You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: inner_connection.rs
    path of file: ./repos/rusqlite/src
    
    the code of the file until where you have to start completion: use std::ffi::CStr;
use std::os::raw::{c_char, c_int};
#[cfg(feature = "load_extension")]
use std::path::Path;
use std::ptr;
use std::str;
use std::sync::{Arc, Mutex};

use super::ffi;
use super::str_for_sqlite;
use super::{Connection, InterruptHandle, OpenFlags, PrepFlags, Result};
use crate::error::{error_from_handle, error_from_sqlite_code, error_with_offset, Error};
use crate::raw_statement::RawStatement;
use crate::statement::Statement;

pub struct InnerConnection {
    pub db: *mut ffi::sqlite3,
    // It's unsafe to call `sqlite3_close` while anothe
    
    fn remove_hooks(&mut self) {}

    pub fn db_readonly(&self, db_name: super::DatabaseName<'_>) -> Result<bool> {
        let name = db_name.as_cstring()?;
        let r = unsafe { ffi::sqlite3_db_readonly(self.db, name.as_ptr()) };
        match r {
            0 => Ok(false),
            1 => Ok(true),
            -1 => Err(Error::SqliteFailure(
                ffi::Error::new(ffi::SQLITE_MISUSE),
                Some(format!("{db_name:?} is not the name of a database")),
            )),
            _ => Err(error_from_sqlite_code(
                r,
                Some("Unexpected result".to_owned()),
            )),
        }
    }

    #[cfg(feature = "modern_sqlite")] // 3.37.0
    pub fn txn_state(
        &self,
        db_name: Option<super::DatabaseName<'_>>,
    ) -> Result<super::transaction::TransactionState> {
        let r = if let Some(ref name) = db_name {
            let name = name.as_cstring()?;
            unsafe { ffi::sqlite3_txn_state(self.db, name.as_ptr()) }
        } else {
            unsafe { ffi::sqlite3_txn_state(self.db, ptr::null()) }
        };
        match r {
            0 => Ok(super::transaction::TransactionState::None),
            1 => Ok(super::transaction::TransactionState::Read),
            2 => Ok(super::transaction::TransactionState::Write),
            -1 => Err(Error::SqliteFailure(
                ffi::Error::new(ffi::SQLITE_MISUSE),
                Some(format!("{db_name:?} is not the name of a valid schema")),
            )),
            _ => Err(error_from_sqlite_code(
                r,
                Some("Unexpected result".to_owned()),
            )),
        }
    }

    #[inline]
    #[cfg(feature = "release_memory")]
    pub fn release_memory(&self) -> Result<()> {
        self.decode_result(unsafe { ffi::sqlite3_db_release_memory(self.db) })
    }

    #[cfg(feature = "modern_sqlite")] // 3.41.0
    pub fn is_interrupted(&self) -> bool {
        unsafe { ffi::sqlite3_is_interrupted(self.db) == 1 }
    }
}