/*
 * Copyright 2020 UT OVERSEAS INC
 *
 * Licensed 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
 *
 * https://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.
 */

use crate::concurrent::broadcast::BroadcastTransmitError;
use crate::utils::{
    bit_utils::is_power_of_two,
    misc::CACHE_LINE_LENGTH,
    types::{Index, I64_SIZE},
};

pub const TAIL_INTENT_COUNTER_OFFSET: Index = 0;
pub const TAIL_COUNTER_OFFSET: Index = TAIL_INTENT_COUNTER_OFFSET + I64_SIZE as Index;
pub const LATEST_COUNTER_OFFSET: Index = TAIL_COUNTER_OFFSET + I64_SIZE as Index;
pub const TRAILER_LENGTH: Index = CACHE_LINE_LENGTH * 2;

pub fn check_capacity(capacity: Index) -> Result<(), BroadcastTransmitError> {
    if !is_power_of_two(capacity) {
        Err(BroadcastTransmitError::NotPowerOfTwo(capacity))
    } else {
        Ok(())
    }
}