argmin/core/observers/
slog_logger.rs

1// Copyright 2018-2020 argmin developers
2//
3// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
4// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
5// http://opensource.org/licenses/MIT>, at your option. This file may not be
6// copied, modified, or distributed except according to those terms.
7
8//! # Loggers based on the `slog` crate
9
10use crate::core::{ArgminKV, ArgminOp, Error, IterState, Observe};
11use slog;
12use slog::{info, o, Drain, Record, Serializer, KV};
13use slog_async;
14use slog_async::OverflowStrategy;
15use slog_json;
16use slog_term;
17use std::fs::OpenOptions;
18use std::sync::Mutex;
19
20/// A logger based on `slog`
21#[derive(Clone)]
22pub struct ArgminSlogLogger {
23    /// the logger
24    logger: slog::Logger,
25}
26
27impl ArgminSlogLogger {
28    /// Log to the terminal in a blocking way
29    pub fn term() -> Self {
30        ArgminSlogLogger::term_internal(OverflowStrategy::Block)
31    }
32
33    /// Log to the terminal in a non-blocking way (in case of overflow, messages are dropped)
34    pub fn term_noblock() -> Self {
35        ArgminSlogLogger::term_internal(OverflowStrategy::Drop)
36    }
37
38    /// Actual implementation of the logging to the terminal
39    fn term_internal(overflow_strategy: OverflowStrategy) -> Self {
40        let decorator = slog_term::TermDecorator::new().build();
41        let drain = slog_term::FullFormat::new(decorator)
42            .use_original_order()
43            .build()
44            .fuse();
45        let drain = slog_async::Async::new(drain)
46            .overflow_strategy(overflow_strategy)
47            .build()
48            .fuse();
49        ArgminSlogLogger {
50            logger: slog::Logger::root(drain, o!()),
51        }
52    }
53
54    /// Log JSON to a file in a blocking way
55    ///
56    /// If `truncate` is set to `true`, the content of existing log files at `file` will be
57    /// cleared.
58    pub fn file(file: &str, truncate: bool) -> Result<Self, Error> {
59        ArgminSlogLogger::file_internal(file, OverflowStrategy::Block, truncate)
60    }
61
62    /// Log JSON to a file in a non-blocking way (in case of overflow, messages are dropped)
63    ///
64    /// If `truncate` is set to `true`, the content of existing log files at `file` will be
65    /// cleared.
66    pub fn file_noblock(file: &str, truncate: bool) -> Result<Self, Error> {
67        ArgminSlogLogger::file_internal(file, OverflowStrategy::Drop, truncate)
68    }
69
70    /// Actual implementaiton of logging JSON to file
71    fn file_internal(
72        file: &str,
73        overflow_strategy: OverflowStrategy,
74        truncate: bool,
75    ) -> Result<Self, Error> {
76        // Logging to file
77        let file = OpenOptions::new()
78            .create(true)
79            .write(true)
80            .truncate(truncate)
81            .open(file)?;
82        let drain = Mutex::new(slog_json::Json::new(file).build()).map(slog::Fuse);
83        let drain = slog_async::Async::new(drain)
84            .overflow_strategy(overflow_strategy)
85            .build()
86            .fuse();
87        Ok(ArgminSlogLogger {
88            logger: slog::Logger::root(drain, o!()),
89        })
90    }
91}
92
93/// This type is necessary in order to be able to implement `slog::KV` on `ArgminKV`
94pub struct ArgminSlogKV {
95    /// Key value store
96    pub kv: Vec<(&'static str, String)>,
97}
98
99impl KV for ArgminSlogKV {
100    fn serialize(&self, _record: &Record, serializer: &mut dyn Serializer) -> slog::Result {
101        for idx in self.kv.clone().iter().rev() {
102            serializer.emit_str(idx.0, &idx.1.to_string())?;
103        }
104        Ok(())
105    }
106}
107
108impl<O: ArgminOp> KV for IterState<O> {
109    fn serialize(&self, _record: &Record, serializer: &mut dyn Serializer) -> slog::Result {
110        serializer.emit_str(
111            "modify_func_count",
112            &self.get_modify_func_count().to_string(),
113        )?;
114        serializer.emit_str(
115            "hessian_func_count",
116            &self.get_hessian_func_count().to_string(),
117        )?;
118        serializer.emit_str(
119            "jacobian_func_count",
120            &self.get_jacobian_func_count().to_string(),
121        )?;
122        serializer.emit_str("grad_func_count", &self.get_grad_func_count().to_string())?;
123        serializer.emit_str("cost_func_count", &self.get_cost_func_count().to_string())?;
124        serializer.emit_str("best_cost", &self.get_best_cost().to_string())?;
125        serializer.emit_str("cost", &self.get_cost().to_string())?;
126        serializer.emit_str("iter", &self.get_iter().to_string())?;
127        Ok(())
128    }
129}
130
131impl<'a> From<&'a ArgminKV> for ArgminSlogKV {
132    fn from(i: &'a ArgminKV) -> ArgminSlogKV {
133        ArgminSlogKV { kv: i.kv.clone() }
134    }
135}
136
137impl<O: ArgminOp> Observe<O> for ArgminSlogLogger {
138    /// Log general info
139    fn observe_init(&self, msg: &str, kv: &ArgminKV) -> Result<(), Error> {
140        info!(self.logger, "{}", msg; ArgminSlogKV::from(kv));
141        Ok(())
142    }
143
144    /// This should be used to log iteration data only (because this is what may be saved in a CSV
145    /// file or a database)
146    fn observe_iter(&mut self, state: &IterState<O>, kv: &ArgminKV) -> Result<(), Error> {
147        info!(self.logger, ""; state, ArgminSlogKV::from(kv));
148        Ok(())
149    }
150}
151
152#[cfg(test)]
153mod tests {
154    use super::*;
155
156    send_sync_test!(argmin_slog_loggerv, ArgminSlogLogger);
157}
argmin/core/observers/slog_logger.rs

argmin/core/observers/
slog_logger.rs
