// Copyright (c) 2016, 2020, Oracle and/or its affiliates. All rights reserved
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//-----------------------------------------------------------------------------
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//
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// You may not use the identified files except in compliance with the Apache
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// License, Version 2.0 (the "License.")
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//
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// You may obtain a copy of the License at
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// http://www.apache.org/licenses/LICENSE-2.0.
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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//
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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//-----------------------------------------------------------------------------
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'use strict';
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const { Duplex } = require('stream');
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const nodbUtil = require('./util.js');
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//-----------------------------------------------------------------------------
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// close()
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// Close the LOB and make it unusable for further operations. If the LOB is
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// already closed, nothing is done in order to support multiple close() calls.
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//
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// This method is deprecated and will be removed in a future version of the
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// node-oracledb driver. Use lob.destroy() instead. NOTE: this method will
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// emit a duplicate "close" event in order to be compatible with previous
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// versions of node-oracledb.
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//-----------------------------------------------------------------------------
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async function close() {
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nodbUtil.checkArgCount(arguments, 0, 0);
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if (this.valid) {
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try {
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await this._close();
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this.emit('close');
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} catch (err) {
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this.destroy(err);
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}
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}
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}
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//-----------------------------------------------------------------------------
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// getData()
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// Returns all of the data in the LOB as a single string or buffer.
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//-----------------------------------------------------------------------------
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async function getData() {
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nodbUtil.checkArgCount(arguments, 0, 0);
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return await this._getData();
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}
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class Lob extends Duplex {
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constructor() {
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super({ decodeStrings: false });
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this.offset = 1;
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this.once('finish', function() {
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if (this._autoCloseLob) {
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this.destroy();
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}
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});
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}
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_extend(oracledb) {
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this._oracledb = oracledb;
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this.close = nodbUtil.callbackify(close);
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this.getData = nodbUtil.callbackify(getData);
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}
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// called by stream.destroy() and ensures that the LOB is closed if it has
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// not already been closed (never called directly)
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async _destroy(err, cb) {
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if (this.valid) {
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try {
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await this._close();
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} catch (closeErr) {
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cb(closeErr);
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return;
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}
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}
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cb(err);
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}
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// implementation of streaming read; if lob is set to auto-close, the lob is
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// automatically closed within the C code when an error occurs or when there
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// are no more bytes to transfer; all that needs to be done in the JS layer
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// is to destroy the streaming LOB
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async _read() {
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try {
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const data = await this.__read(this.offset);
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if (data) {
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this.offset += data.length;
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this.push(data);
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} else {
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this.push(null);
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if (this._autoCloseLob) {
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this.destroy();
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}
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}
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} catch (err) {
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this.destroy(err);
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}
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}
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// implementation of streaming write; if lob is set to auto-close, the lob is
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// automatically closed in the "finish" event; all that needs to be done here
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// is to destroy the streaming LOB
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async _write(data, encoding, cb) {
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// convert data if needed
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if (this.type == this._oracledb.DB_TYPE_BLOB && !Buffer.isBuffer(data)) {
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data = Buffer.from(data);
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} else if (this.type == this._oracledb.DB_TYPE_CLOB &&
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Buffer.isBuffer(data)) {
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data = data.toString();
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}
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try {
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await this.__write(this.offset, data);
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} catch (err) {
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cb(err);
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this.destroy(err);
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return;
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}
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this.offset += data.length;
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cb(null);
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}
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}
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module.exports = Lob;
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