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// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

#![feature(iter_advance_by)]

mod compression;

#[macro_use]
mod errors;

pub use compression::CommonCompression;

pub mod read;
pub mod write;

#[macro_use]
mod util;

const ARROW_MAGIC: [u8; 6] = [b'A', b'R', b'R', b'O', b'W', b'2'];
pub(crate) const CONTINUATION_MARKER: [u8; 4] = [0xff; 4];

#[derive(
    Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd, serde::Serialize, serde::Deserialize,
)]
pub struct ColumnMeta {
    pub offset: u64,
    pub pages: Vec<PageMeta>,
}

impl ColumnMeta {
    // [start_page_index, end_page_index)
    pub fn slice(&self, start_page_index: usize, end_page_index: usize) -> Self {
        assert!(start_page_index < self.pages.len());
        assert!(end_page_index <= self.pages.len());

        let offset = self
            .pages
            .iter()
            .take(start_page_index)
            .map(|meta| meta.length)
            .sum::<u64>()
            + self.offset;
        let pages = self.pages[start_page_index..end_page_index].to_vec();

        Self { offset, pages }
    }

    pub fn skip_one_page(&self) -> Self {
        self.slice(1, self.pages.len())
    }

    pub fn total_len(&self) -> u64 {
        self.pages.iter().map(|m| m.length).sum::<u64>()
    }
}

#[derive(
    Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd, serde::Serialize, serde::Deserialize,
)]
pub struct PageMeta {
    // compressed size of this page
    pub length: u64,
    // num values(rows) of this page
    pub num_values: u64,
}