minix/external/bsd/kyua-cli/dist/utils/sqlite/database.cpp

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// Copyright 2011 Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// * Neither the name of Google Inc. nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "utils/sqlite/database.hpp"
extern "C" {
#include <sqlite3.h>
}
#include <stdexcept>
#include "utils/format/macros.hpp"
#include "utils/logging/macros.hpp"
#include "utils/sanity.hpp"
#include "utils/sqlite/exceptions.hpp"
#include "utils/sqlite/statement.ipp"
#include "utils/sqlite/transaction.hpp"
namespace sqlite = utils::sqlite;
/// Internal implementation for sqlite::database.
struct utils::sqlite::database::impl {
/// The SQLite 3 internal database.
::sqlite3* db;
/// Whether we own the database or not (to decide if we close it).
bool owned;
/// Constructor.
///
/// \param db_ The SQLite internal database.
/// \param owned_ Whether this object owns the db_ object or not. If it
/// does, the internal db_ will be released during destruction.
impl(::sqlite3* db_, const bool owned_) :
db(db_),
owned(owned_)
{
}
/// Destructor.
///
/// It is important to keep this as part of the 'impl' class instead of the
/// container class. The 'impl' class is destroyed exactly once (because it
/// is managed by a shared_ptr) and thus releasing the resources here is
/// OK. However, the container class is potentially released many times,
/// which means that we would be double-freeing the internal object and
/// reusing invalid data.
~impl(void)
{
if (owned && db != NULL)
close();
}
/// Exception-safe version of sqlite3_open_v2.
///
/// \param file The path to the database file to be opened.
/// \param flags The flags to be passed to the open routine.
///
/// \return The opened database.
///
/// \throw std::bad_alloc If there is not enough memory to open the
/// database.
/// \throw api_error If there is any problem opening the database.
static ::sqlite3*
safe_open(const char* file, const int flags)
{
::sqlite3* db;
const int error = ::sqlite3_open_v2(file, &db, flags, NULL);
if (error != SQLITE_OK) {
if (db == NULL)
throw std::bad_alloc();
else {
sqlite::database error_db(db, true);
throw sqlite::api_error::from_database(error_db,
"sqlite3_open_v2");
}
}
INV(db != NULL);
return db;
}
/// Shared code for the public close() method.
void
close(void)
{
PRE(db != NULL);
int error = ::sqlite3_close(db);
// For now, let's consider a return of SQLITE_BUSY an error. We should
// not be trying to close a busy database in our code. Maybe revisit
// this later to raise busy errors as exceptions.
PRE(error == SQLITE_OK);
db = NULL;
}
};
/// Initializes the SQLite database.
///
/// You must share the same database object alongside the lifetime of your
/// SQLite session. As soon as the object is destroyed, the session is
/// terminated.
///
/// \param db_ Raw pointer to the C SQLite 3 object.
/// \param owned_ Whether this instance will own the pointer or not.
sqlite::database::database(void* db_, const bool owned_) :
_pimpl(new impl(static_cast< ::sqlite3* >(db_), owned_))
{
}
/// Destructor for the SQLite 3 database.
///
/// Closes the session unless it has already been closed by calling the
/// close() method. It is recommended to explicitly close the session in the
/// code.
sqlite::database::~database(void)
{
}
/// Opens a memory-based temporary SQLite database.
///
/// \return An in-memory database instance.
///
/// \throw std::bad_alloc If there is not enough memory to open the database.
/// \throw api_error If there is any problem opening the database.
sqlite::database
sqlite::database::in_memory(void)
{
return database(impl::safe_open(":memory:", SQLITE_OPEN_READWRITE), true);
}
/// Opens a named on-disk SQLite database.
///
/// \param file The path to the database file to be opened. This does not
/// accept the values "" and ":memory:"; use temporary() and in_memory()
/// instead.
/// \param open_flags The flags to be passed to the open routine.
///
/// \return A file-backed database instance.
///
/// \throw std::bad_alloc If there is not enough memory to open the database.
/// \throw api_error If there is any problem opening the database.
sqlite::database
sqlite::database::open(const fs::path& file, int open_flags)
{
PRE_MSG(!file.str().empty(), "Use database::temporary() instead");
PRE_MSG(file.str() != ":memory:", "Use database::in_memory() instead");
int flags = 0;
if (open_flags & open_readonly) {
flags |= SQLITE_OPEN_READONLY;
open_flags &= ~open_readonly;
}
if (open_flags & open_readwrite) {
flags |= SQLITE_OPEN_READWRITE;
open_flags &= ~open_readwrite;
}
if (open_flags & open_create) {
flags |= SQLITE_OPEN_CREATE;
open_flags &= ~open_create;
}
PRE(open_flags == 0);
return database(impl::safe_open(file.c_str(), flags), true);
}
/// Opens an unnamed on-disk SQLite database.
///
/// \return A file-backed database instance.
///
/// \throw std::bad_alloc If there is not enough memory to open the database.
/// \throw api_error If there is any problem opening the database.
sqlite::database
sqlite::database::temporary(void)
{
return database(impl::safe_open("", SQLITE_OPEN_READWRITE), true);
}
/// Gets the internal sqlite3 object.
///
/// \return The raw SQLite 3 database. This is returned as a void pointer to
/// prevent including the sqlite3.h header file from our public interface. The
/// only way to call this method is by using the c_gate module, and c_gate takes
/// care of casting this object to the appropriate type.
void*
sqlite::database::raw_database(void)
{
return _pimpl->db;
}
/// Terminates the connection to the database.
///
/// It is recommended to call this instead of relying on the destructor to do
/// the cleanup, but it is not a requirement to use close().
///
/// \pre close() has not yet been called.
void
sqlite::database::close(void)
{
_pimpl->close();
}
/// Executes an arbitrary SQL string.
///
/// As the documentation explains, this is unsafe. The code should really be
/// preparing statements and executing them step by step. However, it is
/// perfectly fine to use this function for, e.g. the initial creation of
/// tables in a database and in tests.
///
/// \param sql The SQL commands to be executed.
///
/// \throw api_error If there is any problem while processing the SQL.
void
sqlite::database::exec(const std::string& sql)
{
const int error = ::sqlite3_exec(_pimpl->db, sql.c_str(), NULL, NULL, NULL);
if (error != SQLITE_OK)
throw api_error::from_database(*this, "sqlite3_exec");
}
/// Opens a new transaction.
///
/// \return An object representing the state of the transaction.
///
/// \throw api_error If there is any problem while opening the transaction.
sqlite::transaction
sqlite::database::begin_transaction(void)
{
exec("BEGIN TRANSACTION");
return transaction(*this);
}
/// Prepares a new statement.
///
/// \param sql The SQL statement to prepare.
///
/// \return The prepared statement.
sqlite::statement
sqlite::database::create_statement(const std::string& sql)
{
LD(F("Creating statement: %s") % sql);
sqlite3_stmt* stmt;
const int error = ::sqlite3_prepare_v2(_pimpl->db, sql.c_str(),
sql.length() + 1, &stmt, NULL);
if (error != SQLITE_OK)
throw api_error::from_database(*this, "sqlite3_prepare_v2");
return statement(*this, static_cast< void* >(stmt));
}
/// Returns the row identifier of the last insert.
///
/// \return A row identifier.
int64_t
sqlite::database::last_insert_rowid(void)
{
return ::sqlite3_last_insert_rowid(_pimpl->db);
}