client/src/utils/importgameStorage.js

   1 // Game object struct: see gameStorgae.js
   2
   3 import { store } from "@/store";
   4
   5 function dbOperation(callback) {
   6   let db = null;
   7   let DBOpenRequest = window.indexedDB.open("vchess_import", 4);
   8
   9   DBOpenRequest.onerror = function(event) {
  10     alert(store.state.tr[
  11       "Database error: stop private browsing, or update your browser"]);
  12     callback("error", null);
  13   };
  14
  15   DBOpenRequest.onsuccess = function() {
  16     db = DBOpenRequest.result;
  17     callback(null, db);
  18     db.close();
  19   };
  20
  21   DBOpenRequest.onupgradeneeded = function(event) {
  22     let db = event.target.result;
  23     let upgradeTransaction = event.target.transaction;
  24     let objectStore = undefined;
  25     if (!db.objectStoreNames.contains("importgames"))
  26       objectStore = db.createObjectStore("importgames", { keyPath: "id" });
  27     else
  28       objectStore = upgradeTransaction.objectStore("importgames");
  29     if (!objectStore.indexNames.contains("created"))
  30       // To search by date intervals. Two games could start at the same time
  31       objectStore.createIndex("created", "created", { unique: false });
  32   };
  33 }
  34
  35 export const ImportgameStorage = {
  36
  37   // Optional callback to get error status
  38   add: function(game, callback) {
  39     dbOperation((err, db) => {
  40       if (!!err) {
  41         callback("error");
  42         return;
  43       }
  44       let transaction = db.transaction("importgames", "readwrite");
  45       transaction.oncomplete = function() {
  46         // Everything's fine
  47         callback();
  48       };
  49       transaction.onerror = function(err) {
  50         // Duplicate key error (most likely)
  51         callback(err.target.error);
  52       };
  53       transaction.objectStore("importgames").add(game);
  54     });
  55   },
  56
  57   // Retrieve next imported games
  58   getNext: function(upperDt, callback) {
  59     dbOperation((err, db) => {
  60       let objectStore = db
  61         .transaction("importgames", "readonly")
  62         .objectStore("importgames");
  63       let index = objectStore.index("created");
  64       const range = IDBKeyRange.upperBound(upperDt);
  65       let games = [];
  66       index.openCursor(range).onsuccess = function(event) {
  67         let cursor = event.target.result;
  68         if (!cursor) {
  69           // Most recent games first:
  70           games = games.sort((g1, g2) => g2.created - g1.created);
  71           // TODO: 20 games showed per request is arbitrary
  72           callback(games.slice(0, 20));
  73         }
  74         else {
  75           // If there is still another cursor to go, keep running this code
  76           let g = cursor.value;
  77           // Do not retrieve moves or clocks (unused in list mode)
  78           g.movesCount = g.moves.length;
  79           delete g.moves;
  80           delete g.clocks;
  81           delete g.initime;
  82           games.push(g);
  83           cursor.continue();
  84         }
  85       };
  86     });
  87   },
  88
  89   // Retrieve any game from its identifier.
  90   // NOTE: need callback because result is obtained asynchronously
  91   get: function(gameId, callback) {
  92     dbOperation((err, db) => {
  93       let objectStore =
  94         db.transaction("importgames").objectStore("importgames");
  95       objectStore.get(gameId).onsuccess = function(event) {
  96         // event.target.result is null if game not found
  97         callback(event.target.result);
  98       };
  99     });
 100   },
 101
 102   // Delete a game in indexedDB
 103   remove: function(gameId, callback) {
 104     dbOperation((err, db) => {
 105       if (!err) {
 106         let transaction = db.transaction("importgames", "readwrite");
 107         transaction.oncomplete = function() {
 108           callback(); //everything's fine
 109         };
 110         transaction.objectStore("importgames").delete(gameId);
 111       }
 112     });
 113   }
 114
 115 };