Enable import / export of database transaction log

db/db.go

@@ -16,6 +16,7 @@ package db
 
 import (
 	"fmt"
+	"io"
 	"sync"
 	"time"
 
@@ -105,14 +106,30 @@ func Exit() {
 
 }
 
-// Begin opens a new manual transaction with the data layer
-func Begin(rw bool) (txn kvs.TX, err error) {
-
-	return db.Begin(rw)
-
+// Import loads database operations from a reader.
+// This can be used to playback a database snapshot
+// into an already running database.
+func Import(r io.Reader) (err error) {
+	return db.Import(r)
 }
 
-// Execute parses the query and executes it against the data layer
+// Export saves all database operations to a writer.
+// This can be used to save a database snapshot
+// to a secondary file or stream.
+func Export(w io.Writer) (err error) {
+	return db.Export(w)
+}
+
+// Begin begins a new read / write transaction
+// with the underlying database, and returns
+// the transaction, or any error which occured.
+func Begin(rw bool) (txn kvs.TX, err error) {
+	return db.Begin(rw)
+}
+
+// Execute parses a single sql query, or multiple
+// sql queries, and executes them serially against
+// the underlying data layer.
 func Execute(ctx *fibre.Context, txt interface{}, vars map[string]interface{}) (out []*Response, err error) {
 
 	// If no preset variables have been defined
@@ -142,6 +159,9 @@ func Execute(ctx *fibre.Context, txt interface{}, vars map[string]interface{}) (
 
 }
 
+// Process takes a parsed set of sql queries and
+// executes them serially against the underlying
+// data layer.
 func Process(ctx *fibre.Context, ast *sql.Query, vars map[string]interface{}) (out []*Response, err error) {
 
 	// Create 2 channels, one for force quitting

kvs/db.go

@@ -14,8 +14,12 @@
 
 package kvs
 
+import "io"
+
 // DB represents a database implementation
 type DB interface {
 	Begin(bool) (TX, error)
+	Import(io.Reader) error
+	Export(io.Writer) error
 	Close() error
 }

kvs/ds.go

@@ -15,6 +15,7 @@
 package kvs
 
 import (
+	"io"
 	"strings"
 
 	"github.com/abcum/surreal/cnf"
@@ -66,6 +67,20 @@ func (ds *DS) Begin(writable bool) (txn TX, err error) {
 	return ds.db.Begin(writable)
 }
 
+// Import loads database operations from a reader.
+// This can be used to playback a database snapshot
+// into an already running database.
+func (ds *DS) Import(r io.Reader) (err error) {
+	return ds.db.Import(r)
+}
+
+// Export saves all database operations to a writer.
+// This can be used to save a database snapshot
+// to a secondary file or stream.
+func (ds *DS) Export(w io.Writer) (err error) {
+	return ds.db.Export(w)
+}
+
 // Close closes the underlying rixxdb / dendrodb
 // database connection, enabling the underlying
 // database to clean up remainging transactions.

kvs/rixxdb/db.go

@@ -15,6 +15,8 @@
 package rixxdb
 
 import (
+	"io"
+
 	"github.com/abcum/rixxdb"
 	"github.com/abcum/surreal/kvs"
 )
@@ -24,22 +26,22 @@ type DB struct {
 }
 
 func (db *DB) Begin(writable bool) (txn kvs.TX, err error) {
-
-	pntr, err := db.pntr.Begin(writable)
-	if err != nil {
-		err = &kvs.DSError{Err: err}
-		if pntr != nil {
-			pntr.Cancel()
-		}
+	var pntr *rixxdb.TX
+	if pntr, err = db.pntr.Begin(writable); err != nil {
+		err = &kvs.DBError{Err: err}
 		return
 	}
-
 	return &TX{pntr: pntr}, err
+}
 
+func (db *DB) Import(r io.Reader) (err error) {
+	return db.pntr.Load(r)
+}
+
+func (db *DB) Export(w io.Writer) (err error) {
+	return db.pntr.Save(w)
 }
 
 func (db *DB) Close() (err error) {
-
 	return db.pntr.Close()
-
 }