class app.DB  NAME = 'docs'  VERSION = 15   constructor: ->    @versionMultipler = if $.isIE() then 1e5 else 1e9    @useIndexedDB = @useIndexedDB()    @callbacks = []   db: (fn) ->    return fn() unless @useIndexedDB    @callbacks.push(fn) if fn    return if @open     try      @open = true      req = indexedDB.open(NAME, VERSION * @versionMultipler + @userVersion())      req.onsuccess = @onOpenSuccess      req.onerror = @onOpenError      req.onupgradeneeded = @onUpgradeNeeded    catch error      @fail 'exception', error    return   onOpenSuccess: (event) =>    db = event.target.result     if db.objectStoreNames.length is 0      try db.close()      @open = false      @fail 'empty'    else if error = @buggyIDB(db)      try db.close()      @open = false      @fail 'buggy', error    else      @runCallbacks(db)      @open = false      db.close()    return   onOpenError: (event) =>    event.preventDefault()    @open = false    error = event.target.error     switch error.name      when 'QuotaExceededError'        @onQuotaExceededError()      when 'VersionError'        @onVersionError()      when 'InvalidStateError'        @fail 'private_mode'      else        @fail 'cant_open', error    return   fail: (reason, error) ->    @cachedDocs = null    @useIndexedDB = false    @reason or= reason    @error or= error    console.error? 'IDB error', error if error    @runCallbacks()    if error and reason is 'cant_open'      Raven.captureMessage "#{error.name}: #{error.message}", level: 'warning', fingerprint: [error.name]    return   onQuotaExceededError: ->    @reset()    @db()    app.onQuotaExceeded()    Raven.captureMessage 'QuotaExceededError', level: 'warning'    return   onVersionError: ->    req = indexedDB.open(NAME)    req.onsuccess = (event) =>      @handleVersionMismatch event.target.result.version    req.onerror = (event) ->      event.preventDefault()      @fail 'cant_open', error    return   handleVersionMismatch: (actualVersion) ->    if Math.floor(actualVersion / @versionMultipler) isnt VERSION      @fail 'version'    else      @setUserVersion actualVersion - VERSION * @versionMultipler      @db()    return   buggyIDB: (db) ->    return if @checkedBuggyIDB    @checkedBuggyIDB = true    try      @idbTransaction(db, stores: $.makeArray(db.objectStoreNames)[0..1], mode: 'readwrite').abort() # https://bugs.webkit.org/show_bug.cgi?id=136937      return    catch error      return error   runCallbacks: (db) ->    fn(db) while fn = @callbacks.shift()    return   onUpgradeNeeded: (event) ->    return unless db = event.target.result     objectStoreNames = $.makeArray(db.objectStoreNames)     unless $.arrayDelete(objectStoreNames, 'docs')      try db.createObjectStore('docs')     for doc in app.docs.all() when not $.arrayDelete(objectStoreNames, doc.slug)      try db.createObjectStore(doc.slug)     for name in objectStoreNames      try db.deleteObjectStore(name)    return   store: (doc, data, onSuccess, onError, _retry = true) ->    @db (db) =>      unless db        onError()        return       txn = @idbTransaction db, stores: ['docs', doc.slug], mode: 'readwrite', ignoreError: false      txn.oncomplete = =>        @cachedDocs?[doc.slug] = doc.mtime        onSuccess()        return      txn.onerror = (event) =>        event.preventDefault()        if txn.error?.name is 'NotFoundError' and _retry          @migrate()          setTimeout =>            @store(doc, data, onSuccess, onError, false)          , 0        else          onError(event)        return       store = txn.objectStore(doc.slug)      store.clear()      store.add(content, path) for path, content of data       store = txn.objectStore('docs')      store.put(doc.mtime, doc.slug)      return    return   unstore: (doc, onSuccess, onError, _retry = true) ->    @db (db) =>      unless db        onError()        return       txn = @idbTransaction db, stores: ['docs', doc.slug], mode: 'readwrite', ignoreError: false      txn.oncomplete = =>        delete @cachedDocs?[doc.slug]        onSuccess()        return      txn.onerror = (event) ->        event.preventDefault()        if txn.error?.name is 'NotFoundError' and _retry          @migrate()          setTimeout =>            @unstore(doc, onSuccess, onError, false)          , 0        else          onError(event)        return       store = txn.objectStore('docs')      store.delete(doc.slug)       store = txn.objectStore(doc.slug)      store.clear()      return    return   version: (doc, fn) ->    if (version = @cachedVersion(doc))?      fn(version)      return     @db (db) =>      unless db        fn(false)        return       txn = @idbTransaction db, stores: ['docs'], mode: 'readonly'      store = txn.objectStore('docs')       req = store.get(doc.slug)      req.onsuccess = ->        fn(req.result)        return      req.onerror = (event) ->        event.preventDefault()        fn(false)        return      return    return   cachedVersion: (doc) ->    return unless @cachedDocs    @cachedDocs[doc.slug] or false   versions: (docs, fn) ->    if versions = @cachedVersions(docs)      fn(versions)      return     @db (db) =>      unless db        fn(false)        return       txn = @idbTransaction db, stores: ['docs'], mode: 'readonly'      txn.oncomplete = ->        fn(result)        return      store = txn.objectStore('docs')      result = {}       docs.forEach (doc) ->        req = store.get(doc.slug)        req.onsuccess = ->          result[doc.slug] = req.result          return        req.onerror = (event) ->          event.preventDefault()          result[doc.slug] = false          return        return      return   cachedVersions: (docs) ->    return unless @cachedDocs    result = {}    result[doc.slug] = @cachedVersion(doc) for doc in docs    result   load: (entry, onSuccess, onError) ->    if @shouldLoadWithIDB(entry)      onError = @loadWithXHR.bind(@, entry, onSuccess, onError)      @loadWithIDB entry, onSuccess, onError    else      @loadWithXHR entry, onSuccess, onError   loadWithXHR: (entry, onSuccess, onError) ->    ajax      url: entry.fileUrl()      dataType: 'html'      success: onSuccess      error: onError   loadWithIDB: (entry, onSuccess, onError) ->    @db (db) =>      unless db        onError()        return       unless db.objectStoreNames.contains(entry.doc.slug)        onError()        @loadDocsCache(db)        return       txn = @idbTransaction db, stores: [entry.doc.slug], mode: 'readonly'      store = txn.objectStore(entry.doc.slug)       req = store.get(entry.dbPath())      req.onsuccess = ->        if req.result then onSuccess(req.result) else onError()        return      req.onerror = (event) ->        event.preventDefault()        onError()        return      @loadDocsCache(db)      return   loadDocsCache: (db) ->    return if @cachedDocs    @cachedDocs = {}     txn = @idbTransaction db, stores: ['docs'], mode: 'readonly'    txn.oncomplete = =>      setTimeout(@checkForCorruptedDocs, 50)      return     req = txn.objectStore('docs').openCursor()    req.onsuccess = (event) =>      return unless cursor = event.target.result      @cachedDocs[cursor.key] = cursor.value      cursor.continue()      return    req.onerror = (event) ->      event.preventDefault()      return    return   checkForCorruptedDocs: =>    @db (db) =>      @corruptedDocs = []      docs = (key for key, value of @cachedDocs when value)      return if docs.length is 0       for slug in docs when not app.docs.findBy('slug', slug)        @corruptedDocs.push(slug)       for slug in @corruptedDocs        $.arrayDelete(docs, slug)       if docs.length is 0        setTimeout(@deleteCorruptedDocs, 0)        return       txn = @idbTransaction(db, stores: docs, mode: 'readonly', ignoreError: false)      txn.oncomplete = =>        setTimeout(@deleteCorruptedDocs, 0) if @corruptedDocs.length > 0        return       for doc in docs        txn.objectStore(doc).get('index').onsuccess = (event) =>          @corruptedDocs.push(event.target.source.name) unless event.target.result          return      return    return   deleteCorruptedDocs: =>    @db (db) =>      txn = @idbTransaction(db, stores: ['docs'], mode: 'readwrite', ignoreError: false)      store = txn.objectStore('docs')      while doc = @corruptedDocs.pop()        @cachedDocs[doc] = false        store.delete(doc)      return    Raven.captureMessage 'corruptedDocs', level: 'info', extra: { docs: @corruptedDocs.join(',') }    return   shouldLoadWithIDB: (entry) ->    @useIndexedDB and (not @cachedDocs or @cachedDocs[entry.doc.slug])   idbTransaction: (db, options) ->    app.lastIDBTransaction = [options.stores, options.mode]    txn = db.transaction(options.stores, options.mode)    unless options.ignoreError is false      txn.onerror = (event) ->        event.preventDefault()        return    unless options.ignoreAbort is false      txn.onabort = (event) ->        event.preventDefault()        return    txn   reset: ->    try indexedDB?.deleteDatabase(NAME) catch    return   useIndexedDB: ->    try      if !app.isSingleDoc() and window.indexedDB        true      else        @reason = 'not_supported'        false    catch      false   migrate: ->    app.settings.set('schema', @userVersion() + 1)    return   setUserVersion: (version) ->    app.settings.set('schema', version)    return   userVersion: ->    app.settings.get('schema')