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   // Optional callback to get error status
  37   add: function(game, callback) {
  38     dbOperation((err, db) => {
  39       if (!!err) {
  40         callback("error");
  41         return;
  42       }
  43       let transaction = db.transaction("importgames", "readwrite");
  44       transaction.oncomplete = function() {
  45         // Everything's fine
  46         callback();
  47       };
  48       transaction.onerror = function(err) {
  49         // Duplicate key error (most likely)
  50         callback(err);
  51       };
  52       transaction.objectStore("importgames").add(game);
  53     });
  54   },
  55
  56   // Retrieve next imported games
  57   getNext: function(upperDt, callback) {
  58     dbOperation((err, db) => {
  59       let objectStore = db
  60         .transaction("importgames", "readonly")
  61         .objectStore("importgames");
  62       let index = objectStore.index("created");
  63       const range = IDBKeyRange.upperBound(upperDt);
  64       let games = [];
  65       index.openCursor(range).onsuccess = function(event) {
  66         let cursor = event.target.result;
  67         if (!cursor) {
  68           // Most recent games first:
  69           games = games.sort((g1, g2) => g2.created - g1.created);
  70           // TODO: 20 games showed per request is arbitrary
  71           callback(games.slice(0, 20));
  72         }
  73         else {
  74           // If there is still another cursor to go, keep running this code
  75           let g = cursor.value;
  76           // Do not retrieve moves or clocks (unused in list mode)
  77           g.movesCount = g.moves.length;
  78           delete g.moves;
  79           delete g.clocks;
  80           delete g.initime;
  81           games.push(g);
  82           cursor.continue();
  83         }
  84       };
  85     });
  86   },
  87
  88   // Retrieve any game from its identifier.
  89   // NOTE: need callback because result is obtained asynchronously
  90   get: function(gameId, callback) {
  91     dbOperation((err, db) => {
  92       let objectStore =
  93         db.transaction("importgames").objectStore("importgames");
  94       objectStore.get(gameId).onsuccess = function(event) {
  95         // event.target.result is null if game not found
  96         callback(event.target.result);
  97       };
  98     });
  99   },
 100
 101   // Delete a game in indexedDB
 102   remove: function(gameId, callback) {
 103     dbOperation((err, db) => {
 104       if (!err) {
 105         let transaction = db.transaction("importgames", "readwrite");
 106         transaction.oncomplete = function() {
 107           callback(); //everything's fine
 108         };
 109         transaction.objectStore("importgames").delete(gameId);
 110       }
 111     });
 112   }
 113 };