A database to hold mappings from origin identifiers to unique directory names.

BUG=NONE
TEST=included


Review URL: http://codereview.chromium.org/6903118

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@84029 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 415 insertions, 1 deletions

diff --git a/webkit/fileapi/file_system_origin_database.cc b/webkit/fileapi/file_system_origin_database.cc
new file mode 100644
index 0000000..a559c1b
--- /dev/null
+++ b/webkit/fileapi/file_system_origin_database.cc
@@ -0,0 +1,190 @@
+// Copyright (c) 2011 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 "webkit/fileapi/file_system_origin_database.h"
+
+#include "base/logging.h"
+#include "base/string_number_conversions.h"
+#include "base/string_util.h"
+#include "base/sys_string_conversions.h"
+#include "third_party/leveldb/include/leveldb/iterator.h"
+#include "third_party/leveldb/include/leveldb/write_batch.h"
+
+namespace {
+
+const char kOriginKeyPrefix[] = "ORIGIN:";
+const char kLastPathKey[] = "LAST_PATH";
+
+std::string OriginToOriginKey(const std::string& origin) {
+  std::string key(kOriginKeyPrefix);
+  return key + origin;
+}
+
+const char* LastPathKey() {
+  return kLastPathKey;
+}
+
+}
+
+namespace fileapi {
+
+FileSystemOriginDatabase::FileSystemOriginDatabase(const FilePath& path) {
+#if defined(OS_POSIX)
+  path_ = path.value();
+#elif defined(OS_WIN)
+  path_ = base::SysWideToUTF8(path.value());
+#endif
+}
+
+FileSystemOriginDatabase::~FileSystemOriginDatabase() {
+}
+
+bool FileSystemOriginDatabase::Init() {
+  if (db_.get())
+    return true;
+
+  leveldb::Options options;
+  options.create_if_missing = true;
+  leveldb::DB* db;
+  leveldb::Status status = leveldb::DB::Open(options, path_, &db);
+  if (status.ok()) {
+    db_.reset(db);
+    return true;
+  }
+  HandleError(status);
+  return false;
+}
+
+void FileSystemOriginDatabase::HandleError(leveldb::Status status) {
+  db_.reset();
+  LOG(ERROR) << "FileSystemOriginDatabase failed with error: " <<
+      status.ToString();
+}
+
+bool FileSystemOriginDatabase::HasOriginPath(const std::string& origin) {
+  if (!Init())
+    return false;
+  if (origin.empty())
+    return false;
+  std::string path;
+  leveldb::Status status =
+      db_->Get(leveldb::ReadOptions(), OriginToOriginKey(origin), &path);
+  if (status.ok())
+    return true;
+  if (status.IsNotFound())
+    return false;
+  HandleError(status);
+  return false;
+}
+
+bool FileSystemOriginDatabase::GetPathForOrigin(
+    const std::string& origin, FilePath* directory) {
+  if (!Init())
+    return false;
+  DCHECK(directory);
+  if (origin.empty())
+    return false;
+  std::string path_string;
+  std::string origin_key = OriginToOriginKey(origin);
+  leveldb::Status status =
+      db_->Get(leveldb::ReadOptions(), origin_key, &path_string);
+  if (status.IsNotFound()) {
+    int last_path_number;
+    if (!GetLastPathNumber(&last_path_number))
+      return false;
+    path_string = base::IntToString(last_path_number + 1);
+    // store both back as a single transaction
+    leveldb::WriteBatch batch;
+    batch.Put(LastPathKey(), path_string);
+    batch.Put(origin_key, path_string);
+    status = db_->Write(leveldb::WriteOptions(), &batch);
+    if (!status.ok()) {
+      HandleError(status);
+      return false;
+    }
+  }
+  if (status.ok()) {
+#if defined(OS_POSIX)
+    *directory = FilePath(path_string);
+#elif defined(OS_WIN)
+    *directory = FilePath(base::SysUTF8ToWide(path_string));
+#endif
+    return true;
+  }
+  HandleError(status);
+  return false;
+}
+
+bool FileSystemOriginDatabase::RemovePathForOrigin(const std::string& origin) {
+  if (!Init())
+    return false;
+  leveldb::Status status =
+      db_->Delete(leveldb::WriteOptions(), OriginToOriginKey(origin));
+  if (status.ok() || status.IsNotFound())
+    return true;
+  HandleError(status);
+  return false;
+}
+
+bool FileSystemOriginDatabase::ListAllOrigins(
+    std::vector<OriginRecord>* origins) {
+  if (!Init())
+    return false;
+  DCHECK(origins);
+  scoped_ptr<leveldb::Iterator> iter(db_->NewIterator(leveldb::ReadOptions()));
+  std::string origin_key_prefix = OriginToOriginKey("");
+  iter->Seek(origin_key_prefix);
+  origins->clear();
+  while(iter->Valid() &&
+      StartsWithASCII(iter->key().ToString(), origin_key_prefix, true)) {
+    std::string origin =
+      iter->key().ToString().substr(origin_key_prefix.length());
+#if defined(OS_POSIX)
+    FilePath path = FilePath(iter->value().ToString());
+#elif defined(OS_WIN)
+    FilePath path = FilePath(base::SysUTF8ToWide(iter->value().ToString()));
+#endif
+    origins->push_back(OriginRecord(origin, path));
+    iter->Next();
+  }
+  return true;
+}
+
+void FileSystemOriginDatabase::DropDatabase() {
+  db_.reset();
+}
+
+bool FileSystemOriginDatabase::GetLastPathNumber(int* number) {
+  if (!Init())
+    return false;
+  DCHECK(number);
+  std::string number_string;
+  leveldb::Status status =
+      db_->Get(leveldb::ReadOptions(), LastPathKey(), &number_string);
+  if (status.ok())
+    return base::StringToInt(number_string, number);
+  if (!status.IsNotFound()) {
+    HandleError(status);
+    return false;
+  }
+  // Verify that this is a totally new database, and initialize it.
+  scoped_ptr<leveldb::Iterator> iter(db_->NewIterator(leveldb::ReadOptions()));
+  iter->SeekToFirst();
+  if (iter->Valid()) {  // DB was not empty, but had no last path number!
+    LOG(ERROR) << "File system origin database is corrupt!";
+    return false;
+  }
+  // This is always the first write into the database.  If we ever add a
+  // version number, they should go in in a single transaction.
+  status =
+      db_->Put(leveldb::WriteOptions(), LastPathKey(), std::string("-1"));
+  if (!status.ok()) {
+    HandleError(status);
+    return false;
+  }
+  *number = -1;
+  return true;
+}
+
+}  // namespace fileapi
diff --git a/webkit/fileapi/file_system_origin_database.h b/webkit/fileapi/file_system_origin_database.h
new file mode 100644
index 0000000..1a28082
--- /dev/null
+++ b/webkit/fileapi/file_system_origin_database.h
@@ -0,0 +1,55 @@
+// Copyright (c) 2011 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.
+
+#ifndef WEBKIT_FILEAPI_FILE_SYSTEM_ORIGIN_DATABASE_H_
+#define WEBKIT_FILEAPI_FILE_SYSTEM_ORIGIN_DATABASE_H_
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "base/file_path.h"
+#include "base/scoped_ptr.h"
+#include "third_party/leveldb/include/leveldb/db.h"
+
+namespace fileapi {
+
+// All methods of this class other than the constructor may be used only from
+// the browser's FILE thread.  The constructor may be used on any thread.
+class FileSystemOriginDatabase {
+ public:
+  typedef std::pair<std::string, FilePath> OriginRecord;
+
+  // Only one instance of FileSystemOriginDatabase should exist for a given path
+  // at a given time.
+  FileSystemOriginDatabase(const FilePath& path);
+  ~FileSystemOriginDatabase();
+
+  bool HasOriginPath(const std::string& origin);
+
+  // This will produce a unique path and add it to its database, if it's not
+  // already present.
+  bool GetPathForOrigin(const std::string& origin, FilePath* directory);
+
+  // Also returns success if the origin is not found.
+  bool RemovePathForOrigin(const std::string& origin);
+
+  bool ListAllOrigins(std::vector<OriginRecord>* origins);
+
+  // This will release all database resources in use; call it to save memory.
+  void DropDatabase();
+
+ private:
+  bool Init();
+  void HandleError(leveldb::Status status);
+  bool GetLastPathNumber(int* number);
+
+  std::string path_;
+  scoped_ptr<leveldb::DB> db_;
+  DISALLOW_COPY_AND_ASSIGN(FileSystemOriginDatabase);
+};
+
+}  // namespace fileapi
+
+#endif  // WEBKIT_FILEAPI_FILE_SYSTEM_ORIGIN_DATABASE_H_
diff --git a/webkit/fileapi/file_system_origin_database_unittest.cc b/webkit/fileapi/file_system_origin_database_unittest.cc
new file mode 100644
index 0000000..c7c4f71
--- /dev/null
+++ b/webkit/fileapi/file_system_origin_database_unittest.cc
@@ -0,0 +1,166 @@
+// Copyright (c) 2011 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 "testing/gtest/include/gtest/gtest.h"
+
+#include <string>
+
+#include "base/file_util.h"
+#include "base/memory/scoped_temp_dir.h"
+#include "webkit/fileapi/file_system_origin_database.h"
+
+namespace fileapi {
+
+TEST(FileSystemOriginDatabaseTest, BasicTest) {
+  ScopedTempDir dir;
+  ASSERT_TRUE(dir.CreateUniqueTempDir());
+  const FilePath kDBFile = dir.path().AppendASCII("fsod.db");
+  EXPECT_FALSE(file_util::PathExists(kDBFile));
+
+  FileSystemOriginDatabase database(kDBFile);
+  std::string origin("origin");
+
+  EXPECT_FALSE(database.HasOriginPath(origin));
+  // Double-check to make sure that had no side effects.
+  EXPECT_FALSE(database.HasOriginPath(origin));
+
+  FilePath path0;
+  FilePath path1;
+
+  // Empty strings aren't valid origins.
+  EXPECT_FALSE(database.GetPathForOrigin(std::string(), &path0));
+
+  EXPECT_TRUE(database.GetPathForOrigin(origin, &path0));
+  EXPECT_TRUE(database.HasOriginPath(origin));
+  EXPECT_TRUE(database.GetPathForOrigin(origin, &path1));
+  EXPECT_FALSE(path0.empty());
+  EXPECT_FALSE(path1.empty());
+  EXPECT_EQ(path0, path1);
+
+  EXPECT_TRUE(file_util::PathExists(kDBFile));
+}
+
+TEST(FileSystemOriginDatabaseTest, TwoPathTest) {
+  ScopedTempDir dir;
+  ASSERT_TRUE(dir.CreateUniqueTempDir());
+  const FilePath kDBFile = dir.path().AppendASCII("fsod.db");
+  EXPECT_FALSE(file_util::PathExists(kDBFile));
+
+  FileSystemOriginDatabase database(kDBFile);
+  std::string origin0("origin0");
+  std::string origin1("origin1");
+
+  EXPECT_FALSE(database.HasOriginPath(origin0));
+  EXPECT_FALSE(database.HasOriginPath(origin1));
+
+  FilePath path0;
+  FilePath path1;
+  EXPECT_TRUE(database.GetPathForOrigin(origin0, &path0));
+  EXPECT_TRUE(database.HasOriginPath(origin0));
+  EXPECT_FALSE(database.HasOriginPath(origin1));
+  EXPECT_TRUE(database.GetPathForOrigin(origin1, &path1));
+  EXPECT_TRUE(database.HasOriginPath(origin1));
+  EXPECT_FALSE(path0.empty());
+  EXPECT_FALSE(path1.empty());
+  EXPECT_NE(path0, path1);
+
+  EXPECT_TRUE(file_util::PathExists(kDBFile));
+}
+
+TEST(FileSystemOriginDatabaseTest, DropDatabaseTest) {
+  ScopedTempDir dir;
+  ASSERT_TRUE(dir.CreateUniqueTempDir());
+  const FilePath kDBFile = dir.path().AppendASCII("fsod.db");
+  EXPECT_FALSE(file_util::PathExists(kDBFile));
+
+  FileSystemOriginDatabase database(kDBFile);
+  std::string origin("origin");
+
+  EXPECT_FALSE(database.HasOriginPath(origin));
+
+  FilePath path0;
+  EXPECT_TRUE(database.GetPathForOrigin(origin, &path0));
+  EXPECT_TRUE(database.HasOriginPath(origin));
+  EXPECT_FALSE(path0.empty());
+
+  EXPECT_TRUE(file_util::PathExists(kDBFile));
+
+  database.DropDatabase();
+
+  FilePath path1;
+  EXPECT_TRUE(database.HasOriginPath(origin));
+  EXPECT_TRUE(database.GetPathForOrigin(origin, &path1));
+  EXPECT_FALSE(path1.empty());
+  EXPECT_EQ(path0, path1);
+}
+
+TEST(FileSystemOriginDatabaseTest, DeleteOriginTest) {
+  ScopedTempDir dir;
+  ASSERT_TRUE(dir.CreateUniqueTempDir());
+  const FilePath kDBFile = dir.path().AppendASCII("fsod.db");
+  EXPECT_FALSE(file_util::PathExists(kDBFile));
+
+  FileSystemOriginDatabase database(kDBFile);
+  std::string origin("origin");
+
+  EXPECT_FALSE(database.HasOriginPath(origin));
+  EXPECT_TRUE(database.RemovePathForOrigin(origin));
+
+  FilePath path0;
+  EXPECT_TRUE(database.GetPathForOrigin(origin, &path0));
+  EXPECT_TRUE(database.HasOriginPath(origin));
+  EXPECT_FALSE(path0.empty());
+
+  EXPECT_TRUE(database.RemovePathForOrigin(origin));
+  EXPECT_FALSE(database.HasOriginPath(origin));
+
+  FilePath path1;
+  EXPECT_TRUE(database.GetPathForOrigin(origin, &path1));
+  EXPECT_FALSE(path1.empty());
+  EXPECT_NE(path0, path1);
+}
+
+TEST(FileSystemOriginDatabaseTest, ListOriginsTest) {
+  ScopedTempDir dir;
+  ASSERT_TRUE(dir.CreateUniqueTempDir());
+  const FilePath kDBFile = dir.path().AppendASCII("fsod.db");
+  EXPECT_FALSE(file_util::PathExists(kDBFile));
+
+  std::vector<FileSystemOriginDatabase::OriginRecord> origins;
+
+  FileSystemOriginDatabase database(kDBFile);
+  EXPECT_TRUE(database.ListAllOrigins(&origins));
+  EXPECT_TRUE(origins.empty());
+  origins.clear();
+
+  std::string origin0("origin0");
+  std::string origin1("origin1");
+
+  EXPECT_FALSE(database.HasOriginPath(origin0));
+  EXPECT_FALSE(database.HasOriginPath(origin1));
+
+  FilePath path0;
+  FilePath path1;
+  EXPECT_TRUE(database.GetPathForOrigin(origin0, &path0));
+  EXPECT_TRUE(database.ListAllOrigins(&origins));
+  EXPECT_EQ(origins.size(), 1UL);
+  EXPECT_EQ(origins[0].first, origin0);
+  EXPECT_EQ(origins[0].second, path0);
+  origins.clear();
+  EXPECT_TRUE(database.GetPathForOrigin(origin1, &path1));
+  EXPECT_TRUE(database.ListAllOrigins(&origins));
+  EXPECT_EQ(origins.size(), 2UL);
+  if (origins[0].first == origin0) {
+    EXPECT_EQ(origins[0].second, path0);
+    EXPECT_EQ(origins[1].first, origin1);
+    EXPECT_EQ(origins[1].second, path1);
+  } else {
+    EXPECT_EQ(origins[0].first, origin1);
+    EXPECT_EQ(origins[0].second, path1);
+    EXPECT_EQ(origins[1].first, origin0);
+    EXPECT_EQ(origins[1].second, path0);
+  }
+}
+
+}  // namespace fileapi
diff --git a/webkit/fileapi/webkit_fileapi.gypi b/webkit/fileapi/webkit_fileapi.gypi
index 258db99..cda2ec0 100644
--- a/webkit/fileapi/webkit_fileapi.gypi
+++ b/webkit/fileapi/webkit_fileapi.gypi
@@ -1,4 +1,4 @@
-# Copyright (c) 2010 The Chromium Authors. All rights reserved.
+# Copyright (c) 2011 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.
 
@@ -12,6 +12,7 @@
         '<(DEPTH)/app/app.gyp:app_base',
         '<(DEPTH)/base/base.gyp:base',
         '<(DEPTH)/net/net.gyp:net',
+        '<(DEPTH)/third_party/leveldb/leveldb.gyp:leveldb',
       ],
       'sources': [
         'file_system_callback_dispatcher.cc',
@@ -29,6 +30,8 @@
         'file_system_operation.h',
         'file_system_operation_context.cc',
         'file_system_operation_context.h',
+        'file_system_origin_database.cc',
+        'file_system_origin_database.h',
         'file_system_path_manager.cc',
         'file_system_path_manager.h',
         'file_system_types.h',