Database usage adjustment for .../history

chrome/browser/history/history_database.cc

Index: chrome/browser/history/history_database.cc
diff --git a/chrome/browser/history/history_database.cc b/chrome/browser/history/history_database.cc
index 7a37245f4dc6d396e254f448f7ede5972c9c351b..8fcb2460f15f53cdf4d6b82b3b5524273d7ef5e7 100644
--- a/chrome/browser/history/history_database.cc
+++ b/chrome/browser/history/history_database.cc
@@ -48,13 +48,13 @@ void ComputeDatabaseMetrics(const FilePath& history_name,
   UMA_HISTOGRAM_MEMORY_MB("History.DatabaseFileMB", file_mb);
 
   sql::Statement url_count(db.GetUniqueStatement("SELECT count(*) FROM urls"));
-  if (!url_count || !url_count.Step())
+  if (!url_count.Step())
     return;
   UMA_HISTOGRAM_COUNTS("History.URLTableCount", url_count.ColumnInt(0));
 
   sql::Statement visit_count(db.GetUniqueStatement(
       "SELECT count(*) FROM visits"));
-  if (!visit_count || !visit_count.Step())
+  if (!visit_count.Step())
     return;
   UMA_HISTOGRAM_COUNTS("History.VisitTableCount", visit_count.ColumnInt(0));
 }
@@ -188,25 +188,18 @@ bool HistoryDatabase::GetNeedsThumbnailMigration() {
 bool HistoryDatabase::SetSegmentID(VisitID visit_id, SegmentID segment_id) {
   sql::Statement s(db_.GetCachedStatement(SQL_FROM_HERE,
       "UPDATE visits SET segment_id = ? WHERE id = ?"));
-  if (!s) {
-    NOTREACHED() << db_.GetErrorMessage();
-    return false;
-  }
   s.BindInt64(0, segment_id);
   s.BindInt64(1, visit_id);
   DCHECK(db_.GetLastChangeCount() == 1);

[Scott Hess - ex-Googler, 2012/01/03 23:41:57]

I'm having troubles seeing how this line could possibly be making the assertions
it seems to think it is asserting.

[Greg Billock, 2012/01/04 19:20:20]

I read it as saying "ASSERT(number of rows changed by the previous UPDATE
statement was exactly 1)"

Meaning that the caller must ensure that visit_id is present and unique in the
visits table.

Of course, by that time it's too late and the DB is corrupted... :-/

On 2012/01/03 23:41:57, shess wrote:

[Scott Hess - ex-Googler, 2012/01/10 22:04:56]

Do you mean an update statement which ran sometime prior to the call to
SetSegmentID()?  Because the UPDATE statement a couple lines above here has not
run, yet.

+
   return s.Run();
 }
 
 SegmentID HistoryDatabase::GetSegmentID(VisitID visit_id) {
   sql::Statement s(db_.GetCachedStatement(SQL_FROM_HERE,
       "SELECT segment_id FROM visits WHERE id = ?"));
-  if (!s) {
-    NOTREACHED() << db_.GetErrorMessage();
-    return 0;
-  }
-
   s.BindInt64(0, visit_id);
+
   if (s.Step()) {
     if (s.ColumnType(0) == sql::COLUMN_TYPE_NULL)
       return 0;