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: crate_handler.rs
    path of file: ./repos/solana/cargo-registry/src
    
    the code of the file until where you have to start completion: use {
    crate::{
        client::{Client, RPCCommandConfig},
        sparse_index::{IndexEntry, RegistryIndex},
    },
    flate2::{
        read::{GzDecoder, GzEncoder},
        Compression,
    },
    hyper::body::Bytes,
    log::*,
    serde::{Deserialize, Serialize},
    serde_json::from_slice,
    sha2::{Digest, Sha256},
    solana_cli::program_v4::{process_deploy_program, process_dump, read_and_verify_elf},
    solana_sdk::{
        pubkey::Pubkey,
        signature::{Keypair, Signer},
        signer::EncodableKey,
    },
    std::{
        collections::BTreeMap,
        fs,
        io::{Cursor, Read},
        mem::size_of,
        ops::Deref,
        path::{Path, PathBuf},
        sync::Arc,
    },
    tar::{Archive, Builder, HeaderMode},
    tempfile::{tempdir, TempDir},
};

const APPEND_CRATE_TO_ELF: bool = true;

pub(crate) type Error = Box<dyn std::error::Error + Send + Sync + 'static>;

#[derive(Clone, Debug, Deserialize, Serialize)]
    
    fn decompress(packed_crate: PackedCrate, meta: PackageMetaData) -> Result<Self, Error> {
        let cksum = format!("{:x}", Sha256::digest(&packed_crate.0));

        let decoder = GzDecoder::new(packed_crate.0.as_ref());
        let mut archive = Archive::new(decoder);

        let tempdir = tempdir()?;
        archive.unpack(tempdir.path())?;

        let lib_name = UnpackedCrate::program_library_name(&tempdir, &meta)?;

        let program_path =
            UnpackedCrate::make_path(&tempdir, &meta, format!("out/{}.so", lib_name))
                .into_os_string()
                .into_string()
                .map_err(|_| "Failed to get program file path")?;

        let keypair = Keypair::read_from_file(UnpackedCrate::make_path(
            &tempdir,
            &meta,
            format!("out/{}-keypair.json", lib_name),
        ))
        .map_err(|e| format!("Failed to get keypair from the file: {}", e))?;

        Ok(UnpackedCrate {
            meta,
            cksum,
            tempdir: Arc::new(tempdir),
            program_path,
            program_id: keypair.pubkey(),
            keypair: Some(keypair),
            packed_crate,
        })
    }