mandoline filesystem: add a sqlite3 vfs to proxy filesystem usage.

sql/test/test_helpers.cc

 // 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.
 
 #include "sql/test/test_helpers.h"
 
 #include <string>
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_file.h"
@@ skipping 51 matching lines @@
 }
 
 }  // namespace
 
 namespace sql {
 namespace test {
 
 bool CorruptSizeInHeader(const base::FilePath& db_path) {
   // See http://www.sqlite.org/fileformat.html#database_header
   const size_t kHeaderSize = 100;
-  const size_t kPageSizeOffset = 16;
-  const size_t kFileChangeCountOffset = 24;
-  const size_t kPageCountOffset = 28;
-  const size_t kVersionValidForOffset = 92;  // duplicate kFileChangeCountOffset
 
   unsigned char header[kHeaderSize];
 
   base::ScopedFILE file(base::OpenFile(db_path, "rb+"));
   if (!file.get())
     return false;
 
   if (0 != fseek(file.get(), 0, SEEK_SET))
     return false;
   if (1u != fread(header, sizeof(header), 1, file.get()))
     return false;
 
   int64_t db_size = 0;
   if (!base::GetFileSize(db_path, &db_size))
     return false;
 
+  CorruptSizeInHeaderMemory(header, db_size);
+
+  if (0 != fseek(file.get(), 0, SEEK_SET))
+    return false;
+  if (1u != fwrite(header, sizeof(header), 1, file.get()))
+    return false;
+
+  return true;
+}
+
+void CorruptSizeInHeaderMemory(unsigned char* header, int64_t db_size) {

[Scott Hess - ex-Googler, 2015/06/17 19:32:59]

Makes sense to me!

+  const size_t kPageSizeOffset = 16;
+  const size_t kFileChangeCountOffset = 24;
+  const size_t kPageCountOffset = 28;
+  const size_t kVersionValidForOffset = 92;  // duplicate kFileChangeCountOffset
+
   const unsigned page_size = ReadBigEndian(header + kPageSizeOffset, 2);
 
   // One larger than the expected size.
   const unsigned page_count =
       static_cast<unsigned>((db_size + page_size) / page_size);
   WriteBigEndian(page_count, header + kPageCountOffset, 4);
 
   // Update change count so outstanding readers know the info changed.
   // Both spots must match for the page count to be considered valid.
   unsigned change_count = ReadBigEndian(header + kFileChangeCountOffset, 4);
   WriteBigEndian(change_count + 1, header + kFileChangeCountOffset, 4);
   WriteBigEndian(change_count + 1, header + kVersionValidForOffset, 4);
-
-  if (0 != fseek(file.get(), 0, SEEK_SET))
-    return false;
-  if (1u != fwrite(header, sizeof(header), 1, file.get()))
-    return false;
-
-  return true;
 }
 
 bool CorruptTableOrIndex(const base::FilePath& db_path,
                          const char* tree_name,
                          const char* update_sql) {
   sql::Connection db;
   if (!db.Open(db_path))
     return false;
 
   int page_size = 0;
@@ skipping 122 matching lines @@
   sql::Statement statement(db->GetUniqueStatement("PRAGMA integrity_check"));
 
   // SQLite should always return a row of data.
   EXPECT_TRUE(statement.Step());
 
   return statement.ColumnString(0);
 }
 
 }  // namespace test
 }  // namespace sql