client/src/utils/gameStorage.js

   1 // Game object: {
   2 //   // Static informations:
   3 //   id: string
   4 //   vname: string,
   5 //   fenStart: string,
   6 //   players: array of sid+id+name,
   7 //   cadence: string,
   8 //   increment: integer (seconds),
   9 //   type: string ("live" or "corr")
  10 //   // Game (dynamic) state:
  11 //   fen: string,
  12 //   moves: array of Move objects,
  13 //   clocks: array of integers,
  14 //   initime: array of integers (when clock start running),
  15 //   score: string (several options; '*' == running),
  16 // }
  17
  18 import { store } from "@/store";
  19
  20 function dbOperation(callback) {
  21   let db = null;
  22   let DBOpenRequest = window.indexedDB.open("vchess", 4);
  23
  24   DBOpenRequest.onerror = function(event) {
  25     alert(store.state.tr["Database error: stop private browsing, or update your browser"]);
  26     callback("error", null);
  27   };
  28
  29   DBOpenRequest.onsuccess = function() {
  30     db = DBOpenRequest.result;
  31     callback(null, db);
  32     db.close();
  33   };
  34
  35   DBOpenRequest.onupgradeneeded = function(event) {
  36     let db = event.target.result;
  37     let objectStore = db.createObjectStore("games", { keyPath: "id" });
  38     // To sarch games by score (useful for running games)
  39     objectStore.createIndex("score", "score", { unique: false });
  40     // To search by date intervals. Two games cannot start at the same time
  41     objectStore.createIndex("created", "created", { unique: true });
  42   };
  43 }
  44
  45 export const GameStorage = {
  46   // Optional callback to get error status
  47   add: function(game, callback) {
  48     dbOperation((err,db) => {
  49       if (!!err) {
  50         callback("error");
  51         return;
  52       }
  53       let transaction = db.transaction("games", "readwrite");
  54       transaction.oncomplete = function() {
  55         // Everything's fine
  56         callback();
  57       };
  58       transaction.onerror = function(err) {
  59         // Duplicate key error (most likely)
  60         callback(err);
  61       };
  62       transaction.objectStore("games").add(game);
  63     });
  64   },
  65
  66   // obj: chat, move, fen, clocks, score[Msg], initime, ...
  67   update: function(gameId, obj) {
  68     // live
  69     dbOperation((err,db) => {
  70       let objectStore = db
  71         .transaction("games", "readwrite")
  72         .objectStore("games");
  73       objectStore.get(gameId).onsuccess = function(event) {
  74         // Ignoring error silently: shouldn't happen now. TODO?
  75         if (event.target.result) {
  76           let game = event.target.result;
  77           // Hidden tabs are delayed, to prevent multi-updates:
  78           if (obj.moveIdx < game.moves.length) return;
  79           Object.keys(obj).forEach(k => {
  80             if (k == "move") game.moves.push(obj[k]);
  81             else game[k] = obj[k];
  82           });
  83           objectStore.put(game); //save updated data
  84         }
  85       };
  86     });
  87   },
  88
  89   // Retrieve (all) running local games
  90   getRunning: function(callback) {
  91     dbOperation((err,db) => {
  92       let objectStore = db
  93         .transaction("games", "readonly")
  94         .objectStore("games");
  95       let index = objectStore.index("score");
  96       const range = IDBKeyRange.only("*");
  97       let games = [];
  98       index.openCursor(range).onsuccess = function(event) {
  99         let cursor = event.target.result;
 100         if (!cursor) callback(games);
 101         else {
 102           // If there is still another cursor to go, keep running this code
 103           let g = cursor.value;
 104           // Do not retrieve moves or clocks (unused in list mode)
 105           g.movesCount = g.moves.length;
 106           delete g.moves;
 107           delete g.clocks;
 108           delete g.initime;
 109           games.push(g);
 110           cursor.continue();
 111         }
 112       };
 113     });
 114   },
 115
 116   // Retrieve completed local games
 117   getNext: function(upperDt, callback) {
 118     dbOperation((err,db) => {
 119       let objectStore = db
 120         .transaction("games", "readonly")
 121         .objectStore("games");
 122       let index = objectStore.index("created");
 123       const range = IDBKeyRange.upperBound(upperDt);
 124       let games = [];
 125       index.openCursor(range).onsuccess = function(event) {
 126         let cursor = event.target.result;
 127         if (!cursor) {
 128           // Most recent games first:
 129           games = games.sort((g1, g2) => g2.created - g1.created);
 130           // TODO: 20 games showed per request is arbitrary
 131           callback(games.slice(0, 20));
 132         }
 133         else {
 134           // If there is still another cursor to go, keep running this code
 135           let g = cursor.value;
 136           if (g.score != "*") {
 137             // Do not retrieve moves or clocks (unused in list mode)
 138             g.movesCount = g.moves.length;
 139             delete g.moves;
 140             delete g.clocks;
 141             delete g.initime;
 142             games.push(g);
 143           }
 144           cursor.continue();
 145         }
 146       };
 147     });
 148   },
 149
 150   // Retrieve any game from its identifiers (locally or on server)
 151   // NOTE: need callback because result is obtained asynchronously
 152   get: function(gameId, callback) {
 153     // Local game
 154     dbOperation((err,db) => {
 155       let objectStore = db.transaction("games").objectStore("games");
 156       objectStore.get(gameId).onsuccess = function(event) {
 157         // event.target.result is null if game not found
 158         callback(event.target.result);
 159       };
 160     });
 161   },
 162
 163   // Delete a game in indexedDB
 164   remove: function(gameId, callback) {
 165     dbOperation((err,db) => {
 166       if (!err) {
 167         let transaction = db.transaction("games", "readwrite");
 168         transaction.oncomplete = function() {
 169           callback(); //everything's fine
 170         };
 171         transaction.objectStore("games").delete(gameId);
 172       }
 173     });
 174   }
 175 };