[polymer] Merge of master into polymer10-migration

netlog_viewer/source_filter_parser.js

+// Copyright (c) 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.
+
+var SourceFilterParser = (function() {
+  'use strict';
+
+  /**
+   * Parses |filterText|, extracting a sort method, a list of filters, and a
+   * copy of |filterText| with all sort parameters removed.
+   */
+  function SourceFilterParser(filterText) {
+    // Final output will be stored here.
+    this.filter = null;
+    this.sort = {};
+    this.filterTextWithoutSort = '';
+    var filterList = parseFilter_(filterText);
+
+    // Text filters are stored here as strings and then added as a function at
+    // the end, for performance reasons.
+    var textFilters = [];
+
+    // Filter functions are first created individually, and then merged.
+    var filterFunctions = [];
+
+    for (var i = 0; i < filterList.length; ++i) {
+      var filterElement = filterList[i].parsed;
+      var negated = filterList[i].negated;
+
+      var sort = parseSortDirective_(filterElement, negated);
+      if (sort) {
+        this.sort = sort;
+        continue;
+      }
+
+      this.filterTextWithoutSort += filterList[i].original;
+
+      var filter = parseRestrictDirective_(filterElement, negated);
+      if (!filter)
+        filter = parseStringDirective_(filterElement, negated);
+      if (filter) {
+        if (negated) {
+          filter = (function(func, sourceEntry) {
+            return !func(sourceEntry);
+          }).bind(null, filter);
+        }
+        filterFunctions.push(filter);
+        continue;
+      }
+      textFilters.push({ text: filterElement, negated: negated });
+    }
+
+    // Create a single filter for all text filters, so they can share a
+    // TabePrinter.
+    filterFunctions.push(textFilter_.bind(null, textFilters));
+
+    // Create function to go through all the filters.
+    this.filter = function(sourceEntry) {
+      for (var i = 0; i < filterFunctions.length; ++i) {
+        if (!filterFunctions[i](sourceEntry))
+          return false;
+      }
+      return true;
+    };
+  }
+
+  /**
+   * Parses a single "sort:" directive, and returns a dictionary containing
+   * the sort function and direction.  Returns null on failure, including
+   * the case when no such sort function exists.
+   */
+  function parseSortDirective_(filterElement, backwards) {
+    var match = /^sort:(.*)$/.exec(filterElement);
+    if (!match)
+      return null;
+    return { method: match[1], backwards: backwards };
+  }
+
+  /**
+   * Tries to parses |filterElement| as a single "is:" directive, and returns a
+   * new filter function.  Returns null on failure.
+   */
+  function parseRestrictDirective_(filterElement) {
+    var match = /^is:(.*)$/.exec(filterElement);
+    if (!match)
+      return null;
+    if (match[1] == 'active') {
+      return function(sourceEntry) { return !sourceEntry.isInactive(); };
+    }
+    if (match[1] == 'error') {
+      return function(sourceEntry) { return sourceEntry.isError(); };
+    }
+    return null;
+  }
+
+  /**
+   * Tries to parse |filterElement| as a single filter of a type that takes
+   * arbitrary strings as input, and returns a new filter function on success.
+   * Returns null on failure.
+   */
+  function parseStringDirective_(filterElement) {
+    var match = RegExp('^([^:]*):(.*)$').exec(filterElement);
+    if (!match)
+      return null;
+
+    // Split parameters around commas and remove empty elements.
+    var parameters = match[2].split(',');
+    parameters = parameters.filter(function(string) {
+      return string.length > 0;
+    });
+
+    if (match[1] == 'type') {
+      return function(sourceEntry) {
+        var i;
+        var sourceType = sourceEntry.getSourceTypeString().toLowerCase();
+        for (i = 0; i < parameters.length; ++i) {
+          if (sourceType.search(parameters[i]) != -1)
+            return true;
+        }
+        return false;
+      };
+    }
+
+    if (match[1] == 'id') {
+      return function(sourceEntry) {
+        return parameters.indexOf(sourceEntry.getSourceId() + '') != -1;
+      };
+    }
+
+    return null;
+  }
+
+  /**
+   * Takes in the text of a filter and returns a list of
+   * {parsed, original, negated} values that correspond to substrings of the
+   * filter before and after filtering, and whether or not it started with a
+   * '-'.  Extra whitespace other than a single character after each element is
+   * ignored.  Parsed strings are all lowercase.
+   */
+  function parseFilter_(filterText) {
+    // Assemble a list of quoted and unquoted strings in the filter.
+    var filterList = [];
+    var position = 0;
+    while (position < filterText.length) {
+      var inQuote = false;
+      var filterElement = '';
+      var negated = false;
+      var startPosition = position;
+      while (position < filterText.length) {
+        var nextCharacter = filterText[position];
+        ++position;
+        if (nextCharacter == '\\' &&
+            position < filterText.length) {
+          // If there's a backslash, skip the backslash and add the next
+          // character to the element.
+          filterElement += filterText[position];
+          ++position;
+          continue;
+        } else if (nextCharacter == '"') {
+          // If there's an unescaped quote character, toggle |inQuote| without
+          // modifying the element.
+          inQuote = !inQuote;
+        } else if (!inQuote && /\s/.test(nextCharacter)) {
+          // If not in a quote and have a whitespace character, that's the
+          // end of the element.
+          break;
+        } else if (nextCharacter == '-' && startPosition == position - 1) {
+          // If this is the first character, and it's a '-', this entry is
+          // negated.
+          negated = true;
+        } else {
+          // Otherwise, add the next character to the element.
+          filterElement += nextCharacter;
+        }
+      }
+
+      if (filterElement.length > 0) {
+        var filter = {
+          parsed: filterElement.toLowerCase(),
+          original: filterText.substring(startPosition, position),
+          negated: negated,
+        };
+        filterList.push(filter);
+      }
+    }
+    return filterList;
+  }
+
+  /**
+   * Takes in a list of text filters and a SourceEntry.  Each filter has
+   * "text" and "negated" fields.  Returns true if the SourceEntry matches all
+   * filters in the (possibly empty) list.
+   */
+  function textFilter_(textFilters, sourceEntry) {
+    var tablePrinter = null;
+    for (var i = 0; i < textFilters.length; ++i) {
+      var text = textFilters[i].text;
+      var negated = textFilters[i].negated;
+      var match = false;
+      // The description is often not contained in one of the log entries.
+      // The source type almost never is, so check for them directly.
+      var description = sourceEntry.getDescription().toLowerCase();
+      var type = sourceEntry.getSourceTypeString().toLowerCase();
+      if (description.indexOf(text) != -1 || type.indexOf(text) != -1) {
+        match = true;
+      } else {
+        if (!tablePrinter)
+          tablePrinter = sourceEntry.createTablePrinter();
+        match = tablePrinter.search(text);
+      }
+      if (negated)
+        match = !match;
+      if (!match)
+        return false;
+    }
+    return true;
+  }
+
+  return SourceFilterParser;
+})();
+