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#![cfg(feature = "serde")]
use serde::de::{
Deserialize, DeserializeSeed, Deserializer, EnumAccess, Error, Unexpected, VariantAccess,
Visitor,
};
use serde::ser::{Serialize, Serializer};
use crate::{Level, LevelFilter, LOG_LEVEL_NAMES};
use std::fmt;
use std::str::{self, FromStr};
// The Deserialize impls are handwritten to be case insensitive using FromStr.
impl Serialize for Level {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
match *self {
Level::Error => serializer.serialize_unit_variant("Level", 0, "ERROR"),
Level::Warn => serializer.serialize_unit_variant("Level", 1, "WARN"),
Level::Info => serializer.serialize_unit_variant("Level", 2, "INFO"),
Level::Debug => serializer.serialize_unit_variant("Level", 3, "DEBUG"),
Level::Trace => serializer.serialize_unit_variant("Level", 4, "TRACE"),
}
}
}
impl<'de> Deserialize<'de> for Level {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
struct LevelIdentifier;
impl<'de> Visitor<'de> for LevelIdentifier {
type Value = Level;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("log level")
}
fn visit_u64<E>(self, v: u64) -> Result<Self::Value, E>
where
E: Error,
{
let variant = LOG_LEVEL_NAMES[1..]
.get(v as usize)
.ok_or_else(|| Error::invalid_value(Unexpected::Unsigned(v), &self))?;
self.visit_str(variant)
}
fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
where
E: Error,
{
// Case insensitive.
FromStr::from_str(s).map_err(|_| Error::unknown_variant(s, &LOG_LEVEL_NAMES[1..]))
}
fn visit_bytes<E>(self, value: &[u8]) -> Result<Self::Value, E>
where
E: Error,
{
let variant = str::from_utf8(value)
.map_err(|_| Error::invalid_value(Unexpected::Bytes(value), &self))?;
self.visit_str(variant)
}
}
impl<'de> DeserializeSeed<'de> for LevelIdentifier {
type Value = Level;
fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
where
D: Deserializer<'de>,
{
deserializer.deserialize_identifier(LevelIdentifier)
}
}
struct LevelEnum;
impl<'de> Visitor<'de> for LevelEnum {
type Value = Level;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("log level")
}
fn visit_enum<A>(self, value: A) -> Result<Self::Value, A::Error>
where
A: EnumAccess<'de>,
{
let (level, variant) = value.variant_seed(LevelIdentifier)?;
// Every variant is a unit variant.
variant.unit_variant()?;
Ok(level)
}
}
deserializer.deserialize_enum("Level", &LOG_LEVEL_NAMES[1..], LevelEnum)
}
}
impl Serialize for LevelFilter {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
match *self {
LevelFilter::Off => serializer.serialize_unit_variant("LevelFilter", 0, "OFF"),
LevelFilter::Error => serializer.serialize_unit_variant("LevelFilter", 1, "ERROR"),
LevelFilter::Warn => serializer.serialize_unit_variant("LevelFilter", 2, "WARN"),
LevelFilter::Info => serializer.serialize_unit_variant("LevelFilter", 3, "INFO"),
LevelFilter::Debug => serializer.serialize_unit_variant("LevelFilter", 4, "DEBUG"),
LevelFilter::Trace => serializer.serialize_unit_variant("LevelFilter", 5, "TRACE"),
}
}
}
impl<'de> Deserialize<'de> for LevelFilter {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
struct LevelFilterIdentifier;
impl<'de> Visitor<'de> for LevelFilterIdentifier {
type Value = LevelFilter;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("log level filter")
}
fn visit_u64<E>(self, v: u64) -> Result<Self::Value, E>
where
E: Error,
{
let variant = LOG_LEVEL_NAMES
.get(v as usize)
.ok_or_else(|| Error::invalid_value(Unexpected::Unsigned(v), &self))?;
self.visit_str(variant)
}
fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
where
E: Error,
{
// Case insensitive.
FromStr::from_str(s).map_err(|_| Error::unknown_variant(s, &LOG_LEVEL_NAMES))
}
fn visit_bytes<E>(self, value: &[u8]) -> Result<Self::Value, E>
where
E: Error,
{
let variant = str::from_utf8(value)
.map_err(|_| Error::invalid_value(Unexpected::Bytes(value), &self))?;
self.visit_str(variant)
}
}
impl<'de> DeserializeSeed<'de> for LevelFilterIdentifier {
type Value = LevelFilter;
fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
where
D: Deserializer<'de>,
{
deserializer.deserialize_identifier(LevelFilterIdentifier)
}
}
struct LevelFilterEnum;
impl<'de> Visitor<'de> for LevelFilterEnum {
type Value = LevelFilter;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("log level filter")
}
fn visit_enum<A>(self, value: A) -> Result<Self::Value, A::Error>
where
A: EnumAccess<'de>,
{
let (level_filter, variant) = value.variant_seed(LevelFilterIdentifier)?;
// Every variant is a unit variant.
variant.unit_variant()?;
Ok(level_filter)
}
}
deserializer.deserialize_enum("LevelFilter", &LOG_LEVEL_NAMES, LevelFilterEnum)
}
}
#[cfg(test)]
mod tests {
use crate::{Level, LevelFilter};
use serde_test::{assert_de_tokens, assert_de_tokens_error, assert_tokens, Token};
fn level_token(variant: &'static str) -> Token {
Token::UnitVariant {
name: "Level",
variant,
}
}
fn level_bytes_tokens(variant: &'static [u8]) -> [Token; 3] {
[
Token::Enum { name: "Level" },
Token::Bytes(variant),
Token::Unit,
]
}
fn level_variant_tokens(variant: u32) -> [Token; 3] {
[
Token::Enum { name: "Level" },
Token::U32(variant),
Token::Unit,
]
}
fn level_filter_token(variant: &'static str) -> Token {
Token::UnitVariant {
name: "LevelFilter",
variant,
}
}
fn level_filter_bytes_tokens(variant: &'static [u8]) -> [Token; 3] {
[
Token::Enum {
name: "LevelFilter",
},
Token::Bytes(variant),
Token::Unit,
]
}
fn level_filter_variant_tokens(variant: u32) -> [Token; 3] {
[
Token::Enum {
name: "LevelFilter",
},
Token::U32(variant),
Token::Unit,
]
}
#[test]
fn test_level_ser_de() {
let cases = &[
(Level::Error, [level_token("ERROR")]),
(Level::Warn, [level_token("WARN")]),
(Level::Info, [level_token("INFO")]),
(Level::Debug, [level_token("DEBUG")]),
(Level::Trace, [level_token("TRACE")]),
];
for (s, expected) in cases {
assert_tokens(s, expected);
}
}
#[test]
fn test_level_case_insensitive() {
let cases = &[
(Level::Error, [level_token("error")]),
(Level::Warn, [level_token("warn")]),
(Level::Info, [level_token("info")]),
(Level::Debug, [level_token("debug")]),
(Level::Trace, [level_token("trace")]),
];
for (s, expected) in cases {
assert_de_tokens(s, expected);
}
}
#[test]
fn test_level_de_bytes() {
let cases = &[
(Level::Error, level_bytes_tokens(b"ERROR")),
(Level::Warn, level_bytes_tokens(b"WARN")),
(Level::Info, level_bytes_tokens(b"INFO")),
(Level::Debug, level_bytes_tokens(b"DEBUG")),
(Level::Trace, level_bytes_tokens(b"TRACE")),
];
for (value, tokens) in cases {
assert_de_tokens(value, tokens);
}
}
#[test]
fn test_level_de_variant_index() {
let cases = &[
(Level::Error, level_variant_tokens(0)),
(Level::Warn, level_variant_tokens(1)),
(Level::Info, level_variant_tokens(2)),
(Level::Debug, level_variant_tokens(3)),
(Level::Trace, level_variant_tokens(4)),
];
for (value, tokens) in cases {
assert_de_tokens(value, tokens);
}
}
#[test]
fn test_level_de_error() {
let msg = "unknown variant `errorx`, expected one of \
`ERROR`, `WARN`, `INFO`, `DEBUG`, `TRACE`";
assert_de_tokens_error::<Level>(&[level_token("errorx")], msg);
}
#[test]
fn test_level_filter_ser_de() {
let cases = &[
(LevelFilter::Off, [level_filter_token("OFF")]),
(LevelFilter::Error, [level_filter_token("ERROR")]),
(LevelFilter::Warn, [level_filter_token("WARN")]),
(LevelFilter::Info, [level_filter_token("INFO")]),
(LevelFilter::Debug, [level_filter_token("DEBUG")]),
(LevelFilter::Trace, [level_filter_token("TRACE")]),
];
for (s, expected) in cases {
assert_tokens(s, expected);
}
}
#[test]
fn test_level_filter_case_insensitive() {
let cases = &[
(LevelFilter::Off, [level_filter_token("off")]),
(LevelFilter::Error, [level_filter_token("error")]),
(LevelFilter::Warn, [level_filter_token("warn")]),
(LevelFilter::Info, [level_filter_token("info")]),
(LevelFilter::Debug, [level_filter_token("debug")]),
(LevelFilter::Trace, [level_filter_token("trace")]),
];
for (s, expected) in cases {
assert_de_tokens(s, expected);
}
}
#[test]
fn test_level_filter_de_bytes() {
let cases = &[
(LevelFilter::Off, level_filter_bytes_tokens(b"OFF")),
(LevelFilter::Error, level_filter_bytes_tokens(b"ERROR")),
(LevelFilter::Warn, level_filter_bytes_tokens(b"WARN")),
(LevelFilter::Info, level_filter_bytes_tokens(b"INFO")),
(LevelFilter::Debug, level_filter_bytes_tokens(b"DEBUG")),
(LevelFilter::Trace, level_filter_bytes_tokens(b"TRACE")),
];
for (value, tokens) in cases {
assert_de_tokens(value, tokens);
}
}
#[test]
fn test_level_filter_de_variant_index() {
let cases = &[
(LevelFilter::Off, level_filter_variant_tokens(0)),
(LevelFilter::Error, level_filter_variant_tokens(1)),
(LevelFilter::Warn, level_filter_variant_tokens(2)),
(LevelFilter::Info, level_filter_variant_tokens(3)),
(LevelFilter::Debug, level_filter_variant_tokens(4)),
(LevelFilter::Trace, level_filter_variant_tokens(5)),
];
for (value, tokens) in cases {
assert_de_tokens(value, tokens);
}
}
#[test]
fn test_level_filter_de_error() {
let msg = "unknown variant `errorx`, expected one of \
`OFF`, `ERROR`, `WARN`, `INFO`, `DEBUG`, `TRACE`";
assert_de_tokens_error::<LevelFilter>(&[level_filter_token("errorx")], msg);
}
}