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| 1 | +use schemars::JsonSchema; |
| 2 | +use serde::de::{DeserializeOwned, SeqAccess, Visitor}; |
| 3 | +use serde::export::PhantomData; |
| 4 | +use serde::ser::SerializeSeq; |
| 5 | +use serde::{Deserialize, Deserializer, Serialize, Serializer}; |
| 6 | +use serde_json::Value; |
| 7 | +use std::fmt; |
| 8 | +use std::fmt::Debug; |
| 9 | + |
| 10 | +#[derive(Debug, Clone, JsonSchema)] |
| 11 | +#[serde(untagged)] |
| 12 | +// TODO: JsonSchema is invalid, we should only allow "Parsed" value as the |
| 13 | +// others will be dropped |
| 14 | +pub enum TryParse<T> { |
| 15 | + Parsed(T), |
| 16 | + Unparsed(Value), |
| 17 | + NotPresent, |
| 18 | +} |
| 19 | + |
| 20 | +impl<'de, T: DeserializeOwned> Deserialize<'de> for TryParse<T> { |
| 21 | + fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> { |
| 22 | + match Option::<Value>::deserialize(deserializer)? { |
| 23 | + None => Ok(TryParse::NotPresent), |
| 24 | + Some(value) => match T::deserialize(&value) { |
| 25 | + Ok(t) => Ok(TryParse::Parsed(t)), |
| 26 | + Err(_) => Ok(TryParse::Unparsed(value)), |
| 27 | + }, |
| 28 | + } |
| 29 | + } |
| 30 | +} |
| 31 | + |
| 32 | +#[derive(Debug, Clone, JsonSchema)] |
| 33 | +#[serde(transparent)] |
| 34 | +pub struct TryVec<T> { |
| 35 | + inner: Vec<TryParse<T>>, |
| 36 | +} |
| 37 | + |
| 38 | +impl<T> TryVec<T> { |
| 39 | + pub fn new(mut vec: Vec<T>) -> Self { |
| 40 | + let mut vec_marked: Vec<TryParse<T>> = Vec::new(); |
| 41 | + for item in vec.drain(..) { |
| 42 | + vec_marked.push(TryParse::Parsed(item)); |
| 43 | + } |
| 44 | + TryVec { inner: vec_marked } |
| 45 | + } |
| 46 | + |
| 47 | + pub fn new_empty() -> Self { |
| 48 | + TryVec { inner: Vec::new() } |
| 49 | + } |
| 50 | + |
| 51 | + pub fn take_inner(self) -> Vec<T> { |
| 52 | + let mut vec: Vec<T> = Vec::new(); |
| 53 | + for item in self.inner { |
| 54 | + match item { |
| 55 | + TryParse::Parsed(i) => vec.push(i), |
| 56 | + _ => continue, |
| 57 | + }; |
| 58 | + } |
| 59 | + return vec; |
| 60 | + } |
| 61 | +} |
| 62 | + |
| 63 | +impl<T> Serialize for TryVec<T> |
| 64 | +where |
| 65 | + T: Serialize, |
| 66 | +{ |
| 67 | + fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> |
| 68 | + where |
| 69 | + S: Serializer, |
| 70 | + { |
| 71 | + let mut seq = serializer.serialize_seq(Some(self.inner.len()))?; |
| 72 | + for element in &self.inner { |
| 73 | + match element { |
| 74 | + TryParse::Parsed(t) => seq.serialize_element(t)?, |
| 75 | + _ => continue, |
| 76 | + }; |
| 77 | + } |
| 78 | + seq.end() |
| 79 | + } |
| 80 | +} |
| 81 | + |
| 82 | +struct TryVecVisitor<T> { |
| 83 | + marker: PhantomData<fn() -> TryVec<T>>, |
| 84 | +} |
| 85 | + |
| 86 | +impl<T> TryVecVisitor<T> { |
| 87 | + fn new() -> Self { |
| 88 | + TryVecVisitor { |
| 89 | + marker: PhantomData, |
| 90 | + } |
| 91 | + } |
| 92 | +} |
| 93 | + |
| 94 | +impl<'de, T> Visitor<'de> for TryVecVisitor<T> |
| 95 | +where |
| 96 | + T: DeserializeOwned, |
| 97 | +{ |
| 98 | + type Value = TryVec<T>; |
| 99 | + |
| 100 | + // Format a message stating what data this Visitor expects to receive. |
| 101 | + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
| 102 | + formatter.write_str("a seqence") |
| 103 | + } |
| 104 | + |
| 105 | + fn visit_seq<M>(self, mut access: M) -> Result<Self::Value, M::Error> |
| 106 | + where |
| 107 | + M: SeqAccess<'de>, |
| 108 | + { |
| 109 | + let mut vec = Vec::new(); |
| 110 | + |
| 111 | + loop { |
| 112 | + let res = match access.next_element() { |
| 113 | + Ok(val) => val, |
| 114 | + Err(err) => { |
| 115 | + println!( |
| 116 | + "Failed to parse event because '{}', the event will be discarded", |
| 117 | + err |
| 118 | + ); |
| 119 | + continue; |
| 120 | + } |
| 121 | + }; |
| 122 | + match res { |
| 123 | + Some(item) => vec.push(item), |
| 124 | + None => break, |
| 125 | + }; |
| 126 | + } |
| 127 | + |
| 128 | + Ok(TryVec { inner: vec }) |
| 129 | + } |
| 130 | +} |
| 131 | + |
| 132 | +impl<'de, T> Deserialize<'de> for TryVec<T> |
| 133 | +where |
| 134 | + T: DeserializeOwned, |
| 135 | +{ |
| 136 | + fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> |
| 137 | + where |
| 138 | + D: Deserializer<'de>, |
| 139 | + { |
| 140 | + deserializer.deserialize_seq(TryVecVisitor::new()) |
| 141 | + } |
| 142 | +} |
| 143 | + |
| 144 | +#[cfg(test)] |
| 145 | +mod test { |
| 146 | + use serde::{Deserialize, Serialize}; |
| 147 | + |
| 148 | + use super::TryVec; |
| 149 | + |
| 150 | + #[derive(Deserialize, Serialize, Debug)] |
| 151 | + struct TestEvent { |
| 152 | + data: String, |
| 153 | + } |
| 154 | + |
| 155 | + fn assert_serialized_deserialized_eq(data: &str, eq: &str) { |
| 156 | + let deserialized = serde_json::from_str::<TryVec<TestEvent>>(data).unwrap(); |
| 157 | + let serialized = serde_json::to_string(&deserialized).unwrap(); |
| 158 | + assert_eq!(serialized, eq); |
| 159 | + } |
| 160 | + |
| 161 | + #[test] |
| 162 | + fn test_serialize_deserialize() { |
| 163 | + println!("test empty array"); |
| 164 | + assert_serialized_deserialized_eq(r#"[]"#, r#"[]"#); |
| 165 | + |
| 166 | + println!("test one valid event"); |
| 167 | + assert_serialized_deserialized_eq(r#"[{"data":"test"}]"#, r#"[{"data":"test"}]"#); |
| 168 | + |
| 169 | + println!("test invalid type int, skip event"); |
| 170 | + assert_serialized_deserialized_eq(r#"[{ "data": 1 }]"#, r#"[]"#); |
| 171 | + |
| 172 | + println!("test invalid type dict, skip event"); |
| 173 | + assert_serialized_deserialized_eq(r#"[{"data":{}}]"#, r#"[]"#); |
| 174 | + |
| 175 | + println!("test invalid type arr, skip event"); |
| 176 | + assert_serialized_deserialized_eq(r#"[{"data":[]}]"#, r#"[]"#); |
| 177 | + |
| 178 | + println!("test multiple valid events"); |
| 179 | + assert_serialized_deserialized_eq( |
| 180 | + r#"[{"data":"test"},{"data":"test2"},{"data":"test3"}]"#, |
| 181 | + r#"[{"data":"test"},{"data":"test2"},{"data":"test3"}]"#, |
| 182 | + ); |
| 183 | + |
| 184 | + println!("test invalid event in middle of sequence, skip one event"); |
| 185 | + assert_serialized_deserialized_eq( |
| 186 | + r#"[{"data":"test"},{"data":2},{"data":"test3"}]"#, |
| 187 | + r#"[{"data":"test"},{"data":"test3"}]"#, |
| 188 | + ); |
| 189 | + |
| 190 | + println!("test utf-16 character"); |
| 191 | + assert_serialized_deserialized_eq(r#"[{"data":"\ud835\udc47"}]"#, r#"[{"data":"𝑇"}]"#); |
| 192 | + |
| 193 | + println!("test invalid utf-8/16, skip event"); |
| 194 | + assert_serialized_deserialized_eq(r#"[{"data":"\ud835"}]"#, r#"[]"#); |
| 195 | + } |
| 196 | + |
| 197 | + #[test] |
| 198 | + fn test_methods() { |
| 199 | + let tryvec = TryVec::<TestEvent>::new_empty(); |
| 200 | + assert_eq!(tryvec.take_inner().len(), Vec::<TestEvent>::new().len()); |
| 201 | + } |
| 202 | +} |
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