musli_web/
json.rs

1use alloc::string::{String, ToString};
2
3#[cfg(feature = "axum-core05")]
4use axum_core05::extract as extract05;
5#[cfg(feature = "axum-core05")]
6use axum_core05::extract::rejection as rejection05;
7#[cfg(feature = "axum-core05")]
8use axum_core05::response as response05;
9use bytes::{BufMut, Bytes, BytesMut};
10use http::header::{self, HeaderValue};
11use http::{HeaderMap, StatusCode};
12use musli::Encode;
13use musli::alloc::Global;
14use musli::context::ErrorMarker;
15use musli::de::DecodeOwned;
16use musli::json::Encoding;
17use musli::mode::Text;
18
19const ENCODING: Encoding = Encoding::new();
20
21/// A rejection from the JSON extractor.
22pub struct JsonRejection {
23    kind: JsonRejectionKind,
24}
25
26impl JsonRejection {
27    #[inline]
28    pub(crate) fn report(report: String) -> Self {
29        Self {
30            kind: JsonRejectionKind::Report(report),
31        }
32    }
33}
34
35enum JsonRejectionKind {
36    ContentType,
37    Report(String),
38    #[cfg(feature = "axum-core05")]
39    BytesRejection05(rejection05::BytesRejection),
40}
41
42#[cfg(feature = "axum-core05")]
43impl From<rejection05::BytesRejection> for JsonRejection {
44    #[inline]
45    fn from(rejection: rejection05::BytesRejection) -> Self {
46        JsonRejection {
47            kind: JsonRejectionKind::BytesRejection05(rejection),
48        }
49    }
50}
51
52#[cfg(feature = "axum-core05")]
53#[cfg_attr(doc_cfg, doc(cfg(feature = "axum-core05")))]
54impl response05::IntoResponse for JsonRejection {
55    fn into_response(self) -> response05::Response {
56        let (status, body) = match self.kind {
57            JsonRejectionKind::ContentType => (
58                StatusCode::UNSUPPORTED_MEDIA_TYPE,
59                String::from("Expected request with `Content-Type: application/json`"),
60            ),
61            JsonRejectionKind::Report(report) => (StatusCode::BAD_REQUEST, report),
62            JsonRejectionKind::BytesRejection05(rejection) => {
63                return rejection.into_response();
64            }
65        };
66
67        (
68            status,
69            [(
70                header::CONTENT_TYPE,
71                HeaderValue::from_static(mime::TEXT_PLAIN_UTF_8.as_ref()),
72            )],
73            body,
74        )
75            .into_response()
76    }
77}
78
79/// Encode the given value as JSON.
80pub struct Json<T>(pub T);
81
82#[cfg(feature = "axum-core05")]
83#[cfg_attr(doc_cfg, doc(cfg(feature = "axum-core05")))]
84impl<T, S> extract05::FromRequest<S> for Json<T>
85where
86    T: DecodeOwned<Text, Global>,
87    S: Send + Sync,
88{
89    type Rejection = JsonRejection;
90
91    async fn from_request(req: extract05::Request, state: &S) -> Result<Self, Self::Rejection> {
92        if !json_content_type(req.headers()) {
93            return Err(JsonRejection {
94                kind: JsonRejectionKind::ContentType,
95            });
96        }
97
98        let bytes = Bytes::from_request(req, state).await?;
99        Self::from_bytes(&bytes)
100    }
101}
102
103fn json_content_type(headers: &HeaderMap) -> bool {
104    let content_type = if let Some(content_type) = headers.get(header::CONTENT_TYPE) {
105        content_type
106    } else {
107        return false;
108    };
109
110    let content_type = if let Ok(content_type) = content_type.to_str() {
111        content_type
112    } else {
113        return false;
114    };
115
116    let mime = if let Ok(mime) = content_type.parse::<mime::Mime>() {
117        mime
118    } else {
119        return false;
120    };
121
122    mime.type_() == "application"
123        && (mime.subtype() == "json" || mime.suffix().is_some_and(|name| name == "json"))
124}
125
126#[cfg(feature = "axum-core05")]
127#[cfg_attr(doc_cfg, doc(cfg(feature = "axum-core05")))]
128impl<T> response05::IntoResponse for Json<T>
129where
130    T: Encode<Text>,
131{
132    fn into_response(self) -> response05::Response {
133        let cx = musli::context::new().with_trace();
134
135        // Use a small initial capacity of 128 bytes like serde_json::to_vec
136        // https://docs.rs/serde_json/1.0.82/src/serde_json/ser.rs.html#2189
137        let mut buf = BytesMut::with_capacity(128).writer();
138
139        match ENCODING.to_writer_with(&cx, &mut buf, &self.0) {
140            Ok(()) => {
141                let content_type = [(
142                    header::CONTENT_TYPE,
143                    HeaderValue::from_static(mime::APPLICATION_JSON.as_ref()),
144                )];
145                let report = buf.into_inner().freeze();
146                (content_type, report).into_response()
147            }
148            Err(ErrorMarker { .. }) => {
149                let status = StatusCode::INTERNAL_SERVER_ERROR;
150                let content_type = [(
151                    header::CONTENT_TYPE,
152                    HeaderValue::from_static(mime::TEXT_PLAIN_UTF_8.as_ref()),
153                )];
154                let report = cx.report().to_string();
155                (status, content_type, report).into_response()
156            }
157        }
158    }
159}
160
161impl<T> Json<T>
162where
163    T: DecodeOwned<Text, Global>,
164{
165    #[inline]
166    fn from_bytes(bytes: &[u8]) -> Result<Self, JsonRejection> {
167        let cx = musli::context::new().with_trace();
168
169        if let Ok(value) = ENCODING.from_slice_with(&cx, bytes) {
170            return Ok(Json(value));
171        }
172
173        let report = cx.report();
174        let report = report.to_string();
175        Err(JsonRejection::report(report))
176    }
177}
musli_web/json.rs

musli_web/
json.rs
