chore: refactor generic web server code into quark

crates/quark/src/web/idempotency.rs

@@ -0,0 +1,103 @@
+use crate::{Error, Result};
+
+use async_std::sync::Mutex;
+use rocket::http::Status;
+use rocket::request::{FromRequest, Outcome};
+use rocket_okapi::gen::OpenApiGenerator;
+use rocket_okapi::okapi::openapi3::{Parameter, ParameterValue};
+use rocket_okapi::request::{OpenApiFromRequest, RequestHeaderInput};
+use schemars::schema::{InstanceType, SchemaObject, SingleOrVec};
+use serde::{Deserialize, Serialize};
+use validator::Validate;
+
+#[derive(Validate, Serialize, Deserialize)]
+pub struct IdempotencyKey {
+    #[validate(length(min = 1, max = 64))]
+    key: String,
+}
+
+lazy_static! {
+    static ref TOKEN_CACHE: Mutex<lru::LruCache<String, ()>> = Mutex::new(lru::LruCache::new(100));
+}
+
+impl IdempotencyKey {
+    // Backwards compatibility.
+    // Issue #109
+    pub async fn consume_nonce(&mut self, v: Option<String>) -> Result<()> {
+        if let Some(v) = v {
+            let mut cache = TOKEN_CACHE.lock().await;
+            if cache.get(&v).is_some() {
+                return Err(Error::DuplicateNonce);
+            }
+
+            cache.put(v.clone(), ());
+            self.key = v;
+        }
+
+        Ok(())
+    }
+
+    pub fn into_key(self) -> String {
+        self.key
+    }
+}
+
+impl<'r> OpenApiFromRequest<'r> for IdempotencyKey {
+    fn from_request_input(
+        _gen: &mut OpenApiGenerator,
+        _name: String,
+        _required: bool,
+    ) -> rocket_okapi::Result<RequestHeaderInput> {
+        Ok(RequestHeaderInput::Parameter(Parameter {
+            name: "Idempotency-Key".to_string(),
+            description: Some("Unique key to prevent duplicate requests".to_string()),
+            allow_empty_value: false,
+            required: false,
+            deprecated: false,
+            extensions: schemars::Map::new(),
+            location: "header".to_string(),
+            value: ParameterValue::Schema {
+                allow_reserved: false,
+                example: None,
+                examples: None,
+                explode: None,
+                style: None,
+                schema: SchemaObject {
+                    instance_type: Some(SingleOrVec::Single(Box::new(InstanceType::String))),
+                    ..Default::default()
+                },
+            },
+        }))
+    }
+}
+
+#[async_trait]
+impl<'r> FromRequest<'r> for IdempotencyKey {
+    type Error = Error;
+
+    async fn from_request(request: &'r rocket::Request<'_>) -> Outcome<Self, Self::Error> {
+        if let Some(key) = request
+            .headers()
+            .get("Idempotency-Key")
+            .next()
+            .map(|k| k.to_string())
+        {
+            let idempotency = IdempotencyKey { key };
+            if let Err(error) = idempotency.validate() {
+                return Outcome::Failure((Status::BadRequest, Error::FailedValidation { error }));
+            }
+
+            let mut cache = TOKEN_CACHE.lock().await;
+            if cache.get(&idempotency.key).is_some() {
+                return Outcome::Failure((Status::Conflict, Error::DuplicateNonce));
+            }
+
+            cache.put(idempotency.key.clone(), ());
+            return Outcome::Success(idempotency);
+        }
+
+        Outcome::Success(IdempotencyKey {
+            key: ulid::Ulid::new().to_string(),
+        })
+    }
+}