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//! Implementation of the [`log`] logging façade for Fastly Compute@Edge.
//!
//! With this logger configured, [`log`'s logging statements][log-use] will send log messages to
//! your chosen [Real-Time Log Streaming][rtls] endpoints. You should initialize the logger as soon
//! as your program starts. Logging statements will not do anything before initialization.
//!
//! See the [Fastly
//! documentation](https://docs.fastly.com/en/guides/integrations#_logging-endpoints) for more
//! information about configuring logging endpoints for your service.
//!
//! # Getting started
//!
//! All you need to get started is your endpoint name and the level of log messages you want to
//! emit. For example, if you have an endpoint called `my_endpoint`, and you only want to emit log
//! messages at the "Warn" or "Error" level, you can use [`init_simple()`]:
//!
//! ```no_run
//! log_fastly::init_simple("my_endpoint", log::LevelFilter::Warn);
//! log::warn!("This will be written to my_endpoint...");
//! log::info!("...but this won't");
//! ```
//!
//! # Advanced configuration
//!
//! For more precise control, including multiple endpoints and default endpoints for different
//! logging levels, use the [`Builder`] interface. The first example is equivalent to:
//!
//! ```no_run
//! log_fastly::Logger::builder()
//! .max_level(log::LevelFilter::Warn)
//! .default_endpoint("my_endpoint")
//! .init();
//! ```
//!
//! The [`Builder::max_level()`] option sets the most verbose level of logging that will be
//! emitted. Logging statements above that level, like `log::info!()` in the first example, will do
//! nothing.
//!
//! **Note:** The default level is `LevelFilter::Off`, which emits no logging at all. You'll want to
//! change this for most configurations.
//!
//! [`Builder::default_endpoint()`] sets the endpoint used whenever a logging statement is called
//! without a `target` field to specify its endpoint. With the default endpoint set to
//! `my_endpoint`, the logging statements in the first example are equivalent to:
//!
//! ```no_run
//! log::warn!(target: "my_endpoint", "This will be written to my_endpoint...");
//! log::info!(target: "my_endpoint", "...but this won't");
//! ```
//!
//! ## Use with Compute@Edge Log Tailing
//!
//! [Compute@Edge Log Tailing][log-tailing] is helpful for getting debugging output quickly from a
//! Compute@Edge program under development by capturing output from `stdout` or `stderr`. To
//! configure logging to output to `stdout` or `stderr` in addition to the specified log endpoint,
//! enable echoing when building the logger:
//!
//! ```no_run
//! log_fastly::Logger::builder()
//! .max_level(log::LevelFilter::Warn)
//! .default_endpoint("my_endpoint")
//! .echo_stdout(true)
//! .init();
//! ```
//!
//! [log-tailing]: https://www.fastly.com/blog/introducing-compute-edge-log-tailing-for-better-observability-and-easier-debugging
//!
//! ## Multiple endpoints
//!
//! Setting an endpoint as the default will automatically register it for use with the logger, but
//! you can register additional endpoints with [`Builder::endpoint()`]:
//!
//! ```no_run
//! log_fastly::Logger::builder()
//! .max_level(log::LevelFilter::Warn)
//! .default_endpoint("my_endpoint")
//! .endpoint("my_other_endpoint")
//! .init();
//! log::warn!(target: "my_endpoint", "This will be written to my_endpoint...");
//! log::warn!(target: "my_other_endpoint", "...but this will be written to my_other_endpoint");
//! ```
//!
//! ## Per-endpoint logging levels
//!
//! You can also set a per-endpoint logging level, though levels higher than `max_level` are always
//! ignored:
//!
//! ```no_run
//! log_fastly::Logger::builder()
//! .max_level(log::LevelFilter::Warn)
//! .default_endpoint("my_endpoint")
//! .endpoint_level("my_other_endpoint", log::LevelFilter::Trace)
//! .endpoint_level("error_only", log::LevelFilter::Error)
//! .init();
//! log::warn!(target: "my_other_endpoint", "This will be written to my_other_endpoint...");
//! log::trace!(target: "my_other_endpoint", "...but this won't, because max_level wins");
//! log::error!(target: "error_only", "This will be written to error_only...");
//! log::warn!(target: "error_only", "...but this won't, because the endpoint's level is lower");
//! ```
//!
//! ## Per-level default endpoints
//!
//! In the previous examples, the same endpoint is set as the default for all logging levels. You
//! can also specify default endpoints for individual levels using
//! [`Builder::default_level_endpoint()`]. The defaults are combined in order, so you can specify an
//! overall default endpoint, and then as many level-specific endpoints as you need:
//!
//! ```no_run
//! log_fastly::Logger::builder()
//! .max_level(log::LevelFilter::Info)
//! .default_endpoint("my_endpoint")
//! .default_level_endpoint("error_only", log::Level::Error)
//! .init();
//! log::info!("This will be written to my_endpoint...");
//! log::warn!(".. and this will too.");
//! log::error!("But this will be written to error_only");
//! ```
//!
//! ## Module name filters
//!
//! In addition to per-endpoint logging levels, you can set logging levels based on the name of the
//! Rust module that contains the logging statement.
//!
//! No filtering is done based on the module name by default, but if any module name patterns are
//! specified, only log statements that match one of the patterns will be emitted. For example, if
//! your application is a crate called `my_app`, you can filter out any messages other than
//! `my_app`'s :
//!
//! ```no_run
//! # mod some_dependency { pub fn function_that_logs() {} }
//! log_fastly::Logger::builder()
//! .max_level(log::LevelFilter::Info)
//! .default_endpoint("my_endpoint")
//! .filter_module("my_app", log::LevelFilter::Warn)
//! .init();
//! log::warn!("This will be written to my_endpoint");
//! // This won't emit any log messages, because no patterns match `some_dependency`
//! some_dependency::function_that_logs();
//! ```
//!
//! The filter expressions support the full syntax of the [`regex`][regex] crate. This is
//! particularly useful if your patterns overlap, but you'd like to still treat them distinctly. For
//! example, suppose you want to set the log level of the module `my_app::my_module` to be more
//! restrictive than the top level `my_app` module. You can use `$` to make sure the
//! less-restrictive pattern matches to the end of the module name, instead of matching any module
//! name that contains `my_app`:
//!
//! ```no_run
//! mod my_module {
//! pub fn do_a_thing() {
//! log::warn!("This won't be written, because this module's max level is Error");
//! }
//! }
//! log_fastly::Logger::builder()
//! .max_level(log::LevelFilter::Info)
//! .default_endpoint("my_endpoint")
//! .filter_module("my_app$", log::LevelFilter::Warn)
//! .filter_module("my_app::my_module", log::LevelFilter::Error)
//! .init();
//! log::warn!("This will be written to my_endpoint");
//! // This won't emit any log messages, because "my_app$" doesn't match, and "my_app::my_module"
//! // is limited to Error
//! my_module::do_a_thing();
//! ```
//!
//! # Registering endpoints
//!
//! All endpoints used by your logging statements must be registered when the logger is created. The
//! following functions automatically register an endpoint if it is not already registered.
//!
//! - [`init_simple()`]
//! - [`Builder::endpoint()`]
//! - [`Builder::endpoint_level()`]
//! - [`Builder::default_endpoint()`]
//! - [`Builder::default_level_endpoint()`]
//!
//! You can pass the endpoint name as a string, or an explicit [`fastly::log::Endpoint`] value. The
//! following examples are equivalent:
//!
//! ```no_run
//! log_fastly::init_simple("my_endpoint", log::LevelFilter::Info);
//! ```
//!
//! ```no_run
//! log_fastly::init_simple(
//! fastly::log::Endpoint::from_name("my_endpoint"),
//! log::LevelFilter::Info,
//! );
//! ```
//!
//! If a logging statement uses `target: "my_endpoint"` but `my_endpoint` is not registered, the
//! message will be logged to the default endpoint for that level, if one exists.
//!
//! # Endpoint and module name collisions
//!
//! Due to a [limitation of `log`][log-issue], logging from a module with the same name as one of
//! your endpoints will cause logs to be sent to that endpoint, even if no `target` is specified,
//! and the endpoint is not a default. For example, if you have an endpoint named `my_app`, and your
//! application is a crate also called `my_app`:
//!
//! ```no_run
//! log_fastly::Logger::builder()
//! .max_level(log::LevelFilter::Info)
//! .default_endpoint("my_endpoint")
//! .endpoint("my_app")
//! .init();
//! log::info!("This will be written to my_app, even though my_endpoint is the default");
//! log::info!(
//! target: "my_endpoint",
//! "This will be written to my_endpoint, because the target is explicit",
//! );
//! ```
//!
//! We hope to address this issue in future releases, but the current workarounds are to either make
//! sure your endpoint names and crate name are distinct, or use the explicit target syntax whenever
//! logging from your top-level module.
//!
//! [log]: https://docs.rs/log
//! [log-use]: https://docs.rs/log#use
//! [rtls]: https://docs.fastly.com/en/guides/about-fastlys-realtime-log-streaming-features
//! [regex]: https://docs.rs/regex#syntax
//! [log-issue]: https://github.com/rust-lang/log/issues/390
// Warnings (other than unused variables) in doctests are promoted to errors.
#![doc(test(attr(deny(warnings))))]
#![doc(test(attr(allow(dead_code))))]
#![doc(test(attr(allow(unused_variables))))]
#![warn(missing_docs)]
#![deny(rustdoc::broken_intra_doc_links)]
#![deny(rustdoc::invalid_codeblock_attributes)]
#[cfg(feature = "native-test-stubs")]
mod native_test_stubs;
#[cfg(feature = "native-test-stubs")]
pub use native_test_stubs::*;
#[cfg(not(feature = "native-test-stubs"))]
use fastly::{
error::{anyhow, Error},
log::Endpoint,
};
use log::{Level, LevelFilter, Log, Metadata, Record};
use regex::{RegexSet, RegexSetBuilder};
use std::collections::HashMap;
use std::io::Write;
/// An implementation of the [`log::Log`] trait for Fastly Compute@Edge.
///
/// Create and initialize a `Logger` by using the builder returned by [`Logger::builder()`].
#[derive(Debug)]
pub struct Logger {
/// All of the endpoints that are registered with the logger.
endpoints: HashMap<String, (Endpoint, Option<LevelFilter>)>,
/// Default endpoints for each of the log levels.
default_endpoints: HashMap<Level, Endpoint>,
/// The maximum log level for all endpoints.
max_level: LevelFilter,
/// An optional matcher for each log level
module_filters: Option<HashMap<Level, RegexSet>>,
/// Whether to echo all log messages to `stdout`.
echo_stdout: bool,
/// Whether to echo all log messages to `stderr`.
echo_stderr: bool,
}
impl Log for Logger {
fn enabled(&self, metadata: &Metadata) -> bool {
self.lookup_endpoint(metadata, None).is_some()
}
fn log(&self, record: &Record) {
if let Some(endpoint) = self.lookup_endpoint(record.metadata(), record.module_path()) {
// Collapse the formatting of the message into a String, so that we only call the
// underlying `write` once. This prevents the message from being split into multiple
// lines in surprising ways, depending on how the format arguments are structured.
let msg = format!("{}", record.args());
// Given the type, we don't really have much of a choice about what to do if this goes
// wrong; panicking is probably not the right thing.
let _ = write!(endpoint.clone(), "{}", msg);
if self.echo_stdout {
println!("{}", msg);
}
if self.echo_stderr {
eprintln!("{}", msg);
}
}
}
fn flush(&self) {}
}
impl Logger {
/// Get a new [`Builder`].
pub fn builder() -> Builder {
Builder::new()
}
fn max_level(&self) -> LevelFilter {
self.max_level
}
/// Look up an endpoint for a log message.
///
/// Returns `None` if no endpoint was found, or if the filter settings would prevent this
/// message from being emitted.
fn lookup_endpoint(&self, metadata: &Metadata, module_path: Option<&str>) -> Option<&Endpoint> {
let level = metadata.level();
// Immediately filter out any messages above the max level
if level > self.max_level {
return None;
}
if let Some(module_path) = module_path {
// If there is a module filter for this level, try to match it
if let Some(filter) = self.module_filters.as_ref().and_then(|fs| fs.get(&level)) {
if !filter.is_match(module_path) {
return None;
}
}
}
// If the target matches an endpoint, apply the endpoint-specific filter
if let Some((endpoint, filter)) = self.endpoints.get(metadata.target()) {
if let Some(filter) = filter {
if level <= *filter {
Some(endpoint)
} else {
None
}
} else {
// If there is no filter, and the level didn't exceed the overall max, log it
Some(endpoint)
}
} else {
// For unrecognized targets, log it if there's a default endpoint for the level
self.default_endpoints.get(&level)
}
}
}
/// A builder type for [`Logger`].
///
/// You can use this builder to register endpoints, set default endpoints, control the levels of
/// logging messages emitted, and filter messages based on module name.
///
/// A `Builder` is consumed by calling [`Builder::init()`] or [`Builder::try_init()`] to build and
/// automatically initialize the logger, or by calling [`Builder::build()`] to build the logger for
/// manual initialization or nesting within another logger. After you call any of these methods, you
/// can no longer call any of them on that same builder.
#[derive(Debug)]
pub struct Builder {
inner: Result<Inner, Error>,
}
#[derive(Debug)]
struct Inner {
/// All of the endpoints that are registered with the logger.
endpoints: HashMap<String, (Endpoint, Option<LevelFilter>)>,
/// Default endpoints for each of the log levels.
default_endpoints: HashMap<Level, Endpoint>,
/// The maximum log level for all endpoints.
max_level: LevelFilter,
/// The module patterns we will match for each log level
module_filters: HashMap<LevelFilter, Vec<String>>,
/// Whether to echo all log messages to `stdout`.
echo_stdout: bool,
/// Whether to echo all log messages to `stderr`.
echo_stderr: bool,
}
impl Default for Builder {
fn default() -> Self {
Self::new()
}
}
impl Builder {
/// Create a new `Builder`.
///
/// By default, no endpoints are registered, the maximum log level is set to `Off`, and no
/// module name filtering is done.
pub fn new() -> Self {
let inner = Inner {
endpoints: HashMap::new(),
default_endpoints: HashMap::new(),
max_level: LevelFilter::Off,
module_filters: HashMap::new(),
echo_stdout: false,
echo_stderr: false,
};
Self { inner: Ok(inner) }
}
/// Run a closure on the inner field, if it exists.
fn with_inner<F: FnOnce(&mut Inner) -> R, R>(&mut self, f: F) {
// It's fine not to use this result, because we're deferring errors to `build()`
let _ = self.inner.as_mut().map(f);
}
/// Run a closure on the inner field if it exists, and a fallible argument.
///
/// If the argument is an `Err`, this replaces `inner` with that `Err`.
fn with_inner_and_then<A, F, R, E>(&mut self, arg: Result<A, E>, f: F)
where
F: FnOnce(&mut Inner, A) -> R,
E: Into<Error>,
{
match arg {
Ok(x) => self.with_inner(|i| f(i, x)),
Err(e) => self.inner = Err(e.into()),
}
}
/// Register an endpoint.
///
/// ```no_run
/// log_fastly::Logger::builder()
/// .max_level(log::LevelFilter::Trace)
/// .endpoint("my_endpoint")
/// .init();
/// log::info!(target: "my_endpoint", "Hello");
/// ```
pub fn endpoint<E>(&mut self, endpoint: E) -> &mut Self
where
E: TryInto<Endpoint>,
<E as TryInto<Endpoint>>::Error: Into<Error>,
{
self.with_inner_and_then(endpoint.try_into(), |i, endpoint| {
i.endpoints
.insert(endpoint.name().to_owned(), (endpoint, None))
});
self
}
/// Register an endpoint and set the maximum logging level for its messages.
///
/// ```no_run
/// log_fastly::Logger::builder()
/// .max_level(log::LevelFilter::Trace)
/// .endpoint_level("debug_endpoint", log::LevelFilter::Debug)
/// .init();
/// log::info!(target: "debug_endpoint", "This will be written to debug_endpoint...");
/// log::trace!(target: "debug_endpoint", "...but this won't be...");
/// ```
pub fn endpoint_level<E>(&mut self, endpoint: E, level: LevelFilter) -> &mut Self
where
E: TryInto<Endpoint>,
<E as TryInto<Endpoint>>::Error: Into<Error>,
{
self.with_inner_and_then(endpoint.try_into(), |i, endpoint| {
i.endpoints
.insert(endpoint.name().to_owned(), (endpoint, Some(level)))
});
self
}
/// Set the default endpoint for all messages.
///
/// The default endpoint is used when the logging statement does not use the `target:
/// "endpoint"` syntax.
///
/// This overrides any previous default endpoints, set either by this method or by
/// [`Builder::default_level_endpoint()`].
///
/// ```no_run
/// log_fastly::Logger::builder()
/// .max_level(log::LevelFilter::Info)
/// .default_level_endpoint("error_only", log::Level::Error)
/// .default_endpoint("my_endpoint")
/// .endpoint("other_endpoint")
/// .init();
/// log::info!("This will be written to my_endpoint...");
/// log::error!("...and this will too");
/// log::warn!(target: "other_endpoint", "This will go to other_endpoint, though");
/// ```
pub fn default_endpoint<E>(&mut self, endpoint: E) -> &mut Self
where
E: TryInto<Endpoint>,
<E as TryInto<Endpoint>>::Error: Into<Error>,
{
self.with_inner_and_then(endpoint.try_into(), |i, endpoint| {
for level in &[
Level::Error,
Level::Warn,
Level::Info,
Level::Debug,
Level::Trace,
] {
i.default_endpoints.insert(*level, endpoint.clone());
}
});
self
}
/// Set the default endpoint for all messages of the given level.
///
/// The default endpoint is used when the logging statement does not use the `target:
/// "endpoint"` syntax.
///
/// This overrides any previous default endpoints set for this level, either by this method or
/// by [`Builder::default_endpoint()`].
///
/// ```no_run
/// log_fastly::Logger::builder()
/// .max_level(log::LevelFilter::Info)
/// .default_endpoint("my_endpoint")
/// .default_level_endpoint("error_only", log::Level::Error)
/// .endpoint("other_endpoint")
/// .init();
/// log::info!("This will be written to my_endpoint...");
/// log::error!("...but this will be written to error_only");
/// log::error!(target: "other_endpoint", "This will go to other_endpoint, though");
/// ```
pub fn default_level_endpoint<E>(&mut self, endpoint: E, level: Level) -> &mut Self
where
E: TryInto<Endpoint>,
<E as TryInto<Endpoint>>::Error: Into<Error>,
{
self.with_inner_and_then(endpoint.try_into(), |i, endpoint| {
i.default_endpoints.insert(level, endpoint.clone());
i.endpoints
.insert(endpoint.name().to_owned(), (endpoint, None))
});
self
}
/// Set the maximum logging level for all messages.
///
/// No messages that exceed this level will be emitted, even if a higher level is set for a
/// specific endpoint or module name.
///
/// **Note:** The default level is `LevelFilter::Off`, which emits no logging at all. You'll
/// want to change this for most configurations.
///
/// ```no_run
/// log_fastly::Builder::new()
/// .max_level(log::LevelFilter::Warn)
/// .endpoint_level("my_endpoint", log::LevelFilter::Info)
/// .init();
/// log::warn!(target: "my_endpoint", "This will be written to my_endpoint...");
/// log::info!(target: "my_endpoint", "...but this won't");
/// ```
pub fn max_level(&mut self, level: LevelFilter) -> &mut Self {
self.with_inner(|i| i.max_level = level);
self
}
/// Set a logging level for modules whose names match the given [regular
/// expression][regex-syntax].
///
/// By default, logging statements in any module are emitted if their level is within
/// [`Builder::max_level()`] and the level for their target endpoint. If you configure filters
/// with this method, the name of the module calling the logging statement must also match one
/// of the patterns, and be within the filter's specified level.
///
/// ```no_run
/// mod my_module {
/// pub fn do_a_thing() {
/// log::warn!("This won't be written, because this module's max level is Error...");
/// log::error!("...but this will be written");
/// }
/// }
///
/// log_fastly::Logger::builder()
/// .max_level(log::LevelFilter::Info)
/// .default_endpoint("my_endpoint")
/// .filter_module("my_module", log::LevelFilter::Error)
/// .init();
/// log::info!("This won't be written, because it's not in my_module");
/// // This will only emit one log message, because "my_app$" doesn't match, and
/// // "my_app::my_module" is limited to Error
/// my_module::do_a_thing();
/// ```
///
/// [regex-syntax]: https://docs.rs/regex#syntax
pub fn filter_module(&mut self, regex: &str, level: LevelFilter) -> &mut Self {
self.with_inner(|i| {
i.module_filters
.entry(level)
.or_insert_with(|| vec![])
.push(regex.to_owned())
});
self
}
/// Set whether all log messages should be echoed to `stdout` (`false` by default).
///
/// If this is set to `true`, all logging statements will write the message to `stdout` in
/// addition to the specified endpoint. This is particularly useful when debugging with
/// [Compute@Edge Log Tailing][log-tailing].
///
/// [log-tailing]: https://www.fastly.com/blog/introducing-compute-edge-log-tailing-for-better-observability-and-easier-debugging
pub fn echo_stdout(&mut self, enabled: bool) -> &mut Self {
self.with_inner(|i| i.echo_stdout = enabled);
self
}
/// Set whether all log messages should be echoed to `stderr` (`false` by default).
///
/// If this is set to `true`, all logging statements will write the message to `stderr` in
/// addition to the specified endpoint. This is particularly useful when debugging with
/// [Compute@Edge Log Tailing][log-tailing].
///
/// [log-tailing]: https://www.fastly.com/blog/introducing-compute-edge-log-tailing-for-better-observability-and-easier-debugging
pub fn echo_stderr(&mut self, enabled: bool) -> &mut Self {
self.with_inner(|i| i.echo_stderr = enabled);
self
}
/// Build the logger and initialize it as the global logger.
///
/// ```no_run
/// log_fastly::Builder::new()
/// .default_endpoint("my_endpoint")
/// .init();
/// log::info!("Hello");
/// ```
///
/// # Panics
///
/// This may panic for any of the reasons that [`Builder::try_init()`] would return an error.
pub fn init(&mut self) {
self.try_init().expect("log_fastly::Builder::init() failed")
}
/// Build the logger and initialize it as the global logger.
///
/// This will fail with an `Err` value if a global logger is already initialized, or for any of
/// the reasons that [`Builder::build()`] can fail.
///
/// ```no_run
/// log_fastly::Builder::new()
/// .default_endpoint("my_endpoint")
/// .try_init()
/// .unwrap();
/// log::info!("Hello");
/// ```
pub fn try_init(&mut self) -> Result<(), Error> {
let logger = self.build()?;
// Get the overall max level while we still own the logger
let max_level = logger.max_level();
// Now try to install the logger
let res = log::set_boxed_logger(Box::new(logger));
if res.is_ok() {
// And finally set the max level in the global `log` state, if we successfully installed
// the logger
log::set_max_level(max_level);
}
res.map_err(Into::into)
}
/// Build a `Logger`, using up this builder.
///
/// This is mainly useful if you want to manually initialize the logger, or nest it within
/// another [`log::Log`] implementation.
///
/// This will fail with an `Err` value if:
///
/// - This builder has already been used to build a `Logger`.
///
/// - Any of the registered endpoint names are invalid.
///
/// - Any of the module name filters set by [`Builder::filter_module()`] have invalid [regex
/// syntax][regex-syntax].
///
/// ```no_run
/// let logger = log_fastly::Builder::new()
/// .default_endpoint("my_endpoint")
/// .build()
/// .unwrap();
/// log::set_boxed_logger(Box::new(logger)).unwrap();
/// ```
///
/// [regex-syntax]: https://docs.rs/regex#syntax
pub fn build(&mut self) -> Result<Logger, Error> {
let inner = std::mem::replace(
&mut self.inner,
Err(anyhow!("Builder can only be built once")),
)?;
// Calculate the overall max logging level, taking into account all the endpoint-specific
// and default filters.
// First, find the max endpoint-specific log level.
let endpoint_max = inner
.endpoints
.values()
// If an endpoint doesn't have a filter, it's only constrained by the overall
// `max_level`.
.map(|e| e.1.unwrap_or_else(LevelFilter::max))
.max()
.unwrap_or(LevelFilter::Off);
// Then, find the highest log level that has a default logger.
let default_max = inner
.default_endpoints
.keys()
.max()
.map(Level::to_level_filter)
.unwrap_or(LevelFilter::Off);
// Take whichever of these is bigger, but then clamp it with our `max_level` which takes
// precedence.
let max_level = std::cmp::min(inner.max_level, std::cmp::max(endpoint_max, default_max));
let module_filters = generate_module_filters(inner.module_filters)?;
Ok(Logger {
endpoints: inner.endpoints,
default_endpoints: inner.default_endpoints,
max_level,
module_filters,
echo_stdout: inner.echo_stdout,
echo_stderr: inner.echo_stderr,
})
}
}
/// Build a [`RegexSet`] for each logging level from the specified filters.
fn generate_module_filters(
mut regex_map: HashMap<LevelFilter, Vec<String>>,
) -> Result<Option<HashMap<Level, RegexSet>>, Error> {
if regex_map.is_empty() {
Ok(None)
} else {
// build from highest level to lowest, extending the set as we go so that each set contains
// all of the regexes specified for the levels above
let levels = [
LevelFilter::Trace,
LevelFilter::Debug,
LevelFilter::Info,
LevelFilter::Warn,
LevelFilter::Error,
];
let mut module_filters = HashMap::with_capacity(levels.len());
let mut running_regexes = vec![];
for level in levels.iter() {
if let Some(regexes) = regex_map.remove(&level) {
running_regexes.extend(regexes);
}
let matcher = RegexSetBuilder::new(running_regexes.iter()).build()?;
let level = level
.to_level()
.expect("only iterating on LevelFilters that match a Level");
module_filters.insert(level, matcher);
}
Ok(Some(module_filters))
}
}
/// Initialize logging with a single endpoint filtered by log level.
///
/// For advanced configuration, see the [`Builder`] type, and the [module-level
/// documentation](index.html#advanced-configuration).
///
/// ```no_run
/// log_fastly::init_simple("my_endpoint", log::LevelFilter::Warn);
/// log::warn!("This will be written to my_endpoint...");
/// log::info!("...but this won't");
/// ```
pub fn init_simple<E>(endpoint: E, level: LevelFilter)
where
E: TryInto<Endpoint>,
<E as TryInto<Endpoint>>::Error: Into<Error>,
{
Logger::builder()
.default_endpoint(endpoint)
.max_level(level)
.try_init()
.expect("log_fastly::init_simple() failed");
}