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// Copyright 2024 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROMEOS_ASH_COMPONENTS_FILE_MANAGER_INDEXING_TEXT_TABLE_H_
#define CHROMEOS_ASH_COMPONENTS_FILE_MANAGER_INDEXING_TEXT_TABLE_H_
#include <memory>
#include <optional>
#include <string>
#include "base/component_export.h"
#include "base/memory/raw_ptr.h"
#include "sql/database.h"
#include "sql/statement.h"
namespace ash::file_manager {
// A table that maintains a mapping from a unique value ID to the value text.
// This is the base class for two tables that are built on top of it: term
// table and URL table. This class is not meant to be used by itself.
class COMPONENT_EXPORT(FILE_MANAGER) TextTable {
public:
// Initializes the table. Returns true on success, and false on failure.
bool Init();
protected:
// Creates a new table and passes the pointer to the SQL database to it. The
// caller must make sure it owns both the sql::Database object and this table.
// The caller also must make sure that the sql::Database outlives the table.
TextTable(sql::Database* db, const std::string& table_name);
virtual ~TextTable();
TextTable(const TextTable&) = delete;
TextTable& operator=(const TextTable&) = delete;
// Deletes the given value from the table. Returns -1, if the value was not
// found. Otherwise, returns the ID that the value was assigned.
int64_t DeleteValue(const std::string& term);
// Gets the value ID for the given value. If the value does not exists, this
// method returns -1. Otherwise it returns the unique ID assigned to the
// value.
int64_t GetValueId(const std::string& value) const;
// Gets or creates an ID for the given value. If the value does not exist,
// it is inserted into the table and the unique key assigned to is returned.
int64_t GetOrCreateValueId(const std::string& value);
// Populates the value with the value for the given ID, if found. If not
// found, returns -1 and leaves `value` unchanged.
std::optional<std::string> GetValue(int64_t value_id) const;
// Without changing the ID associated with the value, it changes it from
// from string, to to string.
int64_t ChangeValue(const std::string& from, const std::string& to);
// To be overridden by the extending classes.
// Returns a statement that gets text ID by value.
virtual std::unique_ptr<sql::Statement> MakeGetValueIdStatement() const = 0;
// Returns a statement that gets text value by its ID.
virtual std::unique_ptr<sql::Statement> MakeGetValueStatement() const = 0;
// Returns a statement that inserts text value into the table.
virtual std::unique_ptr<sql::Statement> MakeInsertStatement() const = 0;
// Returns a statement that deletes a value by its ID.
virtual std::unique_ptr<sql::Statement> MakeDeleteStatement() const = 0;
// Returns a statement that creates a table that maps text ID to text value.
virtual std::unique_ptr<sql::Statement> MakeCreateTableStatement() const = 0;
// Returns a statement that creates an index for the table; may return null.
virtual std::unique_ptr<sql::Statement> MakeCreateIndexStatement() const = 0;
// Returns a statement that changes a value to a new value.
virtual std::unique_ptr<sql::Statement> MakeChangeValueStatement() const = 0;
// The name of the concrete table built on top of this class.
const std::string table_name_;
// The pointer to a database owned by the whoever created this table.
raw_ptr<sql::Database> db_;
};
} // namespace ash::file_manager
#endif // CHROMEOS_ASH_COMPONENTS_FILE_MANAGER_INDEXING_TEXT_TABLE_H_
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