CandidateResponse

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

See Response::append_header.

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

See Response::contains_header.

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

See Response::get_content_type.

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

See Response::get_header.

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

See Response::get_header_all.

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 std::str::from_utf8().

Examples

See Response::get_header_all_str.

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

See Response::get_header_all_str_lossy.

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

Examples

See Response::get_header_names.

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

Examples

See Response::get_header_names_str.

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 std::str::from_utf8().

Examples

See Response::get_header_str.

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

See Response::get_header_str_lossy.

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

Examples

See Response::get_headers.

Get the Time to Live (TTL) in the cache for this response.

The TTL determines the duration of "freshness" for the cached response after it is inserted into the cache.

Gets whether this response should only be stored via PCI/HIPAA-compliant non-volatile caching.

See the Fastly PCI-Compliant Caching and Delivery documentation for details.

Determines whether the cached response is stale.

A cached response is stale if it has been in the cache beyond its TTL period, or if it has been soft purged.

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

See Response::remove_header.

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 std::str::from_utf8().

Examples

See Response::remove_header_str.

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

See Response::remove_header_str_lossy.

Sets a callback to be used for transforming the response body prior to caching.

Body transformations are performed via a callback, rather than by directly working with the body, because not every response contains a fresh body: 304 Not Modified responses, which are used to revalidate a stale cached response, are valuable precisely because they do not retransmit the body.

For any other response status, the backend response will contain a relevant body, and the transform callback will be invoked. The original backend body of type Body is given as the first parameter to the transform. The transform is responsible for writing the new body into the StreamingBody given as its second argument. Upon returning from the transform, StreamingBody::finish() will be called implicitly. This setup allows the transform to work with streamed chunks of the backend body, rather than necessarily reading it entirely into memory.

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

Any existing Content-Type header values will be overwritten.

Examples

See Response::set_content_type.

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

See Response::set_header.

Set the caching behavior of this response to enable or disable PCI/HIPAA-compliant non-volatile caching.

By default, this is false, which means the response may not be PCI/HIPAA-compliant. Set it to true to enable compliant caching.

See the Fastly PCI-Compliant Caching and Delivery documentation for details.

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

See Response::set_status.

Sets the surrogate keys for the cached response.

Surrogate keys must contain only printable ASCII characters (those between 0x21 and 0x7E, inclusive). Any invalid keys will be ignored.

See the Fastly surrogate keys guide for details.

Set the Time to Live (TTL) in the cache for this response.

The TTL determines the duration of "freshness" for the cached response after it is inserted into the cache.

Set the response to not be stored in the cache.

Optionally, if record_uncacheable is true, the cache will record that the originating request led to an uncacheable response, so that future cache lookups will result in immediately going to the backend, rather than attempting to coordinate concurrent requests to reduce backend traffic.

See the Fastly request collapsing guide for more details on the mechanism that record_uncacheable disables.

Returns true if there is a stale-if-error response available from the cache.

A CandidateResponse represents an HTTP response returned from a Backend. However, it may be preferable to return a cached response rather than the Backend's response -- for instance, if the Backend's response is a 5xx error.

This method returns true if there is a cached response that is within the stale-if-error period. If a stale-if-error response is available, and the after_send hook returns an error, the response from the Backend will not be cached, and the Request::send call will return the stale-if-error response.