chrome/browser/download/download_query.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_DOWNLOAD_DOWNLOAD_QUERY_H_
   6 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_QUERY_H_
   7
   8 #include <map>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/callback_forward.h"
  13 #include "content/public/browser/download_item.h"
  14
  15 namespace base {
  16 class Value;
  17 }
  18
  19 // Filter and sort a vector of DownloadItem*s.
  20 //
  21 // The following example copies from |all_items| to |results| those
  22 // DownloadItem*s whose start time is 0 and whose id is odd, sorts primarily by
  23 // bytes received ascending and secondarily by url descending, and limits the
  24 // results to 20 items. Any number of filters or sorters is allowed. If all
  25 // sorters compare two DownloadItems equivalently, then they are sorted by their
  26 // id ascending.
  27 //
  28 // DownloadQuery query;
  29 // base::FundamentalValue start_time(0);
  30 // CHECK(query.AddFilter(FILTER_START_TIME, start_time));
  31 // bool FilterOutOddDownloads(const DownloadItem& item) {
  32 //   return 0 == (item.GetId() % 2);
  33 // }
  34 // CHECK(query.AddFilter(base::Bind(&FilterOutOddDownloads)));
  35 // query.AddSorter(SORT_BYTES_RECEIVED, ASCENDING);
  36 // query.AddSorter(SORT_URL, DESCENDING);
  37 // query.Limit(20);
  38 // DownloadVector all_items, results;
  39 // query.Search(all_items.begin(), all_items.end(), &results);
  40 class DownloadQuery {
  41  public:
  42   typedef std::vector<content::DownloadItem*> DownloadVector;
  43
  44   // FilterCallback is a Callback that takes a DownloadItem and returns true if
  45   // the item matches the filter and false otherwise.
  46   // query.AddFilter(base::Bind(&YourFilterFunction));
  47   typedef base::Callback<bool(const content::DownloadItem&)> FilterCallback;
  48
  49   // All times are ISO 8601 strings.
  50   enum FilterType {
  51     FILTER_BYTES_RECEIVED,       // int
  52     FILTER_DANGER_ACCEPTED,      // bool
  53     FILTER_ENDED_AFTER,          // string
  54     FILTER_ENDED_BEFORE,         // string
  55     FILTER_END_TIME,             // string
  56     FILTER_EXISTS,               // bool
  57     FILTER_FILENAME,             // string
  58     FILTER_FILENAME_REGEX,       // string
  59     FILTER_MIME,                 // string
  60     FILTER_PAUSED,               // bool
  61     FILTER_QUERY,                // vector<base::string16>
  62     FILTER_STARTED_AFTER,        // string
  63     FILTER_STARTED_BEFORE,       // string
  64     FILTER_START_TIME,           // string
  65     FILTER_TOTAL_BYTES,          // int
  66     FILTER_TOTAL_BYTES_GREATER,  // int
  67     FILTER_TOTAL_BYTES_LESS,     // int
  68     FILTER_URL,                  // string
  69     FILTER_URL_REGEX,            // string
  70   };
  71
  72   enum SortType {
  73     SORT_BYTES_RECEIVED,
  74     SORT_DANGER,
  75     SORT_DANGER_ACCEPTED,
  76     SORT_END_TIME,
  77     SORT_EXISTS,
  78     SORT_FILENAME,
  79     SORT_MIME,
  80     SORT_PAUSED,
  81     SORT_START_TIME,
  82     SORT_STATE,
  83     SORT_TOTAL_BYTES,
  84     SORT_URL,
  85   };
  86
  87   enum SortDirection {
  88     ASCENDING,
  89     DESCENDING,
  90   };
  91
  92   DownloadQuery();
  93   ~DownloadQuery();
  94
  95   // Adds a new filter of type |type| with value |value| and returns true if
  96   // |type| is valid and |value| is the correct Value-type and well-formed.
  97   // Returns false if |type| is invalid or |value| is the incorrect Value-type
  98   // or malformed.  Search() will filter out all DownloadItem*s that do not
  99   // match all filters.  Multiple instances of the same FilterType are allowed,
 100   // so you can pass two regexes to AddFilter(URL_REGEX,...) in order to
 101   // Search() for items whose url matches both regexes. You can also pass two
 102   // different DownloadStates to AddFilter(), which will cause Search() to
 103   // filter out all items.
 104   bool AddFilter(const FilterCallback& filter);
 105   bool AddFilter(FilterType type, const base::Value& value);
 106   void AddFilter(content::DownloadDangerType danger);
 107   void AddFilter(content::DownloadItem::DownloadState state);
 108
 109   // Adds a new sorter of type |type| with direction |direction|.  After
 110   // filtering DownloadItem*s, Search() will sort the results primarily by the
 111   // sorter from the first call to Sort(), secondarily by the sorter from the
 112   // second call to Sort(), and so on. For example, if the InputIterator passed
 113   // to Search() yields four DownloadItems {id:0, error:0, start_time:0}, {id:1,
 114   // error:0, start_time:1}, {id:2, error:1, start_time:0}, {id:3, error:1,
 115   // start_time:1}, and Sort is called twice, once with (SORT_ERROR, ASCENDING)
 116   // then with (SORT_START_TIME, DESCENDING), then Search() will return items
 117   // ordered 1,0,3,2.
 118   void AddSorter(SortType type, SortDirection direction);
 119
 120   // Limit the size of search results to |limit|.
 121   void Limit(size_t limit) { limit_ = limit; }
 122
 123   // Filters DownloadItem*s from |iter| to |last| into |results|, sorts
 124   // |results|, and limits the size of |results|. |results| must be non-NULL.
 125   template <typename InputIterator>
 126   void Search(InputIterator iter, const InputIterator last,
 127               DownloadVector* results) const {
 128     results->clear();
 129     for (; iter != last; ++iter) {
 130       if (Matches(**iter)) results->push_back(*iter);
 131     }
 132     FinishSearch(results);
 133   }
 134
 135  private:
 136   struct Sorter;
 137   class DownloadComparator;
 138   typedef std::vector<FilterCallback> FilterCallbackVector;
 139   typedef std::vector<Sorter> SorterVector;
 140
 141   bool FilterRegex(const std::string& regex_str,
 142                    const base::Callback<std::string(
 143                        const content::DownloadItem&)>& accessor);
 144   bool Matches(const content::DownloadItem& item) const;
 145   void FinishSearch(DownloadVector* results) const;
 146
 147   FilterCallbackVector filters_;
 148   SorterVector sorters_;
 149   size_t limit_;
 150
 151   DISALLOW_COPY_AND_ASSIGN(DownloadQuery);
 152 };
 153
 154 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_QUERY_H_