Reorganize more modules and re-exports (smithy-lang#2400)

* Conditionally re-export the Smithy Client Builder in clients
* Reorganize error type re-export
* Reorganize the `paginator` module
* Flatten the `presigning` module
* Hide the `http_body_checksum` module

aws/rust-runtime/aws-inlineable/src/lib.rs

@@ -24,6 +24,8 @@ pub mod no_credentials;
 
 /// Support types required for adding presigning to an operation in a generated service.
 pub mod presigning;
+// TODO(CrateReorganization): Delete the `old_presigning` module
+pub mod old_presigning;
 
 /// Special logic for extracting request IDs from S3's responses.
 pub mod s3_request_id;

aws/rust-runtime/aws-inlineable/src/old_presigning.rs

@@ -0,0 +1,282 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+//! Presigned request types and configuration.
+
+/// Presigning config and builder
+pub mod config {
+    use std::fmt;
+    use std::time::{Duration, SystemTime};
+
+    const ONE_WEEK: Duration = Duration::from_secs(604800);
+
+    /// Presigning config values required for creating a presigned request.
+    #[non_exhaustive]
+    #[derive(Debug, Clone)]
+    pub struct PresigningConfig {
+        start_time: SystemTime,
+        expires_in: Duration,
+    }
+
+    impl PresigningConfig {
+        /// Creates a `PresigningConfig` with the given `expires_in` duration.
+        ///
+        /// The `expires_in` duration is the total amount of time the presigned request should
+        /// be valid for. Other config values are defaulted.
+        ///
+        /// Credential expiration time takes priority over the `expires_in` value.
+        /// If the credentials used to sign the request expire before the presigned request is
+        /// set to expire, then the presigned request will become invalid.
+        pub fn expires_in(expires_in: Duration) -> Result<PresigningConfig, Error> {
+            Self::builder().expires_in(expires_in).build()
+        }
+
+        /// Creates a new builder for creating a `PresigningConfig`.
+        pub fn builder() -> Builder {
+            Builder::default()
+        }
+
+        /// Returns the amount of time the presigned request should be valid for.
+        pub fn expires(&self) -> Duration {
+            self.expires_in
+        }
+
+        /// Returns the start time. The presigned request will be valid between this and the end
+        /// time produced by adding the `expires()` value to it.
+        pub fn start_time(&self) -> SystemTime {
+            self.start_time
+        }
+    }
+
+    #[derive(Debug)]
+    enum ErrorKind {
+        /// Presigned requests cannot be valid for longer than one week.
+        ExpiresInDurationTooLong,
+
+        /// The `PresigningConfig` builder requires a value for `expires_in`.
+        ExpiresInRequired,
+    }
+
+    /// `PresigningConfig` build errors.
+    #[derive(Debug)]
+    pub struct Error {
+        kind: ErrorKind,
+    }
+
+    impl std::error::Error for Error {}
+
+    impl fmt::Display for Error {
+        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+            match self.kind {
+                ErrorKind::ExpiresInDurationTooLong => {
+                    write!(f, "`expires_in` must be no longer than one week")
+                }
+                ErrorKind::ExpiresInRequired => write!(f, "`expires_in` is required"),
+            }
+        }
+    }
+
+    impl From<ErrorKind> for Error {
+        fn from(kind: ErrorKind) -> Self {
+            Self { kind }
+        }
+    }
+
+    /// Builder used to create `PresigningConfig`.
+    #[non_exhaustive]
+    #[derive(Default, Debug)]
+    pub struct Builder {
+        start_time: Option<SystemTime>,
+        expires_in: Option<Duration>,
+    }
+
+    impl Builder {
+        /// Sets the start time for the presigned request.
+        ///
+        /// The request will start to be valid at this time, and will cease to be valid after
+        /// the end time, which can be determined by adding the `expires_in` duration to this
+        /// start time. If not specified, this will default to the current time.
+        ///
+        /// Optional.
+        pub fn start_time(mut self, start_time: SystemTime) -> Self {
+            self.set_start_time(Some(start_time));
+            self
+        }
+
+        /// Sets the start time for the presigned request.
+        ///
+        /// The request will start to be valid at this time, and will cease to be valid after
+        /// the end time, which can be determined by adding the `expires_in` duration to this
+        /// start time. If not specified, this will default to the current time.
+        ///
+        /// Optional.
+        pub fn set_start_time(&mut self, start_time: Option<SystemTime>) {
+            self.start_time = start_time;
+        }
+
+        /// Sets how long the request should be valid after the `start_time` (which defaults
+        /// to the current time).
+        ///
+        /// Credential expiration time takes priority over the `expires_in` value.
+        /// If the credentials used to sign the request expire before the presigned request is
+        /// set to expire, then the presigned request will become invalid.
+        ///
+        /// Required.
+        pub fn expires_in(mut self, expires_in: Duration) -> Self {
+            self.set_expires_in(Some(expires_in));
+            self
+        }
+
+        /// Sets how long the request should be valid after the `start_time` (which defaults
+        /// to the current time).
+        ///
+        /// Credential expiration time takes priority over the `expires_in` value.
+        /// If the credentials used to sign the request expire before the presigned request is
+        /// set to expire, then the presigned request will become invalid.
+        ///
+        /// Required.
+        pub fn set_expires_in(&mut self, expires_in: Option<Duration>) {
+            self.expires_in = expires_in;
+        }
+
+        /// Builds the `PresigningConfig`. This will error if `expires_in` is not
+        /// given, or if it's longer than one week.
+        pub fn build(self) -> Result<PresigningConfig, Error> {
+            let expires_in = self.expires_in.ok_or(ErrorKind::ExpiresInRequired)?;
+            if expires_in > ONE_WEEK {
+                return Err(ErrorKind::ExpiresInDurationTooLong.into());
+            }
+            Ok(PresigningConfig {
+                start_time: self.start_time.unwrap_or_else(SystemTime::now),
+                expires_in,
+            })
+        }
+    }
+}
+
+/// Presigned request
+pub mod request {
+    use std::fmt::{Debug, Formatter};
+
+    /// Represents a presigned request. This only includes the HTTP request method, URI, and headers.
+    ///
+    /// **This struct has conversion convenience functions:**
+    ///
+    /// - [`PresignedRequest::to_http_request<B>`][Self::to_http_request] returns an [`http::Request<B>`](https://docs.rs/http/0.2.6/http/request/struct.Request.html)
+    /// - [`PresignedRequest::into`](#impl-From<PresignedRequest>) returns an [`http::request::Builder`](https://docs.rs/http/0.2.6/http/request/struct.Builder.html)
+    #[non_exhaustive]
+    pub struct PresignedRequest(http::Request<()>);
+
+    impl PresignedRequest {
+        pub(crate) fn new(inner: http::Request<()>) -> Self {
+            Self(inner)
+        }
+
+        /// Returns the HTTP request method.
+        pub fn method(&self) -> &http::Method {
+            self.0.method()
+        }
+
+        /// Returns the HTTP request URI.
+        pub fn uri(&self) -> &http::Uri {
+            self.0.uri()
+        }
+
+        /// Returns any HTTP headers that need to go along with the request, except for `Host`,
+        /// which should be sent based on the endpoint in the URI by the HTTP client rather than
+        /// added directly.
+        pub fn headers(&self) -> &http::HeaderMap<http::HeaderValue> {
+            self.0.headers()
+        }
+
+        /// Given a body, convert this `PresignedRequest` into an `http::Request`
+        pub fn to_http_request<B>(self, body: B) -> Result<http::Request<B>, http::Error> {
+            let builder: http::request::Builder = self.into();
+
+            builder.body(body)
+        }
+    }
+
+    impl Debug for PresignedRequest {
+        fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+            f.debug_struct("PresignedRequest")
+                .field("method", self.method())
+                .field("uri", self.uri())
+                .field("headers", self.headers())
+                .finish()
+        }
+    }
+
+    impl From<PresignedRequest> for http::request::Builder {
+        fn from(req: PresignedRequest) -> Self {
+            let mut builder = http::request::Builder::new()
+                .uri(req.uri())
+                .method(req.method());
+
+            if let Some(headers) = builder.headers_mut() {
+                *headers = req.headers().clone();
+            }
+
+            builder
+        }
+    }
+}
+
+/// Tower middleware service for creating presigned requests
+#[allow(dead_code)]
+pub(crate) mod service {
+    use super::request::PresignedRequest;
+    use aws_smithy_http::operation;
+    use http::header::USER_AGENT;
+    use std::future::{ready, Ready};
+    use std::marker::PhantomData;
+    use std::task::{Context, Poll};
+
+    /// Tower [`Service`](tower::Service) for generated a [`PresignedRequest`] from the AWS middleware.
+    #[derive(Default, Debug)]
+    #[non_exhaustive]
+    pub(crate) struct PresignedRequestService<E> {
+        _phantom: PhantomData<E>,
+    }
+
+    // Required because of the derive Clone on MapRequestService.
+    // Manually implemented to avoid requiring errors to implement Clone.
+    impl<E> Clone for PresignedRequestService<E> {
+        fn clone(&self) -> Self {
+            Self {
+                _phantom: Default::default(),
+            }
+        }
+    }
+
+    impl<E> PresignedRequestService<E> {
+        /// Creates a new `PresignedRequestService`
+        pub(crate) fn new() -> Self {
+            Self {
+                _phantom: Default::default(),
+            }
+        }
+    }
+
+    impl<E> tower::Service<operation::Request> for PresignedRequestService<E> {
+        type Response = PresignedRequest;
+        type Error = E;
+        type Future = Ready<Result<PresignedRequest, E>>;
+
+        fn poll_ready(&mut self, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+            Poll::Ready(Ok(()))
+        }
+
+        fn call(&mut self, req: operation::Request) -> Self::Future {
+            let (mut req, _) = req.into_parts();
+
+            // Remove user agent headers since the request will not be executed by the AWS Rust SDK.
+            req.headers_mut().remove(USER_AGENT);
+            req.headers_mut().remove("X-Amz-User-Agent");
+
+            ready(Ok(PresignedRequest::new(req.map(|_| ()))))
+        }
+    }
+}