libesedb 0.2.7

A safe Rust API for libesedb
Documentation 
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/*
 * A safe Rust API to libesedb
 *
 * Copyright (C) 2022-2024, Oliver Lenehan ~sunsetkookaburra
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

use libesedb_sys::*;
use std::io;
use std::marker::PhantomData;
use std::ptr::null_mut;

use crate::error::ese_result;
use crate::{LongValue, MultiValue};
// use crate::iter::{LoadEntry, IterEntries};
use crate::value::Value;

/// Instance of a ESE database record in a currently open [`crate::Table`].
pub struct Record<'a> {
    ptr: *mut libesedb_record_t,
    _marker: PhantomData<&'a ()>,
}

impl Record<'_> {
    /// Load a specific column/field value by entry number.
    /// Returned [`Value`] is bound to the lifetime of the database record.
    pub fn value(&self, entry: i32) -> io::Result<Value> {
        Value::load(self.ptr, entry)
    }

    pub fn is_long(&self, entry: i32) -> io::Result<bool> {
        Ok(1 == ese_result!(libesedb_record_is_long_value, self.ptr, entry)?)
    }

    pub fn is_multi(&self, entry: i32) -> io::Result<bool> {
        Ok(1 == ese_result!(libesedb_record_is_multi_value, self.ptr, entry)?)
    }

    pub fn long<'a>(&self, entry: i32) -> io::Result<LongValue<'a>> {
        LongValue::load(self.ptr, entry)
    }

    pub fn multi<'a>(&self, entry: i32) -> io::Result<MultiValue<'a>> {
        MultiValue::load(self.ptr, entry)
    }

    /// Returns number of values (columns/fields) in the record.
    pub fn count_values(&self) -> io::Result<i32> {
        let mut n = 0;
        ese_result!(libesedb_record_get_number_of_values, self.ptr, &mut n)?;
        Ok(n)
    }

    /// Create an iterator over all the (column/field) values in the table record.
    /// The [`IterEntries`] iterator and the returned [`Value`]s
    /// are bound to the lifetime of the database record.
    ///
    /// ```no_run
    /// # use libesedb::EseDb;
    /// # use std::io;
    /// # fn main() -> io::Result<()> {
    /// #     let db = EseDb::open("Catalog1.edb")?;
    /// #     let table = db.table(0)?;
    /// #     let record = table.record(0)?;
    /// #
    /// for value in record.iter_values()? {
    ///     println!("{:?}", value?);
    /// }
    /// #
    /// #     Ok(())
    /// # }
    /// ```
    pub fn iter_values(&self) -> io::Result<impl Iterator<Item = io::Result<Value>> + '_> {
        Ok((0..self.count_values()?).map(|i| Value::load(self.ptr, i)))
    }

    #[deprecated]
    /// When done reading, call this to free resources the record is using in memory.
    pub fn close(self) {}

    pub(crate) fn load<'a>(
        table_handle: *mut libesedb_table_t,
        entry: i32,
    ) -> io::Result<Record<'a>> {
        let mut ptr = null_mut();
        ese_result!(libesedb_table_get_record, table_handle, entry, &mut ptr)?;
        Ok(Record::<'a> {
            ptr,
            _marker: PhantomData,
        })
    }
}

impl Drop for Record<'_> {
    fn drop(&mut self) {
        unsafe {
            libesedb_record_free(&mut self.ptr, null_mut());
        }
    }
}