 
@@ -412,14 +416,30 @@ func (ddb *DoltDB) ReadRootValue(ctx context.Context, h hash.Hash) (*RootValue,
 	if err != nil {
 		return nil, err
 	}
+	if val == nil {
+		return nil, errors.New("there is no dolt root value at that hash")
+	}
 
-	if val != nil {
-		if rootSt, ok := val.(types.Struct); ok && rootSt.Name() == ddbRootStructName {
-			return &RootValue{ddb.db, rootSt, nil}, nil
+	rootSt, ok := val.(types.Struct)
+	if !ok || rootSt.Name() != ddbRootStructName {
+		return nil, errors.New("there is no dolt root value at that hash")
+	}
+
+	v, ok, err := rootSt.MaybeGet(featureVersKey)
+	if err != nil {
+		return nil, err
+	}
+	if ok {
+		ver := featureVersion(v.(types.Int))
+		if FeatureVersion < ver {
+			return nil, ErrClientOutOfDate{
+				clientVer: FeatureVersion,
+				repoVer:   ver,
+			}
 		}
 	}
 
-	return nil, errors.New("there is no dolt root value at that hash")
+	return &RootValue{ddb.db, rootSt, nil}, nil
 }
 
 // Commit will update a branch's head value to be that of a previously committed root value hash

go/libraries/doltcore/doltdb/errors.go

@@ -14,7 +14,10 @@
 
 package doltdb
 
-import "errors"
+import (
+	"errors"
+	"fmt"
+)
 
 var ErrInvBranchName = errors.New("not a valid user branch name")
 var ErrInvTagName = errors.New("not a valid user tag name")
@@ -40,6 +43,16 @@ var ErrUpToDate = errors.New("up to date")
 var ErrIsAhead = errors.New("current fast forward from a to b. a is ahead of b already")
 var ErrIsBehind = errors.New("cannot reverse from b to a. b is a is behind a already")
 
+type ErrClientOutOfDate struct {
+	repoVer   featureVersion
+	clientVer featureVersion
+}
+
+func (e ErrClientOutOfDate) Error() string {
+	return fmt.Sprintf(`client (version: %d) is out of date and must upgrade to read this repo (version: %d).
+	visit https://github.com/dolthub/dolt/releases/latest/`, e.clientVer, e.repoVer)
+}
+
 func IsInvalidFormatErr(err error) bool {
 	switch err {
 	case ErrInvBranchName, ErrInvTableName, ErrInvHash, ErrInvalidAncestorSpec, ErrInvalidBranchOrHash:

go/libraries/doltcore/doltdb/root_val.go

@@ -35,6 +35,7 @@ const (
 	tablesKey       = "tables"
 	superSchemasKey = "super_schemas"
 	foreignKeyKey   = "foreign_key"
+	featureVersKey  = "feature_ver"
 )
 
 // RootValue defines the structure used inside all Liquidata noms dbs
@@ -131,6 +132,16 @@ func (root *RootValue) VRW() types.ValueReadWriter {
 	return root.vrw
 }
 
+// GetFeatureVersion returns the feature version of this root, if one is written
+func (root *RootValue) GetFeatureVersion(ctx context.Context) (ver int64, ok bool, err error) {
+	v, ok, err := root.valueSt.MaybeGet(featureVersKey)
+	if err != nil || !ok {
+		return ver, ok, err
+	}
+	ver = int64(v.(types.Int))
+	return ver, ok, err
+}
+
 func (root *RootValue) HasTable(ctx context.Context, tName string) (bool, error) {
 	val, found, err := root.valueSt.MaybeGet(tablesKey)
 

go/store/nbs/file_manifest.go

@@ -24,7 +24,6 @@ package nbs
 import (
 	"context"
 	"errors"
-	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
@@ -48,6 +47,8 @@ const (
 	prefixLen = 5
 )
 
+var ErrUnreadableManifest = errors.New("could not read file manifest")
+
 type manifestParser func(r io.Reader) (manifestContents, error)
 type manifestWriter func(temp io.Writer, contents manifestContents) error
 type manifestChecker func(upstream, contents manifestContents) error
@@ -81,7 +82,7 @@ func MaybeMigrateFileManifest(ctx context.Context, dir string) (bool, error) {
 	}
 	if !ok {
 		// expected v4 or v5
-		return false, fmt.Errorf("could not read file manifest")
+		return false, ErrUnreadableManifest
 	}
 
 	check := func(upstream, contents manifestContents) error {
@@ -127,7 +128,7 @@ func getFileManifest(ctx context.Context, dir string) (manifest, error) {
 		return fm4, nil
 	}
 
-	return nil, fmt.Errorf("could not read file manifest")
+	return nil, ErrUnreadableManifest
 }
 
 // fileManifestV5 provides access to a NomsBlockStore manifest stored on disk in |dir|. The format