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

sql/mojo/sql_test_base.cc

+// Copyright 2015 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/mojo/sql_test_base.h"
+
+#include "mojo/application/public/cpp/application_impl.h"
+#include "mojo/util/capture_util.h"
+#include "sql/mojo/enable_mojo_fs.h"
+#include "sql/test/test_helpers.h"
+
+using mojo::Capture;
+
+namespace sql {
+
+SQLTestBase::SQLTestBase() {
+}
+
+SQLTestBase::~SQLTestBase() {
+}
+
+base::FilePath SQLTestBase::db_path() {
+  return base::FilePath(FILE_PATH_LITERAL("SQLTest.db"));
+}
+
+sql::Connection& SQLTestBase::db() {
+  return db_;
+}
+
+bool SQLTestBase::Reopen() {
+  db_.Close();
+  return db_.Open(db_path());
+}
+
+bool SQLTestBase::GetPathExists(const base::FilePath& path) {
+  filesystem::FileError error = filesystem::FILE_ERROR_FAILED;
+  bool exists = false;
+  vfs_->GetDirectory()->Exists(path.value(), Capture(&error, &exists));
+  vfs_->GetDirectory().WaitForIncomingResponse();
+  if (error != filesystem::FILE_ERROR_OK)
+    return false;
+  return exists;
+}
+
+bool SQLTestBase::CorruptSizeInHeaderOfPath(const base::FilePath& path) {

[Scott Hess - ex-Googler, 2015/06/10 22:35:46]

This duplication bugs me.  WDYT about a helper to read the header, another to
re-write the header, with a function to corrupt the header that composes the
two?  Alternately a function corrupt the header passed to a function to rewrite
the header?

[Elliot Glaysher, 2015/06/12 22:36:44]

Created a corrupt the header function shared with the other impl, leaving this
function that just does the specific IO-y stuff.

+  // 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
+
+  mojo::Array<uint8_t> header;
+
+  filesystem::FileError error = filesystem::FILE_ERROR_FAILED;
+  filesystem::FilePtr file_ptr;
+  vfs_->GetDirectory()->OpenFile(
+      mojo::String(path.value()), GetProxy(&file_ptr),
+      filesystem::kFlagRead | filesystem::kFlagWrite |
+          filesystem::kFlagOpenAlways,
+      Capture(&error));
+  vfs_->GetDirectory().WaitForIncomingResponse();
+  if (error != filesystem::FILE_ERROR_OK)
+    return false;
+
+  file_ptr->Read(kHeaderSize, 0, filesystem::WHENCE_FROM_BEGIN,
+                 Capture(&error, &header));
+  file_ptr.WaitForIncomingResponse();
+  if (error != filesystem::FILE_ERROR_OK)
+    return false;
+
+  filesystem::FileInformationPtr info;
+  file_ptr->Stat(Capture(&error, &info));
+  file_ptr.WaitForIncomingResponse();
+  if (error != filesystem::FILE_ERROR_OK)
+    return false;
+  int64_t db_size = info->size;
+
+  const unsigned page_size =
+      test::ReadBigEndian(&header.front() + kPageSizeOffset, 2);
+
+  // One larger than the expected size.
+  const unsigned page_count =
+      static_cast<unsigned>((db_size + page_size) / page_size);
+  test::WriteBigEndian(page_count, &header.front() + 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 =
+      test::ReadBigEndian(&header.front() + kFileChangeCountOffset, 4);
+  test::WriteBigEndian(change_count + 1,
+                       &header.front() + kFileChangeCountOffset, 4);
+  test::WriteBigEndian(change_count + 1,
+                       &header.front() + kVersionValidForOffset, 4);
+
+  uint32_t num_bytes_written = 0;
+  file_ptr->Write(header.Pass(), 0, filesystem::WHENCE_FROM_BEGIN,
+                  Capture(&error, &num_bytes_written));
+  file_ptr.WaitForIncomingResponse();
+  if (error != filesystem::FILE_ERROR_OK)
+    return false;
+  if (num_bytes_written != kHeaderSize)
+    return false;
+
+  return true;
+}
+
+void SQLTestBase::WriteJunkToDatabase(bool truncate) {
+  uint32_t flags = 0;
+  if (truncate)
+    flags = filesystem::kFlagWrite | filesystem::kFlagCreate;
+  else
+    flags = filesystem::kFlagWrite | filesystem::kFlagOpen;
+
+  filesystem::FileError error = filesystem::FILE_ERROR_FAILED;
+  filesystem::FilePtr file_ptr;
+  vfs_->GetDirectory()->OpenFile(
+      mojo::String(db_path().value()), GetProxy(&file_ptr),
+      flags,
+      Capture(&error));
+  vfs_->GetDirectory().WaitForIncomingResponse();
+  if (error != filesystem::FILE_ERROR_OK)
+    return;
+
+  const char* kJunk = "Now is the winter of our discontent.";
+  mojo::Array<uint8_t> data(strlen(kJunk));
+  memcpy(&data.front(), kJunk, strlen(kJunk));
+
+  uint32_t num_bytes_written = 0;
+  file_ptr->Write(data.Pass(), 0, filesystem::WHENCE_FROM_BEGIN,
+                  Capture(&error, &num_bytes_written));
+  file_ptr.WaitForIncomingResponse();
+}
+
+void SQLTestBase::TruncateDatabase() {
+  filesystem::FileError error = filesystem::FILE_ERROR_FAILED;
+  filesystem::FilePtr file_ptr;
+  vfs_->GetDirectory()->OpenFile(
+      mojo::String(db_path().value()), GetProxy(&file_ptr),
+      filesystem::kFlagWrite | filesystem::kFlagOpen,
+      Capture(&error));
+  vfs_->GetDirectory().WaitForIncomingResponse();
+  if (error != filesystem::FILE_ERROR_OK)
+    return;
+
+  file_ptr->Truncate(0, Capture(&error));
+  file_ptr.WaitForIncomingResponse();
+  ASSERT_EQ(filesystem::FILE_ERROR_OK, error);
+}
+
+void SQLTestBase::SetUp() {
+  ApplicationTestBase::SetUp();
+
+  mojo::URLRequestPtr request(mojo::URLRequest::New());
+  request->url = mojo::String::From("mojo:filesystem");
+  application_impl()->ConnectToService(request.Pass(), &files_);
+
+  filesystem::FileError error = filesystem::FILE_ERROR_FAILED;
+  filesystem::DirectoryPtr directory;
+  files()->OpenFileSystem("temp", GetProxy(&directory), Capture(&error));
+  ASSERT_TRUE(files().WaitForIncomingResponse());
+  ASSERT_EQ(filesystem::FILE_ERROR_OK, error);
+
+  vfs_.reset(new ScopedMojoFilesystemVFS(directory.Pass()));
+  ASSERT_TRUE(db_.Open(db_path()));
+}
+
+void SQLTestBase::TearDown() {
+  db_.Close();
+  vfs_.reset();
+
+  ApplicationTestBase::TearDown();
+}
+
+}  // namespace sql