Move Google search related util methods to page_load_metrics_util

chrome/browser/page_load_metrics/page_load_metrics_util.cc

Index: chrome/browser/page_load_metrics/page_load_metrics_util.cc
diff --git a/chrome/browser/page_load_metrics/page_load_metrics_util.cc b/chrome/browser/page_load_metrics/page_load_metrics_util.cc
index e5f54f3c6f1e7f6ae1a7fdc3c37feb32df3d9a8d..e6d8fd47ffd83d49fe51780dadf9973ac0517610 100644
--- a/chrome/browser/page_load_metrics/page_load_metrics_util.cc
+++ b/chrome/browser/page_load_metrics/page_load_metrics_util.cc
@@ -41,6 +41,59 @@ PageAbortReason GetAbortReasonForEndReason(PageEndReason end_reason) {
   }
 }
 
+// Common helper for QueryContainsComponent and QueryContainsComponentPrefix.
+bool QueryContainsComponentHelper(const base::StringPiece query,
+                                  const base::StringPiece component,
+                                  bool component_is_prefix) {
+  if (query.empty() || component.empty() ||
+      component.length() > query.length()) {
+    return false;
+  }
+
+  // Verify that the provided query string does not include the query or
+  // fragment start character, as the logic below depends on this character not
+  // being included.
+  DCHECK(query[0] != '?' && query[0] != '#');
+
+  // We shouldn't try to find matches beyond the point where there aren't enough
+  // characters left in query to fully match the component.
+  const size_t last_search_start = query.length() - component.length();
+
+  // We need to search for matches in a loop, rather than stopping at the first
+  // match, because we may initially match a substring that isn't a full query
+  // string component. Consider, for instance, the query string 'ab=cd&b=c'. If
+  // we search for component 'b=c', the first substring match will be characters
+  // 1-3 (zero-based) in the query string. However, this isn't a full component
+  // (the full component is ab=cd) so the match will fail. Thus, we must
+  // continue our search to find the second substring match, which in the
+  // example is at characters 6-8 (the end of the query string) and is a
+  // successful component match.
+  for (size_t start_offset = 0; start_offset <= last_search_start;
+       start_offset += component.length()) {
+    start_offset = query.find(component, start_offset);
+    if (start_offset == std::string::npos) {
+      // We searched to end of string and did not find a match.
+      return false;
+    }
+    // Verify that the character prior to the component is valid (either we're
+    // at the beginning of the query string, or are preceded by an ampersand).
+    if (start_offset != 0 && query[start_offset - 1] != '&') {
+      continue;
+    }
+    if (!component_is_prefix) {
+      // Verify that the character after the component substring is valid
+      // (either we're at the end of the query string, or are followed by an
+      // ampersand).
+      const size_t after_offset = start_offset + component.length();
+      if (after_offset < query.length() && query[after_offset] != '&') {
+        continue;
+      }
+    }
+    return true;
+  }
+  return false;
+}
+
 }  // namespace
 
 bool WasStartedInForegroundOptionalEventInForeground(
@@ -110,4 +163,57 @@ bool DidObserveLoadingBehaviorInAnyFrame(
   return (all_frame_loading_behavior_flags & behavior) != 0;
 }
 
+bool IsGoogleSearchHostname(const GURL& url) {
+  base::Optional<std::string> result =
+      page_load_metrics::GetGoogleHostnamePrefix(url);
+  return result && result.value() == "www";
+}
+
+bool IsGoogleSearchResultUrl(const GURL& url) {
+  // NOTE: we do not require 'q=' in the query, as AJAXy search may instead
+  // store the query in the URL fragment.
+  if (!IsGoogleSearchHostname(url)) {
+    return false;
+  }
+
+  if (!QueryContainsComponentPrefix(url.query_piece(), "q=") &&
+      !QueryContainsComponentPrefix(url.ref_piece(), "q=")) {
+    return false;
+  }
+
+  const base::StringPiece path = url.path_piece();
+  return path == "/search" || path == "/webhp" || path == "/custom" ||
+         path == "/";
+}
+
+bool IsGoogleSearchRedirectorUrl(const GURL& url) {
+  if (!IsGoogleSearchHostname(url))
+    return false;
+
+  // The primary search redirector.  Google search result redirects are
+  // differentiated from other general google redirects by 'source=web' in the
+  // query string.
+  if (url.path_piece() == "/url" && url.has_query() &&
+      QueryContainsComponent(url.query_piece(), "source=web")) {
+    return true;
+  }
+
+  // Intent-based navigations from search are redirected through a second
+  // redirector, which receives its redirect URL in the fragment/hash/ref
+  // portion of the URL (the portion after '#'). We don't check for the presence
+  // of certain params in the ref since this redirector is only used for
+  // redirects from search.
+  return url.path_piece() == "/searchurl/r.html" && url.has_ref();
+}
+
+bool QueryContainsComponent(const base::StringPiece query,
+                            const base::StringPiece component) {
+  return QueryContainsComponentHelper(query, component, false);
+}
+
+bool QueryContainsComponentPrefix(const base::StringPiece query,
+                                  const base::StringPiece component) {
+  return QueryContainsComponentHelper(query, component, true);
+}
+
 }  // namespace page_load_metrics