components/autofill/content/renderer/form_cache.h

// Copyright 2013 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 COMPONENTS_AUTOFILL_CONTENT_RENDERER_FORM_CACHE_H_
#define COMPONENTS_AUTOFILL_CONTENT_RENDERER_FORM_CACHE_H_

#include <stddef.h>

#include <map>
#include <set>
#include <string>
#include <vector>

#include "base/gtest_prod_util.h"
#include "base/macros.h"
#include "components/autofill/core/common/field_data_manager.h"
#include "components/autofill/core/common/form_data.h"
#include "components/autofill/core/common/form_data_predictions.h"
#include "components/autofill/core/common/unique_ids.h"

namespace blink {
class WebFormControlElement;
class WebLocalFrame;
}  // namespace blink

namespace autofill {

struct FormData;
struct FormDataPredictions;

// Manages the forms in a single RenderFrame.
class FormCache {
 public:
  explicit FormCache(blink::WebLocalFrame* frame);
  ~FormCache();

  // Scans the DOM in |frame_| extracting and storing forms that have not been
  // seen before. Returns the extracted forms.
  //
  // Note that modified forms are considered new forms.
  //
  // To reduce the computational cost, we limit the number of fields and frames
  // summed over all forms, in addition to the per-form limits in
  // form_util::FormOrFieldsetsToFormData():
  // - if the number of fields over all forms exceeds |kMaxParseableFields|,
  //   only a subset of forms is returned which does not exceed the limit;
  // - if the number of frames over all forms exceeds MaxParseableFrames(), all
  //   forms are returned but only a subset of them have non-empty
  //   FormData::child_frames.
  // In either case, the subset is chosen so that the returned list of forms
  // does not exceed the limits of fields and frames.
  std::vector<FormData> ExtractNewForms(
      const FieldDataManager* field_data_manager);

  // Modified version of ExtractNewForms(). It is used only if
  // `AutofillUseNewFormExtraction` feature is enabled.
  // TODO(crbug/1215333): Remove ExtractNewForms() after the feature is deleted.
  //
  // Extracts and returns the new or modified forms in the |frame_|.
  //
  // To reduce the computational cost, we limit the number of fields and frames
  // summed over all forms, in addition to the per-form limits in
  // form_util::FormOrFieldsetsToFormData():
  // - if the number of fields over all forms exceeds |kMaxParseableFields|,
  //   only a subset of forms is returned which does not exceed the limit;
  // - if the number of frames over all forms exceeds MaxParseableFrames(), all
  //   forms are returned but only a subset of them have non-empty
  //   FormData::child_frames.
  // In either case, the subset is chosen so that the returned list of forms
  // does not exceed the limits of fields and frames.
  //
  // Updates |parsed_forms_by_renderer_id_| to contain the forms that are
  // currently in the DOM.
  std::vector<FormData> UpdateFormCache(
      const FieldDataManager* field_data_manager);

  // Resets the forms.
  void Reset();

  // Clears the values of all input elements in the section of the form that
  // contains |element|.  Returns false if the form is not found.
  bool ClearSectionWithElement(const blink::WebFormControlElement& element);

  // For each field in the |form|, if |attach_predictions_to_dom| is true, sets
  // the title to include the field's heuristic type, server type, and
  // signature; as well as the form's signature and the experiment id for the
  // server predictions. In all cases, may emit console warnings regarding the
  // use of autocomplete attributes.
  bool ShowPredictions(const FormDataPredictions& form,
                       bool attach_predictions_to_dom);

  // Stores the FieldRendererId of the fields that are eligible for manual
  // filling in a set.
  void SetFieldsEligibleForManualFilling(
      const std::vector<FieldRendererId>& fields_eligible_for_manual_filling);

 private:
  friend class FormCacheTestApi;

  // Scans |control_elements| and returns the number of editable elements.
  // Also logs warning messages for deprecated attribute if
  // |log_deprecation_messages| is set.
  size_t ScanFormControlElements(
      const std::vector<blink::WebFormControlElement>& control_elements,
      bool log_deprecation_messages);

  // Saves initial state of checkbox and select elements.
  void SaveInitialValues(
      const std::vector<blink::WebFormControlElement>& control_elements);

  // Clears the value of the |control_element|.
  void ClearElement(blink::WebFormControlElement& control_element,
                    const blink::WebFormControlElement& element);

  // Clears all entries from |initial_select_values_| and
  // |initial_checked_state_| whose keys not contained in |ids_to_retain|.
  void PruneInitialValueCaches(const std::set<FieldRendererId>& ids_to_retain);

  // Update the peak size of the cached forms stored in
  // |peak_size_of_parsed_forms_|.
  // TODO(crbug/1215333): Remove after `Autofill.FormCacheSize` experiment is
  // completed.
  void MaybeUpdateParsedFormsPeak();

  // The frame this FormCache is associated with. Weak reference.
  blink::WebLocalFrame* frame_;

  // The cached forms. Used to prevent re-extraction of forms.
  // TODO(crbug/896689) Move to std::map<unique_rederer_id, FormData>.
  std::set<FormData, FormData::IdentityComparator> parsed_forms_;

  // Same as |parsed_forms_|, but moved to a different type. It is used only if
  // `AutofillUseNewFormExtraction` feature is enabled.
  // TODO(crbug/1215333): Remove |parsed_forms_| after the feature is deleted.
  std::map<FormRendererId, FormData> parsed_forms_by_renderer_id_;

  // Stores the peak size of the cached forms for `Autofill.FormCacheSize`
  // metric. The cached forms are stored in |parsed_forms_| or
  // |parsed_forms_by_renderer_id_| depending on the
  // `AutofillUseNewFormExtraction` feature.
  // TODO(crbug/1215333): Remove after the experiment is completed.
  size_t peak_size_of_parsed_forms_ = 0;

  // The synthetic FormData is for all the fieldsets in the document without a
  // form owner.
  FormData synthetic_form_;

  // The cached initial values for <select> elements. Entries are keyed by
  // unique_renderer_form_control_id of the WebSelectElements.
  std::map<FieldRendererId, std::u16string> initial_select_values_;

  // The cached initial values for checkable <input> elements. Entries are
  // keyed by the unique_renderer_form_control_id of the WebInputElements.
  std::map<FieldRendererId, bool> initial_checked_state_;

  // Fields that are eligible to show manual filling on form interaction.
  base::flat_set<FieldRendererId> fields_eligible_for_manual_filling_;

  DISALLOW_COPY_AND_ASSIGN(FormCache);
};

}  // namespace autofill

#endif  // COMPONENTS_AUTOFILL_CONTENT_RENDERER_FORM_CACHE_H_