fix cookbook

Author: antonilol

heed/src/cookbook.rs

@@ -147,14 +147,15 @@
 //!
 //! ```
 //! use std::borrow::Cow;
+//! use std::convert::Infallible;
 //! use std::error::Error;
 //! use std::fs;
 //! use std::path::Path;
 //!
 //! use heed::types::*;
-//! use heed::{BoxedError, BytesDecode, BytesEncode, Database, EnvOpenOptions};
+//! use heed::{BoxedError, BytesDecode, ToBytes, Database, EnvOpenOptions};
 //!
-//! #[derive(Debug, PartialEq, Eq)]
+//! #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 //! pub enum Level {
 //!     Debug,
 //!     Warn,
@@ -169,21 +170,23 @@
 //!
 //! pub struct LogKeyCodec;
 //!
-//! impl<'a> BytesEncode<'a> for LogKeyCodec {
-//!     type EItem = LogKey;
+//! impl<'a> ToBytes<'a> for LogKeyCodec {
+//!     type SelfType = LogKey;
+//!
+//!     type ReturnBytes = [u8; 5];
+//!
+//!     type Error = Infallible;
 //!
 //!     /// Encodes the u32 timestamp in big endian followed by the log level with a single byte.
-//!     fn bytes_encode(log: &Self::EItem) -> Result<Cow<[u8]>, BoxedError> {
-//!         let (timestamp_bytes, level_byte) = match log {
-//!             LogKey { timestamp, level: Level::Debug } => (timestamp.to_be_bytes(), 0),
-//!             LogKey { timestamp, level: Level::Warn } => (timestamp.to_be_bytes(), 1),
-//!             LogKey { timestamp, level: Level::Error } => (timestamp.to_be_bytes(), 2),
-//!         };
+//!     fn to_bytes(log: &'a Self::SelfType) -> Result<Self::ReturnBytes, Self::Error> {
+//!         let mut output = [0; 5];
 //!
-//!         let mut output = Vec::new();
-//!         output.extend_from_slice(&timestamp_bytes);
-//!         output.push(level_byte);
-//!         Ok(Cow::Owned(output))
+//!         let [timestamp @ .., level] = &mut output;
+//!
+//!         *timestamp = log.timestamp.to_be_bytes();
+//!         *level = log.level as u8;
+//!
+//!         Ok(output)
 //!     }
 //! }
 //!
@@ -215,12 +218,17 @@
 //! /// the logs that appeared during a, rather long, period.
 //! pub struct LogAtHalfTimestampCodec;
 //!
-//! impl<'a> BytesEncode<'a> for LogAtHalfTimestampCodec {
-//!     type EItem = u32;
+//! impl<'a> ToBytes<'a> for LogAtHalfTimestampCodec {
+//!     type SelfType = u32;
+//!
+//!     type ReturnBytes = [u8; 2];
+//!
+//!     type Error = Infallible;
 //!
 //!     /// This method encodes only the prefix of the keys in this particular case, the timestamp.
-//!     fn bytes_encode(half_timestamp: &Self::EItem) -> Result<Cow<[u8]>, BoxedError> {
-//!         Ok(Cow::Owned(half_timestamp.to_be_bytes()[..2].to_vec()))
+//!     fn to_bytes(half_timestamp: &'a Self::SelfType) -> Result<Self::ReturnBytes, Self::Error> {
+//!         let [bytes @ .., _, _] = half_timestamp.to_be_bytes();
+//!         Ok(bytes)
 //!     }
 //! }
 //!
@@ -449,4 +457,4 @@
 // To let cargo generate doc links
 #![allow(unused_imports)]
 
-use crate::{BytesDecode, BytesEncode, Database, EnvOpenOptions};
+use crate::{BytesDecode, Database, EnvOpenOptions, ToBytes};