client/src/utils/gameStorage.js

   1 // Game object: {
   2 //   // Static informations:
   3 //   gameId: string
   4 //   vname: string,
   5 //   fenStart: string,
   6 //   players: array of sid+id+name,
   7 //   timeControl: string,
   8 //   increment: integer (seconds),
   9 //   mode: string ("live" or "corr")
  10 //   imported: boolean (optional, default false)
  11 //   // Game (dynamic) state:
  12 //   fen: string,
  13 //   moves: array of Move objects,
  14 //   clocks: array of integers,
  15 //   initime: integer (when clock start running),
  16 //   score: string (several options; '*' == running),
  17 // }
  18
  19 function dbOperation(callback)
  20 {
  21   let db = null;
  22   let DBOpenRequest = window.indexedDB.open("vchess", 4);
  23
  24   DBOpenRequest.onerror = function(event) {
  25     alert("Database error: " + event.target.errorCode);
  26   };
  27
  28   DBOpenRequest.onsuccess = function(event) {
  29     db = DBOpenRequest.result;
  30     callback(db);
  31     db.close();
  32   };
  33
  34   DBOpenRequest.onupgradeneeded = function(event) {
  35     let db = event.target.result;
  36     db.onerror = function(event) {
  37       alert("Error while loading database: " + event.target.errorCode);
  38     };
  39     // Create objectStore for vchess->games
  40     db.createObjectStore("games", { keyPath: "gameId" });
  41   }
  42 }
  43
  44 export const GameStorage =
  45 {
  46   // Optional callback to get error status
  47   add: function(game, callback)
  48   {
  49     dbOperation((db) => {
  50       let transaction = db.transaction("games", "readwrite");
  51       if (callback)
  52       {
  53         transaction.oncomplete = function() {
  54           callback({}); //everything's fine
  55         }
  56         transaction.onerror = function() {
  57           callback({errmsg: "addGame failed: " + transaction.error});
  58         };
  59       }
  60       let objectStore = transaction.objectStore("games");
  61       objectStore.add(game);
  62     });
  63   },
  64
  65   // TODO: also option to takeback a move ?
  66   // NOTE: for live games only (all on server for corr)
  67   update: function(gameId, obj) //colorIdx, move, fen, addTime, initime, score
  68   {
  69     dbOperation((db) => {
  70       let objectStore = db.transaction("games", "readwrite").objectStore("games");
  71       objectStore.get(gameId).onsuccess = function(event) {
  72         const game = event.target.result;
  73         if (!!obj.move)
  74         {
  75           game.moves.push(obj.move);
  76           game.fen = obj.fen;
  77           if (!!obj.addTime) //NaN if first move in game
  78             game.clocks[obj.colorIdx] += obj.addTime;
  79         }
  80         if (!!obj.initime) //just a flag (true)
  81           game.initime = Date.now();
  82         if (!!obj.score)
  83           game.score = obj.score;
  84         objectStore.put(game); //save updated data
  85       }
  86     });
  87   },
  88
  89   // Retrieve any live game from its identifiers (locally, running or not)
  90   // NOTE: need callback because result is obtained asynchronously
  91   get: function(gameId, callback)
  92   {
  93     dbOperation((db) => {
  94       let objectStore = db.transaction('games').objectStore('games');
  95       if (!gameId) //retrieve all
  96       {
  97         let games = [];
  98         objectStore.openCursor().onsuccess = function(event) {
  99           let cursor = event.target.result;
 100           // if there is still another cursor to go, keep running this code
 101           if (cursor)
 102           {
 103             games.push(cursor.value);
 104             cursor.continue();
 105           }
 106           else
 107             callback(games);
 108         }
 109       }
 110       else //just one game
 111       {
 112         objectStore.get(gameId).onsuccess = function(event) {
 113           callback(event.target.result);
 114         }
 115       }
 116     });
 117   },
 118
 119   // Delete a game in indexedDB
 120   remove: function(gameId, callback)
 121   {
 122     dbOperation((db) => {
 123       let transaction = db.transaction(["games"], "readwrite");
 124       if (callback)
 125       {
 126         transaction.oncomplete = function() {
 127           callback({}); //everything's fine
 128         }
 129         transaction.onerror = function() {
 130           callback({errmsg: "removeGame failed: " + transaction.error});
 131         };
 132       }
 133       transaction.objectStore("games").delete(gameId);
 134     });
 135   },
 136 };