Fixed an issue which stopped applications from connecting to Oracle Database with distinct TNS aliases from more than one tnsnames.ora file

Author: sharadraju

doc/src/release_notes.rst

@@ -23,6 +23,9 @@ Common Changes
 Thin Mode Changes
 +++++++++++++++++
 
+#) Fixed issue which stopped applications from connecting to Oracle Database
+   with distinct TNS aliases from more than one tnsnames.ora file.
+    
 #) Fixed bug that fails to throw an error, when fetching data greater
    than the ``maxSize`` property of outbinds in Oracle Database 12.1. 
 

lib/thin/sqlnet/paramParser.js

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, 2023, Oracle and/or its affiliates.
+// Copyright (c) 2022, 2024, Oracle and/or its affiliates.
 
 //-----------------------------------------------------------------------------
 //
@@ -26,7 +26,7 @@
 
 'use strict';
 
-const {createNVPair, findValue} = require("./nvStrToNvPair.js");
+const {createNVPair} = require("./nvStrToNvPair.js");
 const fs = require('fs');
 const process = require('process');
 const readline = require('readline');
@@ -59,12 +59,21 @@ function tnsnamesFilePath(configDir) {
     return filePathVal;
   }
 }
+//Structure for each tnsnames.ora file
+class tnsnamesElement {
 
+  constructor() {
+    this.readInProgress = false;
+    this.waiters = [];
+    this.aliasht = new Map(); // It will have key as alias and value as its aliases value
+    this.modTime = new Map(); // It will have tnsnames filename and also all its ifile and its modified time
+  }
+}
 class NLParamParser {
 
   constructor() {
-    this.waiters = [];
-    this.readInProgress = false;
+  // key as tnsnames.ora(file_name) and value will be tnsnamesStruct<ht(alias key and value), modTime>
+    this.tnsnamesHT = new Map();
   }
   /**
  * Reads the given file line by line and stores the
@@ -73,29 +82,35 @@ class NLParamParser {
  * @returns {Promise}
  */
   async initializeNlpa(file_path) {
-    if (this.readInProgress) {
+    let tnsFileStruct;
+    if (this.tnsnamesHT.has(file_path))
+      tnsFileStruct = this.tnsnamesHT.get(file_path);
+    else
+      tnsFileStruct = new tnsnamesElement();
+    if (tnsFileStruct.readInProgress) {
       await new Promise((resolve) => {
-        this.waiters.push(resolve);
+        tnsFileStruct.waiters.push(resolve);
       });
     }
-    if (!this.checkModfTime()) {
+    /* check modification time of all files in the cache
+       including the file_path */
+    if (!this.checkModfTime(tnsFileStruct)) {
       /* No File has been modified */
-      return this.ht;
+      return tnsFileStruct.aliasht;
     }
-    this.ht = new Map();
-    this.modTime = new Map(); //stores modified time of each IFile
-    this.readInProgress = true;
-    await this.start(file_path, 0); //start with 0 depth (tnsnames.ora)
-    return this.ht;
+    tnsFileStruct.readInProgress = true;
+    await this.start(file_path, 0, tnsFileStruct); //start with 0 depth (tnsnames.ora)
+    this.tnsnamesHT.set(file_path, tnsFileStruct);
+    return tnsFileStruct.aliasht;
   }
 
-  async start(file_path, depth) {
+  async start(file_path, depth, tnsFileStruct) {
 
     if (depth > MAX_IFILE_DEPTH)
       return; //ignore after max depth
     const stat = fs.statSync(file_path);
     // store file path and its modified time.
-    this.modTime.set(file_path, stat.mtime);
+    tnsFileStruct.modTime.set(file_path, stat.mtime);
     // Creating a readable stream from file
     // readline module reads line by line
     // but from a readable stream only.
@@ -129,7 +144,7 @@ class NLParamParser {
           nvElem = nvElem + line;
 
         } else if (nvElem.length != 0) {
-          await this.addNLPListElement(nvElem, depth); // Add Parameter to Hashtable
+          await this.addNLPListElement(nvElem, depth, tnsFileStruct); // Add Parameter to Hashtable
           nvElem = ""; // Clear first, before storing current line
 
           line = this.checkNLPforComments(line);
@@ -138,12 +153,12 @@ class NLParamParser {
       }
     }
     if (nvElem.length != 0) { // at eof, still one more parameter to read
-      await this.addNLPListElement(nvElem, depth);
+      await this.addNLPListElement(nvElem, depth, tnsFileStruct);
       nvElem = "";      // clear nvElem buffer after added
     }
-    this.readInProgress = false;
+    tnsFileStruct.readInProgress = false;
     let waiter;
-    while ((waiter = this.waiters.pop())) {
+    while ((waiter = tnsFileStruct.waiters.pop())) {
       waiter();
     }
   }
@@ -173,9 +188,11 @@ class NLParamParser {
     return str1.join('');
   }
   // check if any of the IFiles has been changed
-  checkModfTime() {
-    if (this.modTime) {
-      for (const [key, value] of this.modTime) {
+  checkModfTime(tnsFileStruct) {
+    // There may be multiple tnsnames.ora files. So check if the tnsnames.ora
+    // in question is already cached
+    if (tnsFileStruct.modTime.size != 0) {
+      for (const [key, value] of tnsFileStruct.modTime) {
         if (fs.existsSync(key)) {
           const stat = fs.statSync(key);
           if ((stat.mtime - value > 0)) {
@@ -193,7 +210,7 @@ class NLParamParser {
     * adds name value pairs from the input buffer into the hash table.
     * @param {string} ibuf
     */
-  async addNLPListElement(ibuf, depth) {
+  async addNLPListElement(ibuf, depth, tnsFileStruct) {
     const res = ibuf.split(/\r?\n/).filter(element => element);
     for (let i = 0; i < res.length; i++) {
       if (res[i].charAt(0) != '(') {
@@ -205,33 +222,15 @@ class NLParamParser {
       nvp.name = uname;
       // support for ifile
       if (uname == 'IFILE') {
-        await this.start(nvp.atom, depth + 1);
+        await this.start(nvp.atom, depth + 1, tnsFileStruct);
       } else {
         const unames = uname.split(","); //multiple aliases (alias1, alias2, alias3)
         for (let i = 0; i < unames.length; i++) {
-          this.ht.set(unames[i], nvp);
+          tnsFileStruct.aliasht.set(unames[i], nvp);
         }
       }
     }
   }
-  toString() {
-    let out = "";
-    this.ht.forEach((value) => {
-      out = out + value.toString() + "\n";
-    });
-    return out;
-  }
-  /**
-    * if key is address/port then it returns the port value from the
-    * address NVPAIR.
-    * @param {string} key
-    * @returns {string}
-   */
-  findValueOf(key) {
-    const myarr = key.split('/');
-    return (findValue(this.ht.get(myarr[0].toUpperCase()), myarr));
-  }
-
 }
 
 module.exports = {