Add serde support for google.protobuf.Any

pbjson-types/Cargo.toml

@@ -10,13 +10,15 @@ categories = ["encoding"]
 repository = "https://github.com/influxdata/pbjson"
 
 [dependencies] # In alphabetical order
+base64 = "0.13.0"
 bytes = "1.0"
 chrono = "0.4"
 pbjson = { path = "../pbjson", version = "0.2" }
 prost = "0.9"
 serde = { version = "1.0", features = ["derive"] }
 
 [dev-dependencies]
+pretty_assertions = "1.0.0"
 serde_json = "1.0"
 
 [build-dependencies] # In alphabetical order

pbjson-types/build.rs

@@ -29,6 +29,7 @@ fn main() -> Result<()> {
     pbjson_build::Builder::new()
         .register_descriptors(&descriptor_set)?
         .exclude([
+            ".google.protobuf.Any",
             ".google.protobuf.Duration",
             ".google.protobuf.Timestamp",
             ".google.protobuf.Value",

pbjson-types/src/any.rs

@@ -0,0 +1,247 @@
+const TYPE_FIELD: &str = "@type";
+const VALUE_FIELD: &str = "value";
+
+impl serde::Serialize for crate::Any {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        use serde::ser::{SerializeMap, SerializeStruct};
+
+        const NAME: &str = "google.protobuf.Any";
+
+        let value = <crate::Value as prost::Message>::decode(self.value.clone()).map_err(|_| {
+            serde::ser::Error::custom(
+                "Couldn't transcode google.protobuf.Any value into google.protobuf.Value",
+            )
+        })?;
+
+        let mut field_length = 1;
+        match value.kind {
+            Some(crate::value::Kind::StructValue(map)) => {
+                field_length += map.len();
+                let mut map_ser = serializer.serialize_map(Some(field_length))?;
+                map_ser.serialize_entry(TYPE_FIELD, &self.type_url)?;
+
+                for (k, v) in &map {
+                    map_ser.serialize_entry(k, v)?;
+                }
+
+                map_ser.end()
+            }
+            _ => {
+                let mut struct_ser = serializer.serialize_struct(NAME, 2)?;
+                struct_ser.serialize_field(TYPE_FIELD, &self.type_url)?;
+                struct_ser.serialize_field(VALUE_FIELD, &base64::encode(&self.value))?;
+                struct_ser.end()
+            }
+        }
+    }
+}
+
+impl<'de> serde::Deserialize<'de> for crate::Any {
+    #[allow(deprecated)]
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        deserializer.deserialize_map(AnyVisitor)
+    }
+}
+
+struct AnyVisitor;
+
+impl<'de> serde::de::Visitor<'de> for AnyVisitor {
+    type Value = crate::Any;
+
+    fn expecting(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        formatter.write_str("struct google.protobuf.Any")
+    }
+
+    fn visit_map<V>(self, mut map_access: V) -> Result<Self::Value, V::Error>
+    where
+        V: serde::de::MapAccess<'de>,
+    {
+        enum BytesOrValue {
+            Bytes(bytes::Bytes),
+            Value(crate::Value),
+        }
+
+        let mut type_url = None;
+        let mut value: Option<BytesOrValue> = None;
+        let mut map = std::collections::HashMap::new();
+        while let Some(k) = map_access.next_key()? {
+            match k {
+                AnyField::TypeUrl => {
+                    if type_url.is_some() {
+                        return Err(serde::de::Error::duplicate_field(TYPE_FIELD));
+                    }
+                    type_url = Some(map_access.next_value()?);
+                }
+                AnyField::Value => {
+                    if value.is_some() {
+                        return Err(serde::de::Error::duplicate_field(VALUE_FIELD));
+                    }
+
+                    value = if let Ok(bytes) =
+                        map_access.next_value::<::pbjson::private::BytesDeserialize<_>>()
+                    {
+                        Some(BytesOrValue::Bytes(bytes.0))
+                    } else {
+                        Some(BytesOrValue::Value(map_access.next_value()?))
+                    };
+                }
+                AnyField::Unknown(key) => {
+                    if map.contains_key(&key) {
+                        return Err(serde::de::Error::custom(format!(
+                            "Duplicate field: {}",
+                            &key
+                        )));
+                    }
+
+                    map.insert(key, map_access.next_value::<crate::Value>()?);
+                }
+            }
+        }
+
+        macro_rules! encode_map {
+            () => {{
+                use prost::Message;
+
+                let mut buffer = Vec::new();
+                crate::Value::from(map)
+                    .encode(&mut buffer)
+                    .map_err(serde::de::Error::custom)?;
+                buffer.into()
+            }};
+        }
+
+        let value = match value {
+            Some(BytesOrValue::Bytes(bytes)) => bytes,
+            Some(BytesOrValue::Value(value)) => {
+                map.insert("value".into(), value);
+                encode_map!()
+            }
+            None if map.is_empty() => return Err(serde::de::Error::missing_field(VALUE_FIELD)),
+            None => encode_map!(),
+        };
+
+        Ok(crate::Any {
+            type_url: type_url.ok_or_else(|| serde::de::Error::missing_field(TYPE_FIELD))?,
+            value,
+        })
+    }
+}
+
+#[derive(Debug)]
+enum AnyField {
+    TypeUrl,
+    Value,
+    Unknown(String),
+}
+
+impl<'de> serde::Deserialize<'de> for AnyField {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        struct AnyFieldVisitor;
+
+        impl<'de> serde::de::Visitor<'de> for AnyFieldVisitor {
+            type Value = AnyField;
+
+            fn expecting(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                write!(formatter, "expected a string key")
+            }
+
+            fn visit_str<E>(self, value: &str) -> Result<AnyField, E>
+            where
+                E: serde::de::Error,
+            {
+                match value {
+                    TYPE_FIELD => Ok(AnyField::TypeUrl),
+                    VALUE_FIELD => Ok(AnyField::Value),
+                    value => Ok(AnyField::Unknown(value.to_owned())),
+                }
+            }
+        }
+
+        deserializer.deserialize_identifier(AnyFieldVisitor)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use pretty_assertions::assert_eq;
+    use prost::Message;
+
+    #[test]
+    fn object() {
+        let map = crate::Value::from(std::collections::HashMap::from([
+            (String::from("bool"), true.into()),
+            (String::from("unit"), crate::Value::from(None)),
+            (String::from("number"), 5.0.into()),
+            (String::from("string"), "string".into()),
+            (String::from("list"), vec![1.0.into(), 2.0.into()].into()),
+            (
+                String::from("map"),
+                std::collections::HashMap::from([(String::from("key"), "value".into())]).into(),
+            ),
+        ]));
+
+        let any = crate::Any {
+            type_url: "google.protobuf.Value".into(),
+            value: map.encode_to_vec().into(),
+        };
+
+        let json = serde_json::to_value(&any).unwrap();
+
+        assert_eq!(
+            json,
+            serde_json::json!({
+                "@type": "google.protobuf.Value",
+                "bool": true,
+                "unit": null,
+                "number": 5.0,
+                "string": "string",
+                "list": [1.0, 2.0],
+                "map": {
+                    "key": "value",
+                }
+            })
+        );
+
+        let decoded = serde_json::from_value::<crate::Any>(json).unwrap();
+        assert_eq!(decoded.type_url, any.type_url);
+        assert_eq!(
+            crate::Value::decode(decoded.value).unwrap(),
+            crate::Value::decode(any.value).unwrap()
+        );
+    }
+
+    #[test]
+    fn primitive_value() {
+        let boolean = crate::Value::from(true);
+        let protobuf_encoding = boolean.encode_to_vec();
+
+        let any = crate::Any {
+            type_url: "google.protobuf.Value".into(),
+            value: protobuf_encoding.clone().into(),
+        };
+
+        let json = serde_json::to_value(&any).unwrap();
+        let expected = serde_json::json!({
+            "@type": "google.protobuf.Value",
+            "value": base64::encode(&protobuf_encoding),
+        });
+
+        assert_eq!(json, expected);
+
+        let decoded = serde_json::from_value::<crate::Any>(expected).unwrap();
+        assert_eq!(decoded.type_url, any.type_url);
+        assert_eq!(
+            crate::Value::decode(decoded.value).unwrap(),
+            crate::Value::decode(any.value).unwrap()
+        );
+    }
+}

pbjson-types/src/lib.rs

@@ -36,6 +36,7 @@ mod pb {
     }
 }
 
+mod any;
 mod duration;
 mod list_value;
 mod null_value;

pbjson-types/src/struct.rs

@@ -1,15 +1,31 @@
 use crate::Struct;
 
-impl From<std::collections::HashMap<String, crate::Value>> for Struct {
+type ValueMap = std::collections::HashMap<String, crate::Value>;
+type ValueEntry = (String, crate::Value);
+
+impl std::ops::Deref for crate::Struct {
+    type Target = ValueMap;
+    fn deref(&self) -> &Self::Target {
+        &self.fields
+    }
+}
+
+impl std::ops::DerefMut for crate::Struct {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.fields
+    }
+}
+
+impl From<ValueMap> for crate::Struct {
     fn from(fields: std::collections::HashMap<String, crate::Value>) -> Self {
         Self { fields }
     }
 }
 
-impl FromIterator<(String, crate::Value)> for Struct {
+impl FromIterator<ValueEntry> for crate::Struct {
     fn from_iter<T>(iter: T) -> Self
     where
-        T: IntoIterator<Item = (String, crate::Value)>,
+        T: IntoIterator<Item = ValueEntry>,
     {
         Self {
             fields: iter.into_iter().collect(),
@@ -58,6 +74,35 @@ impl<'de> serde::de::Visitor<'de> for StructVisitor {
     }
 }
 
+impl IntoIterator for crate::Struct {
+    type Item = <ValueMap as IntoIterator>::Item;
+    type IntoIter = <ValueMap as IntoIterator>::IntoIter;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.fields.into_iter()
+    }
+}
+
+impl<'r> IntoIterator for &'r crate::Struct {
+    type Item = <&'r ValueMap as IntoIterator>::Item;
+    type IntoIter = <&'r ValueMap as IntoIterator>::IntoIter;
+
+    #[inline]
+    fn into_iter(self) -> Self::IntoIter {
+        self.fields.iter()
+    }
+}
+
+impl<'r> IntoIterator for &'r mut crate::Struct {
+    type Item = <&'r mut ValueMap as IntoIterator>::Item;
+    type IntoIter = <&'r mut ValueMap as IntoIterator>::IntoIter;
+
+    #[inline]
+    fn into_iter(self) -> Self::IntoIter {
+        self.fields.iter_mut()
+    }
+}
+
 #[cfg(test)]
 mod tests {
     #[test]

pbjson/src/lib.rs

@@ -64,7 +64,7 @@ pub mod private {
         where
             D: serde::Deserializer<'de>,
         {
-            let s: &str = Deserialize::deserialize(deserializer)?;
+            let s: String = Deserialize::deserialize(deserializer)?;
             let decoded = base64::decode(s).map_err(serde::de::Error::custom)?;
             Ok(Self(decoded.into()))
         }