Implement chrome.experimental.downloads.search()

content/browser/download/download_query.h

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_QUERY_H_
+#define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_QUERY_H_
+#pragma once
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "base/callback.h"
+#include "content/browser/download/download_item.h"
+
+namespace download_util {
+
+// Filter and sort a vector of DownloadItem*s. See also the macros at the bottom
+// of this file.
+//
+// DownloadQuery query;
+// CHECK(query.Set("startTime", 0));
+// bool FilterOutOddDownloads(const DownloadItem& item) {
+//   return 0 == (item.id() % 2);
+// }
+// CHECK(query.Set("filter", base::Bind(&FilterOutOddDownloads)));
+// OrderTermVector order_by;
+// order_by.push_back(OrderTerm(SORT_FIELD_BYTES_RECEIVED, ASCENDING));
+// order_by.push_back(OrderTerm(SORT_FIELD_URL, DESCENDING));
+// CHECK(query.OrderBy(order_by));
+// query.Limit(20);
+// DownloadVector all_items, results;
+// query.Search(all_items.begin(), all_items.end(), &results);
+class DownloadQuery {
+ public:
+  enum FilterFieldName {
+    FILTER_FIELD_BYTES_RECEIVED,
+    FILTER_FIELD_DANGER,
+    FILTER_FIELD_DANGER_ACCEPTED,
+    FILTER_FIELD_ENDED_AFTER,
+    FILTER_FIELD_ENDED_BEFORE,
+    FILTER_FIELD_END_TIME,
+    FILTER_FIELD_ERROR,
+    FILTER_FIELD_FILENAME,
+    FILTER_FIELD_FILENAME_REGEX,
+    FILTER_FIELD_FILE_SIZE,
+    FILTER_FIELD_FILE_SIZE_GREATER,
+    FILTER_FIELD_FILE_SIZE_LESS,
+    FILTER_FIELD_FILTER,
+    FILTER_FIELD_MIME,
+    FILTER_FIELD_PAUSED,
+    FILTER_FIELD_QUERY,
+    FILTER_FIELD_STARTED_AFTER,
+    FILTER_FIELD_STARTED_BEFORE,
+    FILTER_FIELD_START_TIME,
+    FILTER_FIELD_STATE,
+    FILTER_FIELD_TOTAL_BYTES,
+    FILTER_FIELD_TOTAL_BYTES_GREATER,
+    FILTER_FIELD_TOTAL_BYTES_LESS,
+    FILTER_FIELD_URL,
+    FILTER_FIELD_URL_REGEX,
+  };
+
+  enum SortFieldName {
+    SORT_FIELD_BYTES_RECEIVED,
+    SORT_FIELD_DANGER,
+    SORT_FIELD_DANGER_ACCEPTED,
+    SORT_FIELD_END_TIME,
+    SORT_FIELD_ERROR,
+    SORT_FIELD_FILENAME,
+    SORT_FIELD_FILE_SIZE,
+    SORT_FIELD_MIME,
+    SORT_FIELD_PAUSED,
+    SORT_FIELD_START_TIME,
+    SORT_FIELD_STATE,
+    SORT_FIELD_TOTAL_BYTES,
+    SORT_FIELD_URL,
+  };
+
+  enum SortFieldDirection {
+    ASCENDING,
+    DESCENDING,
+  };
+
+  DownloadQuery();
+  ~DownloadQuery();
+
+  // Returns false if |name| is unrecognized or if |value| is the wrong type or
+  // malformed. Returns true and sets the filter field named |name| to |value|
+  // otherwise. The filter field will be used to filter out DownloadItem*s when
+  // you call Search(). See the implementation for the type of each |name|.
+  // (DRY.)
+  template <typename ValueType>
+  bool Filter(FilterFieldName name, const ValueType& value);
+
+  // XXX comment
+  void Sort(SortFieldName name, SortFieldDirection direction);
+
+  // Remember to limit the size of search results to |limit|.
+  void Limit(size_t limit) { limit_ = limit; }
+
+  typedef std::vector<DownloadItem*> DownloadVector;
+
+  // Filters DownloadItem*s from |iter| to |last| into |results|, sorts
+  // |results|, and limits the size of |results|. |results| must be non-NULL.
+  template <typename InputIterator>
+  void Search(InputIterator iter, const InputIterator last,
+              DownloadVector* results) const;
+
+  // Returns true if |item| matches all set filter fields; returns false if any
+  // filter fields have been set that the item does not match.
+  bool Matches(const DownloadItem& item) const;
+
+ private:
+  class FilterFieldInterface;
+  struct OrderTerm {
+    OrderTerm(SortFieldName _name, SortFieldDirection _direction)
+      : name(_name),
+        direction(_direction) {
+    }
+    SortFieldName name;
+    SortFieldDirection direction;
+  };
+  typedef std::vector<FilterFieldInterface*> FilterFieldVector;
+  typedef std::vector<OrderTerm> OrderTermVector;
+
+  bool AddFilter(FilterFieldInterface* field);
+
+  FilterFieldVector filter_fields_;
+  OrderTermVector order_by_fields_;
+  size_t limit_;
+
+  DISALLOW_COPY_AND_ASSIGN(DownloadQuery);
+};
+}  // namespace download_util
+
+#endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_QUERY_H_