Implement chrome.experimental.downloads.search()

content/browser/download/download_query.cc

Index: content/browser/download/download_query.cc
diff --git a/content/browser/download/download_query.cc b/content/browser/download/download_query.cc
new file mode 100644
index 0000000000000000000000000000000000000000..20ad559276bc71cf3909f3bc0fe02f4e56a7bd89
--- /dev/null
+++ b/content/browser/download/download_query.cc
@@ -0,0 +1,355 @@
+// 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.
+
+#include "content/browser/download/download_query.h"
+
+#include <algorithm>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/stl_util.h"
+#include "base/string16.h"
+#include "base/string_split.h"
+#include "base/utf_string_conversions.h"
+#include "unicode/regex.h"
+#include "content/browser/download/download_item.h"
+
+namespace download_util {
+
+// The FieldInterfaces allow us to keep the templateyness out of the header.
+
+// Filter fields can be used to filter DownloadVector out of the result set.
+class DownloadQuery::FilterFieldInterface {
+ public:
+  virtual ~FilterFieldInterface() {}
+  virtual bool Valid() = 0;
+  virtual bool Matches(const DownloadItem& item) const = 0;
+};
+
+// Sort fields are used by DownloadComparator to sort DownloadVector.
+class SortFieldInterface {
+ public:
+  virtual ~SortFieldInterface() {}
+
+  virtual DownloadQuery::SortFieldDirection direction() const = 0;
+
+  // Return 0 when left's field is equivalent to right's field, -1 when left <
+  // right, or 1 when left > right.
+  virtual int Compare(const DownloadItem& left,
+                      const DownloadItem& right) const = 0;
+};
+
+namespace {
+
+typedef std::vector<SortFieldInterface*> SortFieldVector;
+
+// Functor passed to std::sort to sort DownloadVector.
+class DownloadComparator {
+ public:
+  DownloadComparator(const SortFieldVector& terms)
+    : terms_(terms) {
+  }
+
+  // Returns true if |left| sorts before |right|.
+  bool operator() (const DownloadItem* left, const DownloadItem* right);
+
+ private:
+  const SortFieldVector& terms_;
+
+  // std::sort requires this class to be copyable.
+};
+
+bool DownloadComparator::operator() (const DownloadItem* left,
+                                     const DownloadItem* right) {
+  for (SortFieldVector::const_iterator term = terms_.begin();
+       term != terms_.end(); ++term) {
+    int comparison = (*term)->Compare(*left, *right);
+    if (comparison != 0)
+      return ((*term)->direction() == DownloadQuery::ASCENDING) == (comparison < 0);
+  }
+  if (left->id() != right->id())
+    return left->id() < right->id();
+  CHECK_NE(left->db_handle(), right->db_handle());
+  return left->db_handle() < right->db_handle();
+}
+
+static int get_start_time(const DownloadItem& item) {
+  return (item.start_time() - base::Time::UnixEpoch()).InMilliseconds();
+}
+
+static int get_end_time(const DownloadItem& item) {
+  return 0;  // TODO(benjhayden): endTime
+}
+
+static bool get_danger_accepted(const DownloadItem& item) {
+  return (item.safety_state() == DownloadItem::DANGEROUS_BUT_VALIDATED);
+}
+
+static string16 get_filename(const DownloadItem& item) {
+  return item.full_path().LossyDisplayName();
+}
+
+template <typename ValueType_>
+class FilterField : public DownloadQuery::FilterFieldInterface {
+ public:
+  typedef ValueType_ ValueType;
+  explicit FilterField(const ValueType& value) : value_(value) {}
+  virtual ~FilterField() {}
+  virtual bool Valid() OVERRIDE { return true; }
+
+ protected:
+  const ValueType& value() const { return value_; }
+
+ private:
+  ValueType value_;
+};
+
+template <typename StringType>
+std::string ToUTF8(const StringType& s);
+
+template<> std::string ToUTF8(const std::string& s) {
+  return s;
+}
+
+template<> std::string ToUTF8(const string16& s) {
+  return UTF16ToUTF8(s);
+}
+
+template <typename StringType>
+class FilterFieldRegex : public FilterField<StringType> {
+ public:
+  explicit FilterFieldRegex(const StringType& value)
+    : FilterField<StringType>(value) {
+  }
+  virtual ~FilterFieldRegex() {}
+  using FilterField<StringType>::value;
+  virtual bool Valid() OVERRIDE {
+    UParseError re_err;
+    UErrorCode re_status = U_ZERO_ERROR;
+    pattern_.reset(icu::RegexPattern::compile(
+        icu::UnicodeString::fromUTF8(ToUTF8(value())),
+        re_err, re_status));
+    return U_SUCCESS(re_status);
+  }
+
+ protected:
+  bool RegexMatches(const StringType& text) const {
+    UErrorCode status = U_ZERO_ERROR;
+    scoped_ptr<icu::RegexMatcher> matcher(pattern_->matcher(
+        icu::UnicodeString::fromUTF8(ToUTF8(text)), status));
+    return U_SUCCESS(status) &&
+           matcher->find(0, status);
+  }
+
+ private:
+  scoped_ptr<icu::RegexPattern> pattern_;
+};
+
+template <typename ValueType>
+class SortField : public SortFieldInterface {
+ public:
+  explicit SortField(DownloadQuery::SortFieldDirection direction)
+    : direction_(direction) {
+  }
+  virtual ~SortField() {}
+
+  virtual DownloadQuery::SortFieldDirection direction() const {
+    return direction_;
+  }
+
+  virtual ValueType GetField(const DownloadItem& item) const = 0;
+
+  virtual int Compare(const DownloadItem& left,
+                      const DownloadItem& right) const OVERRIDE {
+    ValueType left_value = GetField(left), right_value = GetField(right);
+    if (left_value > right_value) return 1;
+    if (left_value < right_value) return -1;
+    if (left_value == right_value) return 0;
+    NOTREACHED();
+    return 0;
+  }
+
+ private:
+  DownloadQuery::SortFieldDirection direction_;
+};
+
+#define LAMBDA(__name, __base, __method, __expr, __ctor_arg_type, __ctor_arg) ({ \
+    class __name : public __base { \
+    public: \
+      explicit __name(__ctor_arg_type x) : __base(x) {} \
+      virtual __method(const DownloadItem& item) const OVERRIDE { \
+        return __expr; \
+      } \
+    }; \
+    new __name(__ctor_arg); \
+  })
+
+SortFieldInterface* GetSortField(DownloadQuery::SortFieldName name,
+                                 DownloadQuery::SortFieldDirection direction) {
+  switch (name) {
+#define SORT_FIELD(__name, __type, __expr) \
+    case DownloadQuery::SORT_FIELD_ ## __name: return LAMBDA( \
+      SortField ## __name, SortField<__type>, __type GetField, __expr, \
+      DownloadQuery::SortFieldDirection, direction)
+    SORT_FIELD(START_TIME, int, get_start_time(item));
+    SORT_FIELD(URL, std::string, item.original_url().spec());
+    SORT_FIELD(FILENAME, string16, get_filename(item));
+    SORT_FIELD(DANGER, DownloadItem::DangerType, item.GetDangerType());
+    SORT_FIELD(DANGER_ACCEPTED, bool, get_danger_accepted(item));
+    SORT_FIELD(STATE, DownloadItem::DownloadState, item.state());
+    SORT_FIELD(PAUSED, bool, item.is_paused());
+    SORT_FIELD(MIME, std::string, item.mime_type());
+    SORT_FIELD(END_TIME, int, get_end_time(item));
+    SORT_FIELD(BYTES_RECEIVED, int, item.received_bytes());
+    SORT_FIELD(TOTAL_BYTES, int, item.total_bytes());
+    SORT_FIELD(FILE_SIZE, int, 0);  // TODO
+    SORT_FIELD(ERROR, int, 0);  // TODO
+#undef SORT_FIELD
+    default: return NULL;
+  }
+}
+
+}  // anonymous namespace
+
+DownloadQuery::DownloadQuery()
+  : limit_(kuint32max) {
+}
+
+DownloadQuery::~DownloadQuery() {
+  STLDeleteElements(&filter_fields_);
+}
+
+bool DownloadQuery::AddFilter(FilterFieldInterface* field) {
+  if (!field->Valid()) {
+    delete field;
+    return false;
+  }
+  filter_fields_.push_back(field);
+  return true;
+}
+
+#define START_FILTER_FIELDS(__type) \
+  template<> bool DownloadQuery::Filter(DownloadQuery::FilterFieldName name, \
+                                        const __type& _value) { \
+    typedef __type ValueType; \
+    switch (static_cast<int>(name)) {
+#define FILTER_FIELD(__name, __expr) \
+    case FILTER_FIELD_ ## __name: return AddFilter( \
+      LAMBDA(FilterField ## __name, FilterField<ValueType>, bool Matches, \
+             __expr, const ValueType&, _value));
+#define FILTER_FIELD_REGEX(__name, __expr) \
+    case FILTER_FIELD_ ## __name ## _REGEX: return AddFilter(LAMBDA( \
+        FilterField ## __name ## _REGEX, FilterFieldRegex<ValueType>, \
+        bool Matches, RegexMatches(__expr), const ValueType&, _value));
+#define END_FILTER_FIELDS \
+    } \
+    return false; \
+  }
+
+START_FILTER_FIELDS(int)
+  FILTER_FIELD(START_TIME, get_start_time(item))
+  FILTER_FIELD(END_TIME, get_end_time(item))
+  FILTER_FIELD(BYTES_RECEIVED, item.received_bytes())
+  FILTER_FIELD(TOTAL_BYTES, item.total_bytes())
+  FILTER_FIELD(STARTED_BEFORE, get_start_time(item) < value())
+  FILTER_FIELD(STARTED_AFTER, get_start_time(item) > value())
+  FILTER_FIELD(ENDED_BEFORE, get_end_time(item) < value())
+  FILTER_FIELD(ENDED_AFTER, get_end_time(item) > value())
+  FILTER_FIELD(TOTAL_BYTES_GREATER, item.total_bytes() > value())
+  FILTER_FIELD(TOTAL_BYTES_LESS, item.total_bytes() < value())
+  FILTER_FIELD(FILE_SIZE_GREATER, false)  // TODO
+  FILTER_FIELD(FILE_SIZE_LESS, false)  // TODO
+  FILTER_FIELD(FILE_SIZE, 0)  // TODO
+  FILTER_FIELD(ERROR, 0)  // TODO
+END_FILTER_FIELDS
+
+START_FILTER_FIELDS(bool)
+  FILTER_FIELD(DANGER_ACCEPTED, get_danger_accepted(item))
+  FILTER_FIELD(PAUSED, item.is_paused())
+END_FILTER_FIELDS
+
+START_FILTER_FIELDS(std::string)
+  FILTER_FIELD(URL, item.original_url().spec() == value())
+  FILTER_FIELD_REGEX(URL, item.original_url().spec())
+  FILTER_FIELD(MIME, item.mime_type() == value())
+END_FILTER_FIELDS
+
+START_FILTER_FIELDS(string16)
+  FILTER_FIELD(QUERY, item.MatchesQuery(value()))
+  FILTER_FIELD(FILENAME, get_filename(item) == value())
+  FILTER_FIELD_REGEX(FILENAME, get_filename(item))
+END_FILTER_FIELDS
+
+START_FILTER_FIELDS(base::Callback<bool(const DownloadItem& item)>)
+  FILTER_FIELD(FILTER, value().Run(item))
+END_FILTER_FIELDS
+
+START_FILTER_FIELDS(DownloadItem::DangerType)
+  FILTER_FIELD(DANGER, item.GetDangerType() == value())
+END_FILTER_FIELDS
+
+START_FILTER_FIELDS(DownloadItem::DownloadState)
+  FILTER_FIELD(STATE, item.state() == value())
+END_FILTER_FIELDS
+
+#undef START_FILTER_FIELDS
+#undef FILTER_FIELD
+#undef END_FILTER_FIELDS
+
+void DownloadQuery::Sort(DownloadQuery::SortFieldName name, DownloadQuery::SortFieldDirection direction) {
+  order_by_fields_.push_back(OrderTerm(name, direction));
+}
+
+bool DownloadQuery::Matches(const DownloadItem& item) const {
+  for (FilterFieldVector::const_iterator filter_field = filter_fields_.begin();
+        filter_field != filter_fields_.end(); ++filter_field) {
+    if (!(*filter_field)->Matches(item))
+      return false;
+  }
+  return true;
+}
+
+template <typename InputIterator>
+void DownloadQuery::Search(InputIterator iter, const InputIterator last,
+                           DownloadQuery::DownloadVector* results) const {
+  results->clear();
+  for (; iter != last; ++iter) {
+    if (Matches(**iter))
+      results->push_back(*iter);
+  }
+  if (!order_by_fields_.empty()) {
+    SortFieldVector order_terms;
+    for (OrderTermVector::const_iterator iter = order_by_fields_.begin();
+          iter != order_by_fields_.end(); ++iter) {
+      SortFieldInterface* sort_field = GetSortField(iter->name, iter->direction);
+      if (sort_field)
+        order_terms.push_back(sort_field);
+    }
+    std::partial_sort(results->begin(),
+                      results->begin() + std::min(limit_, results->size()),
+                      results->end(),
+                      DownloadComparator(order_terms));
+    STLDeleteElements(&order_terms);
+  }
+  if (results->size() > limit_)
+    results->resize(limit_);
+}
+
+template void DownloadQuery::Search(
+    std::set<DownloadItem*>::const_iterator iter,
+    const std::set<DownloadItem*>::const_iterator last,
+    DownloadQuery::DownloadVector* results) const;
+template void DownloadQuery::Search(
+    std::vector<DownloadItem*>::const_iterator iter,
+    const std::vector<DownloadItem*>::const_iterator last,
+    DownloadQuery::DownloadVector* results) const;
+template void DownloadQuery::Search(
+    std::vector<DownloadItem*>::iterator iter,
+    const std::vector<DownloadItem*>::iterator last,
+    DownloadQuery::DownloadVector* results) const;
+
+}  // namespace download_util
+