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use std::panic::Location; use serde::de::Deserialize; use crate::{Profile, Provider, Metadata}; use crate::error::{Kind, Result}; use crate::value::{Value, Map, Dict, Tag, ConfiguredValueDe}; use crate::coalesce::{Coalescible, Order}; /// Combiner of [`Provider`]s for configuration value extraction. /// /// # Overview /// /// A `Figment` combines providers by merging or joining their provided data. /// The combined value or a subset of the combined value can be extracted into /// any type that implements [`Deserialize`]. Additionally, values can be nested /// in _profiles_, and a profile can be selected via [`Figment::select()`] for /// extraction; the profile to be extracted can be retrieved with /// [`Figment::profile()`] and defaults to [`Profile::Default`]. The [top-level /// docs](crate) contain a broad overview of these topics. /// /// ## Merging vs. Joining /// /// _Merging_ and _joining_ control whether duplicate values are replaced or /// discarded. A _merged_ value replaces an existing value with the same key, /// while a _joined_ value is discarded if a value with the same key exists: /// /// ```rust /// use figment::Figment; /// /// let figment = Figment::from(("key", "original")); /// /// let original: String = figment.extract_inner("key").unwrap(); /// assert_eq!(original, "original"); /// /// let figment = figment.merge(("key", "replaced")); /// let replaced: String = figment.extract_inner("key").unwrap(); /// assert_eq!(replaced, "replaced"); /// /// let figment = figment.join(("key", "joined")); /// let joined: String = figment.extract_inner("key").unwrap(); /// assert_eq!(joined, "replaced"); /// ``` /// /// ## Extraction /// /// The configuration or a subset thereof can be extracted from a `Figment` in /// one of several ways: /// /// * [`Figment::extract()`], which extracts the complete value into any `T: /// Deserialize`. /// * [`Figment::extract_inner()`], which extracts a subset of the value for a /// given key path. /// * [`Figment::find_value()`], which returns the raw, serialized [`Value`] /// for a given key path. /// /// A "key path" is a string of the form `a.b.c` (e.g, `item`, `item.fruits`, /// etc.) where each component delimited by a `.` is a key for the dictionary of /// the preceding key in the path, or the root dictionary if it is the first key /// in the path. See [`Value::find()`] for examples. /// /// ## Metadata /// /// Every value collected by a `Figment` is accompanied by the metadata produced /// by the value's provider. Additionally, [`Metadata::provide_source`] is set /// by `from`, `merge` and `join` to the caller's location. `Metadata` can be /// retrieved in one of several ways: /// /// * [`Figment::metadata()`], which returns an iterator over all of the /// metadata for all values. /// * [`Figment::find_metadata()`], which returns the metadata for a value at /// a given key path. /// * [`Figment::get_metadata()`], which returns the metadata for a given /// [`Tag`], itself retrieved via [`Tagged`] or [`Value::tag()`]. /// /// [`Tagged`]: crate::value::magic::Tagged #[derive(Clone, Debug)] pub struct Figment { pub(crate) profile: Profile, pub(crate) metadata: Map<Tag, Metadata>, pub(crate) value: Result<Map<Profile, Dict>>, } impl Figment { /// Creates a new `Figment` with the default profile selected and no /// providers. /// /// ```rust /// use figment::Figment; /// /// let figment = Figment::new(); /// # assert_eq!(figment.profile(), "default"); /// assert_eq!(figment.metadata().count(), 0); /// ``` pub fn new() -> Self { Figment { metadata: Map::new(), profile: Profile::Default, value: Ok(Map::new()), } } /// Creates a new `Figment` with the default profile selected and an initial /// `provider`. /// /// ```rust /// use figment::Figment; /// use figment::providers::Env; /// /// let figment = Figment::from(Env::raw()); /// # assert_eq!(figment.profile(), "default"); /// assert_eq!(figment.metadata().count(), 1); /// ``` #[track_caller] pub fn from<T: Provider>(provider: T) -> Self { Figment::new().merge(provider) } #[track_caller] fn provide<T: Provider>(mut self, provider: T, order: Order) -> Self { if let Some(map) = provider.__metadata_map() { self.metadata.extend(map); } if let Some(profile) = provider.profile() { self.profile = self.profile.coalesce(profile, order); } let mut metadata = provider.metadata(); metadata.provide_location = Some(Location::caller()); let id = Tag::next(); self.metadata.insert(id, metadata); let tag = Tag::from(id); match (provider.data(), self.value) { (Ok(_), e@Err(_)) => self.value = e, (Err(e), Ok(_)) => self.value = Err(e.retagged(tag)), (Err(e), Err(prev)) => self.value = Err(e.retagged(tag).chain(prev)), (Ok(mut new), Ok(old)) => { new.iter_mut() .map(|(p, map)| std::iter::repeat(p).zip(map.values_mut())) .flatten() .for_each(|(p, v)| v.map_tag(|t| *t = tag.for_profile(p))); self.value = Ok(old.coalesce(new, order)); } } self } /// Joins `provider` into the current figment. See [merging vs. /// joining](#merging-vs-joining) for details. /// /// ```rust /// use figment::Figment; /// use figment::providers::Env; /// /// let figment = Figment::new().join(Env::raw()); /// assert_eq!(figment.metadata().count(), 1); /// ``` #[track_caller] pub fn join<T: Provider>(self, provider: T) -> Self { self.provide(provider, Order::Join) } /// Merges `provider` into the current figment. See [merging vs. /// joining](#merging-vs-joining) for details. /// /// ```rust /// use figment::Figment; /// use figment::providers::Env; /// /// let figment = Figment::new().merge(Env::raw()); /// assert_eq!(figment.metadata().count(), 1); /// ``` #[track_caller] pub fn merge<T: Provider>(self, provider: T) -> Self { self.provide(provider, Order::Merge) } /// Sets the profile to extract from to `profile`. /// /// # Example /// /// ``` /// use figment::Figment; /// /// let figment = Figment::new().select("staging"); /// assert_eq!(figment.profile(), "staging"); /// ``` pub fn select<P: Into<Profile>>(mut self, profile: P) -> Self { self.profile = profile.into(); self } /// Merges the selected profile with the default and global profiles. fn merged(&self) -> Result<Value> { let mut map = self.value.clone()?; let def = map.remove(&Profile::Default).unwrap_or(Dict::new()); let global = map.remove(&Profile::Global).unwrap_or(Dict::new()); let map = match map.remove(&self.profile) { Some(v) if self.profile.is_custom() => def.merge(v).merge(global), _ => def.merge(global) }; Ok(Value::Dict(Tag::Default, map)) } /// Deserializes the collected value into `T`. /// /// # Example /// /// ```rust /// use serde::Deserialize; /// /// use figment::{Figment, providers::{Format, Toml, Json, Env}}; /// /// #[derive(Debug, PartialEq, Deserialize)] /// struct Config { /// name: String, /// numbers: Option<Vec<usize>>, /// debug: bool, /// } /// /// figment::Jail::expect_with(|jail| { /// jail.create_file("Config.toml", r#" /// name = "test" /// numbers = [1, 2, 3, 10] /// "#)?; /// /// jail.set_env("config_name", "env-test"); /// /// jail.create_file("Config.json", r#" /// { /// "name": "json-test", /// "debug": true /// } /// "#)?; /// /// let config: Config = Figment::new() /// .merge(Toml::file("Config.toml")) /// .merge(Env::prefixed("CONFIG_")) /// .join(Json::file("Config.json")) /// .extract()?; /// /// assert_eq!(config, Config { /// name: "env-test".into(), /// numbers: vec![1, 2, 3, 10].into(), /// debug: true /// }); /// /// Ok(()) /// }); /// ``` pub fn extract<'a, T: Deserialize<'a>>(&self) -> Result<T> { let merged = self.merged().map_err(|e| e.resolved(self))?; T::deserialize(ConfiguredValueDe::from(self, &merged)) } /// Deserializes the value at the `key` path in the collected value into /// `T`. /// /// # Example /// /// ```rust /// use figment::{Figment, providers::{Format, Toml, Json}}; /// /// figment::Jail::expect_with(|jail| { /// jail.create_file("Config.toml", r#" /// numbers = [1, 2, 3, 10] /// "#)?; /// /// jail.create_file("Config.json", r#"{ "debug": true } "#)?; /// /// let numbers: Vec<usize> = Figment::new() /// .merge(Toml::file("Config.toml")) /// .join(Json::file("Config.json")) /// .extract_inner("numbers")?; /// /// assert_eq!(numbers, vec![1, 2, 3, 10]); /// /// Ok(()) /// }); /// ``` pub fn extract_inner<'a, T: Deserialize<'a>>(&self, key: &str) -> Result<T> { let merged = self.merged().map_err(|e| e.resolved(self))?; let inner = merged.find(key).ok_or(Kind::MissingField(key.to_string().into()))?; T::deserialize(ConfiguredValueDe::from(self, &inner)) } /// Returns an iterator over the metadata for all of the collected values in /// the order in which they were added to `self`. /// /// # Example /// /// ```rust /// use figment::{Figment, providers::{Format, Toml, Json}}; /// /// let figment = Figment::new() /// .merge(Toml::file("Config.toml")) /// .join(Json::file("Config.json")); /// /// assert_eq!(figment.metadata().count(), 2); /// for (i, md) in figment.metadata().enumerate() { /// match i { /// 0 => assert!(md.name.starts_with("TOML")), /// 1 => assert!(md.name.starts_with("JSON")), /// _ => unreachable!(), /// } /// } /// ``` // In fact, the order in which they were added globally. Why? Because // `BTreeMap` returns values in order of keys, and we generate a new ID, // monotonically greater than the previous, each time a new item is // provided. It's important that the IDs are unique globally since we can // allow combining `Figment`s. pub fn metadata(&self) -> impl Iterator<Item = &Metadata> { self.metadata.values() } /// Returns the selected profile. /// /// # Example /// /// ``` /// use figment::Figment; /// /// let figment = Figment::new(); /// assert_eq!(figment.profile(), "default"); /// /// let figment = figment.select("staging"); /// assert_eq!(figment.profile(), "staging"); /// ``` pub fn profile(&self) -> &Profile { &self.profile } /// Returns an iterator over profiles with valid configurations in this /// figment. **Note:** this may not include the selected profile if the /// selected profile has no configured values. /// /// # Example /// /// ``` /// use figment::{Figment, providers::Serialized}; /// /// let figment = Figment::new(); /// let profiles = figment.profiles().collect::<Vec<_>>(); /// assert_eq!(profiles.len(), 0); /// /// let figment = Figment::new() /// .join(Serialized::default("key", "hi")) /// .join(Serialized::default("key", "hey").profile("debug")); /// /// let mut profiles = figment.profiles().collect::<Vec<_>>(); /// profiles.sort(); /// assert_eq!(profiles, &["debug", "default"]); /// /// let figment = Figment::new() /// .join(Serialized::default("key", "hi").profile("release")) /// .join(Serialized::default("key", "hi").profile("testing")) /// .join(Serialized::default("key", "hey").profile("staging")) /// .select("debug"); /// /// let mut profiles = figment.profiles().collect::<Vec<_>>(); /// profiles.sort(); /// assert_eq!(profiles, &["release", "staging", "testing"]); /// ``` pub fn profiles(&self) -> impl Iterator<Item = &Profile> { self.value.as_ref() .ok() .map(|v| v.keys()) .into_iter() .flatten() } /// Finds the value at `key` path in the combined value. See /// [`Value::find()`] for details on the syntax for `key`. /// /// # Example /// /// ```rust /// use serde::Deserialize; /// /// use figment::{Figment, providers::{Format, Toml, Json, Env}}; /// /// figment::Jail::expect_with(|jail| { /// jail.create_file("Config.toml", r#" /// name = "test" /// /// [package] /// name = "my-package" /// "#)?; /// /// jail.create_file("Config.json", r#" /// { /// "author": { "name": "Bob" } /// } /// "#)?; /// /// let figment = Figment::new() /// .merge(Toml::file("Config.toml")) /// .join(Json::file("Config.json")); /// /// let name = figment.find_value("name")?; /// assert_eq!(name.as_str(), Some("test")); /// /// let package_name = figment.find_value("package.name")?; /// assert_eq!(package_name.as_str(), Some("my-package")); /// /// let author_name = figment.find_value("author.name")?; /// assert_eq!(author_name.as_str(), Some("Bob")); /// /// Ok(()) /// }); /// ``` pub fn find_value(&self, key: &str) -> Result<Value> { self.merged()? .find(key) .ok_or_else(|| Kind::MissingField(key.to_string().into()).into()) } /// Finds the metadata for the value at `key` path. See [`Value::find()`] /// for details on the syntax for `key`. /// /// # Example /// /// ```rust /// use serde::Deserialize; /// /// use figment::{Figment, providers::{Format, Toml, Json, Env}}; /// /// figment::Jail::expect_with(|jail| { /// jail.create_file("Config.toml", r#" name = "test" "#)?; /// jail.set_env("CONF_AUTHOR", "Bob"); /// /// let figment = Figment::new() /// .merge(Toml::file("Config.toml")) /// .join(Env::prefixed("CONF_").only(&["author"])); /// /// let name_md = figment.find_metadata("name").unwrap(); /// assert!(name_md.name.starts_with("TOML")); /// /// let author_md = figment.find_metadata("author").unwrap(); /// assert!(author_md.name.contains("CONF_")); /// assert!(author_md.name.contains("environment")); /// /// Ok(()) /// }); /// ``` pub fn find_metadata(&self, key: &str) -> Option<&Metadata> { self.metadata.get(&self.find_value(key).ok()?.tag()) } /// Returns the metadata with the given `tag` if this figment contains a /// value with said metadata. /// /// # Example /// /// ```rust /// use serde::Deserialize; /// /// use figment::{Figment, providers::{Format, Toml, Json, Env}}; /// /// figment::Jail::expect_with(|jail| { /// jail.create_file("Config.toml", r#" name = "test" "#)?; /// jail.create_file("Config.json", r#" { "author": "Bob" } "#)?; /// /// let figment = Figment::new() /// .merge(Toml::file("Config.toml")) /// .join(Json::file("Config.json")); /// /// let name = figment.find_value("name").unwrap(); /// let metadata = figment.get_metadata(name.tag()).unwrap(); /// assert!(metadata.name.starts_with("TOML")); /// /// let author = figment.find_value("author").unwrap(); /// let metadata = figment.get_metadata(author.tag()).unwrap(); /// assert!(metadata.name.starts_with("JSON")); /// /// Ok(()) /// }); /// ``` pub fn get_metadata(&self, tag: Tag) -> Option<&Metadata> { self.metadata.get(&tag) } } impl Provider for Figment { fn metadata(&self) -> Metadata { Metadata::default() } fn data(&self) -> Result<Map<Profile, Dict>> { self.value.clone() } fn profile(&self) -> Option<Profile> { Some(self.profile.clone()) } fn __metadata_map(&self) -> Option<Map<Tag, Metadata>> { Some(self.metadata.clone()) } } impl Default for Figment { fn default() -> Self { Figment::new() } } #[test] #[cfg(test)] fn is_send_sync() { fn check_for_send_sync<T: Send + Sync>() {} check_for_send_sync::<Figment>(); }