This commit fixes a memory leak in ServerSentEventHttpMessageWriter
that occurs when the input stream contains an error. Test added as well.
Issue: SPR-17419
The fix for SPR-17178 switched from debug to warn level warning for
all sub-classes of AbstractHandlerExceptionResolver where the request
concerned the DefaultHandlerExceptionResolver only.
This commit restores the original DEBUG level logging that was in
AbstractHandlerExceptionResolver from before SPR-17178. In addition
DefaultHandlerExceptionResolver registers a warnLogCategory by default
which enables warn logging and hence fulfilling the original goal
for SPR-17178.
Issue: SPR-17383
Review and update Servlet and Undertow adapters to release any data
buffers they be holding on to at the time of error or cancellation.
Also remove onDiscard hooks from Reactor and Undertow request body.
For Reactor we expect it to be handled. For Undertow there isn't
any Reactor Core upstream for the callback to be useful.
Issue: SPR-17410
This commit harmonizes the `HeadersAdapter` implementations across all
supported servers with regards to the `get(Object key)` contract; some
server implementations are not sticking to a `Map`-like contract and
return empty `List` instead of `null` when a header is not present.
This also fixes the `size()` implementations to reflect the number of
header keys, as some implementations consider multiple values for the
same header as different entries.
Issue: SPR-17396
This commit adds special processing of some HTTP response headers in
Jetty and Tomcat; they both consider some headers like "Content-Length"
as specific and require explicit calls on the `HttpServletResponse`
itself on top of setting the HTTP response header.
Issue: SPR-17250
This commit avoids copying HTTP headers when mutating an HTTP request.
Instead, we're now unwrapping the `ReadOnlyHttpHeaders` (which is most
likely backed by the native request headers).
Issue: SPR-17250
Several benchmarks underlined a few hotspots for CPU and GC pressure in
the Spring Framework codebase:
1. `org.springframework.util.MimeType.<init>(String, String, Map)`
2. `org.springframework.util.LinkedCaseInsensitiveMap.convertKey(String)`
Both are linked with HTTP request headers parsing and response headers
writin during the exchange processing phase.
1) is linked to repeated calls to `HttpHeaders.getContentType`
within a single request handling. The media type parsing operation
is expensive and the result doesn't change between calls, since
the request headers are immutable at that point.
This commit improves this by caching the parsed `MediaType` for the
`"Content-Type"` request header in the `ReadOnlyHttpHeaders` class.
This change is available for both Spring MVC and Spring WebFlux.
2) is linked to insertions/lookups in the `LinkedCaseInsensitiveMap`,
which is the data structure behind `HttpHeaders`.
Those operations are creating a lot of garbage (including a lot of
`String` created by `toLowerCase`). We could choose a more efficient
data structure for storing HTTP headers data.
As a first step, this commit is focusing on Spring WebFlux and
introduces `MultiValueMap` implementations mapped by native HTTP headers
for the following servers: Tomcat, Jetty, Netty and Undertow.
Such implementations avoid unnecessary copying of the headers
and leverages as much as possible optimized operations provided by the
native implementations.
This change has a few consequences:
* `HttpHeaders` can now wrap a `MultiValueMap` directly
* The default constructor of `HttpHeaders` is still backed by a
`LinkedCaseInsensitiveMap`
* The HTTP request headers for the websocket HTTP handshake now need to
be cloned, because native headers are likely to be pooled/recycled by
the server implementation, hence gone when the initial HTTP exchange is
done
Issue: SPR-17250
In order to be able to leverage WebFlux configuration in a functional
way, WebHttpHandlerBuilder and RouterFunctionMapping should leverage
new ObjectProvider capabilities to get a sorted list of beans by type
instead of using autowired containers.
Issue: SPR-17327
1. Helper method to eliminate duplication in formatting (de-)serialized
values for logging introduced with prior commit #e62298.
2. Helper method for TRACE vs DEBUG logging with different details.
Issue: SPR-17254
