[sql] Tests for updates to mmap state.

sql/connection_unittest.cc

 // Copyright (c) 2012 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 <stddef.h>
 #include <stdint.h>
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_file.h"
@@ skipping 1528 matching lines @@
   ASSERT_GT(db().GetAppropriateMmapSize(), kMmapAlot);
   ASSERT_TRUE(!db().DoesTableExist("meta"));
 
   // When the meta table is first created, it sets up to map everything.
   MetaTable().Init(&db(), 1, 1);
   ASSERT_TRUE(db().DoesTableExist("meta"));
   ASSERT_GT(db().GetAppropriateMmapSize(), kMmapAlot);
   ASSERT_TRUE(MetaTable::GetMmapStatus(&db(), &mmap_status));
   ASSERT_EQ(MetaTable::kMmapSuccess, mmap_status);
 
+  // Preload with partial progress of one page.  Should map everything.
+  ASSERT_TRUE(db().Execute("REPLACE INTO meta VALUES ('mmap_status', 1)"));
+  ASSERT_GT(db().GetAppropriateMmapSize(), kMmapAlot);
+  ASSERT_TRUE(MetaTable::GetMmapStatus(&db(), &mmap_status));
+  ASSERT_EQ(MetaTable::kMmapSuccess, mmap_status);
+
   // Failure status maps nothing.
   ASSERT_TRUE(db().Execute("REPLACE INTO meta VALUES ('mmap_status', -2)"));
   ASSERT_EQ(0UL, db().GetAppropriateMmapSize());
 
   // Re-initializing the meta table does not re-create the key if the table
   // already exists.
   ASSERT_TRUE(db().Execute("DELETE FROM meta WHERE key = 'mmap_status'"));
   MetaTable().Init(&db(), 1, 1);
   ASSERT_EQ(MetaTable::kMmapSuccess, mmap_status);
   ASSERT_TRUE(MetaTable::GetMmapStatus(&db(), &mmap_status));
@@ skipping 27 matching lines @@
   ASSERT_FALSE(db().DoesViewExist("MmapStatus"));
 
   // Using alt status, everything should be mapped, with state in the view.
   db().set_mmap_alt_status();
   ASSERT_GT(db().GetAppropriateMmapSize(), kMmapAlot);
   ASSERT_FALSE(db().DoesTableExist("meta"));
   ASSERT_TRUE(db().DoesViewExist("MmapStatus"));
   EXPECT_EQ(base::IntToString(MetaTable::kMmapSuccess),
             ExecuteWithResult(&db(), "SELECT * FROM MmapStatus"));
 
-  // Also maps everything when kMmapSuccess is in the view.
+  // Also maps everything when kMmapSuccess is already in the view.
   ASSERT_GT(db().GetAppropriateMmapSize(), kMmapAlot);
 
+  // Preload with partial progress of one page.  Should map everything.
+  ASSERT_TRUE(db().Execute("DROP VIEW MmapStatus"));
+  ASSERT_TRUE(db().Execute("CREATE VIEW MmapStatus AS SELECT 1"));

[pavely, 2017/03/17 23:21:35]

nit: When Connection::SetMmapAltStatus creates view it sets column name to
"value" as well. It is not an issue as long as it reads value with "select *".
Might cause test failures if query changes to "select value from MmapStatus".

[Scott Hess - ex-Googler, 2017/03/19 23:47:15]

Good point.  I'm changing the variant a few lines down, too (I think that's
where this one came from, as I'm far too lazy to write new code for something
like this).

+  ASSERT_GT(db().GetAppropriateMmapSize(), kMmapAlot);
+  EXPECT_EQ(base::IntToString(MetaTable::kMmapSuccess),
+            ExecuteWithResult(&db(), "SELECT * FROM MmapStatus"));
+
   // Failure status leads to nothing being mapped.
   ASSERT_TRUE(db().Execute("DROP VIEW MmapStatus"));
   ASSERT_TRUE(db().Execute("CREATE VIEW MmapStatus AS SELECT -2"));
   ASSERT_EQ(0UL, db().GetAppropriateMmapSize());
   EXPECT_EQ(base::IntToString(MetaTable::kMmapFailure),
             ExecuteWithResult(&db(), "SELECT * FROM MmapStatus"));
 }
 
 // To prevent invalid SQL from accidentally shipping to production, prepared
 // statements which fail to compile with SQLITE_ERROR call DLOG(FATAL).  This
 // case cannot be suppressed with an error callback.
 TEST_F(SQLConnectionTest, CompileError) {
   // DEATH tests not supported on Android or iOS.
 #if !defined(OS_ANDROID) && !defined(OS_IOS)
   if (DLOG_IS_ON(FATAL)) {
     db().set_error_callback(base::Bind(&IgnoreErrorCallback));
     ASSERT_DEATH({
         db().GetUniqueStatement("SELECT x");
       }, "SQL compile error no such column: x");
   }
 #endif
 }
 
 }  // namespace sql