serde serializer + deserializer for NvList

Add a serde serializer that can serialize structs to NvList's.

Add a serde deserializer that can deserialize NvList's into structs.

Author: ahrens

Cargo.lock

@@ -13,6 +13,7 @@ edition = "2018"
 cstr-argument = "0.1"
 nvpair-sys = { path = "../nvpair-sys", version = "0.4.0" }
 foreign-types = "0.5.0"
+serde = "1.0"
 
 [badges]
 travis-ci = { repository = "jmesmon/rust-libzfs" }

nvpair/Cargo.toml

@@ -0,0 +1,270 @@
+use crate::*;
+use ::serde::de::{DeserializeSeed, MapAccess, SeqAccess, Visitor};
+use ::serde::{de, forward_to_deserialize_any, Deserialize};
+use serde::de::DeserializeOwned;
+use std::ffi::CStr;
+use std::marker::PhantomData;
+
+pub fn from_bytes<T>(buf: &[u8]) -> Result<T>
+where
+    T: DeserializeOwned,
+{
+    from_nvlist(&NvList::try_unpack(buf)?)
+}
+
+pub fn from_nvlist<'a, T>(s: &'a NvList) -> Result<T>
+where
+    T: Deserialize<'a>,
+{
+    let mut deserializer = Deserializer::from_nvlist(s);
+    let t = T::deserialize(&mut deserializer)?;
+    /*
+    match deserializer.iterator.next() {
+        Some(pair) => Err(Error::Message(format!(
+            "unconsumed nvpairs, including {:?}",
+            pair
+        ))),
+        None => Ok(t),
+    }
+    */
+    Ok(t)
+}
+
+#[derive(Debug)]
+struct Deserializer<'de> {
+    iterator: NvListIter<'de>,
+    data: Option<NvData<'de>>,
+}
+
+impl<'de> Deserializer<'de> {
+    fn from_nvlist(input: &'de NvListRef) -> Self {
+        Deserializer {
+            iterator: input.iter(),
+            data: None,
+        }
+    }
+}
+
+impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
+    type Error = Error;
+
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_map(self)
+    }
+
+    forward_to_deserialize_any! {
+        bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
+        bytes byte_buf option unit unit_struct newtype_struct seq tuple
+        tuple_struct map struct enum identifier ignored_any
+    }
+}
+
+impl<'de> MapAccess<'de> for Deserializer<'de> {
+    type Error = Error;
+
+    fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>>
+    where
+        K: DeserializeSeed<'de>,
+    {
+        let nvpair = match self.iterator.next() {
+            Some(nvpair) => nvpair,
+            None => return Ok(None),
+        };
+
+        let mut key_deserializer = KeyDeserializer { key: nvpair.name() };
+        self.data = Some(nvpair.data());
+
+        seed.deserialize(&mut key_deserializer).map(Some)
+    }
+
+    fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value>
+    where
+        V: DeserializeSeed<'de>,
+    {
+        match self.data.take() {
+            Some(data) => {
+                let mut value_deserializer = ValueDeserializer { data };
+                seed.deserialize(&mut value_deserializer)
+            }
+            None => Err(Error::Message("expected value but not present".to_string())),
+        }
+    }
+}
+
+#[derive(Debug)]
+struct KeyDeserializer<'de> {
+    key: &'de CStr,
+}
+
+impl<'de, 'a> de::Deserializer<'de> for &'a mut KeyDeserializer<'de> {
+    type Error = Error;
+
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_borrowed_str(self.key.to_str()?)
+    }
+
+    forward_to_deserialize_any! {
+        bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
+        bytes byte_buf option unit unit_struct newtype_struct seq tuple
+        tuple_struct map struct enum identifier ignored_any
+    }
+}
+
+#[derive(Debug)]
+struct ValueDeserializer<'de> {
+    data: NvData<'de>,
+}
+
+impl<'de, 'a> de::Deserializer<'de> for &'a mut ValueDeserializer<'de> {
+    type Error = Error;
+
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: Visitor<'de>,
+    {
+        match self.data {
+            NvData::Unknown => Err(Error::UnknownNvPairType),
+            NvData::Bool => visitor.visit_none(),
+            NvData::BoolV(v) => visitor.visit_bool(v),
+            NvData::Byte(v) => visitor.visit_u8(v),
+            NvData::Int8(v) => visitor.visit_i8(v),
+            NvData::Uint8(v) => visitor.visit_u8(v),
+            NvData::Int16(v) => visitor.visit_i16(v),
+            NvData::Uint16(v) => visitor.visit_u16(v),
+            NvData::Int32(v) => visitor.visit_i32(v),
+            NvData::Uint32(v) => visitor.visit_u32(v),
+            NvData::Int64(v) => visitor.visit_i64(v),
+            NvData::Uint64(v) => visitor.visit_u64(v),
+            NvData::Str(v) => visitor.visit_borrowed_str(v.to_str()?),
+            NvData::NvListRef(v) => visitor.visit_map(Deserializer::from_nvlist(v)),
+            NvData::ByteArray(v) => visitor.visit_borrowed_bytes(v),
+            NvData::Int8Array(v) => visitor.visit_seq(SeqAccessor::new(v.iter())),
+            NvData::Uint8Array(v) => visitor.visit_borrowed_bytes(v),
+            NvData::Int16Array(v) => visitor.visit_seq(SeqAccessor::new(v.iter())),
+            NvData::Uint16Array(v) => visitor.visit_seq(SeqAccessor::new(v.iter())),
+            NvData::Int32Array(v) => visitor.visit_seq(SeqAccessor::new(v.iter())),
+            NvData::Uint32Array(v) => visitor.visit_seq(SeqAccessor::new(v.iter())),
+            NvData::Int64Array(v) => visitor.visit_seq(SeqAccessor::new(v.iter())),
+            NvData::Uint64Array(v) => visitor.visit_seq(SeqAccessor::new(v.iter())),
+            NvData::NvListRefArray(_) => Err(Error::UnknownNvPairType),
+        }
+    }
+
+    forward_to_deserialize_any! {
+        bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
+        bytes byte_buf option unit unit_struct newtype_struct seq tuple
+        tuple_struct map struct enum identifier ignored_any
+    }
+}
+
+#[derive(Debug)]
+struct SeqAccessor<'de, I>
+where
+    I: Iterator,
+    <I as Iterator>::Item: Into<NvData<'de>>,
+{
+    iterator: I,
+    _phantom: std::marker::PhantomData<&'de I>,
+}
+
+impl<'de, I> SeqAccessor<'de, I>
+where
+    I: Iterator,
+    <I as Iterator>::Item: Into<NvData<'de>>,
+{
+    fn new(iterator: I) -> Self {
+        Self {
+            iterator,
+            _phantom: PhantomData,
+        }
+    }
+}
+
+impl<'de, I> SeqAccess<'de> for SeqAccessor<'de, I>
+where
+    I: Iterator,
+    <I as Iterator>::Item: Into<NvData<'de>>,
+{
+    type Error = Error;
+
+    fn next_element_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>>
+    where
+        K: DeserializeSeed<'de>,
+    {
+        let item = match self.iterator.next() {
+            Some(item) => item,
+            None => return Ok(None),
+        };
+
+        let mut vd = ValueDeserializer { data: item.into() };
+        seed.deserialize(&mut vd).map(Some)
+    }
+}
+
+impl From<&u64> for NvData<'_> {
+    fn from(v: &u64) -> Self {
+        NvData::Uint64(*v)
+    }
+}
+
+impl From<&i64> for NvData<'_> {
+    fn from(v: &i64) -> Self {
+        NvData::Int64(*v)
+    }
+}
+
+impl From<&u32> for NvData<'_> {
+    fn from(v: &u32) -> Self {
+        NvData::Uint32(*v)
+    }
+}
+
+impl From<&i32> for NvData<'_> {
+    fn from(v: &i32) -> Self {
+        NvData::Int32(*v)
+    }
+}
+
+impl From<&u16> for NvData<'_> {
+    fn from(v: &u16) -> Self {
+        NvData::Uint16(*v)
+    }
+}
+
+impl From<&i16> for NvData<'_> {
+    fn from(v: &i16) -> Self {
+        NvData::Int16(*v)
+    }
+}
+
+impl From<&u8> for NvData<'_> {
+    fn from(v: &u8) -> Self {
+        NvData::Uint8(*v)
+    }
+}
+
+impl From<&i8> for NvData<'_> {
+    fn from(v: &i8) -> Self {
+        NvData::Int8(*v)
+    }
+}
+
+/*
+impl<'a> From<&'a NvListRef> for NvData<'a> {
+    fn from(v: &'a NvListRef) -> Self {
+        NvData::NvListRef(v)
+    }
+}
+
+impl<'a> From<&&'a NvListRef> for NvData<'a> {
+    fn from(v: &&'a NvListRef) -> Self {
+        NvData::NvListRef(*v)
+    }
+}
+*/

nvpair/src/de.rs

@@ -0,0 +1,74 @@
+use ::serde::{de, ser};
+use std::ffi::NulError;
+use std::fmt;
+use std::fmt::Display;
+
+pub type Result<T> = std::result::Result<T, Error>;
+
+#[derive(Debug)]
+pub enum Error {
+    Message(String),
+    UnknownNvPairType,
+
+    // Zero or more variants that can be created directly by the Serializer and
+    // Deserializer without going through `ser::Error` and `de::Error`. These
+    // are specific to the format, in this case JSON.
+    //Eof,
+    NulError(NulError),
+    IoError(std::io::Error),
+    Utf8Error(std::str::Utf8Error),
+    /*
+    Syntax,
+    ExpectedBoolean,
+    ExpectedInteger,
+    ExpectedString,
+    ExpectedNull,
+    ExpectedArray,
+    ExpectedArrayComma,
+    ExpectedArrayEnd,
+    ExpectedMap,
+    ExpectedMapColon,
+    ExpectedMapComma,
+    ExpectedMapEnd,
+    ExpectedEnum,
+    TrailingCharacters,
+    */
+}
+
+impl ser::Error for Error {
+    fn custom<T: Display>(msg: T) -> Self {
+        Error::Message(msg.to_string())
+    }
+}
+
+impl de::Error for Error {
+    fn custom<T: Display>(msg: T) -> Self {
+        Error::Message(msg.to_string())
+    }
+}
+
+impl Display for Error {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(self, formatter)
+    }
+}
+
+impl From<NulError> for Error {
+    fn from(e: NulError) -> Self {
+        Error::NulError(e)
+    }
+}
+
+impl From<std::io::Error> for Error {
+    fn from(e: std::io::Error) -> Self {
+        Error::IoError(e)
+    }
+}
+
+impl From<std::str::Utf8Error> for Error {
+    fn from(e: std::str::Utf8Error) -> Self {
+        Error::Utf8Error(e)
+    }
+}
+
+impl std::error::Error for Error {}