third_party/WebKit/public/platform/WebStorageArea.h

   1 /*
   2  * Copyright (C) 2009 Google Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  * copyright notice, this list of conditions and the following disclaimer
  12  * in the documentation and/or other materials provided with the
  13  * distribution.
  14  *     * Neither the name of Google Inc. nor the names of its
  15  * contributors may be used to endorse or promote products derived from
  16  * this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #ifndef WebStorageArea_h
  32 #define WebStorageArea_h
  33
  34 #include "WebCommon.h"
  35 #include "WebString.h"
  36
  37 namespace blink {
  38
  39 class WebURL;
  40
  41 class WebStorageArea {
  42 public:
  43     virtual ~WebStorageArea() { }
  44
  45     enum Result {
  46         ResultOK = 0,
  47         ResultBlockedByQuota,
  48         ResultLast = ResultBlockedByQuota
  49     };
  50
  51     // The number of key/value pairs in the storage area.
  52     virtual unsigned length() = 0;
  53
  54     // Get a value for a specific key. Valid key indices are 0 through length() - 1.
  55     // Indexes may change on any set/removeItem call. Will return null if the index
  56     // provided is out of range.
  57     virtual WebString key(unsigned index) = 0;
  58
  59     // Get the value that corresponds to a specific key. This returns null if there is
  60     // no entry for that key.
  61     virtual WebString getItem(const WebString& key) = 0;
  62
  63     // Set the value that corresponds to a specific key. Result will either be ResultOK
  64     // or some particular error. The value is NOT set when there's an error. |pageUrl| is the
  65     // url that should be used if a storage event fires.
  66     virtual void setItem(const WebString& key, const WebString& newValue, const WebURL& pageUrl, Result& result)
  67     {
  68         WebString unused;
  69         setItem(key, newValue, pageUrl, result, unused);
  70     }
  71
  72
  73     // Remove the value associated with a particular key. |pageUrl| is the url that should be used
  74     // if a storage event fires.
  75     virtual void removeItem(const WebString& key, const WebURL& pageUrl)
  76     {
  77         WebString unused;
  78         removeItem(key, pageUrl, unused);
  79     }
  80
  81     // Clear all key/value pairs. |pageUrl| is the url that should be used if a storage event fires.
  82     virtual void clear(const WebURL& pageUrl)
  83     {
  84         bool unused;
  85         clear(pageUrl, unused);
  86     }
  87
  88     // Returns amount of bytes occupied by the storage cache in physical memory.
  89     virtual size_t memoryBytesUsedByCache() const { return 0; }
  90
  91     // DEPRECATED - being replaced by the async variants above which do not return oldValues or block until completion.
  92     virtual void setItem(const WebString& key, const WebString& newValue, const WebURL&, Result&, WebString& oldValue) { }
  93     virtual void removeItem(const WebString& key, const WebURL& pageUrl, WebString& oldValue)  { }
  94     virtual void clear(const WebURL& pageUrl, bool& somethingCleared)  { }
  95 };
  96
  97 } // namespace blink
  98
  99 #endif // WebStorageArea_h