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: array of integers (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     let objectStore = db.createObjectStore("games", { keyPath: "gameId" });
  41     objectStore.createIndex("score", "score"); //to search by game result
  42   }
  43 }
  44
  45 export const GameStorage =
  46 {
  47   // Optional callback to get error status
  48   add: function(game, callback)
  49   {
  50     dbOperation((db) => {
  51       let transaction = db.transaction("games", "readwrite");
  52       if (callback)
  53       {
  54         transaction.oncomplete = function() {
  55           callback({}); //everything's fine
  56         }
  57         transaction.onerror = function() {
  58           callback({errmsg: "addGame failed: " + transaction.error});
  59         };
  60       }
  61       let objectStore = transaction.objectStore("games");
  62       objectStore.add(game);
  63     });
  64   },
  65
  66   // TODO: also option to takeback a move ?
  67   // NOTE: for live games only (all on server for corr)
  68   update: function(gameId, obj) //colorIdx, nextIdx, move, fen, addTime, score
  69   {
  70     dbOperation((db) => {
  71       let objectStore = db.transaction("games", "readwrite").objectStore("games");
  72       objectStore.get(gameId).onsuccess = function(event) {
  73         const game = event.target.result;
  74         if (!!obj.move)
  75         {
  76           game.moves.push(obj.move);
  77           game.fen = obj.fen;
  78           game.clocks[obj.colorIdx] += obj.addTime;
  79           game.initime[obj.nextIdx] = Date.now();
  80         }
  81         if (!!obj.score)
  82           game.score = obj.score;
  83         objectStore.put(game); //save updated data
  84       }
  85     });
  86   },
  87
  88   // Retrieve any live game from its identifiers (locally, running or not)
  89   // NOTE: need callback because result is obtained asynchronously
  90   get: function(gameId, callback)
  91   {
  92     dbOperation((db) => {
  93       let objectStore = db.transaction('games').objectStore('games');
  94       if (!gameId) //retrieve all
  95       {
  96         let games = [];
  97         objectStore.openCursor().onsuccess = function(event) {
  98           let cursor = event.target.result;
  99           // if there is still another cursor to go, keep running this code
 100           if (cursor)
 101           {
 102             games.push(cursor.value);
 103             cursor.continue();
 104           }
 105           else
 106             callback(games);
 107         }
 108       }
 109       else //just one game
 110       {
 111         objectStore.get(gameId).onsuccess = function(event) {
 112           callback(event.target.result);
 113         }
 114       }
 115     });
 116   },
 117
 118   getCurrent: function(callback)
 119   {
 120     dbOperation((db) => {
 121       let objectStore = db.transaction('games').objectStore('games');
 122       objectStore.get("*").onsuccess = function(event) {
 123         callback(event.target.result);
 124       };
 125     });
 126   },
 127
 128   // Delete a game in indexedDB
 129   remove: function(gameId, callback)
 130   {
 131     dbOperation((db) => {
 132       let transaction = db.transaction(["games"], "readwrite");
 133       if (callback)
 134       {
 135         transaction.oncomplete = function() {
 136           callback({}); //everything's fine
 137         }
 138         transaction.onerror = function() {
 139           callback({errmsg: "removeGame failed: " + transaction.error});
 140         };
 141       }
 142       transaction.objectStore("games").delete(gameId);
 143     });
 144   },
 145 };