Added start_lsn and end_lsn

wal2json.c

@@ -211,6 +211,12 @@ pg_decode_begin_txn(LogicalDecodingContext *ctx, ReorderBufferTXN *txn)
 	if (data->include_xids)
 		appendStringInfo(ctx->out, "\t\"xid\": %u,\n", txn->xid);
 
+	if (data->include_lsn) {
+		char *lsn_str = DatumGetCString(DirectFunctionCall1(pg_lsn_out, ctx->write_location));
+		appendStringInfo(ctx->out, "\t\"start_lsn\": \"%s\",", lsn_str);
+		pfree(lsn_str);
+	}
+
 	if (data->include_timestamp)
 		appendStringInfo(ctx->out, "\t\"timestamp\": \"%s\",\n", timestamptz_to_str(txn->commit_time));
 
@@ -236,13 +242,14 @@ pg_decode_commit_txn(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
 	/* Transaction ends */
 	OutputPluginPrepareWrite(ctx, true);
 
-	appendStringInfoString(ctx->out, "\t],\n");
+	// TODO: what if not, bad commas...
+	appendStringInfoString(ctx->out, "\t]");
 	if (data->include_lsn) {
 		char *lsn_str = DatumGetCString(DirectFunctionCall1(pg_lsn_out, commit_lsn));
-		appendStringInfo(ctx->out, "\t\"lsn\": \"%s\"\n", lsn_str);
+		appendStringInfo(ctx->out, ",\n\t\"end_lsn\": \"%s\"", lsn_str);
 		pfree(lsn_str);
 	}
-	appendStringInfoString(ctx->out, "}");
+	appendStringInfoString(ctx->out, "\n}");
 
 	OutputPluginWrite(ctx, true);
 }