pub struct Response { /* private fields */ }
Expand description

An HTTP response, including body, headers, and status code.

Sending to the client

Each execution of a Compute@Edge program may send a single response back to the client:

If no response is explicitly sent by the program, a default 200 OK response is sent.

Creation and conversion

Responses can be created programmatically:

Responses are also returned from backend requests:

For interoperability with other Rust libraries, Response can be converted to and from the http crate’s http::Response type using the From and Into traits.

Builder-style methods

Response can be used as a builder, allowing responses to be constructed and used through method chaining. Methods with the with_ name prefix, such as with_header(), return Self to allow chaining. The builder style is typically most useful when constructing and using a response in a single expression. For example:

Response::new()
    .with_header("my-header", "hello!")
    .with_header("my-other-header", "Здравствуйте!")
    .send_to_client();

Setter methods

Setter methods, such as set_header(), are prefixed by set_, and can be used interchangeably with the builder-style methods, allowing you to mix and match styles based on what is most convenient for your program. Setter methods tend to work better than builder-style methods when constructing a value involves conditional branches or loops. For example:

let mut resp = Response::new().with_header("my-header", "hello!");
if needs_translation {
    resp.set_header("my-other-header", "Здравствуйте!");
}
resp.send_to_client();

Implementations

Create a new Response.

The new response is created with status code 200 OK, no headers, and an empty body.

Return whether the response is from a backend request.

Make a new response with the same headers, status, and version of this response, but no body.

If you also need to clone the response body, use clone_with_body()

Examples
let original = Response::from_body("hello")
    .with_header("hello", "world!")
    .with_status(418);
let new = original.clone_without_body();
assert_eq!(original.get_header("hello"), new.get_header("hello"));
assert_eq!(original.get_status(), new.get_status());
assert_eq!(original.get_version(), new.get_version());
assert!(original.has_body());
assert!(!new.has_body());

Clone this response by reading in its body, and then writing the same body to the original and the cloned response.

This method requires mutable access to this response because reading from and writing to the body can involve an HTTP connection.

This operation is potentially expensive if the body is large. Take care when using this method on bodies with unknown sizes. Consider using methods like BufRead::lines() or Body::read_chunks() to incrementally process a body while limiting the maximum size.

Examples
let mut original = Response::from_body("hello")
    .with_header("hello", "world!")
    .with_status(418);
let mut new = original.clone_with_body();
assert_eq!(original.get_header("hello"), new.get_header("hello"));
assert_eq!(original.get_status(), new.get_status());
assert_eq!(original.get_version(), new.get_version());
assert_eq!(original.take_body_bytes(), new.take_body_bytes());

Create a new Response with the given value as the body.

Argument type conversion.

See Body for details on which types can be used as a body.

Examples
let resp = Response::from_body("hello");
assert_eq!(&resp.into_body_str(), "hello");
let body_bytes: &[u8] = &[1, 2, 3];
let resp = Response::from_body(body_bytes);
assert_eq!(resp.into_body_bytes().as_slice(), body_bytes);

Create a new response with the given status code.

Argument type conversion.

See Body for details on which types can be used as a body.

Examples
use fastly::http::StatusCode;
let resp = Response::from_status(StatusCode::NOT_FOUND);
assert_eq!(resp.get_status().as_u16(), 404);
use fastly::http::StatusCode;
let resp = Response::from_status(404);
assert_eq!(resp.get_status(), StatusCode::NOT_FOUND);

Create a 303 See Other response with the given value as the Location header.

Examples
let resp = Response::see_other("https://www.fastly.com");
assert_eq!(resp.get_status(), StatusCode::SEE_OTHER);
assert_eq!(resp.get_header_str(header::LOCATION).unwrap(), "https://www.fastly.com");

Create a 308 Permanent Redirect response with the given value as the Location header.

Examples
let resp = Response::redirect("https://www.fastly.com");
assert_eq!(resp.get_status(), StatusCode::PERMANENT_REDIRECT);
assert_eq!(resp.get_header_str(header::LOCATION).unwrap(), "https://www.fastly.com");

Create a 307 Temporary Redirect response with the given value as the Location header.

Examples
let resp = Response::temporary_redirect("https://www.fastly.com");
assert_eq!(resp.get_status(), StatusCode::TEMPORARY_REDIRECT);
assert_eq!(resp.get_header_str(header::LOCATION).unwrap(), "https://www.fastly.com");

Builder-style equivalent of set_body().

Returns true if this response has a body.

Get a mutable reference to the body of this response.

An empty body is returned if no body has been set, or if it has previously been returned by a method like take_body().

Examples
use std::io::Write;

let mut resp = Response::from_body("hello,");
write!(resp.get_body_mut(), " world!").unwrap();
assert_eq!(&resp.into_body_str(), "hello, world!");

Get a shared reference to the body of this response if it has one, otherwise return None.

Examples
use std::io::Write;

let mut resp = Response::new();
assert!(resp.try_get_body_mut().is_none());

resp.set_body("hello,");
write!(resp.try_get_body_mut().expect("body now exists"), " world!").unwrap();
assert_eq!(&resp.into_body_str(), "hello, world!");

Get a prefix of this response’s body containing up to the given number of bytes.

See Body::get_prefix_mut() for details.

Get a prefix of this response’s body as a string containing up to the given number of bytes.

See Body::get_prefix_str_mut() for details.

Panics

If the prefix contains invalid UTF-8 bytes, this function will panic. The exception to this is if the bytes are invalid because a multi-byte codepoint is cut off by the requested prefix length. In this case, the invalid bytes are left off the end of the prefix.

To explicitly handle the possibility of invalid UTF-8 bytes, use try_get_body_prefix_str_mut(), which returns an error on failure rather than panicking.

Try to get a prefix of the body as a string containing up to the given number of bytes.

See Body::try_get_prefix_str_mut() for details.

Set the given value as the response’s body.

Argument type conversion.

See Body for details on which types can be used as a body. Any previous body that may have been set on the response is discarded. To add to an existing body, use get_body_mut() and write to the returned Body.

Take and return the body from this response.

After calling this method, this response will no longer have a body.

An empty body is returned if no body has been set, or if it has previously been returned by a method like take_body().

Take and return the body from this response if it has one, otherwise return None.

After calling this method, this response will no longer have a body.

Append another Body to the body of this response without reading or writing any body contents.

If this response does not have a body, the appended body is set as the response’s body.

This operation is performed in amortized constant time, and so should always be preferred to reading an entire body and then writing the same contents to another body.

This method should be used when combining bodies that have not necessarily been read yet, such as a body returned from a backend response. To append contents that are already in memory as strings or bytes, use get_body_mut() to write the contents to the end of the body.

Examples
let mut resp = Response::from_body("hello! backend says: ");
let backend_resp = Request::get("https://example.com/").send("example_backend").unwrap();
resp.append_body(backend_resp.into_body());
resp.send_to_client();

Consume the response and return its body as a byte vector.

Memory usage

This method will cause the entire body to be buffering in WebAssembly memory. You should take care not to exceed the WebAssembly memory limits, and consider using methods like read_body_lines() or read_body_chunks() to control how much of the body you process at once.

Examples
let resp = Response::from_body(b"hello, world!".to_vec());
let bytes = resp.into_body_bytes();
assert_eq!(&bytes, b"hello, world!");

Consume the response and return its body as a string.

Memory usage

This method will cause the entire body to be buffering in WebAssembly memory. You should take care not to exceed the WebAssembly memory limits, and consider using methods like read_body_lines() or read_body_chunks() to control how much of the body you process at once.

Panics

If the body does not contain a valid UTF-8 string, this function will panic. To explicitly handle the possibility of invalid UTF-8 data, use into_body_str_lossy() for lossy conversion, or use into_body_bytes() and then convert the bytes explicitly with a function like String::from_utf8.

Examples
let resp = Response::from_body("hello, world!");
let string = resp.into_body_str();
assert_eq!(&string, "hello, world!");

Consume the response and return its body as a string, including invalid characters.

Only the valid UTF-8 characters present are returned. Invalid UTF-8 characters are replaced with U+FFFD REPLACEMENT CHARACTER.

Memory usage

This method will cause the entire body to be buffering in WebAssembly memory. You should take care not to exceed the WebAssembly memory limits, and consider using methods like read_body_lines() or read_body_chunks() to control how much of the body you process at once.

Examples
let mut resp = Response::new();
resp.set_body_octet_stream(b"\xF0\x90\x80 hello, world!");
let string = resp.into_body_str_lossy();
assert_eq!(&string, "� hello, world!");

Consume the response and return its body.

An empty body is returned if no body has been set, or if it has previously been returned by a method like take_body().

Consume the response and return its body if it has one, otherwise return None.

👎Deprecated since 0.7.0: renamed to Response::with_body_text_plain()

Deprecated alias of with_body_text_plain()

Builder-style equivalent of set_body_text_plain().

👎Deprecated since 0.7.0: renamed to Response::set_body_text_plain()

Deprecated alias of set_body_text_plain()

Set the given string as the response’s body with content type text/plain; charset=UTF-8.

Any previous body that may have been set on the response is discarded. To add to an existing body, use get_body_mut() and write to the returned Body.

Content type

This method sets the content type to text/plain; charset=utf-8.

Examples
let mut resp = Response::new();
resp.set_body_text_plain("hello, world!");
assert_eq!(resp.get_content_type(), Some(fastly::mime::TEXT_PLAIN_UTF_8));
assert_eq!(&resp.into_body_str(), "hello, world!");

Builder-style equivalent of set_body_text_html().

Set the given string as the request’s body with content type text/html; charset=UTF-8.

Any previous body that may have been set on the response is discarded. To add to an existing body, use get_body_mut() and write to the returned Body.

Content type

This method sets the content type to text/html; charset=utf-8.

Examples
let mut resp = Response::new();
resp.set_body_text_html("<p>hello, world!</p>");
assert_eq!(resp.get_content_type(), Some(fastly::mime::TEXT_HTML_UTF_8));
assert_eq!(&resp.into_body_str(), "<p>hello, world!</p>");

Take and return the body from this response as a string.

After calling this method, this response will no longer have a body.

Memory usage

This method will cause the entire body to be buffering in WebAssembly memory. You should take care not to exceed the WebAssembly memory limits, and consider using methods like read_body_lines() or read_body_chunks() to control how much of the body you process at once.

Panics

If the body does not contain a valid UTF-8 string, this function will panic. To handle the possibility of invalid UTF-8 data, use take_body_str_lossy() for lossy conversion, or use take_body_bytes() and then convert the bytes with a function like String::from_utf8.

Examples
let mut resp = Response::from_body("hello, world!");
let string = resp.take_body_str();
assert!(resp.try_take_body().is_none());
assert_eq!(&string, "hello, world!");

Take and return the body from this response as a string, including invalid characters.

Only the valid UTF-8 characters present are returned. Invalid UTF-8 characters are replaced with U+FFFD REPLACEMENT CHARACTER.

After calling this method, this response will no longer have a body.

Memory usage

This method will cause the entire body to be buffering in WebAssembly memory. You should take care not to exceed the WebAssembly memory limits, and consider using methods like read_body_lines() or read_body_chunks() to control how much of the body you process at once.

Examples
let mut resp = Response::new();
resp.set_body_octet_stream(b"\xF0\x90\x80 hello, world!");
let string = resp.take_body_str_lossy();
assert!(resp.try_take_body().is_none());
assert_eq!(&string, "� hello, world!");

Return a Lines iterator that reads the response body a line at a time.

Examples
use std::io::Write;

fn remove_es(resp: &mut Response) {
    let mut no_es = Body::new();
    for line in resp.read_body_lines() {
        writeln!(no_es, "{}", line.unwrap().replace("e", "")).unwrap();
    }
    resp.set_body(no_es);
}
👎Deprecated since 0.8.1: renamed to Response::with_body_octet_stream()

Deprecated alias of with_body_octet_stream()

👎Deprecated since 0.8.1: renamed to Response::set_body_octet_stream()

Deprecated alias of set_body_octet_stream()

Builder-style equivalent of set_body_octet_stream().

Set the given bytes as the response’s body.

Any previous body that may have been set on the response is discarded. To add to an existing body, use get_body_mut() and write to the returned Body.

Content type

This method sets the content type to application/octet-stream.

Examples
let mut resp = Response::new();
resp.set_body_octet_stream(b"hello, world!");
assert_eq!(resp.get_content_type(), Some(fastly::mime::APPLICATION_OCTET_STREAM));
assert_eq!(&resp.into_body_bytes(), b"hello, world!");

Take and return the body from this response as a string.

After calling this method, this response will no longer have a body.

Memory usage

This method will cause the entire body to be buffering in WebAssembly memory. You should take care not to exceed the WebAssembly memory limits, and consider using methods like read_body_lines() or read_body_chunks() to control how much of the body you process at once.

Examples
let mut resp = Response::from_body(b"hello, world!".to_vec());
let bytes = resp.take_body_bytes();
assert!(resp.try_take_body().is_none());
assert_eq!(&bytes, b"hello, world!");

Return an iterator that reads the response body in chunks of at most the given number of bytes.

If chunk_size does not evenly divide the length of the body, then the last chunk will not have length chunk_size.

Examples
fn remove_0s(resp: &mut Response) {
    let mut no_0s = Body::new();
    for chunk in resp.read_body_chunks(4096) {
        let mut chunk = chunk.unwrap();
        chunk.retain(|b| *b != 0);
        no_0s.write_bytes(&chunk);
    }
    resp.set_body(no_0s);
}

Builder-style equivalent of set_body_json().

Convert the given value to JSON and set that JSON as the response’s body.

The given value must implement serde::Serialize. You can either implement that trait for your own custom type, or use serde_json::Value to create untyped JSON values. See serde_json for details.

Any previous body that may have been set on the response is discarded. To add to an existing body, use get_body_mut() and write to the returned Body.

Content type

This method sets the content type to application/json.

Errors

This method returns serde_json::Error if serialization fails.

Examples

Using a type that derives serde::Serialize:

#[derive(serde::Serialize)]
struct MyData {
    name: String,
    count: u64,
}
let my_data = MyData { name: "Computers".to_string(), count: 1024 };
let mut resp = Response::new();
resp.set_body_json(&my_data).unwrap();
assert_eq!(resp.get_content_type(), Some(fastly::mime::APPLICATION_JSON));
assert_eq!(&resp.into_body_str(), r#"{"name":"Computers","count":1024}"#);

Using untyped JSON and the serde_json::json macro:

let my_data = serde_json::json!({
    "name": "Computers",
    "count": 1024,
});
let mut resp = Response::new();
resp.set_body_json(&my_data).unwrap();
assert_eq!(resp.get_content_type(), Some(fastly::mime::APPLICATION_JSON));
assert_eq!(&resp.into_body_str(), r#"{"count":1024,"name":"Computers"}"#);

Take the response body and attempt to parse it as a JSON value.

The return type must implement serde::Deserialize without any non-static lifetimes. You can either implement that trait for your own custom type, or use serde_json::Value to deserialize untyped JSON values. See serde_json for details.

After calling this method, this response will no longer have a body.

Errors

This method returns serde_json::Error if deserialization fails.

Examples

Using a type that derives serde::de::DeserializeOwned:

#[derive(serde::Deserialize)]
struct MyData {
    name: String,
    count: u64,
}
let mut resp = Response::from_body(r#"{"name":"Computers","count":1024}"#);
let my_data = resp.take_body_json::<MyData>().unwrap();
assert_eq!(&my_data.name, "Computers");
assert_eq!(my_data.count, 1024);

Using untyped JSON with serde_json::Value:

let my_data = serde_json::json!({
    "name": "Computers",
    "count": 1024,
});
let mut resp = Response::from_body(r#"{"name":"Computers","count":1024}"#);
let my_data = resp.take_body_json::<serde_json::Value>().unwrap();
assert_eq!(my_data["name"].as_str(), Some("Computers"));
assert_eq!(my_data["count"].as_u64(), Some(1024));

Builder-style equivalent of set_body_form().

Convert the given value to application/x-www-form-urlencoded format and set that data as the response’s body.

The given value must implement serde::Serialize; see the trait documentation for details.

Any previous body that may have been set on the response is discarded. To add to an existing body, use get_body_mut() and write to the returned Body.

Content type

This method sets the content type to application/x-www-form-urlencoded.

Errors

This method returns serde_urlencoded::ser::Error if serialization fails.

Examples
#[derive(serde::Serialize)]
struct MyData {
    name: String,
    count: u64,
}
let my_data = MyData { name: "Computers".to_string(), count: 1024 };
let mut resp = Response::new();
resp.set_body_form(&my_data).unwrap();
assert_eq!(resp.get_content_type(), Some(fastly::mime::APPLICATION_WWW_FORM_URLENCODED));
assert_eq!(&resp.into_body_str(), "name=Computers&count=1024");

Take the response body and attempt to parse it as a application/x-www-form-urlencoded formatted string.

The return type chosen for this function must implement serde::de::Deserialize without any non-static lifetimes; see the trait documentation for details.

After calling this method, this response will no longer have a body.

Errors

This method returns serde_urlencoded::de::Error if deserialization fails.

Examples
#[derive(serde::Deserialize)]
struct MyData {
    name: String,
    count: u64,
}
let mut resp = Response::from_body("name=Computers&count=1024");
let my_data = resp.take_body_form::<MyData>().unwrap();
assert_eq!(&my_data.name, "Computers");
assert_eq!(my_data.count, 1024);

Get the MIME type described by the response’s Content-Type header, or None if that header is absent or contains an invalid MIME type.

Examples
let resp = Response::new().with_body_text_plain("hello, world!");
assert_eq!(resp.get_content_type(), Some(fastly::mime::TEXT_PLAIN_UTF_8));

Builder-style equivalent of set_content_type().

Set the MIME type described by the response’s Content-Type header.

Any existing Content-Type header values will be overwritten.

Examples
let mut resp = Response::new().with_body("hello,world!");
resp.set_content_type(fastly::mime::TEXT_CSV_UTF_8);

Get the value of the response’s Content-Length header, if it exists.

Returns whether the given header name is present in the response.

Argument type conversion

The header name argument can be any type that implements ToHeaderName; see that trait for details on which types can be used and when panics may arise during conversion.

Examples
let resp = Response::new().with_header("hello", "world!");
assert!(resp.contains_header("hello"));
assert!(!resp.contains_header("not-present"));

Builder-style equivalent of set_header().

Get the value of a header as a string, or None if the header is not present.

If there are multiple values for the header, only one is returned, which may be any of the values. See get_header_all_str() if you need to get all of the values.

Argument type conversion

The header name argument can be any type that implements ToHeaderName; see that trait for details on which types can be used and when panics may arise during conversion.

Panics

This method panics if the value of the header is not a valid UTF-8 string. To handle the possibility of invalid UTF-8 data, use get_header_str_lossy() for lossy conversion, or use get_header() and then convert the bytes with HeaderValue::to_str().

Examples
let resp = Response::new().with_header("hello", "world!");
assert_eq!(resp.get_header_str("hello"), Some("world"));

Get the value of a header as a string, including invalid characters, or None if the header is not present.

Only the valid UTF-8 characters present are returned. Invalid UTF-8 characters are replaced with U+FFFD REPLACEMENT CHARACTER.

If there are multiple values for the header, only one is returned, which may be any of the values. See get_header_all_str_lossy() if you need to get all of the values.

Argument type conversion

The header name argument can be any type that implements ToHeaderName; see that trait for details on which types can be used and when panics may arise during conversion.

Examples
let header_value = HeaderValue::from_bytes(b"\xF0\x90\x80 world!").unwrap();
let resp = Response::new().with_header("hello", header_value);
assert_eq!(resp.get_header_str_lossy("hello"), Some(Cow::from("� world")));

Get the value of a header, or None if the header is not present.

If there are multiple values for the header, only one is returned, which may be any of the values. See get_header_all() if you need to get all of the values.

Argument type conversion

The header name argument can be any type that implements ToHeaderName; see that trait for details on which types can be used and when panics may arise during conversion.

Examples

Handling UTF-8 values explicitly:

let resp = Response::new().with_header("hello", "world!");
assert_eq!(resp.get_header("hello"), Some(&HeaderValue::from_static("world")));

Safely handling invalid UTF-8 values:

let invalid_utf8 = &"🐈".as_bytes()[0..3];
let resp = Response::new().with_header("hello", invalid_utf8);
assert_eq!(resp.get_header("hello").unwrap().as_bytes(), invalid_utf8);

Get all values of a header as strings, or an empty vector if the header is not present.

Argument type conversion

The header name argument can be any type that implements ToHeaderName; see that trait for details on which types can be used and when panics may arise during conversion.

Panics

This method panics if any of the header values are not valid UTF-8 strings. To handle the possibility of non-UTF-8 data, use get_header_all_str_lossy() for lossy conversion, or use get_header_all() and then convert the bytes with HeaderValue::to_str().

Examples
let resp = Response::new()
    .with_header("hello", "world!")
    .with_header("hello", "universe!");
let values = resp.get_header_all_str("hello");
assert_eq!(values.len(), 2);
assert!(values.contains(&"world!"));
assert!(values.contains(&"universe!"));

Get an iterator of all the response’s header names and values.

Examples

You can turn the iterator into a collection, like Vec:

let resp = Response::new()
    .with_header("hello", "world!")
    .with_header("hello", "universe!");

let headers: Vec<(&HeaderName, &HeaderValue)> = resp.get_headers().collect();
assert_eq!(headers.len(), 2);
assert!(headers.contains(&(&HeaderName::from_static("hello"), &HeaderValue::from_static("world!"))));
assert!(headers.contains(&(&HeaderName::from_static("hello"), &HeaderValue::from_static("universe!"))));

You can use the iterator in a loop:

let resp = Response::new()
    .with_header("hello", "world!")
    .with_header("hello", "universe!");

for (n, v) in resp.get_headers() {
    println!("Header -  {}: {:?}", n, v);
}

Get all values of a header as strings, including invalid characters, or an empty vector if the header is not present.

Only the valid UTF-8 characters present are returned. Invalid UTF-8 characters are replaced with U+FFFD REPLACEMENT CHARACTER.

Argument type conversion

The header name argument can be any type that implements ToHeaderName; see that trait for details on which types can be used and when panics may arise during conversion.

Examples
let world_value = HeaderValue::from_bytes(b"\xF0\x90\x80 world!").unwrap();
let universe_value = HeaderValue::from_bytes(b"\xF0\x90\x80 universe!").unwrap();
let resp = Response::new()
    .with_header("hello", world_value)
    .with_header("hello", universe_value);
let values = resp.get_header_all_str_lossy("hello");
assert_eq!(values.len(), 2);
assert!(values.contains(&Cow::from("� world!")));
assert!(values.contains(&Cow::from("� universe!")));

Get an iterator of all the values of a header.

Argument type conversion

The header name argument can be any type that implements ToHeaderName; see that trait for details on which types can be used and when panics may arise during conversion.

Examples

You can turn the iterator into collection, like Vec:

let invalid_utf8 = &"🐈".as_bytes()[0..3];
let resp = Response::new()
    .with_header("hello", "world!")
    .with_header("hello", invalid_utf8);

let values: Vec<&HeaderValue> = resp.get_header_all("hello").collect();
assert_eq!(values.len(), 2);
assert!(values.contains(&&HeaderValue::from_static("world!")));
assert!(values.contains(&&HeaderValue::from_bytes(invalid_utf8).unwrap()));

You can use the iterator in a loop:

let invalid_utf8 = &"🐈".as_bytes()[0..3];
let resp = Response::new()
    .with_header("hello", "world!")
    .with_header("hello", invalid_utf8);

for value in resp.get_header_all("hello") {
    if let Ok(s) = value.to_str() {
        println!("hello, {}", s);
    } else {
        println!("hello, invalid UTF-8!");
    }
}

Get all of the response’s header names as strings, or an empty vector if no headers are present.

Examples
let resp = Response::new()
    .with_header("hello", "world!")
    .with_header("goodbye", "latency!");
let names = resp.get_header_names_str();
assert_eq!(names.len(), 2);
assert!(names.contains(&"hello"));
assert!(names.contains(&"goodbye"));

Get an iterator of all the response’s header names.

Examples

You can turn the iterator into a collection, like Vec:

let resp = Response::new()
    .with_header("hello", "world!")
    .with_header("goodbye", "latency!");

let values: Vec<&HeaderName> = resp.get_header_names().collect();
assert_eq!(values.len(), 2);
assert!(values.contains(&&HeaderName::from_static("hello")));
assert!(values.contains(&&HeaderName::from_static("goodbye")));

You can use the iterator in a loop:

let resp = Response::new()
    .with_header("hello", "world!")
    .with_header("goodbye", "latency!");

for name in resp.get_header_names() {
    println!("saw header: {:?}", name);
}

Set a response header to the given value, discarding any previous values for the given header name.

Argument type conversion

The header name and value arguments can be any types that implement ToHeaderName and ToHeaderValue, respectively. See those traits for details on which types can be used and when panics may arise during conversion.

Examples
let mut resp = Response::new();

resp.set_header("hello", "world!");
assert_eq!(resp.get_header_str("hello"), Some("world!"));

resp.set_header("hello", "universe!");

let values = resp.get_header_all_str("hello");
assert_eq!(values.len(), 1);
assert!(!values.contains(&"world!"));
assert!(values.contains(&"universe!"));

Add a response header with given value.

Unlike set_header(), this does not discard existing values for the same header name.

Argument type conversion

The header name and value arguments can be any types that implement ToHeaderName and ToHeaderValue, respectively. See those traits for details on which types can be used and when panics may arise during conversion.

Examples
let mut resp = Response::new();

resp.set_header("hello", "world!");
assert_eq!(resp.get_header_str("hello"), Some("world!"));

resp.append_header("hello", "universe!");

let values = resp.get_header_all_str("hello");
assert_eq!(values.len(), 2);
assert!(values.contains(&"world!"));
assert!(values.contains(&"universe!"));

Remove all response headers of the given name, and return one of the removed header values if any were present.

If the header has multiple values, one is returned arbitrarily. To get all of the removed header values, or to get a specific value, use get_header_all().

Argument type conversion

The header name argument can be any type that implements ToHeaderName; see that trait for details on which types can be used and when panics may arise during conversion.

Examples
let mut resp = Response::new().with_header("hello", "world!");
assert_eq!(resp.get_header_str("hello"), Some("world!"));
assert_eq!(resp.remove_header("hello"), Some(HeaderValue::from_static("world!")));
assert!(resp.remove_header("not-present").is_none());

Remove all response headers of the given name, and return one of the removed header values as a string if any were present.

If the header has multiple values, one is returned arbitrarily. To get all of the removed header values, use get_header_all() before removing.

Argument type conversion

The header name argument can be any type that implements ToHeaderName; see that trait for details on which types can be used and when panics may arise during conversion.

Panics

This method panics if the value of the header is not a valid UTF-8 string. To handle the possibility of invalid UTF-8 data, use remove_header_str_lossy for lossy conversion, or use remove_header() and then convert the bytes with HeaderValue::to_str().

Examples
let mut resp = Response::new().with_header("hello", "world!");
assert_eq!(resp.get_header_str("hello"), Some("world!"));
assert_eq!(resp.remove_header_str("hello"), Some("world!".to_string()));
assert!(resp.remove_header_str("not-present").is_none());

Remove all response headers of the given name, and return one of the removed header values as a string, including invalid characters, if any were present.

Only the valid UTF-8 characters present are returned. Invalid UTF-8 characters are replaced with U+FFFD REPLACEMENT CHARACTER.

If the header has multiple values, one is returned arbitrarily. To get all of the removed header values, use get_header_all() before removing.

Argument type conversion

The header name argument can be any type that implements ToHeaderName; see that trait for details on which types can be used and when panics may arise during conversion.

Examples
let header_value = HeaderValue::from_bytes(b"\xF0\x90\x80 world!").unwrap();
let mut resp = Response::new().with_header("hello", header_value);
assert_eq!(resp.get_header_str_lossy("hello"), Some(Cow::from("� world")));
assert_eq!(resp.remove_header_str_lossy("hello"), Some(String::from("� world")));
assert!(resp.remove_header_str_lossy("not-present").is_none());

Builder-style equivalent of set_status().

Get the HTTP status code of the response.

Set the HTTP status code of the response.

Argument type conversion

The status code argument can be any type that implements ToStatusCode; see that trait for details on which types can be used and when panics may arise during conversion.

Examples

Using the constants from StatusCode:

use fastly::http::StatusCode;

let mut resp = Response::from_body("not found!");
resp.set_status(StatusCode::NOT_FOUND);
resp.send_to_client();

Using a u16:

let mut resp = Response::from_body("not found!");
resp.set_status(404);
resp.send_to_client();

Builder-style equivalent of set_version().

Get the HTTP version of this response.

Set the HTTP version of this response.

Sets how Content-Length and Transfer-Encoding will be determined when sending this request.

See FramingHeadersMode for details on the options.

Builder-style equivalent of set_framing_headers_mode().

Get the name of the Backend this response came from, or None if the response is synthetic.

Examples

From a backend response:

let backend_resp = Request::get("https://example.com/").send("example_backend").unwrap();
assert_eq!(backend_resp.get_backend_name(), Some("example_backend"));

From a synthetic response:

let synthetic_resp = Response::new();
assert!(synthetic_resp.get_backend_name().is_none());

Get the backend this response came from, or None if the response is synthetic.

Examples

From a backend response:

let backend_resp = Request::get("https://example.com/").send("example_backend").unwrap();
assert_eq!(backend_resp.get_backend(), Some(&Backend::from_name("example_backend").unwrap()));

From a synthetic response:

let synthetic_resp = Response::new();
assert!(synthetic_resp.get_backend().is_none());

Get the request this response came from, or None if the response is synthetic.

Note that the returned request will only have the headers and metadata of the original request, as the body is consumed when sending the request.

This method only returns a reference to the backend request. To instead take and return the owned request (for example, to subsequently send the request again), use take_backend_request().

Examples

From a backend response:

let backend_resp = Request::post("https://example.com/")
    .with_body("hello")
    .send("example_backend")
    .unwrap();
let backend_req = backend_resp.get_backend_request().expect("response is not synthetic");
assert_eq!(backend_req.get_url_str(), "https://example.com/");
assert!(!backend_req.has_body());

From a synthetic response:

let synthetic_resp = Response::new();
assert!(synthetic_resp.get_backend_request().is_none());

Take and return the request this response came from, or None if the response is synthetic.

Note that the returned request will only have the headers and metadata of the original request, as the body is consumed when sending the request.

Examples

From a backend response:

let mut backend_resp = Request::post("https://example.com/")
    .with_body("hello")
    .send("example_backend")
    .unwrap();
let backend_req = backend_resp.take_backend_request().expect("response is not synthetic");
assert_eq!(backend_req.get_url_str(), "https://example.com/");
assert!(!backend_req.has_body());
backend_req.with_body("goodbye").send("example_backend").unwrap();

From a synthetic response:

let mut synthetic_resp = Response::new();
assert!(synthetic_resp.take_backend_request().is_none());

Begin sending the response to the client.

This method returns as soon as the response header begins sending to the client, and transmission of the response will continue in the background.

Once this method is called, nothing else may be added to the response body. To stream additional data to a response body after it begins to send, use stream_to_client.

Panics

This method panics if another response has already been sent to the client by this method, by stream_to_client(), or by the equivalent methods of ResponseHandle.

Examples

Sending a backend response without modification:

Request::get("https://example.com/").send("example_backend").unwrap().send_to_client();

Removing a header from a backend response before sending to the client:

let mut backend_resp = Request::get("https://example.com/").send("example_backend").unwrap();
backend_resp.remove_header("bad-header");
backend_resp.send_to_client();

Sending a synthetic response:

Response::from_body("hello, world!").send_to_client();
👎Deprecated since 0.6.0: renamed to Response::send_to_client()

Deprecated alias of Response::send_to_client()

Begin sending the response to the client, and return a StreamingBody that can accept further data to send.

This method is most useful for programs that do some sort of processing or inspection of a potentially-large backend response body. Streaming allows the program to operate on small parts of the body rather than having to read it all into memory at once.

This method returns as soon as the response header begins sending to the client, and transmission of the response will continue in the background.

Note that the client connection is only closed once the StreamingBody is dropped. You can explicitly drop the body once finished to avoid holding the connection open longer than necessary.

Panics

This method panics if another response has already been sent to the client by this method, by send_to_client(), or by the equivalent methods of ResponseHandle.

Examples

Count the number of lines in a UTF-8 backend response body while sending it to the client:

use std::io::BufRead;

let mut backend_resp = Request::get("https://example.com/").send("example_backend").unwrap();
// Take the body so we can iterate through its lines later
let backend_resp_body = backend_resp.take_body();
// Start sending the backend response to the client with a now-empty body
let mut client_body = backend_resp.stream_to_client();

let mut num_lines = 0;
for line in backend_resp_body.lines() {
    let line = line.unwrap();
    num_lines += 1;
    // Write the line to the streaming client body
    client_body.write_str(&line);
}
// Drop the streaming body to allow the client connection to close
drop(client_body);

println!("backend response body contained {} lines", num_lines);
👎Deprecated since 0.6.0: renamed to Response::stream_to_client()

Deprecated alias of Response::stream_to_client()

Create a Response from the a ResponseHandle and a BodyHandle, returning an error if any ResponseLimits are exceeded.

The extra metadata associated with a backend response is not tracked by the low-level handle APIs. As a result, methods like get_backend() and get_backend_request() will always return None for a request created from handles.

Create a ResponseHandle/BodyHandle pair from a Response.

The extra metadata associated with a backend response is not tracked by the low-level handle APIs. As a result, converting to handles will cause the backend and request associated with a backend response to be lost.

Trait Implementations

Formats the value using the given formatter. Read more
Converts to this type from the input type.
Converts this type into the (usually inferred) input type.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Should always be Self
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.