2020-10-24 00:44:01 +02:00

689 lines
25 KiB
Rust

//! Details of the `request` section of the procedural macro.
use std::{collections::BTreeSet, convert::TryFrom, mem};
use proc_macro2::TokenStream;
use quote::{quote, quote_spanned, ToTokens};
use syn::{spanned::Spanned, Attribute, Field, Ident, Lifetime};
use crate::{
api::{
attribute::{Meta, MetaNameValue},
strip_serde_attrs, RawRequest,
},
util,
};
#[derive(Debug, Default)]
pub struct RequestLifetimes {
body: BTreeSet<Lifetime>,
path: BTreeSet<Lifetime>,
query: BTreeSet<Lifetime>,
header: BTreeSet<Lifetime>,
}
/// The result of processing the `request` section of the macro.
pub struct Request {
/// The attributes that will be applied to the struct definition.
attributes: Vec<Attribute>,
/// The fields of the request.
fields: Vec<RequestField>,
/// The collected lifetime identifiers from the declared fields.
lifetimes: RequestLifetimes,
// Guarantee `ruma_api` is available and named something we can refer to.
ruma_api_import: TokenStream,
}
impl Request {
/// Produces code to add necessary HTTP headers to an `http::Request`.
pub fn append_header_kvs(&self) -> TokenStream {
let import_path = &self.ruma_api_import;
self.header_fields().map(|request_field| {
let (field, header_name) = match request_field {
RequestField::Header(field, header_name) => (field, header_name),
_ => unreachable!("expected request field to be header variant"),
};
let field_name = &field.ident;
match &field.ty {
syn::Type::Path(syn::TypePath { path: syn::Path { segments, .. }, .. })
if segments.last().unwrap().ident == "Option" =>
{
quote! {
if let Some(header_val) = self.#field_name.as_ref() {
req_builder = req_builder.header(
#import_path::exports::http::header::#header_name,
#import_path::exports::http::header::HeaderValue::from_str(header_val)?,
);
}
}
}
_ => quote! {
req_builder = req_builder.header(
#import_path::exports::http::header::#header_name,
#import_path::exports::http::header::HeaderValue::from_str(self.#field_name.as_ref())?,
);
},
}
}).collect()
}
/// Produces code to extract fields from the HTTP headers in an `http::Request`.
pub fn parse_headers_from_request(&self) -> TokenStream {
let import_path = &self.ruma_api_import;
let fields = self.header_fields().map(|request_field| {
let (field, header_name) = match request_field {
RequestField::Header(field, header_name) => (field, header_name),
_ => panic!("expected request field to be header variant"),
};
let field_name = &field.ident;
let header_name_string = header_name.to_string();
let (some_case, none_case) = match &field.ty {
syn::Type::Path(syn::TypePath { path: syn::Path { segments, .. }, .. })
if segments.last().unwrap().ident == "Option" =>
{
(quote! { Some(header.to_owned()) }, quote! { None })
}
_ => (
quote! { header.to_owned() },
quote! {{
use #import_path::exports::serde::de::Error as _;
// FIXME: Not a missing json field, a missing header!
return Err(#import_path::error::RequestDeserializationError::new(
#import_path::exports::serde_json::Error::missing_field(
#header_name_string
),
request,
)
.into());
}},
),
};
quote! {
#field_name: match headers
.get(#import_path::exports::http::header::#header_name)
.and_then(|v| v.to_str().ok()) // FIXME: Should have a distinct error message
{
Some(header) => #some_case,
None => #none_case,
}
}
});
quote! {
#(#fields,)*
}
}
/// Whether or not this request has any data in the HTTP body.
pub fn has_body_fields(&self) -> bool {
self.fields.iter().any(|field| field.is_body())
}
/// Whether or not this request has any data in HTTP headers.
pub fn has_header_fields(&self) -> bool {
self.fields.iter().any(|field| field.is_header())
}
/// Whether or not this request has any data in the URL path.
pub fn has_path_fields(&self) -> bool {
self.fields.iter().any(|field| field.is_path())
}
/// Whether or not this request has any data in the query string.
pub fn has_query_fields(&self) -> bool {
self.fields.iter().any(|field| field.is_query())
}
/// Produces an iterator over all the body fields.
pub fn body_fields(&self) -> impl Iterator<Item = &Field> {
self.fields.iter().filter_map(|field| field.as_body_field())
}
/// The number of unique lifetime annotations for `body` fields.
pub fn body_lifetime_count(&self) -> usize {
self.lifetimes.body.len()
}
/// Whether any `body` field has a lifetime annotation.
pub fn has_body_lifetimes(&self) -> bool {
!self.lifetimes.body.is_empty()
}
/// Whether any `query` field has a lifetime annotation.
pub fn has_query_lifetimes(&self) -> bool {
!self.lifetimes.query.is_empty()
}
/// Whether any field has a lifetime.
pub fn contains_lifetimes(&self) -> bool {
!(self.lifetimes.body.is_empty()
&& self.lifetimes.path.is_empty()
&& self.lifetimes.query.is_empty()
&& self.lifetimes.header.is_empty())
}
/// The combination of every fields unique lifetime annotation.
pub fn combine_lifetimes(&self) -> TokenStream {
util::unique_lifetimes_to_tokens(
self.lifetimes
.body
.iter()
.chain(self.lifetimes.path.iter())
.chain(self.lifetimes.query.iter())
.chain(self.lifetimes.header.iter())
.collect::<BTreeSet<_>>()
.into_iter(),
)
}
/// The lifetimes on fields with the `query` attribute.
pub fn query_lifetimes(&self) -> TokenStream {
util::unique_lifetimes_to_tokens(self.lifetimes.query.iter())
}
/// The lifetimes on fields with the `body` attribute.
pub fn body_lifetimes(&self) -> TokenStream {
util::unique_lifetimes_to_tokens(self.lifetimes.body.iter())
}
// /// The lifetimes on fields with the `header` attribute.
// pub fn header_lifetimes(&self) -> TokenStream {
// util::generics_to_tokens(self.lifetimes.header.iter())
// }
/// Produces an iterator over all the header fields.
pub fn header_fields(&self) -> impl Iterator<Item = &RequestField> {
self.fields.iter().filter(|field| field.is_header())
}
/// Gets the number of path fields.
pub fn path_field_count(&self) -> usize {
self.fields.iter().filter(|field| field.is_path()).count()
}
/// Returns the body field.
pub fn newtype_body_field(&self) -> Option<&Field> {
self.fields.iter().find_map(RequestField::as_newtype_body_field)
}
/// Returns the body field.
pub fn newtype_raw_body_field(&self) -> Option<&Field> {
self.fields.iter().find_map(RequestField::as_newtype_raw_body_field)
}
/// Returns the query map field.
pub fn query_map_field(&self) -> Option<&Field> {
self.fields.iter().find_map(RequestField::as_query_map_field)
}
/// Produces code for a struct initializer for body fields on a variable named `request`.
pub fn request_body_init_fields(&self) -> TokenStream {
self.struct_init_fields(RequestFieldKind::Body, quote!(self))
}
/// Produces code for a struct initializer for query string fields on a variable named
/// `request`.
pub fn request_query_init_fields(&self) -> TokenStream {
self.struct_init_fields(RequestFieldKind::Query, quote!(self))
}
/// Produces code for a struct initializer for body fields on a variable named `request_body`.
pub fn request_init_body_fields(&self) -> TokenStream {
self.struct_init_fields(RequestFieldKind::Body, quote!(request_body))
}
/// Produces code for a struct initializer for query string fields on a variable named
/// `request_query`.
pub fn request_init_query_fields(&self) -> TokenStream {
self.struct_init_fields(RequestFieldKind::Query, quote!(request_query))
}
/// Produces code for a struct initializer for the given field kind to be accessed through the
/// given variable name.
fn struct_init_fields(
&self,
request_field_kind: RequestFieldKind,
src: TokenStream,
) -> TokenStream {
let process_field = |f: &RequestField| {
f.field_of_kind(request_field_kind).map(|field| {
let field_name =
field.ident.as_ref().expect("expected field to have an identifier");
let span = field.span();
let cfg_attrs =
field.attrs.iter().filter(|a| a.path.is_ident("cfg")).collect::<Vec<_>>();
quote_spanned! {span=>
#( #cfg_attrs )*
#field_name: #src.#field_name
}
})
};
let mut fields = vec![];
let mut new_type_body = None;
for field in &self.fields {
if let RequestField::NewtypeRawBody(_) = field {
new_type_body = process_field(field);
} else {
fields.extend(process_field(field));
}
}
// Move field that consumes `request` to the end of the init list.
fields.extend(new_type_body);
quote! { #(#fields,)* }
}
}
impl TryFrom<RawRequest> for Request {
type Error = syn::Error;
fn try_from(raw: RawRequest) -> syn::Result<Self> {
let mut newtype_body_field = None;
let mut query_map_field = None;
let mut lifetimes = RequestLifetimes::default();
let fields = raw
.fields
.into_iter()
.map(|mut field| {
let mut field_kind = None;
let mut header = None;
for attr in mem::replace(&mut field.attrs, Vec::new()) {
let meta = match Meta::from_attribute(&attr)? {
Some(m) => m,
None => {
field.attrs.push(attr);
continue;
}
};
if field_kind.is_some() {
return Err(syn::Error::new_spanned(
attr,
"There can only be one field kind attribute",
));
}
field_kind = Some(match meta {
Meta::Word(ident) => match &ident.to_string()[..] {
attr @ "body" | attr @ "raw_body" => util::req_res_meta_word(
attr,
&field,
&mut newtype_body_field,
RequestFieldKind::NewtypeBody,
RequestFieldKind::NewtypeRawBody,
)?,
"path" => RequestFieldKind::Path,
"query" => RequestFieldKind::Query,
"query_map" => {
if let Some(f) = &query_map_field {
let mut error = syn::Error::new_spanned(
field,
"There can only be one query map field",
);
error.combine(syn::Error::new_spanned(
f,
"Previous query map field",
));
return Err(error);
}
query_map_field = Some(field.clone());
RequestFieldKind::QueryMap
}
_ => {
return Err(syn::Error::new_spanned(
ident,
"Invalid #[ruma_api] argument, expected one of \
`body`, `path`, `query`, `query_map`",
));
}
},
Meta::NameValue(MetaNameValue { name, value }) => util::req_res_name_value(
name,
value,
&mut header,
RequestFieldKind::Header,
)?,
});
}
match field_kind.unwrap_or(RequestFieldKind::Body) {
RequestFieldKind::Header => {
util::collect_lifetime_ident(&mut lifetimes.header, &field.ty)
}
RequestFieldKind::Body => {
util::collect_lifetime_ident(&mut lifetimes.body, &field.ty)
}
RequestFieldKind::NewtypeBody => {
util::collect_lifetime_ident(&mut lifetimes.body, &field.ty)
}
RequestFieldKind::NewtypeRawBody => {
util::collect_lifetime_ident(&mut lifetimes.body, &field.ty)
}
RequestFieldKind::Path => {
util::collect_lifetime_ident(&mut lifetimes.path, &field.ty)
}
RequestFieldKind::Query => {
util::collect_lifetime_ident(&mut lifetimes.query, &field.ty)
}
RequestFieldKind::QueryMap => {
util::collect_lifetime_ident(&mut lifetimes.query, &field.ty)
}
}
Ok(RequestField::new(field_kind.unwrap_or(RequestFieldKind::Body), field, header))
})
.collect::<syn::Result<Vec<_>>>()?;
if newtype_body_field.is_some() && fields.iter().any(|f| f.is_body()) {
// TODO: highlight conflicting fields,
return Err(syn::Error::new_spanned(
raw.request_kw,
"Can't have both a newtype body field and regular body fields",
));
}
if query_map_field.is_some() && fields.iter().any(|f| f.is_query()) {
return Err(syn::Error::new_spanned(
// TODO: raw,
raw.request_kw,
"Can't have both a query map field and regular query fields",
));
}
// TODO when/if `&[(&str, &str)]` is supported remove this
if query_map_field.is_some() && !lifetimes.query.is_empty() {
return Err(syn::Error::new_spanned(
raw.request_kw,
"Lifetimes are not allowed for query_map fields",
));
}
Ok(Self {
attributes: raw.attributes,
fields,
lifetimes,
ruma_api_import: util::import_ruma_api(),
})
}
}
impl ToTokens for Request {
fn to_tokens(&self, tokens: &mut TokenStream) {
let import_path = &self.ruma_api_import;
let struct_attributes = &self.attributes;
let request_def = if self.fields.is_empty() {
quote!(;)
} else {
let fields =
self.fields.iter().map(|request_field| strip_serde_attrs(request_field.field()));
quote! { { #(#fields),* } }
};
let request_generics = self.combine_lifetimes();
let request_body_struct =
if let Some(body_field) = self.fields.iter().find(|f| f.is_newtype_body()) {
let field = Field { ident: None, colon_token: None, ..body_field.field().clone() };
// Though we don't track the difference between new type body and body
// for lifetimes, the outer check and the macro failing if it encounters
// an illegal combination of field attributes, is enough to guarantee
// `body_lifetimes` correctness.
let (derive_deserialize, lifetimes) = if self.has_body_lifetimes() {
(TokenStream::new(), self.body_lifetimes())
} else {
(quote!(#import_path::exports::serde::Deserialize), TokenStream::new())
};
Some((derive_deserialize, quote! { #lifetimes (#field); }))
} else if self.has_body_fields() {
let fields = self.fields.iter().filter(|f| f.is_body());
let (derive_deserialize, lifetimes) = if self.has_body_lifetimes() {
(TokenStream::new(), self.body_lifetimes())
} else {
(quote!(#import_path::exports::serde::Deserialize), TokenStream::new())
};
let fields = fields.map(RequestField::field);
Some((derive_deserialize, quote! { #lifetimes { #(#fields),* } }))
} else {
None
}
.map(|(derive_deserialize, def)| {
quote! {
/// Data in the request body.
#[derive(
Debug,
#import_path::exports::ruma_common::Outgoing,
#import_path::exports::serde::Serialize,
#derive_deserialize
)]
struct RequestBody #def
}
});
let request_query_struct = if let Some(f) = self.query_map_field() {
let field = Field { ident: None, colon_token: None, ..f.clone() };
let (derive_deserialize, lifetime) = if self.has_query_lifetimes() {
(TokenStream::new(), self.query_lifetimes())
} else {
(quote!(#import_path::exports::serde::Deserialize), TokenStream::new())
};
quote! {
/// Data in the request's query string.
#[derive(
Debug,
#import_path::exports::ruma_common::Outgoing,
#import_path::exports::serde::Serialize,
#derive_deserialize
)]
struct RequestQuery #lifetime (#field);
}
} else if self.has_query_fields() {
let fields = self.fields.iter().filter_map(RequestField::as_query_field);
let (derive_deserialize, lifetime) = if self.has_query_lifetimes() {
(TokenStream::new(), self.query_lifetimes())
} else {
(quote!(#import_path::exports::serde::Deserialize), TokenStream::new())
};
quote! {
/// Data in the request's query string.
#[derive(
Debug,
#import_path::exports::ruma_common::Outgoing,
#import_path::exports::serde::Serialize,
#derive_deserialize
)]
struct RequestQuery #lifetime {
#(#fields),*
}
}
} else {
TokenStream::new()
};
let request = quote! {
#[derive(Debug, Clone, #import_path::exports::ruma_common::Outgoing)]
#[cfg_attr(not(feature = "unstable-exhaustive-types"), non_exhaustive)]
#[incoming_derive(!Deserialize)]
#( #struct_attributes )*
pub struct Request #request_generics #request_def
#request_body_struct
#request_query_struct
};
request.to_tokens(tokens);
}
}
/// The types of fields that a request can have.
pub enum RequestField {
/// JSON data in the body of the request.
Body(Field),
/// Data in an HTTP header.
Header(Field, Ident),
/// A specific data type in the body of the request.
NewtypeBody(Field),
/// Arbitrary bytes in the body of the request.
NewtypeRawBody(Field),
/// Data that appears in the URL path.
Path(Field),
/// Data that appears in the query string.
Query(Field),
/// Data that appears in the query string as dynamic key-value pairs.
QueryMap(Field),
}
impl RequestField {
/// Creates a new `RequestField`.
fn new(kind: RequestFieldKind, field: Field, header: Option<Ident>) -> Self {
match kind {
RequestFieldKind::Body => RequestField::Body(field),
RequestFieldKind::Header => {
RequestField::Header(field, header.expect("missing header name"))
}
RequestFieldKind::NewtypeBody => RequestField::NewtypeBody(field),
RequestFieldKind::NewtypeRawBody => RequestField::NewtypeRawBody(field),
RequestFieldKind::Path => RequestField::Path(field),
RequestFieldKind::Query => RequestField::Query(field),
RequestFieldKind::QueryMap => RequestField::QueryMap(field),
}
}
/// Gets the kind of the request field.
fn kind(&self) -> RequestFieldKind {
match self {
RequestField::Body(..) => RequestFieldKind::Body,
RequestField::Header(..) => RequestFieldKind::Header,
RequestField::NewtypeBody(..) => RequestFieldKind::NewtypeBody,
RequestField::NewtypeRawBody(..) => RequestFieldKind::NewtypeRawBody,
RequestField::Path(..) => RequestFieldKind::Path,
RequestField::Query(..) => RequestFieldKind::Query,
RequestField::QueryMap(..) => RequestFieldKind::QueryMap,
}
}
/// Whether or not this request field is a body kind.
fn is_body(&self) -> bool {
self.kind() == RequestFieldKind::Body
}
/// Whether or not this request field is a header kind.
fn is_header(&self) -> bool {
self.kind() == RequestFieldKind::Header
}
/// Whether or not this request field is a newtype body kind.
fn is_newtype_body(&self) -> bool {
self.kind() == RequestFieldKind::NewtypeBody
}
/// Whether or not this request field is a path kind.
fn is_path(&self) -> bool {
self.kind() == RequestFieldKind::Path
}
/// Whether or not this request field is a query string kind.
fn is_query(&self) -> bool {
self.kind() == RequestFieldKind::Query
}
/// Return the contained field if this request field is a body kind.
fn as_body_field(&self) -> Option<&Field> {
self.field_of_kind(RequestFieldKind::Body)
}
/// Return the contained field if this request field is a body kind.
fn as_newtype_body_field(&self) -> Option<&Field> {
self.field_of_kind(RequestFieldKind::NewtypeBody)
}
/// Return the contained field if this request field is a raw body kind.
fn as_newtype_raw_body_field(&self) -> Option<&Field> {
self.field_of_kind(RequestFieldKind::NewtypeRawBody)
}
/// Return the contained field if this request field is a query kind.
fn as_query_field(&self) -> Option<&Field> {
self.field_of_kind(RequestFieldKind::Query)
}
/// Return the contained field if this request field is a query map kind.
fn as_query_map_field(&self) -> Option<&Field> {
self.field_of_kind(RequestFieldKind::QueryMap)
}
/// Gets the inner `Field` value.
fn field(&self) -> &Field {
match self {
RequestField::Body(field)
| RequestField::Header(field, _)
| RequestField::NewtypeBody(field)
| RequestField::NewtypeRawBody(field)
| RequestField::Path(field)
| RequestField::Query(field)
| RequestField::QueryMap(field) => field,
}
}
/// Gets the inner `Field` value if it's of the provided kind.
fn field_of_kind(&self, kind: RequestFieldKind) -> Option<&Field> {
if self.kind() == kind {
Some(self.field())
} else {
None
}
}
}
/// The types of fields that a request can have, without their values.
#[derive(Clone, Copy, PartialEq, Eq)]
enum RequestFieldKind {
/// See the similarly named variant of `RequestField`.
Body,
/// See the similarly named variant of `RequestField`.
Header,
/// See the similarly named variant of `RequestField`.
NewtypeBody,
/// See the similarly named variant of `RequestField`.
NewtypeRawBody,
/// See the similarly named variant of `RequestField`.
Path,
/// See the similarly named variant of `RequestField`.
Query,
/// See the similarly named variant of `RequestField`.
QueryMap,
}