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// Copyright 2019-2021 Parity Technologies (UK) Ltd.
//
// Permission is hereby granted, free of charge, to any
// person obtaining a copy of this software and associated
// documentation files (the "Software"), to deal in the
// Software without restriction, including without
// limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of
// the Software, and to permit persons to whom the Software
// is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice
// shall be included in all copies or substantial portions
// of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
// ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
// TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
// PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
// SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
// IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//! Types to handle JSON-RPC request parameters according to the [spec](https://www.jsonrpc.org/specification#parameter_structures).
//! Some types come with a "*Ser" variant that implements [`serde::Serialize`]; these are used in the client.
use crate::error::CallError;
use alloc::collections::BTreeMap;
use beef::Cow;
use serde::de::{self, Deserializer, Unexpected, Visitor};
use serde::ser::Serializer;
use serde::{Deserialize, Serialize};
use serde_json::Value as JsonValue;
/// JSON-RPC v2 marker type.
#[derive(Clone, Copy, Debug, Default, PartialEq)]
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pub struct TwoPointZero;
struct TwoPointZeroVisitor;
impl<'de> Visitor<'de> for TwoPointZeroVisitor {
type Value = TwoPointZero;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str(r#"a string "2.0""#)
}
fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
where
E: de::Error,
{
match s {
"2.0" => Ok(TwoPointZero),
_ => Err(de::Error::invalid_value(Unexpected::Str(s), &self)),
}
}
}
impl<'de> Deserialize<'de> for TwoPointZero {
fn deserialize<D>(deserializer: D) -> Result<TwoPointZero, D::Error>
where
D: Deserializer<'de>,
{
deserializer.deserialize_str(TwoPointZeroVisitor)
}
}
impl Serialize for TwoPointZero {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
serializer.serialize_str("2.0")
}
}
/// Parameters sent with an incoming JSON-RPC request.
///
/// The data containing the params is a `Cow<&str>` and can either be a borrowed `&str` of JSON from an incoming
/// [`super::request::Request`] (which in turn borrows it from the input buffer that is shared between requests);
/// or, it can be an owned [`String`].
/// Create params
pub fn new(raw: Option<&'a str>) -> Self {
Self(raw.map(|r| r.trim().into()))
/// Returns true if the contained JSON is an object
pub fn is_object(&self) -> bool {
let json: &str = match self.0 {
Some(ref cow) => cow,
None => return false,
};
json.starts_with('{')
///
/// This allows sequential parsing of the incoming params, using an `Iterator`-style API and is useful when the RPC
/// request has optional parameters at the tail that may or may not be present.
let json = match self.0.as_ref() {
// It's assumed that params is `[a,b,c]`, if empty regard as no params.
Some(json) if json == "[]" => "",
Some(json) => json,
None => "",
};
}
/// Attempt to parse all parameters as an array or map into type `T`.
pub fn parse<T>(&'a self) -> Result<T, CallError>
where
T: Deserialize<'a>,
{
// NOTE(niklasad1): Option::None is serialized as `null` so we provide that here.
let params = self.0.as_ref().map(AsRef::as_ref).unwrap_or("null");
serde_json::from_str(params).map_err(|e| CallError::InvalidParams(e.into()))
}
/// Attempt to parse parameters as an array of a single value of type `T`, and returns that value.
pub fn one<T>(&'a self) -> Result<T, CallError>
where
T: Deserialize<'a>,
{
self.parse::<[T; 1]>().map(|[res]| res)
/// Convert `Params<'a>` to `Params<'static>` so that it can be moved across threads.
///
/// This will cause an allocation if the params internally are using a borrowed JSON slice.
pub fn into_owned(self) -> Params<'static> {
Params(self.0.map(|s| Cow::owned(s.into_owned())))
/// Return the length of underlying JSON string in number of bytes.
pub fn len_bytes(&self) -> usize {
match self.0 {
Some(ref cow) => cow.len(),
None => 0,
}
}
/// An `Iterator`-like parser for a sequence of [`Params`].
///
/// This will parse the params one at a time, and allows for graceful handling of optional parameters at the tail; other
/// use cases are likely better served by [`Params::parse`]. The reason this is not an actual [`Iterator`] is that
/// params parsing (often) yields values of different types.
///
/// Regards empty array `[]` as no parameters provided.
fn next_inner<T>(&mut self) -> Option<Result<T, CallError>>
where
T: Deserialize<'a>,
{
let mut json = self.0;
tracing::trace!("[next_inner] Params JSON: {:?}", json);
match json.as_bytes().get(0)? {
b']' => {
tracing::trace!("[next_inner] Reached end of sequence.");
return None;
}
b'[' | b',' => json = &json[1..],
_ => {
let errmsg = format!("Invalid params. Expected one of '[', ']' or ',' but found {:?}", json);
tracing::error!("[next_inner] {}", errmsg);
return Some(Err(CallError::InvalidParams(anyhow!(errmsg))));
}
}
let mut iter = serde_json::Deserializer::from_str(json).into_iter::<T>();
match iter.next()? {
Ok(value) => {
self.0 = json[iter.byte_offset()..].trim_start();
"[next_inner] Deserialization to {:?} failed. Error: {:?}, input JSON: {:?}",
std::any::type_name::<T>(),
e,
json
);
Some(Err(CallError::InvalidParams(e.into())))
}
}
}
/// Parse the next parameter to type `T`
///
/// ```
/// let params = Params::new(Some(r#"[true, 10, "foo"]"#));
/// let mut seq = params.sequence();
/// let a: bool = seq.next().unwrap();
/// let b: i32 = seq.next().unwrap();
/// let c: &str = seq.next().unwrap();
///
/// assert_eq!(a, true);
/// assert_eq!(b, 10);
/// assert_eq!(c, "foo");
/// ```
#[allow(clippy::should_implement_trait)]
pub fn next<T>(&mut self) -> Result<T, CallError>
where
T: Deserialize<'a>,
{
match self.next_inner() {
Some(result) => result,
None => Err(CallError::InvalidParams(anyhow!("No more params"))),
}
}
/// Parse the next optional parameter to type `Option<T>`.
///
/// The result will be `None` for `null`, and for missing values in the supplied JSON array.
///
/// ```
/// let params = Params::new(Some(r#"[1, 2, null]"#));
/// let mut seq = params.sequence();
///
/// let params: [Option<u32>; 4] = [
/// seq.optional_next().unwrap(),
/// seq.optional_next().unwrap(),
/// seq.optional_next().unwrap(),
/// seq.optional_next().unwrap(),
/// ];
///
/// assert_eq!(params, [Some(1), Some(2), None, None]);
/// ```
pub fn optional_next<T>(&mut self) -> Result<Option<T>, CallError>
where
T: Deserialize<'a>,
{
match self.next_inner::<Option<T>>() {
Some(result) => result,
None => Ok(None),
}
}
/// [Serializable JSON-RPC parameters](https://www.jsonrpc.org/specification#parameter_structures)
///
/// If your type implements `Into<JsonValue>`, call that in favor of `serde_json::to:value` to
/// construct the parameters. Because `serde_json::to_value` serializes the type which allocates
/// whereas `Into<JsonValue>` doesn't in most cases.
/// Positional params (heap allocated).
ArrayRef(&'a [JsonValue]),
/// Params by name.
Map(BTreeMap<&'a str, JsonValue>),
}
impl<'a> From<BTreeMap<&'a str, JsonValue>> for ParamsSer<'a> {
fn from(map: BTreeMap<&'a str, JsonValue>) -> Self {
Self::Map(map)
}
}
fn from(arr: Vec<JsonValue>) -> Self {
Self::Array(arr)
}
}
impl<'a> From<&'a [JsonValue]> for ParamsSer<'a> {
fn from(slice: &'a [JsonValue]) -> Self {
Self::ArrayRef(slice)
}
}
/// Id of a subscription, communicated by the server.
#[derive(Debug, PartialEq, Clone, Hash, Eq, Deserialize, Serialize)]
#[serde(deny_unknown_fields)]
#[serde(untagged)]
pub enum SubscriptionId<'a> {
/// Numeric id
Num(u64),
/// String id
#[serde(borrow)]
Str(Cow<'a, str>),
impl<'a> From<SubscriptionId<'a>> for JsonValue {
fn from(sub_id: SubscriptionId) -> Self {
match sub_id {
SubscriptionId::Num(n) => n.into(),
SubscriptionId::Str(s) => s.into_owned().into(),
}
}
}
impl<'a> From<u64> for SubscriptionId<'a> {
fn from(sub_id: u64) -> Self {
Self::Num(sub_id)
}
}
impl<'a> From<String> for SubscriptionId<'a> {
fn from(sub_id: String) -> Self {
Self::Str(sub_id.into())
}
}
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impl<'a> TryFrom<JsonValue> for SubscriptionId<'a> {
type Error = ();
fn try_from(json: JsonValue) -> Result<SubscriptionId<'a>, ()> {
match json {
JsonValue::String(s) => Ok(SubscriptionId::Str(s.into())),
JsonValue::Number(n) => {
if let Some(n) = n.as_u64() {
Ok(SubscriptionId::Num(n))
} else {
Err(())
}
}
_ => Err(()),
}
}
}
impl<'a> SubscriptionId<'a> {
/// Convert `SubscriptionId<'a>` to `SubscriptionId<'static>` so that it can be moved across threads.
///
/// This can cause an allocation if the id is a string.
pub fn into_owned(self) -> SubscriptionId<'static> {
match self {
SubscriptionId::Num(num) => SubscriptionId::Num(num),
SubscriptionId::Str(s) => SubscriptionId::Str(Cow::owned(s.into_owned())),
}
}
}
/// Request Id
#[derive(Debug, PartialEq, Clone, Hash, Eq, Deserialize, Serialize, PartialOrd, Ord)]
#[serde(deny_unknown_fields)]
#[serde(untagged)]
pub enum Id<'a> {
/// Null
Null,
/// Numeric id
Number(u64),
/// String id
#[serde(borrow)]
Str(Cow<'a, str>),
impl<'a> Id<'a> {
/// If the Id is a number, returns the associated number. Returns None otherwise.
pub fn as_number(&self) -> Option<&u64> {
match self {
_ => None,
}
}
/// If the Id is a String, returns the associated str. Returns None otherwise.
pub fn as_str(&self) -> Option<&str> {
match self {
Self::Str(s) => Some(s.as_ref()),
_ => None,
}
}
/// If the ID is Null, returns (). Returns None otherwise.
pub fn as_null(&self) -> Option<()> {
match self {
/// Convert `Id<'a>` to `Id<'static>` so that it can be moved across threads.
///
/// This can cause an allocation if the id is a string.
pub fn into_owned(self) -> Id<'static> {
Id::Null => Id::Null,
Id::Number(num) => Id::Number(num),
Id::Str(s) => Id::Str(Cow::owned(s.into_owned())),
#[cfg(test)]
mod test {
use super::{Cow, Id, JsonValue, Params, ParamsSer, SubscriptionId, TwoPointZero};
#[test]
fn id_deserialization() {
let s = r#""2""#;
let deserialized: Id = serde_json::from_str(s).unwrap();
match deserialized {
Id::Str(ref cow) => {
assert!(cow.is_borrowed());
assert_eq!(cow, "2");
}
_ => panic!("Expected Id::Str"),
}
let s = r#"2"#;
let deserialized: Id = serde_json::from_str(s).unwrap();
assert_eq!(deserialized, Id::Number(2));
let s = r#""2x""#;
let deserialized: Id = serde_json::from_str(s).unwrap();
assert_eq!(deserialized, Id::Str(Cow::const_str("2x")));
let s = r#"[1337]"#;
assert!(serde_json::from_str::<Id>(s).is_err());
let s = r#"[null, 0, 2, "\"3"]"#;
let deserialized: Vec<Id> = serde_json::from_str(s).unwrap();
assert_eq!(deserialized, vec![Id::Null, Id::Number(0), Id::Number(2), Id::Str("\"3".into())]);
}
#[test]
fn id_serialization() {
let d =
vec![Id::Null, Id::Number(0), Id::Number(2), Id::Number(3), Id::Str("\"3".into()), Id::Str("test".into())];
let serialized = serde_json::to_string(&d).unwrap();
assert_eq!(serialized, r#"[null,0,2,3,"\"3","test"]"#);
#[test]
fn params_serialize() {
let test_vector = &[
("[]", ParamsSer::Array(serde_json::from_str("[]").unwrap())),
("[42,23]", ParamsSer::Array(serde_json::from_str("[42,23]").unwrap())),
(
r#"{"a":42,"b":null,"c":"aa"}"#,
ParamsSer::Map(serde_json::from_str(r#"{"a":42,"b":null,"c":"aa"}"#).unwrap()),
),
];
for (initial_ser, params) in test_vector {
let serialized = serde_json::to_string(params).unwrap();
assert_eq!(&serialized, initial_ser);
}
}
#[test]
fn params_parse() {
assert!(none.sequence().next::<u64>().is_err());
assert!(none.parse::<Option<u64>>().is_ok());
let array_params = Params::new(Some("[1, 2, 3]"));
let arr: Result<[u64; 3], _> = array_params.parse();
assert!(arr.is_ok());
let mut seq = array_params.sequence();
assert_eq!(seq.next::<u64>().unwrap(), 1);
assert_eq!(seq.next::<u64>().unwrap(), 2);
assert_eq!(seq.next::<u64>().unwrap(), 3);
assert!(seq.next::<u64>().is_err());
let one: Result<u64, _> = array_one.one();
assert!(one.is_ok());
let object_params = Params::new(Some(r#"{"beef":99,"dinner":0}"#));
let obj: Result<JsonValue, _> = object_params.parse();
assert!(obj.is_ok());
}
#[test]
fn params_parse_empty_json() {
let arr: Result<Vec<u64>, _> = array_params.parse();
assert!(arr.is_ok());
let obj: Result<JsonValue, _> = obj_params.parse();
assert!(obj.is_ok());
}
#[test]
fn params_sequence_borrows() {
let params = Params::new(Some(r#"["foo", "bar"]"#));
let mut seq = params.sequence();
assert_eq!(seq.next::<&str>().unwrap(), "foo");
assert_eq!(seq.next::<&str>().unwrap(), "bar");
assert!(seq.next::<&str>().is_err());
// It's ok to parse the params again.
let params: (&str, &str) = params.parse().unwrap();
assert_eq!(params, ("foo", "bar"));
}
#[test]
fn two_point_zero_serde_works() {
let initial_ser = r#""2.0""#;
// The fact that it was deserialized is enough.
let two_point_zero: TwoPointZero = serde_json::from_str(initial_ser).unwrap();
let serialized = serde_json::to_string(&two_point_zero).unwrap();
assert_eq!(serialized, initial_ser);
}
#[test]
fn subscription_id_serde_works() {
let test_vector = &[("42", SubscriptionId::Num(42)), (r#""one""#, SubscriptionId::Str("one".into()))];
for (initial_ser, expected) in test_vector {
let id: SubscriptionId = serde_json::from_str(initial_ser).unwrap();
assert_eq!(&id, expected);
let serialized = serde_json::to_string(&id).unwrap();
assert_eq!(&serialized, initial_ser);
}
}
#[test]
fn subscription_params_serialize_work() {
let ser = serde_json::to_string(&SubscriptionPayload { subscription: SubscriptionId::Num(12), result: "goal" })
.unwrap();
let exp = r#"{"subscription":12,"result":"goal"}"#;
assert_eq!(ser, exp);
}
#[test]
fn subscription_params_deserialize_work() {
let ser = r#"{"subscription":"9","result":"offside"}"#;
assert!(
serde_json::from_str::<SubscriptionPayload<()>>(ser).is_err(),
"invalid type should not be deserializable"
);
let dsr: SubscriptionPayload<JsonValue> = serde_json::from_str(ser).unwrap();
assert_eq!(dsr.subscription, SubscriptionId::Str("9".into()));
assert_eq!(dsr.result, serde_json::json!("offside"));
}
#[test]
fn params_sequence_optional_ignore_empty() {
let params = Params::new(Some(r#"["foo", "bar"]"#));
let mut seq = params.sequence();
assert_eq!(seq.optional_next::<&str>().unwrap(), Some("foo"));
assert_eq!(seq.optional_next::<&str>().unwrap(), Some("bar"));
let mut seq = params.sequence();
assert!(seq.optional_next::<&str>().unwrap().is_none());
let mut seq = params.sequence();
assert!(seq.optional_next::<&str>().unwrap().is_none());
let mut seq = params.sequence();
assert!(seq.optional_next::<&str>().is_err(), "JSON object not supported by RpcSequence");
let params = Params::new(Some(r#"[12, "[]", [], {}]"#));
let mut seq = params.sequence();
assert_eq!(seq.optional_next::<u64>().unwrap(), Some(12));
assert_eq!(seq.optional_next::<&str>().unwrap(), Some("[]"));
assert_eq!(seq.optional_next::<Vec<u8>>().unwrap(), Some(vec![]));
assert_eq!(seq.optional_next::<serde_json::Value>().unwrap(), Some(serde_json::json!({})));
}
#[test]
fn params_sequence_optional_nesting_works() {
let nested = Params::new(Some(r#"[1, [2], [3, 4], [[5], [6,7], []], {"named":7}]"#));
let mut seq = nested.sequence();
assert_eq!(seq.optional_next::<i8>().unwrap(), Some(1));
assert_eq!(seq.optional_next::<[i8; 1]>().unwrap(), Some([2]));
assert_eq!(seq.optional_next::<Vec<u16>>().unwrap(), Some(vec![3, 4]));
assert_eq!(seq.optional_next::<Vec<Vec<u32>>>().unwrap(), Some(vec![vec![5], vec![6, 7], vec![]]));
assert_eq!(seq.optional_next::<serde_json::Value>().unwrap(), Some(serde_json::json!({"named":7})));
}