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Diffstat (limited to 'vendor/log/src/kv/key.rs')
-rw-r--r-- | vendor/log/src/kv/key.rs | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/vendor/log/src/kv/key.rs b/vendor/log/src/kv/key.rs new file mode 100644 index 0000000..4f9a506 --- /dev/null +++ b/vendor/log/src/kv/key.rs @@ -0,0 +1,157 @@ +//! Structured keys. + +use std::borrow::Borrow; +use std::fmt; + +/// A type that can be converted into a [`Key`](struct.Key.html). +pub trait ToKey { + /// Perform the conversion. + fn to_key(&self) -> Key; +} + +impl<'a, T> ToKey for &'a T +where + T: ToKey + ?Sized, +{ + fn to_key(&self) -> Key { + (**self).to_key() + } +} + +impl<'k> ToKey for Key<'k> { + fn to_key(&self) -> Key { + Key { key: self.key } + } +} + +impl ToKey for str { + fn to_key(&self) -> Key { + Key::from_str(self) + } +} + +/// A key in a structured key-value pair. +// These impls must only be based on the as_str() representation of the key +// If a new field (such as an optional index) is added to the key they must not affect comparison +#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)] +pub struct Key<'k> { + key: &'k str, +} + +impl<'k> Key<'k> { + /// Get a key from a borrowed string. + pub fn from_str(key: &'k str) -> Self { + Key { key } + } + + /// Get a borrowed string from this key. + pub fn as_str(&self) -> &str { + self.key + } + + /// Try get a string borrowed for the `'k` lifetime from this key. + pub fn to_borrowed_str(&self) -> Option<&'k str> { + // NOTE: This API leaves room for keys to be owned + Some(self.key) + } +} + +impl<'k> fmt::Display for Key<'k> { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + self.key.fmt(f) + } +} + +impl<'k> AsRef<str> for Key<'k> { + fn as_ref(&self) -> &str { + self.as_str() + } +} + +impl<'k> Borrow<str> for Key<'k> { + fn borrow(&self) -> &str { + self.as_str() + } +} + +impl<'k> From<&'k str> for Key<'k> { + fn from(s: &'k str) -> Self { + Key::from_str(s) + } +} + +#[cfg(feature = "std")] +mod std_support { + use super::*; + + use std::borrow::Cow; + + impl ToKey for String { + fn to_key(&self) -> Key { + Key::from_str(self) + } + } + + impl<'a> ToKey for Cow<'a, str> { + fn to_key(&self) -> Key { + Key::from_str(self) + } + } +} + +#[cfg(feature = "kv_unstable_sval")] +mod sval_support { + use super::*; + + extern crate sval; + extern crate sval_ref; + + use self::sval::Value; + use self::sval_ref::ValueRef; + + impl<'a> Value for Key<'a> { + fn stream<'sval, S: sval::Stream<'sval> + ?Sized>( + &'sval self, + stream: &mut S, + ) -> sval::Result { + self.key.stream(stream) + } + } + + impl<'a> ValueRef<'a> for Key<'a> { + fn stream_ref<S: self::sval::Stream<'a> + ?Sized>( + &self, + stream: &mut S, + ) -> self::sval::Result { + self.key.stream(stream) + } + } +} + +#[cfg(feature = "kv_unstable_serde")] +mod serde_support { + use super::*; + + extern crate serde; + + use self::serde::{Serialize, Serializer}; + + impl<'a> Serialize for Key<'a> { + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + { + self.key.serialize(serializer) + } + } +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn key_from_string() { + assert_eq!("a key", Key::from_str("a key").as_str()); + } +} |