Move visitors to a shared module

RustCrypto · Aug 6, 2023 · 7d02cda · 7d02cda
1 parent d7cccf4
commit 7d02cda
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Showing 3 changed files with 18 additions and 202 deletions.
diff --git a/serdect/src/array.rs b/serdect/src/array.rs
@@ -1,6 +1,6 @@
 //! Serialization primitives for arrays.
 
-// Unfortunately, we currently cannot assert generically that we are serializing
+// Unfortunately, we currently cannot tell `serde` in a uniform fashion that we are serializing
 // a fixed-size byte array.
 // See https://github.com/serde-rs/serde/issues/2120 for the discussion.
 // Therefore we have to fall back to the slice methods,
@@ -13,7 +13,7 @@ use core::marker::PhantomData;
 
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
 
-use crate::slice;
+use crate::common::{self, ExactLength, SliceVisitor, StrIntoBufVisitor};
 
 #[cfg(feature = "zeroize")]
 use zeroize::Zeroize;
@@ -25,7 +25,7 @@ where
     S: Serializer,
     T: AsRef<[u8]>,
 {
-    slice::serialize_hex_lower_or_bin(value, serializer)
+    common::serialize_hex_lower_or_bin(value, serializer)
 }
 
 /// Serialize the given type as upper case hex when using human-readable
@@ -35,7 +35,7 @@ where
     S: Serializer,
     T: AsRef<[u8]>,
 {
-    slice::serialize_hex_upper_or_bin(value, serializer)
+    common::serialize_hex_upper_or_bin(value, serializer)
 }
 
 /// Deserialize from hex when using human-readable formats or binary if the
@@ -46,12 +46,9 @@ where
     D: Deserializer<'de>,
 {
     if deserializer.is_human_readable() {
-        deserializer.deserialize_str(slice::StrVisitor::<slice::ExactLength>(buffer, PhantomData))
+        deserializer.deserialize_str(StrIntoBufVisitor::<ExactLength>(buffer, PhantomData))
     } else {
-        deserializer.deserialize_byte_buf(slice::SliceVisitor::<slice::ExactLength>(
-            buffer,
-            PhantomData,
-        ))
+        deserializer.deserialize_byte_buf(SliceVisitor::<ExactLength>(buffer, PhantomData))
     }
 }
 

diff --git a/serdect/src/lib.rs b/serdect/src/lib.rs
@@ -131,35 +131,7 @@
 extern crate alloc;
 
 pub mod array;
+mod common;
 pub mod slice;
 
 pub use serde;
-
-use serde::Serializer;
-
-#[cfg(not(feature = "alloc"))]
-use serde::ser::Error;
-
-#[cfg(feature = "alloc")]
-use serde::Serialize;
-
-fn serialize_hex<S, T, const UPPERCASE: bool>(value: &T, serializer: S) -> Result<S::Ok, S::Error>
-where
-    S: Serializer,
-    T: AsRef<[u8]>,
-{
-    #[cfg(feature = "alloc")]
-    if UPPERCASE {
-        return base16ct::upper::encode_string(value.as_ref()).serialize(serializer);
-    } else {
-        return base16ct::lower::encode_string(value.as_ref()).serialize(serializer);
-    }
-    #[cfg(not(feature = "alloc"))]
-    {
-        let _ = value;
-        let _ = serializer;
-        return Err(S::Error::custom(
-            "serializer is human readable, which requires the `alloc` crate feature",
-        ));
-    }
-}
diff --git a/serdect/src/slice.rs b/serdect/src/slice.rs
@@ -1,16 +1,19 @@
 //! Serialization primitives for slices.
 
-use core::fmt;
 use core::marker::PhantomData;
 
-use serde::de::{Error, Visitor};
 use serde::{Deserializer, Serializer};
 
+use crate::common::{self, SliceVisitor, StrIntoBufVisitor, UpperBound};
+
 #[cfg(feature = "alloc")]
-use serde::Serialize;
+use ::{
+    alloc::vec::Vec,
+    serde::{Deserialize, Serialize},
+};
 
 #[cfg(feature = "alloc")]
-use ::{alloc::vec::Vec, serde::Deserialize};
+use crate::common::{StrIntoVecVisitor, VecVisitor};
 
 #[cfg(feature = "zeroize")]
 use zeroize::Zeroize;
@@ -22,11 +25,7 @@ where
     S: Serializer,
     T: AsRef<[u8]>,
 {
-    if serializer.is_human_readable() {
-        crate::serialize_hex::<_, _, false>(value, serializer)
-    } else {
-        serializer.serialize_bytes(value.as_ref())
-    }
+    common::serialize_hex_lower_or_bin(value, serializer)
 }
 
 /// Serialize the given type as upper case hex when using human-readable
@@ -36,118 +35,7 @@ where
     S: Serializer,
     T: AsRef<[u8]>,
 {
-    if serializer.is_human_readable() {
-        crate::serialize_hex::<_, _, true>(value, serializer)
-    } else {
-        serializer.serialize_bytes(value.as_ref())
-    }
-}
-
-pub(crate) trait LengthCheck {
-    fn length_check(buffer_length: usize, data_length: usize) -> bool;
-    fn expecting(
-        formatter: &mut fmt::Formatter<'_>,
-        data_type: &str,
-        data_length: usize,
-    ) -> fmt::Result;
-}
-
-pub(crate) struct ExactLength;
-
-impl LengthCheck for ExactLength {
-    fn length_check(buffer_length: usize, data_length: usize) -> bool {
-        buffer_length == data_length
-    }
-    fn expecting(
-        formatter: &mut fmt::Formatter<'_>,
-        data_type: &str,
-        data_length: usize,
-    ) -> fmt::Result {
-        write!(formatter, "{} of length {}", data_type, data_length)
-    }
-}
-
-struct UpperBound;
-
-impl LengthCheck for UpperBound {
-    fn length_check(buffer_length: usize, data_length: usize) -> bool {
-        buffer_length >= data_length
-    }
-    fn expecting(
-        formatter: &mut fmt::Formatter<'_>,
-        data_type: &str,
-        data_length: usize,
-    ) -> fmt::Result {
-        write!(
-            formatter,
-            "{} with a maximum length of {}",
-            data_type, data_length
-        )
-    }
-}
-
-pub(crate) struct StrVisitor<'b, T: LengthCheck>(pub &'b mut [u8], pub PhantomData<T>);
-
-impl<'de, 'b, T: LengthCheck> Visitor<'de> for StrVisitor<'b, T> {
-    type Value = ();
-
-    fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-        T::expecting(formatter, "a string", self.0.len() * 2)
-    }
-
-    fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
-    where
-        E: Error,
-    {
-        if !T::length_check(self.0.len() * 2, v.len()) {
-            return Err(Error::invalid_length(v.len(), &self));
-        }
-        // TODO: Map `base16ct::Error::InvalidLength` to `Error::invalid_length`.
-        base16ct::mixed::decode(v, self.0)
-            .map(|_| ())
-            .map_err(E::custom)
-    }
-}
-
-pub(crate) struct SliceVisitor<'b, T: LengthCheck>(pub &'b mut [u8], pub PhantomData<T>);
-
-impl<'de, 'b, T: LengthCheck> Visitor<'de> for SliceVisitor<'b, T> {
-    type Value = ();
-
-    fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-        T::expecting(formatter, "an array", self.0.len())
-    }
-
-    fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
-    where
-        E: Error,
-    {
-        // Workaround for
-        // https://github.com/rust-lang/rfcs/blob/b1de05846d9bc5591d753f611ab8ee84a01fa500/text/2094-nll.md#problem-case-3-conditional-control-flow-across-functions
-        if T::length_check(self.0.len(), v.len()) {
-            let buffer = &mut self.0[..v.len()];
-            buffer.copy_from_slice(v);
-            return Ok(());
-        }
-
-        Err(E::invalid_length(v.len(), &self))
-    }
-
-    #[cfg(feature = "alloc")]
-    fn visit_byte_buf<E>(self, mut v: Vec<u8>) -> Result<Self::Value, E>
-    where
-        E: Error,
-    {
-        // Workaround for
-        // https://github.com/rust-lang/rfcs/blob/b1de05846d9bc5591d753f611ab8ee84a01fa500/text/2094-nll.md#problem-case-3-conditional-control-flow-across-functions
-        if T::length_check(self.0.len(), v.len()) {
-            let buffer = &mut self.0[..v.len()];
-            buffer.swap_with_slice(&mut v);
-            return Ok(());
-        }
-
-        Err(E::invalid_length(v.len(), &self))
-    }
+    common::serialize_hex_upper_or_bin(value, serializer)
 }
 
 /// Deserialize from hex when using human-readable formats or binary if the
@@ -158,7 +46,7 @@ where
     D: Deserializer<'de>,
 {
     if deserializer.is_human_readable() {
-        deserializer.deserialize_str(StrVisitor::<UpperBound>(buffer, PhantomData))
+        deserializer.deserialize_str(StrIntoBufVisitor::<UpperBound>(buffer, PhantomData))
     } else {
         deserializer.deserialize_byte_buf(SliceVisitor::<UpperBound>(buffer, PhantomData))
     }
@@ -172,49 +60,8 @@ where
     D: Deserializer<'de>,
 {
     if deserializer.is_human_readable() {
-        struct StrVisitor;
-
-        impl<'de> Visitor<'de> for StrVisitor {
-            type Value = Vec<u8>;
-
-            fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-                write!(formatter, "a string")
-            }
-
-            fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
-            where
-                E: Error,
-            {
-                base16ct::mixed::decode_vec(v).map_err(E::custom)
-            }
-        }
-
-        deserializer.deserialize_str(StrVisitor)
+        deserializer.deserialize_str(StrIntoVecVisitor)
     } else {
-        struct VecVisitor;
-
-        impl<'de> Visitor<'de> for VecVisitor {
-            type Value = Vec<u8>;
-
-            fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-                write!(formatter, "a bytestring")
-            }
-
-            fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
-            where
-                E: Error,
-            {
-                Ok(v.into())
-            }
-
-            fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
-            where
-                E: Error,
-            {
-                Ok(v)
-            }
-        }
-
         deserializer.deserialize_byte_buf(VecVisitor)
     }
 }