bindings/haskell/src/logger.rs

// 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.

use std::ffi::c_char;
use std::ffi::CString;

pub struct HsLogger {
    pub callback: extern "C" fn(u32, *const c_char),
}

impl log::Log for HsLogger {
    fn enabled(&self, _: &log::Metadata) -> bool {
        true
    }

    fn log(&self, record: &log::Record) {
        let msg = format!("{}", record.args());
        let c_str_msg = CString::new(msg).unwrap();
        let c_level = match record.level() {
            log::Level::Debug => 0,
            log::Level::Info => 1,
            log::Level::Warn => 2,
            log::Level::Error => 3,
            _ => 0,
        };
        (self.callback)(c_level, c_str_msg.as_ptr());
    }

    fn flush(&self) {}
}