valico/common/
error.rs

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1use std::error::Error;
2use std::fmt::Debug;
3use std::any::{Any, TypeId};
4use std::mem;
5use serde::{Serialize, Serializer};
6use serde_json::{Value, to_value};
7
8pub trait GetTypeId: Any { fn typeid(&self) -> TypeId { TypeId::of::<Self>() } }
9impl<T: Any> GetTypeId for T {}
10
11pub fn get_data_ptr<T: ?Sized>(d: *const T) -> *const () {
12    d as *const ()
13}
14
15pub trait ValicoError : Error + Send + Debug + GetTypeId {
16    fn get_code(&self) -> &str;
17    fn get_path(&self) -> &str;
18    fn get_title(&self) -> &str;
19    fn get_detail(&self) -> Option<&str> { None }
20}
21
22impl ValicoError {
23    /// Is this `Error` object of type `E`?
24    pub fn is<E: ValicoError>(&self) -> bool { self.typeid() == TypeId::of::<E>() }
25
26    /// If this error is `E`, downcast this error to `E`, by reference.
27    pub fn downcast<E: ValicoError>(&self) -> Option<&E> {
28        if self.is::<E>() {
29            unsafe { Some(mem::transmute(get_data_ptr(self))) }
30        } else {
31            None
32        }
33    }
34}
35
36impl Serialize for ValicoError {
37    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer {
38        let mut map = ::serde_json::Map::new();
39        map.insert("code".to_string(), to_value(self.get_code()).unwrap());
40        map.insert("title".to_string(), to_value(self.get_title()).unwrap());
41        map.insert("path".to_string(), to_value(self.get_path()).unwrap());
42        match self.get_detail() {
43            Some(ref detail) => { map.insert("detail".to_string(), to_value(detail).unwrap()); },
44            None => ()
45        }
46        Value::Object(map).serialize(serializer)
47    }
48}
49
50pub type ValicoErrors = Vec<Box<ValicoError>>;
51
52macro_rules! impl_basic_err {
53    ($err:ty, $code:expr) => {
54        impl ::std::error::Error for $err {
55            fn description(&self) -> &str {
56                $code
57            }
58        }
59
60        impl ::std::fmt::Display for $err {
61            fn fmt(&self, formatter: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
62                self.description().fmt(formatter)
63            }
64        }
65    }
66}
67
68macro_rules! impl_err {
69    ($err:ty, $code:expr, $title:expr) => {
70        impl_basic_err!($err, $code);
71
72        impl $crate::common::error::ValicoError for $err {
73            fn get_code(&self) -> &str { $code }
74            fn get_title(&self) -> &str { $title }
75            fn get_path(&self) -> &str { self.path.as_ref() }
76        }
77    };
78
79    ($err:ty, $code:expr, $title:expr, +detail) => {
80        impl_basic_err!($err, $code);
81
82        impl $crate::common::error::ValicoError for $err {
83            fn get_code(&self) -> &str { $code }
84            fn get_title(&self) -> &str { $title }
85            fn get_path(&self) -> &str { self.path.as_ref() }
86            fn get_detail(&self) -> Option<&str> { Some(self.detail.as_ref()) }
87        }
88    };
89
90    ($err:ty, $code:expr, $title:expr, +opt_detail) => {
91        impl_basic_err!($err, $code);
92
93        impl $crate::common::error::ValicoError for $err {
94            fn get_code(&self) -> &str { $code }
95            fn get_title(&self) -> &str { $title }
96            fn get_path(&self) -> &str { self.path.as_ref() }
97            fn get_detail(&self) -> Option<&str> { self.detail.as_ref().map(|s| s.as_ref()) }
98        }
99    }
100}
101
102macro_rules! impl_serialize{
103    ($err:ty) => {
104        impl Serialize for $err {
105            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer {
106                let mut map = ::serde_json::Map::new();
107                map.insert("code".to_string(), to_value(self.get_code()).unwrap());
108                map.insert("title".to_string(), to_value(self.get_title()).unwrap());
109                map.insert("path".to_string(), to_value(self.get_path()).unwrap());
110                match self.get_detail() {
111                    Some(ref detail) => { map.insert("detail".to_string(), to_value(detail).unwrap()); },
112                    None => ()
113                }
114                Value::Object(map).serialize(serializer)
115            }
116        }
117    };
118    ($err:ty, $($sp:expr),+) => {
119        impl Serialize for $err {
120            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer {
121                let mut map = ::serde_json::Map::new();
122                map.insert("code".to_string(), to_value(self.get_code()).unwrap());
123                map.insert("title".to_string(), to_value(self.get_title()).unwrap());
124                map.insert("path".to_string(), to_value(self.get_path()).unwrap());
125                match self.get_detail() {
126                    Some(ref detail) => { map.insert("detail".to_string(), to_value(detail).unwrap()); },
127                    None => ()
128                }
129                $({
130                    let closure = $sp;
131                    closure(self, &mut map);
132                })+
133                Value::Object(map).serialize(serializer)
134            }
135        }
136    }
137}
valico/common/error.rs

valico/common/
error.rs
