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api: move router to router.rs

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We'll have a separate router for the command line, so the
http router won't live in the root module.

It is still exported at the root level, though, via
proxmox::api::Router.

Also move ApiType into api_type.rs, makes more sense.

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
This commit is contained in:
Wolfgang Bumiller 2019-06-08 13:11:24 +02:00
parent dcfa3ca9a2
commit 60df564f73
3 changed files with 313 additions and 300 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

154
proxmox-api/src/api_type.rs
View File

@ -1,5 +1,11 @@
//! This contains traits used to implement methods to be added to the `Router`. //! This contains traits used to implement methods to be added to the `Router`.
use std::cell::Cell;
use std::sync::Once;
use bytes::Bytes;
use failure::Error;
use http::Response;
use serde_json::Value; use serde_json::Value;
/// Method entries in a `Router` are actually just `&dyn ApiMethodInfo` trait objects. /// Method entries in a `Router` are actually just `&dyn ApiMethodInfo` trait objects.
@ -74,3 +80,151 @@ impl ApiMethodInfo for ApiMethod {
self.handler self.handler
} }
} }
/// We're supposed to only use types in the API which implement `ApiType`, which forces types ot
/// have a `verify` method. The idea is that all parameters used in the API are documented
/// somewhere with their formats and limits, which are checked when entering and leaving API entry
/// points.
///
/// Any API type is also required to implement `Serialize` and `DeserializeOwned`, since they're
/// read out of json `Value` types.
///
/// While this is very useful for structural types, we sometimes to want to be able to pass a
/// simple unconstrainted type like a `String` with no restrictions, so most basic types implement
/// `ApiType` as well.
//
// FIXME: I've actually moved most of this into the types in `api_type.rs` now, so this is
// probably unused at this point?
// `verify` should be moved to `TypeInfo` (for the type related verifier), and `Parameter` should
// get an additional verify method for constraints added by *methods*.
//
// We actually have 2 layers of validation:
// When entering the API: The type validation
// obviously a `String` should also be a string in the json object...
// This does not happen when we call the method from rust-code as we have no json layer
// there.
// When entering the function: The input validation
// if the function says `Integer`, the type itself has no validation other than that it has
// to be an integer type, but the function may still say `minimum: 5, maximum: 10`.
// This should also happen for direct calls from within rust, the `#[api]` macro can take
// care of this.
// When leaving the function: The output validation
// Yep, we need to add this ;-)
pub trait ApiType {
/// API types need to provide a `TypeInfo`, providing details about the underlying type.
fn type_info() -> &'static TypeInfo;
/// Additionally, ApiTypes must provide a way to verify their constraints!
fn verify(&self) -> Result<(), Error>;
/// This is a workaround for when we cannot name the type but have an object available we can
/// call a method on. (We cannot call associated methods on objects without being able to write
/// out the type, and rust has some restrictions as to what types are available.)
// eg. nested generics:
// fn foo<T>() {
// fn bar<U>(x: &T) {
// cannot use T::method() here, but can use x.method()
// (compile error "can't use generic parameter of outer function",
// and yes, that's a stupid restriction as it is still completely static...)
// }
// }
fn get_type_info(&self) -> &'static TypeInfo {
Self::type_info()
}
}
/// Option types are supposed to wrap their underlying types with an `optional:` text in their
/// description.
// BUT it requires some anti-static magic. And while this looks like the result of lazy_static!,
// it's not exactly the same, lazy_static! here does not actually work as it'll curiously produce
// the same error as we pointed out above in the `get_type_info` method (as it does a lot more
// extra stuff we don't need)...
impl<T: ApiType> ApiType for Option<T> {
fn verify(&self) -> Result<(), Error> {
if let Some(inner) = self {
inner.verify()?
}
Ok(())
}
fn type_info() -> &'static TypeInfo {
struct Data {
info: Cell<Option<TypeInfo>>,
once: Once,
name: Cell<Option<String>>,
description: Cell<Option<String>>,
}
unsafe impl Sync for Data {}
static DATA: Data = Data {
info: Cell::new(None),
once: Once::new(),
name: Cell::new(None),
description: Cell::new(None),
};
DATA.once.call_once(|| {
let info = T::type_info();
DATA.name.set(Some(format!("optional: {}", info.name)));
DATA.info.set(Some(TypeInfo {
name: unsafe { (*DATA.name.as_ptr()).as_ref().unwrap().as_str() },
description: unsafe { (*DATA.description.as_ptr()).as_ref().unwrap().as_str() },
complete_fn: None,
}));
});
unsafe { (*DATA.info.as_ptr()).as_ref().unwrap() }
}
}
/// Any `Result<T, Error>` of course gets the same info as `T`, since this only means that it can
/// fail...
impl<T: ApiType> ApiType for Result<T, Error> {
fn verify(&self) -> Result<(), Error> {
if let Ok(inner) = self {
inner.verify()?
}
Ok(())
}
fn type_info() -> &'static TypeInfo {
<T as ApiType>::type_info()
}
}
/// This is not supposed to be used, but can be if needed. This will provide an empty `ApiType`
/// declaration with no description and no verifier.
///
/// This rarely makes sense, but sometimes a `string` is just a `string`.
#[macro_export]
macro_rules! unconstrained_api_type {
($type:ty $(, $more:ty)*) => {
impl $crate::ApiType for $type {
fn verify(&self) -> Result<(), ::failure::Error> {
Ok(())
}
fn type_info() -> &'static $crate::TypeInfo {
const INFO: $crate::TypeInfo = $crate::TypeInfo {
name: stringify!($type),
description: stringify!($type),
complete_fn: None,
};
&INFO
}
}
$crate::unconstrained_api_type!{$($more),*}
};
() => {};
}
unconstrained_api_type! {Value} // basically our API's "any" type
unconstrained_api_type! {&str}
unconstrained_api_type! {String, isize, usize, i64, u64, i32, u32, i16, u16, i8, u8, f64, f32}
unconstrained_api_type! {Vec<String>}
// Raw return types are also okay:
unconstrained_api_type! {Response<Bytes>}
// FIXME: make const once feature(const_fn) is stable!
pub fn get_type_info<T: ApiType>() -> &'static TypeInfo {
T::type_info()
}

303
proxmox-api/src/lib.rs
View File

@ -6,16 +6,12 @@
//! Note that you'll rarely need the [`Router`] type itself, as you'll most likely be creating them //! Note that you'll rarely need the [`Router`] type itself, as you'll most likely be creating them
//! with the `router` macro provided by the `proxmox-api-macro` crate. //! with the `router` macro provided by the `proxmox-api-macro` crate.
use std::cell::Cell;
use std::collections::HashMap;
use std::future::Future; use std::future::Future;
use std::pin::Pin; use std::pin::Pin;
use std::sync::Once;
use bytes::Bytes; use bytes::Bytes;
use failure::Error; use failure::Error;
use http::Response; use http::Response;
use serde_json::Value;
mod api_output; mod api_output;
pub use api_output::*; pub use api_output::*;
@ -23,304 +19,11 @@ pub use api_output::*;
mod api_type; mod api_type;
pub use api_type::*; pub use api_type::*;
mod router;
pub use router::*;
/// Return type of an API method. /// Return type of an API method.
pub type ApiOutput = Result<Response<Bytes>, Error>; pub type ApiOutput = Result<Response<Bytes>, Error>;
/// Future type of an API method. In order to support `async fn` this is a pinned box. /// Future type of an API method. In order to support `async fn` this is a pinned box.
pub type ApiFuture = Pin<Box<dyn Future<Output = ApiOutput>>>; pub type ApiFuture = Pin<Box<dyn Future<Output = ApiOutput>>>;
/// This enum specifies what to do when a subdirectory is requested from the current router.
///
/// For plain subdirectories a `Directories` entry is used.
///
/// When subdirectories are supposed to be passed as a `String` parameter to methods beneath the
/// current directory, a `Parameter` entry is used. Note that the parameter name is fixed at this
/// point, so all method calls beneath will receive a parameter ot that particular name.
pub enum SubRoute {
/// This is used for plain subdirectories.
Directories(HashMap<&'static str, Router>),
/// Match subdirectories as the given parameter name to the underlying router.
Parameter(&'static str, Box<Router>),
}
/// A router is a nested structure. On the one hand it contains HTTP method entries (`GET`, `PUT`,
/// ...), and on the other hand it contains sub directories. In some cases we want to match those
/// sub directories as parameters, so the nesting uses a `SubRoute` `enum` representing which of
/// the two is the case.
#[derive(Default)]
pub struct Router {
/// The `GET` http method.
pub get: Option<&'static dyn ApiMethodInfo>,
/// The `PUT` http method.
pub put: Option<&'static dyn ApiMethodInfo>,
/// The `POST` http method.
pub post: Option<&'static dyn ApiMethodInfo>,
/// The `DELETE` http method.
pub delete: Option<&'static dyn ApiMethodInfo>,
/// Specifies the behavior of sub directories. See [`SubRoute`].
pub subroute: Option<SubRoute>,
}
impl Router {
/// Create a new empty router.
pub fn new() -> Self {
Self::default()
}
/// Lookup a path in the router. Note that this returns a tuple: the router we ended up on
/// (providing methods and subdirectories available for the given path), and optionally a json
/// value containing all the matched parameters ([`SubRoute::Parameter`] subdirectories).
pub fn lookup<T: AsRef<str>>(&self, path: T) -> Option<(&Self, Option<Value>)> {
self.lookup_do(path.as_ref())
}
// The actual implementation taking the parameter as &str
fn lookup_do(&self, path: &str) -> Option<(&Self, Option<Value>)> {
let mut matched_params = None;
let mut this = self;
for component in path.split('/') {
if component.is_empty() {
// `foo//bar` or the first `/` in `/foo`
continue;
}
this = match &this.subroute {
Some(SubRoute::Directories(subdirs)) => subdirs.get(component)?,
Some(SubRoute::Parameter(param_name, router)) => {
let previous = matched_params
.get_or_insert_with(serde_json::Map::new)
.insert(param_name.to_string(), Value::String(component.to_string()));
if previous.is_some() {
panic!("API contains the same parameter twice in route");
}
&*router
}
None => return None,
};
}
Some((this, matched_params.map(Value::Object)))
}
/// Builder method to provide a `GET` method info.
pub fn get<I>(mut self, method: &'static I) -> Self
where
I: ApiMethodInfo,
{
self.get = Some(method);
self
}
/// Builder method to provide a `PUT` method info.
pub fn put<I>(mut self, method: &'static I) -> Self
where
I: ApiMethodInfo,
{
self.put = Some(method);
self
}
/// Builder method to provide a `POST` method info.
pub fn post<I>(mut self, method: &'static I) -> Self
where
I: ApiMethodInfo,
{
self.post = Some(method);
self
}
/// Builder method to provide a `DELETE` method info.
pub fn delete<I>(mut self, method: &'static I) -> Self
where
I: ApiMethodInfo,
{
self.delete = Some(method);
self
}
/// Builder method to make this router match the next subdirectory into a parameter.
///
/// This is supposed to be used statically (via `lazy_static!), therefore we panic if we
/// already have a subdir entry!
pub fn parameter_subdir(mut self, parameter_name: &'static str, router: Router) -> Self {
if self.subroute.is_some() {
panic!("match_parameter can only be used once and without sub directories");
}
self.subroute = Some(SubRoute::Parameter(parameter_name, Box::new(router)));
self
}
/// Builder method to add a regular directory entro to this router.
///
/// This is supposed to be used statically (via `lazy_static!), therefore we panic if we
/// already have a subdir entry!
pub fn subdir(mut self, dir_name: &'static str, router: Router) -> Self {
let previous = match self.subroute {
Some(SubRoute::Directories(ref mut map)) => map.insert(dir_name, router),
None => {
let mut map = HashMap::new();
map.insert(dir_name, router);
self.subroute = Some(SubRoute::Directories(map));
None
}
_ => panic!("subdir and match_parameter are mutually exclusive"),
};
if previous.is_some() {
panic!("duplicate subdirectory: {}", dir_name);
}
self
}
}
/// We're supposed to only use types in the API which implement `ApiType`, which forces types ot
/// have a `verify` method. The idea is that all parameters used in the API are documented
/// somewhere with their formats and limits, which are checked when entering and leaving API entry
/// points.
///
/// Any API type is also required to implement `Serialize` and `DeserializeOwned`, since they're
/// read out of json `Value` types.
///
/// While this is very useful for structural types, we sometimes to want to be able to pass a
/// simple unconstrainted type like a `String` with no restrictions, so most basic types implement
/// `ApiType` as well.
//
// FIXME: I've actually moved most of this into the types in `api_type.rs` now, so this is
// probably unused at this point?
// `verify` should be moved to `TypeInfo` (for the type related verifier), and `Parameter` should
// get an additional verify method for constraints added by *methods*.
//
// We actually have 2 layers of validation:
// When entering the API: The type validation
// obviously a `String` should also be a string in the json object...
// This does not happen when we call the method from rust-code as we have no json layer
// there.
// When entering the function: The input validation
// if the function says `Integer`, the type itself has no validation other than that it has
// to be an integer type, but the function may still say `minimum: 5, maximum: 10`.
// This should also happen for direct calls from within rust, the `#[api]` macro can take
// care of this.
// When leaving the function: The output validation
// Yep, we need to add this ;-)
pub trait ApiType {
/// API types need to provide a `TypeInfo`, providing details about the underlying type.
fn type_info() -> &'static TypeInfo;
/// Additionally, ApiTypes must provide a way to verify their constraints!
fn verify(&self) -> Result<(), Error>;
/// This is a workaround for when we cannot name the type but have an object available we can
/// call a method on. (We cannot call associated methods on objects without being able to write
/// out the type, and rust has some restrictions as to what types are available.)
// eg. nested generics:
// fn foo<T>() {
// fn bar<U>(x: &T) {
// cannot use T::method() here, but can use x.method()
// (compile error "can't use generic parameter of outer function",
// and yes, that's a stupid restriction as it is still completely static...)
// }
// }
fn get_type_info(&self) -> &'static TypeInfo {
Self::type_info()
}
}
/// Option types are supposed to wrap their underlying types with an `optional:` text in their
/// description.
// BUT it requires some anti-static magic. And while this looks like the result of lazy_static!,
// it's not exactly the same, lazy_static! here does not actually work as it'll curiously produce
// the same error as we pointed out above in the `get_type_info` method (as it does a lot more
// extra stuff we don't need)...
impl<T: ApiType> ApiType for Option<T> {
fn verify(&self) -> Result<(), Error> {
if let Some(inner) = self {
inner.verify()?
}
Ok(())
}
fn type_info() -> &'static TypeInfo {
struct Data {
info: Cell<Option<TypeInfo>>,
once: Once,
name: Cell<Option<String>>,
description: Cell<Option<String>>,
}
unsafe impl Sync for Data {}
static DATA: Data = Data {
info: Cell::new(None),
once: Once::new(),
name: Cell::new(None),
description: Cell::new(None),
};
DATA.once.call_once(|| {
let info = T::type_info();
DATA.name.set(Some(format!("optional: {}", info.name)));
DATA.info.set(Some(TypeInfo {
name: unsafe { (*DATA.name.as_ptr()).as_ref().unwrap().as_str() },
description: unsafe { (*DATA.description.as_ptr()).as_ref().unwrap().as_str() },
complete_fn: None,
}));
});
unsafe { (*DATA.info.as_ptr()).as_ref().unwrap() }
}
}
/// Any `Result<T, Error>` of course gets the same info as `T`, since this only means that it can
/// fail...
impl<T: ApiType> ApiType for Result<T, Error> {
fn verify(&self) -> Result<(), Error> {
if let Ok(inner) = self {
inner.verify()?
}
Ok(())
}
fn type_info() -> &'static TypeInfo {
<T as ApiType>::type_info()
}
}
/// This is not supposed to be used, but can be if needed. This will provide an empty `ApiType`
/// declaration with no description and no verifier.
///
/// This rarely makes sense, but sometimes a `string` is just a `string`.
#[macro_export]
macro_rules! unconstrained_api_type {
($type:ty $(, $more:ty)*) => {
impl $crate::ApiType for $type {
fn verify(&self) -> Result<(), ::failure::Error> {
Ok(())
}
fn type_info() -> &'static $crate::TypeInfo {
const INFO: $crate::TypeInfo = $crate::TypeInfo {
name: stringify!($type),
description: stringify!($type),
complete_fn: None,
};
&INFO
}
}
$crate::unconstrained_api_type!{$($more),*}
};
() => {};
}
unconstrained_api_type! {Value} // basically our API's "any" type
unconstrained_api_type! {&str}
unconstrained_api_type! {String, isize, usize, i64, u64, i32, u32, i16, u16, i8, u8, f64, f32}
unconstrained_api_type! {Vec<String>}
// Raw return types are also okay:
unconstrained_api_type! {Response<Bytes>}
// FIXME: make const once feature(const_fn) is stable!
pub fn get_type_info<T: ApiType>() -> &'static TypeInfo {
T::type_info()
}

156
proxmox-api/src/router.rs Normal file
View File

@ -0,0 +1,156 @@
//! This module provides a router used for http servers.
use std::collections::HashMap;
use serde_json::Value;
use super::ApiMethodInfo;
/// This enum specifies what to do when a subdirectory is requested from the current router.
///
/// For plain subdirectories a `Directories` entry is used.
///
/// When subdirectories are supposed to be passed as a `String` parameter to methods beneath the
/// current directory, a `Parameter` entry is used. Note that the parameter name is fixed at this
/// point, so all method calls beneath will receive a parameter ot that particular name.
pub enum SubRoute {
/// This is used for plain subdirectories.
Directories(HashMap<&'static str, Router>),
/// Match subdirectories as the given parameter name to the underlying router.
Parameter(&'static str, Box<Router>),
}
/// A router is a nested structure. On the one hand it contains HTTP method entries (`GET`, `PUT`,
/// ...), and on the other hand it contains sub directories. In some cases we want to match those
/// sub directories as parameters, so the nesting uses a `SubRoute` `enum` representing which of
/// the two is the case.
#[derive(Default)]
pub struct Router {
/// The `GET` http method.
pub get: Option<&'static dyn ApiMethodInfo>,
/// The `PUT` http method.
pub put: Option<&'static dyn ApiMethodInfo>,
/// The `POST` http method.
pub post: Option<&'static dyn ApiMethodInfo>,
/// The `DELETE` http method.
pub delete: Option<&'static dyn ApiMethodInfo>,
/// Specifies the behavior of sub directories. See [`SubRoute`].
pub subroute: Option<SubRoute>,
}
impl Router {
/// Create a new empty router.
pub fn new() -> Self {
Self::default()
}
/// Lookup a path in the router. Note that this returns a tuple: the router we ended up on
/// (providing methods and subdirectories available for the given path), and optionally a json
/// value containing all the matched parameters ([`SubRoute::Parameter`] subdirectories).
pub fn lookup<T: AsRef<str>>(&self, path: T) -> Option<(&Self, Option<Value>)> {
self.lookup_do(path.as_ref())
}
// The actual implementation taking the parameter as &str
fn lookup_do(&self, path: &str) -> Option<(&Self, Option<Value>)> {
let mut matched_params = None;
let mut this = self;
for component in path.split('/') {
if component.is_empty() {
// `foo//bar` or the first `/` in `/foo`
continue;
}
this = match &this.subroute {
Some(SubRoute::Directories(subdirs)) => subdirs.get(component)?,
Some(SubRoute::Parameter(param_name, router)) => {
let previous = matched_params
.get_or_insert_with(serde_json::Map::new)
.insert(param_name.to_string(), Value::String(component.to_string()));
if previous.is_some() {
panic!("API contains the same parameter twice in route");
}
&*router
}
None => return None,
};
}
Some((this, matched_params.map(Value::Object)))
}
/// Builder method to provide a `GET` method info.
pub fn get<I>(mut self, method: &'static I) -> Self
where
I: ApiMethodInfo,
{
self.get = Some(method);
self
}
/// Builder method to provide a `PUT` method info.
pub fn put<I>(mut self, method: &'static I) -> Self
where
I: ApiMethodInfo,
{
self.put = Some(method);
self
}
/// Builder method to provide a `POST` method info.
pub fn post<I>(mut self, method: &'static I) -> Self
where
I: ApiMethodInfo,
{
self.post = Some(method);
self
}
/// Builder method to provide a `DELETE` method info.
pub fn delete<I>(mut self, method: &'static I) -> Self
where
I: ApiMethodInfo,
{
self.delete = Some(method);
self
}
/// Builder method to make this router match the next subdirectory into a parameter.
///
/// This is supposed to be used statically (via `lazy_static!), therefore we panic if we
/// already have a subdir entry!
pub fn parameter_subdir(mut self, parameter_name: &'static str, router: Router) -> Self {
if self.subroute.is_some() {
panic!("match_parameter can only be used once and without sub directories");
}
self.subroute = Some(SubRoute::Parameter(parameter_name, Box::new(router)));
self
}
/// Builder method to add a regular directory entro to this router.
///
/// This is supposed to be used statically (via `lazy_static!), therefore we panic if we
/// already have a subdir entry!
pub fn subdir(mut self, dir_name: &'static str, router: Router) -> Self {
let previous = match self.subroute {
Some(SubRoute::Directories(ref mut map)) => map.insert(dir_name, router),
None => {
let mut map = HashMap::new();
map.insert(dir_name, router);
self.subroute = Some(SubRoute::Directories(map));
None
}
_ => panic!("subdir and match_parameter are mutually exclusive"),
};
if previous.is_some() {
panic!("duplicate subdirectory: {}", dir_name);
}
self
}
}