exporting to changelog table, not to file

go/base/context.go

@@ -8,7 +8,6 @@ package base
 import (
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"regexp"
 	"strings"
@@ -221,14 +220,8 @@ func GetMigrationContext() *MigrationContext {
 	return context
 }
 
-// ToJSON exports this config to JSON string
-func (this *MigrationContext) ToJSON() (string, error) {
-	b, err := json.Marshal(this)
-	return string(b), err
-}
-
 // DumpJSON exports this config to JSON string and writes it to file
-func (this *MigrationContext) DumpJSON() (fileName string, err error) {
+func (this *MigrationContext) ToJSON() (string, error) {
 	if this.MigrationRangeMinValues != nil {
 		this.EncodedRangeValues["MigrationRangeMinValues"], _ = this.MigrationRangeMinValues.ToBase64()
 	}
@@ -243,12 +236,9 @@ func (this *MigrationContext) DumpJSON() (fileName string, err error) {
 	}
 	jsonBytes, err := json.Marshal(this)
 	if err != nil {
-		return fileName, err
+		return "", err
 	}
-	fileName = fmt.Sprintf("%s/gh-ost.%s.%d.context.json", "/tmp", this.OriginalTableName, this.ElapsedTime())
+	return string(jsonBytes), nil
-	err = ioutil.WriteFile(fileName, jsonBytes, 0644)
-
-	return fileName, err
 }
 
 // GetGhostTableName generates the name of ghost table, based on original table name

go/logic/applier.go

@@ -195,7 +195,7 @@ func (this *Applier) CreateChangelogTable() error {
 			id bigint auto_increment,
 			last_update timestamp not null DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
 			hint varchar(64) charset ascii not null,
-			value varchar(255) charset ascii not null,
+			value text charset ascii not null,
 			primary key(id),
 			unique key hint_uidx(hint)
 		) auto_increment=256
@@ -220,7 +220,7 @@ func (this *Applier) dropTable(tableName string) error {
 		sql.EscapeName(this.migrationContext.DatabaseName),
 		sql.EscapeName(tableName),
 	)
-	log.Infof("Droppping table %s.%s",
+	log.Infof("Dropping table %s.%s",
 		sql.EscapeName(this.migrationContext.DatabaseName),
 		sql.EscapeName(tableName),
 	)
@@ -257,6 +257,8 @@ func (this *Applier) WriteChangelog(hint, value string) (string, error) {
 		explicitId = 2
 	case "throttle":
 		explicitId = 3
+	case "context":
+		explicitId = 4
 	}
 	query := fmt.Sprintf(`
 			insert /* gh-ost */ into %s.%s

go/logic/migrator.go

@@ -128,13 +128,8 @@ func (this *Migrator) initiateContextDump() (err error) {
 	go func() {
 		contextDumpTick := time.Tick(contextDumpInterval)
 		for range contextDumpTick {
-			if dumpFile, err := this.migrationContext.DumpJSON(); err == nil {
+			if jsonString, err := this.migrationContext.ToJSON(); err == nil {
-				this.contextDumpFiles = append(this.contextDumpFiles, dumpFile)
+				this.applier.WriteChangelog("context", jsonString)
-				if len(this.contextDumpFiles) > 2 {
-					oldDumpFile := this.contextDumpFiles[0]
-					this.contextDumpFiles = this.contextDumpFiles[1:]
-					os.Remove(oldDumpFile)
-				}
 			}
 		}
 	}()