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This includes a rationale and description of the overall design of Hyper as well as providing a guide to understanding and navigating the source.
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hyper
A Modern HTTP library for Rust.
Overview
Hyper is a fast, modern HTTP implementation written in and for Rust. It is a low-level typesafe abstraction over raw HTTP, providing an elegant layer over "stringly-typed" HTTP.
Hyper offers both an HTTP/S client an HTTP server which can be used to drive complex web applications written entirely in Rust.
The documentation is located at http://hyperium.github.io/hyper.
Scientific* Benchmarks
running 3 tests
test bench_curl ... bench: 1696689 ns/iter (+/- 540497)
test bench_http ... bench: 2222778 ns/iter (+/- 1159060)
test bench_hyper ... bench: 1435613 ns/iter (+/- 359384)
test result: ok. 0 passed; 0 failed; 0 ignored; 3 measured
running 3 tests
test bench_mock_curl ... bench: 329240 ns/iter (+/- 50413)
test bench_mock_http ... bench: 61291 ns/iter (+/- 19253)
test bench_mock_hyper ... bench: 54458 ns/iter (+/- 15792)
test result: ok. 0 passed; 0 failed; 0 ignored; 3 measured
running 3 tests
test bench_curl ... bench: 234539 ns/iter (+/- 22228)
test bench_http ... bench: 290370 ns/iter (+/- 69179)
test bench_hyper ... bench: 224482 ns/iter (+/- 95197)
test result: ok. 0 passed; 0 failed; 0 ignored; 3 measured
* No science was harmed in the making of this benchmark.
Internal Design
Hyper is designed as a relatively low-level wrapped over raw HTTP. It should allow the implementation of higher-level abstractions with as little pain as possible, and should not irrevocably hide any information from its users.
Common Functionality
Functionality and code shared between the Server and Client implementations can
be found in src directly - this includes NetworkStreams, Methods,
StatusCode, and so on.
Methods
Methods are represented as a single enum to remain as simple as possible.
Extension Methods are represented as raw Strings. A method's safety and
idempotence can be accessed using the safe and idempotent methods.
StatusCode
Status codes are also represented as a single, exhaustive, enum. This
representation is efficient, typesafe, and ergonomic as it allows the use of
match to disambiguate known status codes.
Headers
Hyper's header representation is likely the most complex API exposed by Hyper.
Hyper's headers are an abstraction over an internal HashMap and provides a
typesafe API for interacting with headers that does not rely on the use of
"string-typing."
Each HTTP header in Hyper has an associated type and implementation of the
Header trait, which defines an HTTP headers name as a string, how to parse
that header, and how to format that header.
Headers are then parsed from the string representation lazily when the typed representation of a header is requested and formatted back into their string representation when headers are written back to the client.
NetworkStream and NetworkAcceptor
These are found in src/net.rs and define the interface that acceptors and
streams must fulfill for them to be used within Hyper. They are by and large
internal tools and you should only need to mess around with them if you want to
mock or replace TcpStream and TcpAcceptor.
Server
Server-specific functionality, such as Request and Response
representations, are found in in src/server.
Request
An incoming HTTP Request is represented as a struct containing
a Reader over a NetworkStream, which represents the body, headers, a remote
address, an HTTP version, and a Method - relatively standard stuff.
Request implements Reader itself, meaning that you can ergonomically get
the body out of a Request using standard Reader methods and helpers.
Response
An outgoing HTTP Response is also represented as a struct containing a Writer
over a NetworkStream which represents the Response body in addition to
standard items such as the StatusCode and HTTP version. Response's Writer
implementation provides a streaming interface for sending data over to the
client.
One of the traditional problems with representing outgoing HTTP Responses is tracking the write-status of the Response - have we written the status-line, the headers, the body, etc.? Hyper tracks this information statically using the type system and prevents you, using the type system, from writing headers after you have started writing to the body or vice versa.
Hyper does this through a phantom type parameter in the definition of Response,
which tracks whether you are allowed to write to the headers or the body. This
phantom type can have two values Fresh or Streaming, with Fresh
indicating that you can write the headers and Streaming indicating that you
may write to the body, but not the headers.
Client
Client-specific functionality, such as Request and Response
representations, are found in src/client.
Request
An outgoing HTTP Request is represented as a struct containing a Writer over
a NetworkStream which represents the Request body in addition to the standard
information such as headers and the request method.
Outgoing Requests track their write-status in almost exactly the same way as outgoing HTTP Responses do on the Server, so we will defer to the explanation in the documentation for sever Response.
Requests expose an efficient streaming interface instead of a builder pattern, but they also provide the needed interface for creating a builder pattern over the API exposed by core Hyper.
Response
Incoming HTTP Responses are represented as a struct containing a Reader over
a NetworkStream and contain headers, a status, and an http version. They
implement Reader and can be read to get the data out of a Response.