Merge pull request #7032 from dolthub/steph/reflog

CLI command for reflog

go/cmd/dolt/cli/arg_parser_helpers.go

@@ -280,6 +280,12 @@ func CreateCountCommitsArgParser() *argparser.ArgParser {
 	return ap
 }
 
+func CreateReflogArgParser() *argparser.ArgParser {
+	ap := argparser.NewArgParserWithMaxArgs("reflog", 1)
+	ap.SupportsFlag(AllFlag, "", "Show all refs, including hidden refs, such as DoltHub workspace refs")
+	return ap
+}
+
 func CreateGlobalArgParser(name string) *argparser.ArgParser {
 	ap := argparser.NewArgParserWithVariableArgs(name)
 	if name == "dolt" {

go/cmd/dolt/commands/reflog.go

@@ -0,0 +1,197 @@
+// Copyright 2023 Dolthub, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package commands
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/dolthub/go-mysql-server/sql"
+	"github.com/gocraft/dbr/v2"
+	"github.com/gocraft/dbr/v2/dialect"
+
+	"github.com/dolthub/dolt/go/cmd/dolt/cli"
+	"github.com/dolthub/dolt/go/cmd/dolt/errhand"
+	eventsapi "github.com/dolthub/dolt/go/gen/proto/dolt/services/eventsapi/v1alpha1"
+	"github.com/dolthub/dolt/go/libraries/doltcore/env"
+	"github.com/dolthub/dolt/go/libraries/utils/argparser"
+	"github.com/dolthub/dolt/go/store/util/outputpager"
+)
+
+var reflogDocs = cli.CommandDocumentationContent{
+	ShortDesc: "Shows a history of named refs",
+	LongDesc: `Shows the history of named refs (e.g. branches and tags), which is useful for understanding how a branch 
+or tag changed over time to reference different commits, particularly for information not surfaced through {{.EmphasisLeft}}dolt log{{.EmphasisRight}}.
+The data from Dolt's reflog comes from [Dolt's journaling chunk store](https://www.dolthub.com/blog/2023-03-08-dolt-chunk-journal/). 
+This data is local to a Dolt database and never included when pushing, pulling, or cloning a Dolt database. This means when you clone a Dolt database, it will not have any reflog data until you perform operations that change what commit branches or tags reference.
+
+Dolt's reflog is similar to [Git's reflog](https://git-scm.com/docs/git-reflog), but there are a few differences:
+- The Dolt reflog currently only supports named references, such as branches and tags, and not any of Git's special refs (e.g. {{.EmphasisLeft}}HEAD{{.EmphasisRight}}, {{.EmphasisLeft}}FETCH-HEAD{{.EmphasisRight}}, {{.EmphasisLeft}}MERGE-HEAD{{.EmphasisRight}}).
+- The Dolt reflog can be queried for the log of references, even after a reference has been deleted. In Git, once a branch or tag is deleted, the reflog for that ref is also deleted and to find the last commit a branch or tag pointed to you have to use Git's special {{.EmphasisLeft}}HEAD{{.EmphasisRight}} reflog to find the commit, which can sometimes be challenging. Dolt makes this much easier by allowing you to see the history for a deleted ref so you can easily see the last commit a branch or tag pointed to before it was deleted.`,
+	Synopsis: []string{
+		`[--all] {{.LessThan}}ref{{.GreaterThan}}`,
+	},
+}
+
+type ReflogCmd struct{}
+
+// Name is returns the name of the Dolt cli command. This is what is used on the command line to invoke the command
+func (cmd ReflogCmd) Name() string {
+	return "reflog"
+}
+
+// Description returns a description of the command
+func (cmd ReflogCmd) Description() string {
+	return "Show history of named refs."
+}
+
+// EventType returns the type of the event to log
+func (cmd ReflogCmd) EventType() eventsapi.ClientEventType {
+	return eventsapi.ClientEventType_REFLOG
+}
+
+func (cmd ReflogCmd) Docs() *cli.CommandDocumentation {
+	ap := cmd.ArgParser()
+	return cli.NewCommandDocumentation(reflogDocs, ap)
+}
+
+func (cmd ReflogCmd) ArgParser() *argparser.ArgParser {
+	return cli.CreateReflogArgParser()
+}
+
+func (cmd ReflogCmd) RequiresRepo() bool {
+	return false
+}
+
+// Exec executes the command
+func (cmd ReflogCmd) Exec(ctx context.Context, commandStr string, args []string, dEnv *env.DoltEnv, cliCtx cli.CliContext) int {
+	ap := cmd.ArgParser()
+	help, usage := cli.HelpAndUsagePrinters(cli.CommandDocsForCommandString(commandStr, reflogDocs, ap))
+	apr := cli.ParseArgsOrDie(ap, args, help)
+
+	queryist, sqlCtx, closeFunc, err := cliCtx.QueryEngine(ctx)
+	if err != nil {
+		return HandleVErrAndExitCode(errhand.VerboseErrorFromError(err), usage)
+	}
+	if closeFunc != nil {
+		defer closeFunc()
+	}
+
+	query, err := constructInterpolatedDoltReflogQuery(apr)
+	if err != nil {
+		return HandleVErrAndExitCode(errhand.VerboseErrorFromError(err), usage)
+	}
+
+	rows, err := GetRowsForSql(queryist, sqlCtx, query)
+	if err != nil {
+		return HandleVErrAndExitCode(errhand.VerboseErrorFromError(err), usage)
+	}
+
+	return printReflog(rows, queryist, sqlCtx)
+}
+
+// constructInterpolatedDoltReflogQuery generates the sql query necessary to call the DOLT_REFLOG() function.
+// Also interpolates this query to prevent sql injection
+func constructInterpolatedDoltReflogQuery(apr *argparser.ArgParseResults) (string, error) {
+	var params []interface{}
+	var args []string
+
+	if apr.NArg() == 1 {
+		params = append(params, apr.Arg(0))
+		args = append(args, "?")
+	}
+	if apr.Contains(cli.AllFlag) {
+		args = append(args, "'--all'")
+	}
+
+	query := fmt.Sprintf("SELECT ref, commit_hash, commit_message FROM DOLT_REFLOG(%s)", strings.Join(args, ", "))
+	interpolatedQuery, err := dbr.InterpolateForDialect(query, params, dialect.MySQL)
+	if err != nil {
+		return "", err
+	}
+
+	return interpolatedQuery, nil
+}
+
+type ReflogInfo struct {
+	ref           string
+	commitHash    string
+	commitMessage string
+}
+
+// printReflog takes a list of sql rows with columns ref, commit hash, commit message. Prints the reflog to stdout
+func printReflog(rows []sql.Row, queryist cli.Queryist, sqlCtx *sql.Context) int {
+	var reflogInfo []ReflogInfo
+
+	// Get the hash of HEAD for the `HEAD ->` decoration
+	headHash := ""
+	res, err := GetRowsForSql(queryist, sqlCtx, "SELECT hashof('HEAD')")
+	if err == nil {
+		// still print the reflog even if we can't get the hash
+		headHash = res[0][0].(string)
+	}
+
+	for _, row := range rows {
+		ref := row[0].(string)
+		commitHash := row[1].(string)
+		commitMessage := row[2].(string)
+		reflogInfo = append(reflogInfo, ReflogInfo{ref, commitHash, commitMessage})
+	}
+
+	reflogToStdOut(reflogInfo, headHash)
+
+	return 0
+}
+
+// reflogToStdOut takes a list of ReflogInfo and prints the reflog to stdout
+func reflogToStdOut(reflogInfo []ReflogInfo, headHash string) {
+	if cli.ExecuteWithStdioRestored == nil {
+		return
+	}
+	cli.ExecuteWithStdioRestored(func() {
+		pager := outputpager.Start()
+		defer pager.Stop()
+
+		for _, info := range reflogInfo {
+			// TODO: use short hash instead
+			line := []string{fmt.Sprintf("\033[33m%s\033[0m", info.commitHash)} // commit hash in yellow (33m)
+
+			processedRef := processRefForReflog(info.ref)
+			if headHash != "" && headHash == info.commitHash {
+				line = append(line, fmt.Sprintf("\033[33m(\033[36;1mHEAD -> %s\033[33m)\033[0m", processedRef)) // HEAD in cyan (36;1)
+			} else {
+				line = append(line, fmt.Sprintf("\033[33m(%s\033[33m)\033[0m", processedRef)) // () in yellow (33m)
+			}
+			line = append(line, fmt.Sprintf("%s\n", info.commitMessage))
+			pager.Writer.Write([]byte(strings.Join(line, " ")))
+		}
+	})
+}
+
+// processRefForReflog takes a full ref (e.g. refs/heads/master) or tag name and returns the ref name (e.g. master) with relevant decoration.
+func processRefForReflog(fullRef string) string {
+	if strings.HasPrefix(fullRef, "refs/heads/") {
+		return fmt.Sprintf("\033[32;1m%s\033[0m", strings.TrimPrefix(fullRef, "refs/heads/")) // branch in green (32;1m)
+	} else if strings.HasPrefix(fullRef, "refs/tags/") {
+		return fmt.Sprintf("\033[33mtag: %s\033[0m", strings.TrimPrefix(fullRef, "refs/tags/")) // tag in yellow (33m)
+	} else if strings.HasPrefix(fullRef, "refs/remotes/") {
+		return fmt.Sprintf("\033[31;1m%s\033[0m", strings.TrimPrefix(fullRef, "refs/remotes/")) // remote in red (31;1m)
+	} else if strings.HasPrefix(fullRef, "refs/workspaces/") {
+		return fmt.Sprintf("\033[35;1mworkspace: %s\033[0m", strings.TrimPrefix(fullRef, "refs/workspaces/")) // workspace in magenta (35;1m)
+	} else {
+		return fullRef
+	}
+}

go/cmd/dolt/dolt.go

@@ -122,6 +122,7 @@ var doltSubCommands = []cli.Command{
 	&commands.Assist{},
 	commands.ProfileCmd{},
 	commands.QueryDiff{},
+	commands.ReflogCmd{},
 }
 
 var commandsWithoutCliCtx = []cli.Command{

go/gen/proto/dolt/services/eventsapi/v1alpha1/event_constants.pb.go

@@ -155,6 +155,7 @@ const (
 	ClientEventType_STASH_POP                        ClientEventType = 60
 	ClientEventType_SHOW                             ClientEventType = 61
 	ClientEventType_PROFILE                          ClientEventType = 62
+	ClientEventType_REFLOG                           ClientEventType = 63
 )
 
 // Enum value maps for ClientEventType.

go/libraries/doltcore/sqle/enginetest/dolt_queries.go

@@ -4317,7 +4317,7 @@ var DoltReflogTestScripts = []queries.ScriptTest{
 		Assertions: []queries.ScriptTestAssertion{
 			{
 				Query:          "select * from dolt_reflog('foo', 'bar');",
-				ExpectedErrStr: "function 'dolt_reflog' expected 0 or 1 arguments, 2 received",
+				ExpectedErrStr: "error: dolt_reflog has too many positional arguments. Expected at most 1, found 2: ['foo' 'bar']",
 			},
 			{
 				Query:          "select * from dolt_reflog(NULL);",

go/libraries/doltcore/sqle/reflog_table_function.go

@@ -29,9 +29,9 @@ import (
 )
 
 type ReflogTableFunction struct {
-	ctx      *sql.Context
-	database sql.Database
-	refExpr  sql.Expression
+	ctx            *sql.Context
+	database       sql.Database
+	refAndArgExprs []sql.Expression
 }
 
 var _ sql.TableFunction = (*ReflogTableFunction)(nil)
@@ -65,17 +65,30 @@ func (rltf *ReflogTableFunction) RowIter(ctx *sql.Context, row sql.Row) (sql.Row
 	}
 
 	var refName string
-	if rltf.refExpr != nil {
-		target, err := rltf.refExpr.Eval(ctx, row)
+	showAll := false
+	for _, expr := range rltf.refAndArgExprs {
+		target, err := expr.Eval(ctx, row)
 		if err != nil {
 			return nil, fmt.Errorf("error evaluating expression (%s): %s",
-				rltf.refExpr.String(), err.Error())
+				expr.String(), err.Error())
 		}
-
-		refName, ok = target.(string)
+		targetStr, ok := target.(string)
 		if !ok {
 			return nil, fmt.Errorf("argument (%v) is not a string value, but a %T", target, target)
 		}
+
+		if targetStr == "--all" {
+			if showAll {
+				return nil, fmt.Errorf("error: multiple values provided for `all`")
+			}
+			showAll = true
+		} else {
+			if refName != "" {
+				return nil, fmt.Errorf("error: %s has too many positional arguments. Expected at most %d, found %d: %s",
+					rltf.Name(), 1, 2, rltf.refAndArgExprs)
+			}
+			refName = targetStr
+		}
 	}
 
 	ddb := sqlDb.DbData().Ddb
@@ -109,9 +122,15 @@ func (rltf *ReflogTableFunction) RowIter(ctx *sql.Context, row sql.Row) (sql.Row
 			if doltRef.GetType() == ref.InternalRefType {
 				return nil
 			}
+			// skip workspace refs by default
+			if doltRef.GetType() == ref.WorkspaceRefType {
+				if !showAll {
+					return nil
+				}
+			}
 
 			// If a ref expression to filter on was specified, see if we match the current ref
-			if rltf.refExpr != nil {
+			if refName != "" {
 				// If the caller has supplied a branch or tag name, without the fully qualified ref path,
 				// take the first match and use that as the canonical ref to filter on
 				if strings.HasSuffix(strings.ToLower(id), "/"+strings.ToLower(refName)) {
@@ -172,14 +191,21 @@ func (rltf *ReflogTableFunction) Schema() sql.Schema {
 }
 
 func (rltf *ReflogTableFunction) Resolved() bool {
-	if rltf.refExpr != nil {
-		return rltf.refExpr.Resolved()
+	for _, expr := range rltf.refAndArgExprs {
+		if !expr.Resolved() {
+			return false
+		}
 	}
 	return true
 }
 
 func (rltf *ReflogTableFunction) String() string {
-	return fmt.Sprintf("DOLT_REFLOG(%s)", rltf.refExpr.String())
+	var args []string
+
+	for _, expr := range rltf.refAndArgExprs {
+		args = append(args, expr.String())
+	}
+	return fmt.Sprintf("DOLT_REFLOG(%s)", strings.Join(args, ", "))
 }
 
 func (rltf *ReflogTableFunction) Children() []sql.Node {
@@ -204,21 +230,17 @@ func (rltf *ReflogTableFunction) IsReadOnly() bool {
 }
 
 func (rltf *ReflogTableFunction) Expressions() []sql.Expression {
-	if rltf.refExpr != nil {
-		return []sql.Expression{rltf.refExpr}
-	}
-	return []sql.Expression{}
+	return rltf.refAndArgExprs
 }
 
 func (rltf *ReflogTableFunction) WithExpressions(expression ...sql.Expression) (sql.Node, error) {
-	if len(expression) > 1 {
-		return nil, sql.ErrInvalidArgumentNumber.New(rltf.Name(), "0 or 1", len(expression))
+	if len(expression) > 2 {
+		return nil, sql.ErrInvalidArgumentNumber.New(rltf.Name(), "0 to 2", len(expression))
 	}
 
 	new := *rltf
-	if len(expression) > 0 {
-		new.refExpr = expression[0]
-	}
+	new.refAndArgExprs = expression
+
 	return &new, nil
 }
 

integration-tests/bats/helper/local-remote.bash

@@ -135,6 +135,7 @@ SKIP_SERVER_TESTS=$(cat <<-EOM
 ~cli-hosted.bats~
 ~profile.bats~
 ~ls.bats~
+~reflog.bats~
 EOM
 )
 

integration-tests/bats/reflog.bats

@@ -6,40 +6,27 @@ teardown() {
     teardown_common
 }
 
-# Asserts that when DOLT_DISABLE_REFLOG is set, the dolt_reflog() table
-# function returns an empty result set with no error.
+# Asserts that when DOLT_DISABLE_REFLOG is set, dolt reflog returns nothing with no error.
 @test "reflog: disabled with DOLT_DISABLE_REFLOG" {
     export DOLT_DISABLE_REFLOG=true
-    setup_common
+    setup_common    # need to set env vars before setup_common for remote tests
+
     dolt sql -q "create table t (i int primary key, j int);"
     dolt sql -q "insert into t values (1, 1), (2, 2), (3, 3)";
     dolt commit -Am "initial commit"
     dolt commit --allow-empty -m "test commit 1"
 
-    run dolt sql -q "select * from dolt_reflog();"
+    run dolt reflog
     [ "$status" -eq 0 ]
     [ "${#lines[@]}" -eq 0 ]
 }
 
-# Sanity check for the most basic case of querying the Dolt reflog
-@test "reflog: enabled by default" {
-    setup_common
-    dolt sql -q "create table t (i int primary key, j int);"
-    dolt sql -q "insert into t values (1, 1), (2, 2), (3, 3)";
-    dolt commit -Am "initial commit"
-
-    run dolt sql -q "select * from dolt_reflog();"
-    [ "$status" -eq 0 ]
-    [ "${#lines[@]}" -eq 6 ]
-    [[ "$output"  =~ "initial commit" ]] || false
-    [[ "$output"  =~ "Initialize data repository" ]] || false
-}
-
 # Asserts that when DOLT_REFLOG_RECORD_LIMIT has been set, the reflog only contains the
 # most recent entries and is limited by the env var's value.
 @test "reflog: set DOLT_REFLOG_RECORD_LIMIT" {
     export DOLT_REFLOG_RECORD_LIMIT=2
-    setup_common
+    setup_common    # need to set env vars before setup_common for remote tests
+
     dolt sql -q "create table t (i int primary key, j int);"
     dolt sql -q "insert into t values (1, 1), (2, 2), (3, 3)";
     dolt commit -Am "initial commit"
@@ -47,10 +34,227 @@ teardown() {
     dolt commit --allow-empty -m "test commit 2"
 
     # Only the most recent two ref changes should appear in the log
-    run dolt sql -q "select * from dolt_reflog();"
+    run dolt reflog
     [ "$status" -eq 0 ]
     [[ "$output" =~ "test commit 1" ]] || false
     [[ "$output" =~ "test commit 2" ]] || false
     [[ ! "$output" =~ "initial commit" ]] || false
     [[ ! "$output" =~ "Initialize data repository" ]] || false
 }
+
+@test "reflog: simple reflog" {
+    setup_common
+
+    dolt sql -q "create table t (i int primary key, j int);"
+    dolt sql -q "insert into t values (1, 1), (2, 2), (3, 3)";
+    dolt commit -Am "initial commit"
+
+    run dolt reflog
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 2 ]
+    out=$(echo "$output" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$out" =~ "(HEAD -> main) initial commit" ]] || false
+    [[ "$out" =~ "Initialize data repository" ]] || false
+}
+
+@test "reflog: reflog with ref given" {
+    setup_common
+
+    dolt sql <<SQL
+create table t1(pk int primary key);
+call dolt_commit('-Am', 'creating table t1');
+
+insert into t1 values(1);
+call dolt_commit('-Am', 'inserting row 1');
+call dolt_tag('tag1');
+
+call dolt_checkout('-b', 'branch1');
+insert into t1 values(2);
+call dolt_commit('-Am', 'inserting row 2');
+
+insert into t1 values(3);
+call dolt_commit('-Am', 'inserting row 3');
+call dolt_tag('-d', 'tag1');
+call dolt_tag('tag1');
+SQL
+
+    run dolt reflog refs/heads/main
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 3 ]
+    out=$(echo "$output" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$out" =~ "(HEAD -> main) inserting row 1" ]] || false
+    [[ "$out" =~ "creating table t1" ]] || false
+    [[ "$out" =~ "Initialize data repository" ]] || false
+
+    # ref is case-insensitive
+    run dolt reflog rEFs/heAdS/MAIN
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 3 ]
+    out=$(echo "$output" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$out" =~ "(HEAD -> main) inserting row 1" ]] || false
+    [[ "$out" =~ "creating table t1" ]] || false
+    [[ "$out" =~ "Initialize data repository" ]] || false
+
+    run dolt reflog main
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 3 ]
+    out=$(echo "$output" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$out" =~ "(HEAD -> main) inserting row 1" ]] || false
+    [[ "$out" =~ "creating table t1" ]] || false
+    [[ "$out" =~ "Initialize data repository" ]] || false
+
+    # ref is case-insensitive
+    run dolt reflog MaIn
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 3 ]
+    out=$(echo "$output" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$out" =~ "(HEAD -> main) inserting row 1" ]] || false
+    [[ "$out" =~ "creating table t1" ]] || false
+    [[ "$out" =~ "Initialize data repository" ]] || false
+
+    run dolt reflog refs/heads/branch1
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 3 ]
+    out=$(echo "$output" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$out" =~ "(branch1) inserting row 3" ]] || false
+    [[ "$out" =~ "inserting row 2" ]] || false
+    [[ "$out" =~ "inserting row 1" ]] || false
+
+    run dolt reflog branch1
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 3 ]
+    out=$(echo "$output" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$out" =~ "(branch1) inserting row 3" ]] || false
+    [[ "$out" =~ "inserting row 2" ]] || false
+    [[ "$out" =~ "inserting row 1" ]] || false
+
+    run dolt reflog refs/tags/tag1
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 2 ]
+    out=$(echo "$output" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$out" =~ "(tag: tag1) inserting row 3" ]] || false
+    [[ "$out" =~ "inserting row 1" ]] || false
+
+    # ref is case-insensitive
+    run dolt reflog Refs/tAGs/TaG1
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 2 ]
+    out=$(echo "$output" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$out" =~ "(tag: tag1) inserting row 3" ]] || false
+    [[ "$out" =~ "inserting row 1" ]] || false
+
+    run dolt reflog tag1
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 2 ]
+    out=$(echo "$output" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$out" =~ "(tag: tag1) inserting row 3" ]] || false
+    [[ "$out" =~ "inserting row 1" ]] || false
+
+    # ref is case-insensitive
+    run dolt reflog TAg1
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 2 ]
+    out=$(echo "$output" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$out" =~ "(tag: tag1) inserting row 3" ]] || false
+    [[ "$out" =~ "inserting row 1" ]] || false
+
+    dolt branch -D branch1
+
+    run dolt reflog branch1
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 3 ]
+    out=$(echo "$output" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$out" =~ "(branch1) inserting row 3" ]] || false
+    [[ "$out" =~ "inserting row 2" ]] || false
+    [[ "$out" =~ "inserting row 1" ]] || false
+
+    dolt tag -d tag1
+    run dolt reflog tag1
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 2 ]
+    out=$(echo "$output" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$out" =~ "(tag: tag1) inserting row 3" ]] || false
+    [[ "$out" =~ "inserting row 1" ]] || false
+}
+
+@test "reflog: garbage collection with no newgen data" {
+    setup_common
+
+    run dolt reflog
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 1 ]
+    out=$(echo "$output" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$out" =~ "(HEAD -> main) Initialize data repository" ]] || false
+
+    dolt gc
+
+    run dolt reflog
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 0 ]
+}
+
+@test "reflog: garbage collection with newgen data" {
+    setup_common
+
+    dolt sql <<SQL
+create table t1(pk int primary key);
+call dolt_commit('-Am', 'creating table t1');
+insert into t1 values(1);
+call dolt_commit('-Am', 'inserting row 1');
+call dolt_tag('tag1');
+insert into t1 values(2);
+call dolt_commit('-Am', 'inserting row 2');
+SQL
+
+    run dolt reflog main
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 4 ]
+    out=$(echo "$output" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$out" =~ "(HEAD -> main) inserting row 2" ]] || false
+    [[ "$out" =~ "inserting row 1" ]] || false
+    [[ "$out" =~ "creating table t1" ]] || false
+    [[ "$out" =~ "Initialize data repository" ]] || false
+
+    dolt gc
+
+    run dolt reflog main
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 0 ]
+}
+
+@test "reflog: too many arguments given" {
+    setup_common
+
+    run dolt reflog foo bar
+    [ "$status" -eq 1 ]
+    [[ "$output" =~ "error: reflog has too many positional arguments" ]] || false
+}
+
+@test "reflog: unknown ref returns nothing" {
+    setup_common
+
+    dolt sql -q "create table t (i int primary key, j int);"
+    dolt sql -q "insert into t values (1, 1), (2, 2), (3, 3)";
+    dolt commit -Am "initial commit"
+
+    run dolt reflog foo
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 0 ]
+}
+
+@test "reflog: 'HEAD -> ' decoration only appears on HEAD entries" {
+    setup_common
+
+    dolt sql -q "create table t (i int primary key, j int);"
+    dolt sql -q "insert into t values (1, 1), (2, 2), (3, 3)";
+    dolt commit -Am "initial commit"
+
+    run dolt reflog
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 2 ]
+    line1=$(echo "${lines[0]}" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    line2=$(echo "${lines[1]}" | sed -E 's/\x1b\[[0-9;]*m//g') # remove special characters for color
+    [[ "$line1" =~ "(HEAD -> main) initial commit" ]] || false
+    [[ "$line2" =~ "Initialize data repository" ]] || false
+    [[ ! "$line2" =~ "HEAD" ]] || false
+}

integration-tests/bats/sql-local-remote.bats

@@ -1270,3 +1270,27 @@ SQL
 
     [[ "$localOutput" == "$remoteOutput" ]] || false
 }
+
+@test "sql-local-remote: verify dolt reflog behavior" {
+    cd altDB
+    dolt sql -q "create table t (i int primary key, j int);"
+    dolt sql -q "insert into t values (1, 1), (2, 2), (3, 3)";
+    dolt commit -Am "initial commit"
+
+    run dolt --verbose-engine-setup reflog
+    [ $status -eq 0 ]
+    [[ "$output" =~ "starting local mode" ]] || false
+    [[ "$output" =~ "initial commit" ]] || false
+    run dolt reflog
+    localOutput=$output
+
+    start_sql_server altDB
+    run dolt --verbose-engine-setup reflog
+    [ $status -eq 0 ]
+    [[ "$output" =~ "starting remote mode" ]] || false
+    [[ "$output" =~ "initial commit" ]] || false
+    run dolt reflog
+    remoteOutput=$output
+
+    [[ "$localOutput" == "$remoteOutput" ]] || false
+}

integration-tests/bats/sql-reflog.bats

@@ -0,0 +1,59 @@
+#!/usr/bin/env bats
+load $BATS_TEST_DIRNAME/helper/common.bash
+
+teardown() {
+    assert_feature_version
+    teardown_common
+}
+
+# Asserts that when DOLT_DISABLE_REFLOG is set, the dolt_reflog() table
+# function returns an empty result set with no error.
+@test "sql-reflog: disabled with DOLT_DISABLE_REFLOG" {
+    export DOLT_DISABLE_REFLOG=true
+    setup_common    # need to set env vars before setup_common for remote tests
+
+    dolt sql -q "create table t (i int primary key, j int);"
+    dolt sql -q "insert into t values (1, 1), (2, 2), (3, 3)";
+    dolt commit -Am "initial commit"
+    dolt commit --allow-empty -m "test commit 1"
+
+    run dolt sql -q "select * from dolt_reflog();"
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 0 ]
+}
+
+# Sanity check for the most basic case of querying the Dolt reflog
+@test "sql-reflog: enabled by default" {
+    setup_common
+
+    dolt sql -q "create table t (i int primary key, j int);"
+    dolt sql -q "insert into t values (1, 1), (2, 2), (3, 3)";
+    dolt commit -Am "initial commit"
+
+    run dolt sql -q "select * from dolt_reflog();"
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 6 ]
+    [[ "$output"  =~ "initial commit" ]] || false
+    [[ "$output"  =~ "Initialize data repository" ]] || false
+}
+
+# Asserts that when DOLT_REFLOG_RECORD_LIMIT has been set, the reflog only contains the
+# most recent entries and is limited by the env var's value.
+@test "sql-reflog: set DOLT_REFLOG_RECORD_LIMIT" {
+    export DOLT_REFLOG_RECORD_LIMIT=2
+    setup_common    # need to set env vars before setup_common for remote tests
+
+    dolt sql -q "create table t (i int primary key, j int);"
+    dolt sql -q "insert into t values (1, 1), (2, 2), (3, 3)";
+    dolt commit -Am "initial commit"
+    dolt commit --allow-empty -m "test commit 1"
+    dolt commit --allow-empty -m "test commit 2"
+
+    # Only the most recent two ref changes should appear in the log
+    run dolt sql -q "select * from dolt_reflog();"
+    [ "$status" -eq 0 ]
+    [[ "$output" =~ "test commit 1" ]] || false
+    [[ "$output" =~ "test commit 2" ]] || false
+    [[ ! "$output" =~ "initial commit" ]] || false
+    [[ ! "$output" =~ "Initialize data repository" ]] || false
+}

proto/dolt/services/eventsapi/v1alpha1/event_constants.proto

@@ -92,6 +92,7 @@ enum ClientEventType {
     STASH_POP = 60;
     SHOW = 61;
     PROFILE = 62;
+    REFLOG = 63;
 }
 
 enum MetricID {