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: compaction.rs
    path of file: ./repos/cube/rust/cubestore/cubestore/src/cachestore
    
    the code of the file until where you have to start completion: use crate::metastore::{
    IndexId, RocksSecondaryIndexValue, RocksSecondaryIndexValueVersion, RowKey, SecondaryIndexInfo,
};
use crate::TableId;

use chrono::{DateTime, Utc};
use log::trace;
use rocksdb::compaction_filter::CompactionFilter;
use rocksdb::compaction_filter_factory::{CompactionFilterContext, CompactionFilterFactory};
use rocksdb::CompactionDecision;
use std::collections::HashMap;
use std::ffi::{CStr, CString};
use std::sync::{Arc, Mutex};
use tracing::{error, warn};

pub struct MetaStoreCacheCompactionFilter {
    name: CString,
    current: DateTime<Utc>,
    scanned: u64,
    removed: u64,
    orphaned: u64,
    state: CompactionSharedState,
    context: CompactionFilterContext,
}

impl MetaStoreCacheCompactionFilter {
    pub fn new(state: CompactionSharedState, context: CompactionFilterContext) -> Self {
        Self {
            name: CString::new("cache-expire-check").unwrap(),
            current: Utc::now(),
            scanned: 0,
            removed: 0,
            orphaned: 0,
            state,
            context,
        }
    }
}

impl Drop for MetaStoreCacheCompact
    
    fn filter_table_row_key(&mut self, table_id: TableId, value: &[u8]) -> CompactionDecision {
        if !table_id.has_ttl() {
            return CompactionDecision::Keep;
        }

        let reader = match flexbuffers::Reader::get_root(&value) {
            Ok(r) => r,
            Err(err) => {
                warn!(r#"Unable to deserialize row, error: {}"#, err);

                self.orphaned += 1;

                return CompactionDecision::Remove;
            }
        };

        let root = reader.as_map();
        let expire_key_id = match root.index_key(&"expire") {
            None => {
                return CompactionDecision::Keep;
            }
            Some(idx) => idx,
        };

        let expire = root.idx(expire_key_id);

        if expire.flexbuffer_type() == flexbuffers::FlexBufferType::Null {
            return CompactionDecision::Keep;
        }

        match chrono::NaiveDateTime::from_timestamp_opt(expire.as_i64(), 0) {
            Some(expire) => {
                if DateTime::<Utc>::from_utc(expire, Utc) <= self.current {
                    self.removed += 1;

                    CompactionDecision::Remove
                } else {
                    CompactionDecision::Keep
                }
            }
            None => {
                warn!(
                    r#"Unable to parser date from expire field with value "{}""#,
                    expire
                );

                self.orphaned += 1;

                CompactionDecision::Remove
            }
        }
    }