turso/core/pager.rs

use crate::buffer_pool;
use crate::buffer_pool::BufferPool;
use crate::sqlite3_ondisk;
use crate::IO;
use anyhow::Result;
use std::sync::Arc;

pub struct Pager {
    _io: Arc<dyn IO>,
    _buffer_pool: BufferPool,
}

impl Pager {
    pub fn open(io: Arc<dyn IO>, path: &str) -> Result<Self> {
        let database_ref = io.open(path)?;
        let db_header = sqlite3_ondisk::read_database_header(io.clone(), database_ref)?;
        let page_size = db_header.page_size as usize;
        let mut buffer_pool = buffer_pool::BufferPool::new(page_size);
        let _ = sqlite3_ondisk::read_btree_page(io.clone(), database_ref, &mut buffer_pool, 1)?;
        Ok(Self {
            _io: io,
            _buffer_pool: buffer_pool,
        })
    }
}