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: lib.rs
    path of file: ./repos/streamdal/libs/wasm/validjson/src
    
    the code of the file until where you have to start completion: use protos::sp_wsm::{WASMExitCode, WASMRequest};
use streamdal_gjson;

#[no_mangle]
pub extern "C" fn f(ptr: *mut u8, length: usize) -> u64 {
    // Read request
    let wasm_request = match common::read_request(ptr, length) {
        Ok(req) => req,
        Err(e) => {
            return common::write_response(
                None,
                None,
                None,
                WASMExitCode::WASM_EXIT_CODE_ERROR,
                format!("unable to read request: {}", e),
            );
        }
    };

    // Validate request
    if let Err(err) = validate_wasm_request(&wasm_request) {
        common::write_response(
            None,
            None,
            None,
            WASMExitCode::WASM_EXIT_CODE_ERROR,
            format!("invalid wasm request: {}", err),
        );
    }

    let orig_payload = wasm_request.input_payload.as_slice();

    let str_json = match String::from_utf8(orig_payload.to_vec()) {
        Ok(v) => v,
        Err(e) => {
            return common::write_response(
                None,
                None,
                None,
                WASMExitCode::WASM_EXIT_CODE_ERROR,
                format!("u
    
pub extern "C" fn f(ptr: *mut u8, length: usize) -> u64 {
    // Read request
    let wasm_request = match common::read_request(ptr, length) {
        Ok(req) => req,
        Err(e) => {
            return common::write_response(
                None,
                None,
                None,
                WASMExitCode::WASM_EXIT_CODE_ERROR,
                format!("unable to read request: {}", e),
            );
        }
    };

    // Validate request
    if let Err(err) = validate_wasm_request(&wasm_request) {
        common::write_response(
            None,
            None,
            None,
            WASMExitCode::WASM_EXIT_CODE_ERROR,
            format!("invalid wasm request: {}", err),
        );
    }

    let orig_payload = wasm_request.input_payload.as_slice();

    let str_json = match String::from_utf8(orig_payload.to_vec()) {
        Ok(v) => v,
        Err(e) => {
            return common::write_response(
                None,
                None,
                None,
                WASMExitCode::WASM_EXIT_CODE_ERROR,
                format!("unable to convert input_payload to string: {}", e),
            );
        }
    };

    if streamdal_gjson::valid(str_json.as_str()) {
        common::write_response(
            Some(orig_payload),
            None,
            None,
            WASMExitCode::WASM_EXIT_CODE_TRUE,
            "".to_string(),
        )
    } else {
        common::write_response(
            Some(orig_payload),
            None,
            None,
            WASMExitCode::WASM_EXIT_CODE_FALSE,
            "invalid JSON".to_string(),
        )
    }
}