Motivation:
Fix the regression recently introduced that causes already encoded responses to be encoded again as gzip
Modification:
instead of just looking for IDENTITY, anything set for Content-Encoding should be respected and left as-is
added unit tests to capture this use case
Result:
Fixes#6784
Motivation
RFC 1945 (see section 3.1) says that request lines may not have a version in which case the request is assumed to be HTTP/0.9. We don't necessarily want to support that but the existing Exception should indicate the possibility of the request being HTTP/0.9 and give the user a chance to track it down.
Modifications
Indicate in the Exception's message that the request is possibly HTTP/0.9.
Result
Fixes#6739
Motivation:
The status 308 is defined by RFC7538.
This RFC has currently the state Proposed Standard since 2 years, but the status code is already handle by all browsers (Chrome, Firefox, Edge, Safari, …).
To let developer handles easily this status code, it is added into this list.
Modifications:
Added this status code in the list of all status codes and changed the valudOf() method
Result:
Status code 308 included
__Motivation__
`HttpClientCodec` skips HTTP decoding on the connection after a successful HTTP CONNECT response is received.
This behavior follows the spec for a client but pragmatically, if one creates a client to use a proxy transparently, the codec becomes useless after HTTP CONNECT.
Ideally, one should be able to configure whether HTTP CONNECT should result in pass-through or not. This will enable client writers to continue using HTTP decoding even after HTTP CONNECT.
__Modification__
Added overloaded constructors to accept `parseHttpPostConnect`. If this parameter is `true` then the codec continues decoding even after a successful HTTP CONNECT.
Also fixed a bug in the codec that was incrementing request count post HTTP CONNECT but not decrementing it on response. Now, the request count is only incremented if the codec is not `done`.
__Result__
Easier usage by HTTP client writers who wants to connect to a proxy but still decode HTTP for their users for subsequent requests.
Motivation:
Some JUnit assert calls can be replaced by simpler.
Modifications:
Replacement with a more suitable methods.
Result:
More informative JUnit reports.
Motivation:
HttpServerKeepAliveHandler throws unexpected error when I do ctx.writeAndFlush(msg, ctx.voidPromise()); where msg is with header "Connection:close".
Modification:
HttpServerKeepAliveHandler does promise.unvoid() before adding close listener.
Result:
No error for VoidChannelPromise with HttpServerKeepAliveHandler. Fixes [#6698].
Motivation:
It would be more flexible to make getCharset and getMimeType code usable not only for HttpMessage entity but just for any CharSequence. This will improve usability in general purpose code and will help to avoid multiple fetching of ContentType header from a message. It could be done in an external code once and CharSequence method versions could be applied.
Modification:
Expose HttpUtil#getMimeType, HttpUtil#getCharsetAsString, HttpUtil#getCharset versions which works with CharSequence. New methods are reused in the old ones which work with HttpMessage entity.
Result:
More flexible methods set with a good code reusing.
Motivation:
WebSocket decoding throws exceptions on failure that should cause the
pipline to close. These are currently ignored in the
`WebSocketProtocolHandler` and `WebSocketServerProtocolHandler`. In
particular, this means that messages exceding the max message size will
cause the channel to close with no reported failure.
Modifications:
Re-fire the event just before closing the socket to allow it to be
handled appropriately.
Result:
Closes [#3063].
Motivation:
If Content-Encoding: IDENTITY is used we should not try to compress the http message but just let it pass-through.
Modifications:
Remove "!"
Result:
Fixes [#6689]
It is generally useful to have origin http servers respond to
"expect: continue-100" as soon as possible but applications without a
HttpObjectAggregator in their pipelines must use boiler plate to do so.
Modifications:
Introduce the HttpServerExpectContinueHandler handler to make it easier.
Result:
Less boiler plate for http application authors.
Motivation:
DiskFileUpload creates temporary files for storing user uploads containing the user provided file name as part of the temporary file name. While most security problems are prevented by using "new File(userFileName).getName()" a small risk for bugs or security issues remains.
Modifications:
Use a constant string as file name and rely on the callers use of File.createTemp to ensure unique disk file names.
Result:
A slight security improvement at the cost of a little more obfuscated temp file names.
Motivation:
We miss to retain a slice before return it to the user and so an reference count error may accour later on.
Modifications:
Use readRetainedSlice(...) and so ensure we retain the buffer before hand it of to the user.
Result:
Fixes [#6626].
Motivation:
Commit #d675febf07d14d4dff82471829f974369705655a introduced a regression in QueryStringEncoder, resulting in whitespace being converted into a literal `+` sign instead of `%20`.
Modification:
Modify `encodeComponent` to pattern match and replace on the result of the call to `URLEncoder#encode`
Result:
Fixes regression
Motivation:
https://tools.ietf.org/html/rfc7230#section-3.3.2 states that a 204 response MUST NOT include a Content-Length header. If the HTTP version permits keep alive these responses should be treated as keeping the connection alive even if there is no Content-Length header.
Modifications:
- HttpServerKeepAliveHandler#isSelfDefinedMessageLength should account for 204 respones
Result:
Fixes https://github.com/netty/netty/issues/6549.
Motivation:
Currently netty is receiving HTTP request by ByteBuf and store it as "CharSequence" on HttpObjectDecoder. During this operation, all character on ByteBuf is moving to char[] without breaking encoding.
But in process() function, type casting from byte to char does not consider msb (sign-bit). So the value over 127 can be casted wrong value. (ex : 0xec in byte -> 0xffec in char). This is type casting bug.
Modification:
Fix type casting
Result:
Non-latin characters work.
Motivation:
The updated HTTP/1.x RFC allows for header values to be CSV and separated by OWS [1]. CombinedHttpHeaders should remove this OWS on insertion.
[1] https://tools.ietf.org/html/rfc7230#section-7
Modification:
CombinedHttpHeaders doesn't account for the OWS and returns it back to the user as part of the value.
Result:
Fixes#6452
Motivation:
We used some deprecated Mockito methods.
Modifications:
- Replace deprecated method usage
- Some cleanup
Result:
No more usage of deprecated Mockito methods. Fixes [#6482].
Motivation:
Some classes have fields which can be local.
Modifications:
Convert fields to the local variable when possible.
Result:
Clean up. More chances for young generation or scalar replacement.
Motivation:
We only need to add the port to the HOST header value if its not a standard port.
Modifications:
- Only add port if needed.
- Fix parsing of ipv6 address which is enclosed by [].
Result:
Fixes [#6426].
Motivation:
Make code easier to read, make WebSocketServerProtocolHandshakeHandler.getWebSocketLocation method faster.
Modification:
WebSocket path check moved to separate method. Get header operation moved out from concat operation.
Result:
WebSocketServerProtocolHandshakeHandler.getWebSocketLocation is faster as OptimizeStringConcat could be applied. Code easier to read.
Motivation:
QueryStringDecoder and QueryStringEncoder contained some code that could either cleaned-up or optimized.
Modifications:
- Fix typos in exception messages and javadocs
- Precompile Pattern
- Make use of StringUtil.EMPTY_STRING
Result:
Faster and cleaner code.
Motivation:
Calling a static method is faster then dynamic
Modifications:
Add 'static' keyword for methods where it missed
Result:
A bit faster method calls
Motivation:
We have our own ThreadLocalRandom implementation to support older JDKs . That said we should prefer the JDK provided when running on JDK >= 7
Modification:
Using ThreadLocalRandom implementation of the JDK when possible.
Result:
Make use of JDK implementations when possible.
Motivation:
The allowMaskMismatch parameter used throughout websocketx allows frames
with noncompliant masks when set to true, not false.
Modification:
Changed the javadoc comment everywhere it appears.
Result:
Fixes#6387
Motivation:
Today, the HTTP codec in Netty responds to HTTP/1.1 requests containing
an "expect: 100-continue" header and a content-length that exceeds the
max content length for the server with a 417 status (Expectation
Failed). This is a violation of the HTTP specification. The purpose of
this commit is to address this situation by modifying the HTTP codec to
respond in this situation with a 413 status (Request Entity Too
Large). Additionally, the HTTP codec ignores expectations in the expect
header that are currently unsupported. This commit also addresses this
situation by responding with a 417 status.
Handling the expect header is tricky business as the specification (RFC
2616) is more complicated than it needs to be. The specification defines
the legitimate values for this header as "100-continue" and defines the
notion of expectatation extensions. Further, the specification defines a
417 status (Expectation Failed) and this is where implementations go
astray. The intent of the specification was for servers to respond with
417 status when they do not support the expectation in the expect
header.
The key sentence from the specification follows:
The server MUST respond with a 417 (Expectation Failed) status if
any of the expectations cannot be met or, if there are other
problems with the request, some other 4xx status.
That is, a server should respond with a 417 status if and only if there
is an expectation that the server does not support (whether it be
100-continue, or another expectation extension), and should respond with
another 4xx status code if the expectation is supported but there is
something else wrong with the request.
Modifications:
This commit modifies the HTTP codec by changing the handling for the
expect header in the HTTP object aggregator. In particular, the codec
will now respond with 417 status if any expectation other than
100-continue is present in the expect header, the codec will respond
with 413 status if the 100-continue expectation is present in the expect
header and the content-length is larger than the max content length for
the aggregator, and otherwise the codec will respond with 100 status.
Result:
The HTTP codec can now be used to correctly reply to clients that send a
100-continue expectation with a content-length that is too large for the
server with a 413 status, and servers that use the HTTP codec will now
no longer ignore expectations that are not supported (any value other
than 100-continue).
Motivation:
Netty 4.1 introduced AsciiString and defines HttpHeaderNames constants
as such.
It would be convenient to be able to pass them to `exposeHeaders` and
`allowedRequestHeaders` directly without having to call `toString`.
Modifications:
Add `exposeHeaders` and `allowedRequestHeaders` overloads that take a
`CharSequence`.
Result:
More convenient API
Motivation:
DefaultCookie currently used an undocumented magic value for undefined
maxAge.
Clients need to be able to identify such value so they can implement a
proper CookieJar.
Ideally, we should add a `Cookie::isMaxAgeDefined` method but I guess
we can’t add a new method without breaking API :(
Modifications:
Add a new constant on `Cookie` interface so clients can use it to
compare with value return by `Cookie.maxAge` and decide if `maxAge` was
actually defined.
Result:
Clients have a better documented way to check if the maxAge attribute
was defined.
Motivation:
We used various mocking frameworks. We should only use one...
Modifications:
Make usage of mocking framework consistent by only using Mockito.
Result:
Less dependencies and more consistent mocking usage.
Motivation:
HttpObjectAggregator yields full HTTP messgaes (AggregatedFullHttpMessages) that don't respect decoder result when copied/replaced.
Modifications:
Copy the decoding result over to a new instance produced by AggregatedFullHttpRequest.replace or AggregatedFullHttpResponse.replace .
Result:
DecoderResult is now copied over when an original AggregatedFullHttpMessage is being replaced (i.e., AggregatedFullHttpRequest.replace or AggregatedFullHttpResponse.replace is being called).
New unit tests are passing on this branch but are failing on master.
Motivation:
HttpUtil.setTransferEncodingChunked could add a second Transfer-Encoding
header if one was already present. While this is technically valid, it
does not appear to be the intent of the method.
Result:
Only one Transfer-Encoding header is present after calling this method.
Motivation:
In Netty, currently, the HttpPostRequestEncoder only supports POST, PUT, PATCH and OPTIONS, while the RFC 7231 allows with a warning that GET, HEAD, DELETE and CONNECT use a body too (but not TRACE where it is explicitely not allowed).
The RFC in chapter 4.3 says:
"A payload within a XXX request message has no defined semantics;
sending a payload body on a XXX request might cause some existing
implementations to reject the request."
where XXX can be replaced by one of GET, HEAD, DELETE or CONNECT.
Current usages, on particular in REST mode, tend to use those extra HttpMethods for such queries.
So this PR proposes to remove the current restrictions, leaving only TRACE as explicitely not supported.
Modification:
In the constructor, where the test is done, replacing all by checking only against TRACE, and adding one test to check that all methods are supported or not.
Result:
Fixes#6138.
Motivation:
cb139043f3 introduced special handling of response to HEAD requests. Due a bug we failed to handle FullHttpResponse correctly.
Modifications:
Correctly handle FullHttpResponse for HEAD requests.
Result:
Works as expected.
Motivation:
We should have a unit test which explicitly tests a HTTP message being split between multiple ByteBuf objects.
Modifications:
- Add a unit test to HttpRequestDecoderTest which splits a request between 2 ByteBuf objects
Result:
More unit test coverage for HttpObjectDecoder.
Motivation:
Enables optional .startsWith() matching of req.uri() with websocketPath.
Modifications:
New checkStartsWith boolean option with default false value added to both WebSocketServerProtocolHandler and WebSocketServerProtocolHandshakeHandler. req.uri() matching is based on this option.
Result:
By default old behavior matching via .equal() is preserved. To use checkStartsWith use constructor shortcut: new WebSocketServerProtocolHandler(websocketPath, true) or fill this flag on full form of constructor among other options.
request with a 'content-encoding: chunked' header
Motivation:
It is valid to send a response to a HEAD request that contains a transfer-encoding: chunked header, but it is not valid to include a body, and there is no way to do this using the netty4 HttpServerCodec.
The root cause is that the netty4 HttpObjectEncoder will transition to the state ST_CONTENT_CHUNK and the only way to transition back to ST_INIT is through the encodeChunkedContent method which will write the terminating length (0\r\n\r\n\r\n), a protocol error when responding to a HEAD request
Modifications:
- Keep track of the method of the request and depending on it handle the response differently when encoding it.
- Added a unit test.
Result:
Correclty handle HEAD responses that are chunked.
Motivation:
According to https://www.ietf.org/rfc/rfc2388.txt 4.4, filename after "content-disposition" is optional and arbitrary (does not need to match a real filename).
Modifications:
This change supports an extra addBodyFileUpload overload to precise the filename (default to File.getName). If empty or null this argument should be ignored during encoding.
Result:
- A backward-compatible addBodyFileUpload(String, File, String, boolean) to use file.getName() as filename.
- A new addBodyFileUpload(String, String, File, String, boolean) overload to precise filename
- Couple of tests for the empty use case
Motivation:
IntelliJ issues several warnings.
Modifications:
* `ClientCookieDecoder` and `ServerCookieDecoder`:
* `nameEnd`, `valueBegin` and `valueEnd` don't need to be initialized
* `keyValLoop` loop doesn't been to be labelled, as it's the most inner one (same thing for labelled breaks)
* Remove `if (i != headerLen)` as condition is always true
* `ClientCookieEncoder` javadoc still mention old logic
* `DefaultCookie`, `ServerCookieEncoder` and `DefaultHttpHeaders` use ternary ops that can be turned into simple boolean ones
* `DefaultHeaders` uses a for(int) loop over an array. It can be turned into a foreach one as javac doesn't allocate an iterator to iterate over arrays
* `DefaultHttp2Headers` and `AbstractByteBuf` `equal` can be turned into a single boolean statement
Result:
Cleaner code
Motivation:
* DefaultHeaders from netty-codec has some duplicated logic for header date parsing
* Several classes keep on using deprecated HttpHeaderDateFormat
Modifications:
* Move HttpHeaderDateFormatter to netty-codec and rename it into HeaderDateFormatter
* Make DefaultHeaders use HeaderDateFormatter
* Replace HttpHeaderDateFormat usage with HeaderDateFormatter
Result:
Faster and more consistent code
Motivation:
code assumes a numeric value of 0 means no digits were read between separators, which fails for timestamps like 00:00:00.
also code accepts invalid timestamps like 0:0:000
Modifications:
explicitly check for number of digits between separators instead of relying on the numeric value.
also add tests.
Result:
timestamps with 00 successfully parse, timestamps with 000 no longer
Signed-off-by: radai-rosenblatt <radai.rosenblatt@gmail.com>
Motivation:
The method HttpUtil.getCharsetAsString(...) is missleading as its return type is CharSequence and not String.
Modifications:
Deprecate HttpUtil.getCharsetAsString(...) and introduce HttpUtil.getCharsetAsSe
quence(...).
Result:
Less confusing method name.
Motivation:
* RFC6265 defines its own parser which is different from RFC1123 (it accepts RFC1123 format but also other ones). Basically, it's very lax on delimiters, ignores day of week and timezone. Currently, ClientCookieDecoder uses HttpHeaderDateFormat underneath, and can't parse valid cookies such as Github ones whose expires attribute looks like "Sun, 27 Nov 2016 19:37:15 -0000"
* ServerSideCookieEncoder currently uses HttpHeaderDateFormat underneath for formatting expires field, and it's slow.
Modifications:
* Introduce HttpHeaderDateFormatter that correctly implement RFC6265
* Use HttpHeaderDateFormatter in ClientCookieDecoder and ServerCookieEncoder
* Deprecate HttpHeaderDateFormat
Result:
* Proper RFC6265 dates support
* Faster ServerCookieEncoder and ClientCookieDecoder
* Faster tool for handling headers such as "Expires" and "Date"
Motiviation:
We used ReferenceCountUtil.releaseLater(...) in our tests which simplifies a bit the releasing of ReferenceCounted objects. The problem with this is that while it simplifies stuff it increase memory usage a lot as memory may not be freed up in a timely manner.
Modifications:
- Deprecate releaseLater(...)
- Remove usage of releaseLater(...) in tests.
Result:
Less memory needed to build netty while running the tests.
Motivation:
If the wsURL contains an encoded query, it will be decoded when generating the raw path. For example if the wsURL is http://test.org/path?a=1%3A5, the returned raw path would be /path?a=1:5
Modifications:
Use wsURL.getRawQuery() rather than wsURL.getQuery()
Result:
rawPath will now return /path?a=1%3A5
Motivation:
Some commons values are missing from HttpHeader values constants.
Modifications:
- Add constants for "application/json" Content-Type
- Add constants for "gzip,deflate" Content-Encoding
Result:
More HttpHeader values constants available, both in
`HttpHeaders.Values` and `HttpHeaderValues`.
Motivation:
The HttpObjectAggregator never appends a 'Connection: close' header to
the response of oversized messages even though in the majority of cases
its going to close the connection.
Modification:
This PR addresses that by ensuring the requisite header is present when
the connection is going to be closed.
Result:
Gracefully signal that we are about to close the connection.
Motivation:
We need to ensure we not add the Transfer-Encoding header if the HttpMessage is EOF terminated.
Modifications:
Only add the Transfer-Encoding header if an Content-Length header is present.
Result:
Correctly handle HttpMessage that is EOF terminated.
Motivation:
We want to reject the upgrade as quickly as possible, so that we can
support streamed responses.
Modifications:
Reject the upgrade as soon as we inspect the headers if they're wrong,
instead of waiting for the entire response body.
Result:
If a remote server doesn't know how to use the http upgrade and tries to
responsd with a streaming response that never ends, the client doesn't
buffer forever, but can instead pass it along. Fixes#5954
Motivation:
the build doesnt seem to enforce this, so they piled up
Modifications:
removed unused import lines
Result:
less unused imports
Signed-off-by: radai-rosenblatt <radai.rosenblatt@gmail.com>
Motivation:
The Javadocs of HttpUtil.getContentLength(HttpMessage, long) and its int overload state that the provided default value is returned if the Content-Length value is not a number. NumberFormatException is thrown instead.
Modifications:
Correctly handle when the value is not a number.
Result:
API works as stated in javadocs.
Motivation:
HttpObjectDecoder maintains a resetRequested flag which is used to determine if internal state should be reset when a decode occurs. However after a reset is done the resetRequested flag is not set to false. This leads to all data after this point being discarded.
Modifications:
- Set resetRequested to false when a reset is done
Result:
HttpObjectDecoder can still function after a reset.
Motivation:
As discussed in #5738, developers need to concern themselves with setting
connection: keep-alive on the response as well as whether to close a
connection or not after writing a response. This leads to special keep-alive
handling logic in many different places. The purpose of the HttpServerKeepAliveHandler
is to allow developers to add this handler to their pipeline and therefore
free themselves of having to worry about the details of how Keep-Alive works.
Modifications:
Added HttpServerKeepAliveHandler to the io.netty.handler.codec.http package.
Result:
Developers can start using HttpServerKeepAliveHandler in their pipeline instead
of worrying about when to close a connection for keep-alive.
Motivation:
As described in #5734
Before this change, if the server had to do some sort of setup after a
handshake was completed based on handshake's information, the only way
available was to wait (in a separate thread) for the handshaker to be
added as an attribute to the channel. Too much hassle.
Modifications:
Handshake completed event need to be stateful now, so I've added a tiny
class holding just the HTTP upgrade request and the selected subprotocol
which is fired as an event after the handshake has finished.
I've also deprecated the old enum used as stateless event and I left the
code that fires it for backward compatibility. It should be removed in
the next mayor release.
Result:
It should be much simpler now to do initialization stuff based on
subprotocol or request headers on handshake completion. No asynchronous
waiting needed anymore.
Motivation:
The CorsHandler currently closes the channel when it responds to a preflight (OPTIONS)
request or in the event of a short circuit due to failed validation.
Especially in an environment where there's a proxy in front of the service this causes
unnecessary connection churn.
Modifications:
CorsHandler now uses HttpUtil to determine if the connection should be closed
after responding and to set the Connection header on the response.
Result:
Channel will stay open when the CorsHandler responds unless the client specifies otherwise
or the protocol version is HTTP/1.0
Motivation:
Documentation was added in #2401 to aid developers in understanding
how HttpObjectAggregator works and that it needs an encoder before it.
In #2471 it was pointed out that the documentation added can actually
add to the confusion and that it might have a typo.
This is an attempt at clearing up that confusion. Feedback is welcome.
Modifications:
- Adjust class level javadoc for HttpObjectAggregator
* Remove reference to HttpRequestEncoder
* Point out when HttpResponseEncoder is needed
* Point out that either HttpRequestDecoder or HttpResponseDecoder is needed
* Make clear everything must be added before HttpObjectAggregator
* Mention HttpServerCodec
Result:
Avoid confusion about dependencies for HttpObjectAggregator on the pipeline.
Motivation:
The CorsHandler currently closes the channel when it responds to a preflight (OPTIONS)
request or in the event of a short circuit due to failed validation.
Especially in an environment where there's a proxy in front of the service this causes
unnecessary connection churn.
Modifications:
CorsHandler now uses HttpUtil to determine if the connection should be closed
after responding
Result:
Channel will stay open when the CorsHandler responds unless the client specifies otherwise
or the protocol version is HTTP/1.0
Motivation:
RFC 6265 does not state that cookie names must be case insensitive.
Modifications:
Fix io.netty.handler.codec.http.cookie.DefaultCookie#equals() method to
use case sensitive String#equals() and String#compareTo().
Result:
It is possible to parse several cookies with same names but with
different cases.
Motivation:
The CorsHandler currently returns the Access-Control-Allow-Headers
header as on a Non-Preflight CORS request (Simple request).
As per the CORS specification the Access-Control-Allow-Headers header
should only be returned on Preflight requests. (not on simple requests).
https://www.w3.org/TR/2014/REC-cors-20140116/#access-control-allow-headers-response-headerhttp://www.html5rocks.com/static/images/cors_server_flowchart.png
Modifications:
Modified CorsHandler.java to not add the Access-Control-Allow-Headers
header when responding to Non-preflight CORS request.
Result:
Access-Control-Allow-Headers header will not be returned on a Simple
request (Non-preflight CORS request).
Motivation:
There are few duplicated byte[] CRLF fields in code.
Modifications:
Removed duplicated fields as they could be inherited from parent encoder.
Result:
Less static fields.
Motivation :
Unboxing operations allocate unnecessary objects when it could be avoided.
Modifications:
Replaced Float.valueOf with Number.parseFloat where possible.
Result:
Less unnecessary objects allocations.
Motivation:
retainSlice() currently does not unwrap the ByteBuf when creating the ByteBuf wrapper. This effectivley forms a linked list of ByteBuf when it is only necessary to maintain a reference to the unwrapped ByteBuf.
Modifications:
- retainSlice() and retainDuplicate() variants should only maintain a reference to the unwrapped ByteBuf
- create new unit tests which generally verify the retainSlice() behavior
- Remove unecessary generic arguments from AbstractPooledDerivedByteBuf
- Remove unecessary int length member variable from the unpooled sliced ByteBuf implementation
- Rename the unpooled sliced/derived ByteBuf to include Unpooled in their name to be more consistent with the Pooled variants
Result:
Fixes https://github.com/netty/netty/issues/5582
Motivation:
Currently, QueryStringDecoder#path simply returns the path info as is, without decoding it as the Javadoc states.
Modifications:
* Make QueryStringDecoder#path decode the path info.
* Add tests to QueryStringDecoderTest.
Result:
QueryStringDecoder#path now decodes the path info as expected.
Motivation:
DiskFileUpload and MemoryFileUpload.equals(...) are broken.
Modifications:
Fix implementation and add unit test.
Result:
Equals method are correct now.
Motivation:
We don't have an argument named {@code value} but have {@code set} and
{@code expected} in HttpHeaders and HttpUtil respectively.
Modifications:
I replaced {@code value} to {@code set} and {@code expected} in HttpHeaders
and HttpUtil respectively.
Result:
Now javadoc says;
If {@code set} is {@code true}, the {@code "Expect: 100-continue"} header is
set and all other previous {@code "Expect"} headers are removed. Otherwise,
all {@code "Expect"} headers are removed completely. in HttpHeaders
If {@code expected} is {@code true}, the {@code "Expect: 100-continue"} header
is set and all other previous {@code "Expect"} headers are removed. Otherwise,
all {@code "Expect"} headers are removed completely. in HttpUtil
Motivation:
These methods were recently deprecated. However, they remained in use in several locations in Netty's codebase.
Modifications:
Netty's code will now access the bootstrap config to get the group or child group.
Result:
No impact on functionality.
Motivation:
We use pre-instantiated exceptions in various places for performance reasons. These exceptions don't include a stacktrace which makes it hard to know where the exception was thrown. This is especially true as we use the same exception type (for example ChannelClosedException) in different places. Setting some StackTraceElements will provide more context as to where these exceptions original and make debugging easier.
Modifications:
Set a generated StackTraceElement on these pre-instantiated exceptions which at least contains the origin class and method name. The filename and linenumber are specified as unkown (as stated in the javadocs of StackTraceElement).
Result:
Easier to find the origin of a pre-instantiated exception.
Motivation:
When HTTPS is used we should use https in the sec-websocket-origin / origin header
Modifications:
- Correctly generate the sec-websocket-origin / origin header
- Add unit tests.
Result:
Generate correct header.
`HttpContentDecoder` was removing `Content-Length` header but not adding a `Transfer-Encoding` header which goes against the HTTP spec.
Added `Transfer-Encoding` header with value `chunked` when `Content-Length` is removed.
Modified existing unit test to also check for this condition.
Compliance with HTTP spec.
Motivation:
When using HttpContentCompressor and the HttpResponse is protocol version 1.0, HttpContentEncoder.encode() should not set the transfer-encoding header to chunked. Chunked transfer-encoding is not valid for HTTP 1.0 - this causes ERR_CONTENT_DECODING_FAILED errors in chrome and similar failures in IE.
Modifications:
Skip HTTP/1.0 messages
Result:
Be able to serve HTTP/1.0 as well when HttpContentEncoder is in the pipeline.
Motivation:
Its completly fine for ChunkedInput.readChunk(...) to return null to indicate there is currently not any data to read. We need to handle this in HttpChunkedInput to not produce a NPE when constructing the HttpContent.
Modifications:
If readChunk(...) return null just return null as well.
Result:
No more NPE.
Motivation:
I cherry-picked 819b26b too soon. There were entries added to a deprecated class which should only go into the non-deprecated version of the class.
Modifications:
- Remove the static final variables that were added as duplicates to the deprecated class
Result:
Deprecated code does not grown in volume without need.
Motivation:
Some commons values are missing from HttpHeader values constants.
Modifications:
- Add constants for "application/json" Content-Type
- Add constants for "gzip,deflate" Content-Encoding
Result:
More HttpHeader values constants available, both in
`HttpHeaders.Values` and `HttpHeaderValues`.
Motivation:
Support fetches data chunk by chunk for use with WebSocket chunked transfers.
Modifications:
Create a WebSocketChunkedInput.java that add to io.netty.handler.codec.http.websocketx package
Result:
The WebSocket transfers/fetches data chunk by chunk.
Motivation:
JCTools supports both non-unsafe, unsafe versions of queues and JDK6 which allows us to shade the library in netty-common allowing it to stay "zero dependency".
Modifications:
- Remove copy paste JCTools code and shade the library (dependencies that are shaded should be removed from the <dependencies> section of the generated POM).
- Remove usage of OneTimeTask and remove it all together.
Result:
Less code to maintain and easier to update JCTools and less GC pressure as the queue implementation nt creates so much garbage
Motivation:
When the channel is closed while we still decode the headers we currently not preserve correct message sequence. In this case we should generate an invalid message with a current cause.
Modifications:
Create an invalid message with a PrematureChannelClosureException as cause when the channel is closed while we decode the headers.
Result:
Correct message sequence preserved and correct DecoderResult if the channel is closed while decode headers.
Motivation:
The user may specify to use a different allocator then the default. In this case we need to ensure it is shared when creating the EmbeddedChannel inside of a ChannelHandler
Modifications:
Use the config of the "original" Channel in the EmbeddedChannel and so share the same allocator etc.
Result:
Same type of buffers are used.
Motivation:
At the moment the user is responsible to increase the writer index of the composite buffer when a new component is added. We should add some methods that handle this for the user as this is the most popular usage of the composite buffer.
Modifications:
Add new methods that autoamtically increase the writerIndex when buffers are added.
Result:
Easier usage of CompositeByteBuf.
Motivation:
The HPACK code currently disallows empty header names. This is not explicitly forbidden by the HPACK RFC https://tools.ietf.org/html/rfc7541. However the HTTP/1.x RFC https://tools.ietf.org/html/rfc7230#section-3.2 and thus HTTP/2 both disallow empty header names, and so this precondition check should be moved from the HPACK code to the protocol level.
HPACK also requires that string literals which are huffman encoded must be treated as an encoding error if the string has more than 7 trailing padding bits https://tools.ietf.org/html/rfc7541#section-5.2, but this is currently not enforced.
Result:
- HPACK to allow empty header names
- HTTP/1.x and HTTP/2 header validation should not allow empty header names
- Enforce max of 7 trailing padding bits
Result:
Code is more compliant with the above mentioned RFCs
Fixes https://github.com/netty/netty/issues/5228
Related: #4333#4421#5128
Motivation:
slice(), duplicate() and readSlice() currently create a non-recyclable
derived buffer instance. Under heavy load, an application that creates a
lot of derived buffers can put the garbage collector under pressure.
Modifications:
- Add the following methods which creates a non-recyclable derived buffer
- retainedSlice()
- retainedDuplicate()
- readRetainedSlice()
- Add the new recyclable derived buffer implementations, which has its
own reference count value
- Add ByteBufHolder.retainedDuplicate()
- Add ByteBufHolder.replace(ByteBuf) so that..
- a user can replace the content of the holder in a consistent way
- copy/duplicate/retainedDuplicate() can delegate the holder
construction to replace(ByteBuf)
- Use retainedDuplicate() and retainedSlice() wherever possible
- Miscellaneous:
- Rename DuplicateByteBufTest to DuplicatedByteBufTest (missing 'D')
- Make ReplayingDecoderByteBuf.reject() return an exception instead of
throwing it so that its callers don't need to add dummy return
statement
Result:
Derived buffers are now recycled when created via retainedSlice() and
retainedDuplicate() and derived from a pooled buffer
Motivation:
At the moment we let the IllegalArgumentException escape when parsing form parameters. This is not expected.
Modifications:
Correctly catch IllegalArgumentException and rethrow as ErrorDataDecoderException.
Result:
Throw correct exception.
Motivation:
Currently the way a 'null' origin, a request that most often indicated
that the request is coming from a file on the local file system, is
handled is incorrect. We are currently returning a wildcard origin '*'
but should be returning 'null' for the 'Access-Control-Allow-Origin'
which is valid according to the specification [1].
Modifications:
Updated CorsHandler to add a 'null' origin instead of the '*' origin in
the case the request origin is 'null.
Result:
All test pass and the CORS example as does the cors.html example if you
try to serve it by opening the file directly in a web browser.
[1]
https://www.w3.org/TR/cors/#access-control-allow-origin-response-header
Motivation:
Checking if a key exists on a TreeMap has a Big O of "log 2 N",
doing it twice is not cheap.
Modifications:
Get the key instead which has the same cost and check if it is null.
Result:
Faster code due to one expensive operation removed.
Motivation:
We missed to reset the decoder when asked for it in HttpObjectDecoder and so sometimes could produce more then one LastHttpContent in a sequence during channelInactive.
This did show up as AssertionError:
22:22:35.499 [nioEventLoopGroup-3-1] WARN i.n.channel.DefaultChannelPipeline - An exceptionCaught() event was fired, and it reached at the tail of the pipeline. It usually means the last handler in the pipeline did not handle the exception.
java.lang.AssertionError: null
at io.netty.handler.codec.http.HttpObjectAggregator.decode(HttpObjectAggregator.java:205) ~[classes/:na]
at io.netty.handler.codec.http.HttpObjectAggregator.decode(HttpObjectAggregator.java:57) ~[classes/:na]
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:89) ~[classes/:na]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:292) [classes/:na]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:278) [classes/:na]
at io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:428) [classes/:na]
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:277) [classes/:na]
at io.netty.handler.codec.ByteToMessageDecoder.channelInputClosed(ByteToMessageDecoder.java:343) [classes/:na]
at io.netty.handler.codec.ByteToMessageDecoder.channelInactive(ByteToMessageDecoder.java:309) [classes/:na]
at io.netty.handler.codec.http.HttpClientCodec$Decoder.channelInactive(HttpClientCodec.java:228) [classes/:na]
at io.netty.channel.CombinedChannelDuplexHandler.channelInactive(CombinedChannelDuplexHandler.java:213) [classes/:na]
...
Modifications:
Correctly reset decoder.
Result:
Correctly only produce one LastHttpContent per sequence.
Motivation:
When upgrading h2c, I found that sometimes both of http2 settings frame and http response message was arrived before receiving upgrade success event. It was because ByteToMessageDecoder propagated its internally buffered message to the next handler when removing itself from pipeline.(refer to ByteToMessageDecoder#handlerRemoved)
I think it's better to propagate upgrade success event when handling 101 switching protocol response.
Modifications:
Upgrade success event will be propagated before removing source codec.
Result:
It guarantees that upgrade success event will be arrived first at the next handler.
Motivation:
There is a spelling error in FileRegion.transfered() as it should be transferred().
Modifications:
Deprecate old method and add a new one.
Result:
Fix typo and can remove the old method later.
Motivation:
DefaultCookie constructor performs a name validation that doesn’t match
RFC6265. Moreover, such validation is already performed in strict
encoders and decoders.
Modifications:
Drop DefaultCookie name validation, rely on encoders and decoders.
Result:
no more duplicate broken validation
Motivation:
We missed to pass the decrement value to the wrapped FullHttpRequest and so missed to decrement the reference count in the correct way.
Modifications:
Correctly pass the decrement value to the wrapped request.
Result:
UpgradeEvent.release(decrement) works as expected.
Motivation:
HttpServerUpgradeHandler.UpgradeCodec.prepareUpgradeResponse should allow to abort the upgrade and so just continue with using HTTP. Beside this we should only pass in the response HttpHeaders as this is inline with the docs.
Modifications:
- UpgradeCodec.prepareUpgradeResponse now allows to return a boolean and so allows to specifiy if the upgrade should take place.
- Change the param from FullHttpResponse to HttpHeaders to be inline with the javadocs.
Result:
More flexible and correct handling of upgrades.
Motivation:
upgradeTo(...) takes the response as paramater, but the respone itself was already written to the Channel. This gives the user the impression the response can be changed or even act on it which may not be safe anymore once it was written and has been released.
Modifications:
Remove the response param from the method.
Result:
Less confusion and safer usage.
Motivation:
The current HttpPostMultipartRequestDecoder can decode multipart/form-data parts with a Content-Type that specifies a charset. When this charset is invalid the Charset.forName() throws an unchecked UnsupportedCharsetException. This exception is not catched by the decoder. It should actually be rethrown as an ErrorDataDecoderException, because the developer using the API would expect this validation failure to be reported as such.
Modifications:
Add a catch block for UnsupportedCharsetException and rethrow it as an ErrorDataDecoderException.
Result:
UnsupportedCharsetException are now rethrown as ErrorDataDecoderException.
Motivation:
It will be easier to support websockets in server application by using WebSocketServerProtocolHandshakeHandler class and not reinvent its functionality. But currently it handles all http requests as if they were websocket handshake requests.
Modifications:
Check if http request path is equals to adjusted websocket path.
Fixed example of websocket server implementation.
Result:
WebSocketServerProtocolHandshakeHandler handles only websocket handshake requests.
Motivation:
If the input buffer is empty we should not have decodeLast(...) call decode(...) as the user may not expect this.
Modifications:
- Not call decode(...) in decodeLast(...) if the input buffer is empty.
- Add testcases.
Result:
decodeLast(...) will not call decode(...) if input buffer is empty.
Modifications:
When constructing the FullHttpMessage pass in the ByteBuf to use via the ByteBufAllocator assigned via the context.
Result:
The ByteBuf assigned to the FullHttpMessage can now be configured as a pooled/unpooled, direct/heap based ByteBuf via the ByteBufAllocator used.
Motivation:
See #4855
Modifications:
Unfortunately, unescapeCsv cannot be used here because the input could be a CSV line like `"a,b",c`. Hence this patch adds unescapeCsvFields to parse a CSV line and split it into multiple fields and unescaped them. The unit tests should define the behavior of unescapeCsvFields.
Then this patch just uses unescapeCsvFields to implement `CombinedHttpHeaders.getAll`.
Result:
`CombinedHttpHeaders.getAll` will return the unescaped values of a header.
Motivation:
b714297a44 introduced ChannelInputShutdownEvent support for HttpObjectDecoder. However this should have been added to the super class ByteToMessageDecoder, and ByteToMessageDecoder should not propegate a channelInactive event through the pipeline in this case.
Modifications:
- Move the ChannelInputShutdownEvent handling from HttpObjectDecoder to ByteToMessageDecoder
- ByteToMessageDecoder doesn't call ctx.fireChannelInactive() on ChannelInputShutdownEvent
Result:
Half closed events are treated more generically, and don't get translated into a channelInactive pipeline event.
Motivation:
The initial buffer size used to decode HTTP objects is currently fixed at 128. This may be too small for some use cases and create a high amount of overhead associated with resizing/copying. The user should be able to configure the initial size as they please.
Modifications:
- Make HttpObjectDecoder's AppendableCharSequence initial size configurable
Result:
Users can more finely tune initial buffer size for increased performance or to save memory.
Fixes https://github.com/netty/netty/issues/4807
Motivation:
"CorsConfigBuilder.allowNullOrigin()" should be public otherwise people can not set it. See #4835
Modifications:
Make "CorsConfigBuilder.allowNullOrigin()" public.
Result:
The user can call "CorsConfigBuilder.allowNullOrigin()" now.
Motivation:
If the Connection header contains multiple values (which is valid) we fail to detect a websocket upgrade
Modification:
- Add new method which allows to check if a header field contains a specific value (and also respect multiple header values)
- Use this method to detect handshake
Result:
Correct detect handshake if Connection header contains multiple values (seperated by ',').
Motivation:
If the ZlibCodecFactory can support using a custom window size we should support it by default in the websocket extensions as well.
Modifications:
Detect if a custom window size can be handled by the ZlibCodecFactory and if so enable it by default for PerMessageDeflate*ExtensionHandshaker.
Result:
Support window size flag by default in most installations.
Motivation:
If the user calls handshake.finishHandshake() we need to ensure that the user has the chance to setup the pipeline before any WebSocketFrames are read. Because of this we need
to delay the removal of the HttpRequestDecoder.
Modifications:
- Remove the HttpRequestDecoder via the EventLoop and so delay it which gives the user a chance to setup the pipeline after finishHandshake() completes
- Add unit test for this.
Result:
Less surpising and correct behaviour even if the http response and websocket frame are received in one read operation.
Motivation:
Request bodies can easily be larger than Integer.MAX_VALUE in practice.
There's no reason, or intention, for Netty to impose this artificial constraint.
Worse, it currently does not fail if the body is larger than this value;
it just silently only reads the first Integer.MAX_VALUE bytes and discards the rest.
This restriction doesn't effect chunked transfers, with no Content-Length header.
Modifications:
Force the use of `long HttpUtil.getContentLength(HttpMessage, long)` instead of
`long HttpUtil.getContentLength(HttpMessage, long)`.
Result:
Netty will support HTTP request bodies of up to Long.MAX_VALUE length.
Motivation:
When HttpClientUpgradeHandler upgrades from HTTP/1 to another protocol,
it performs a two-step opertion:
1. Remove the SourceCodec (HttpClientCodec)
2. Add the UpgradeCodec
When HttpClientCodec is removed from the pipeline, the decoder being
removed triggers channelRead() event with the data left in its
cumulation buffer. However, this is not received by the UpgradeCodec
becuase it's not added yet. e.g. HTTP/2 SETTINGS frame sent by the
server can be missed out.
To fix the problem, we need to reverse the steps:
1. Add the UpgradeCodec
2. Remove the SourceCodec
However, this does not work as expected either, because UpgradeCodec can
send a greeting message such as HTTP/2 Preface. Such a greeting message
will be handled by the SourceCodec and will trigger an 'unsupported
message type' exception.
To fix the problem really, we need to make the upgrade process 3-step:
1. Remove/disable the encoder of SourceCodec
2. Add the UpgradeCodec
3. Remove the SourceCodec
Modifications:
- Add SourceCodec.prepareUpgradeFrom() so that SourceCodec can remove or
disable its encoder
- Implement HttpClientCodec.prepareUpgradeFrom() properly
- Miscellaneous:
- Log the related channel as well When logging the failure to send a
GOAWAY
Result:
Cleartext HTTP/1-to-HTTP/2 upgrade works again.
Motivation:
See #3411. A reusable ArrayList in InternalThreadLocalMap can avoid allocations in the following pattern:
```
List<...> list = new ArrayList<...>();
add something to list but never use InternalThreadLocalMap
return list.toArray(new ...[list.size()]);
```
Modifications:
Add a reusable ArrayList to InternalThreadLocalMap and update codes to use it.
Result:
Reuse a thread local ArrayList to avoid allocations.
Motivation:
WebSocketClientCompressionHandler is stateless so it should be @Sharable.
Modifications:
Add @Sharable annotation to WebSocketClientCompressionHandler, make constructor private and add static field to get the instance.
Result:
Less object creation.
Motivation:
I am use netty as a http server, it fail to decode some POST request when the request absent Content-Type in the multipart/form-data body.
Modifications:
Set content_type with default application/octet-stream to parse the uploaded file data when the Content-Type is absent in multipart request body
Result:
Can decode the http request as normal.
Motivation:
ChannelInboundHandler and ChannelOutboundHandler both can implement exceptionCaught(...) method and so we need to dispatch to both of them.
Modifications:
- Correctly first dispatch exceptionCaught to the ChannelInboundHandler but also make sure the next handler it will be dispatched to will be the ChannelOutboundHandler
- Add removeInboundHandler() and removeOutboundHandler() which allows to remove one of the combined handlers
- Let *Codec extends it and not ChannelHandlerAppender
- Remove ChannelHandlerAppender
Result:
Correctly handle events and also have same behavior as in 4.0
Motivation:
InternalAttribute doesn't extend Attribute, but its equals only returns true when it compares with an Attribute. So it will return false when comparing with itself.
Modifications:
Make sure InternalAttribute return false for non InternalAttribute objects.
Result:
InternalAttribute's equals works correctly.
Motivation:
Boxing/unboxing can be avoided.
Modifications:
Use parseInt/parseLong to avoid unnecessary boxing/unboxing.
Result:
Remove unnecessary boxing/unboxing.
Motivation:
Warnings in IDE, unclean code, negligible performance impact.
Modification:
Deletion of unused imports
Result:
No more warnings in IDE, cleaner code, negligible performance improvement.
Motivation:
I missed to reset the MessageDigest before reusing it. This bug was introduced by 79634e661b.
Modifications:
Call reset() on the MessageDigest.
Result:
Correctly reset MessageDigest before re-using
Motivation:
SpdySession.StreamComparator should not be Serializable since SpdySession is not Serializable
Modifications:
Remove Serializable fom SpdySession.StreamComparator
Result:
StreamComparator is not Serializable any more
Motivation:
Typos in javadoc, in "combine" and "recommendations", IllegalReferenceCountException
Modification:
Rename incorrect reference, typos are modified
Result:
Reference is correct, typos are fixed
Motivation:
Creating a new MessageDigest every time is wasteful, we should store them in FastThreadLocal.
Modifications:
Change WebSocketUtil to store MD5 and SHA1 MessageDigest in FastThreadLocal and use these.
Result:
Less overhead and less GC.
Motivation:
- AbstractHttp2ConnectionHandlerBuilder.encoderEnforceMaxConcurrentStreams can be the primitive boolean
- SpdySession.StreamComparator should not be Serializable since SpdySession is not Serializable
Modifications:
Use boolean instead and remove Serializable
Result:
- Minor improvement for AbstractHttp2ConnectionHandlerBuilder
- StreamComparator is not Serializable any more
Motivation:
Allow passing HttpHeaders instance to DefaultHttpMessage
in order to avoid eager creation of Headers to
allow users reuse their Headers instance.
Modifications:
Added a constructor with HttpHeaders to DefaultHttpMessage,
Modified DefaultHttpResponse and DefaultHttpRequest
to receive HttpHeaders instances.
Modified DefaultFullHttpReqest and DefaultFullHttpResponse
to receive HttpHeaders, and updated `duplicate` and
`copy` to use new constructors.
Result:
Users can now pass HttpHeaders instance when
constructing Http Requests and Responses.
Motivation:
As we not used Unpooled anymore for allocate buffers in Base64.* methods we need to ensure we realease all the buffers.
Modifications:
Correctly release buffers
Result:
No more buffer leaks
Motivation:
Javadoc reports errors about invalid docs.
Modifications:
Fix some errors reported by javadoc.
Result:
A lot of javadoc errors are fixed by this patch.
Motivation:
There are some wrong links and tags in javadoc.
Modifications:
Fix the wrong links and tags in javadoc.
Result:
These links will work correctly in javadoc.
Motivation:
ChunkedInput.readChunk currently takes a ChannelHandlerContext object as a parameters. All current implementations of this interface only use this object to get the ByteBufAllocator object. Thus taking a ChannelHandlerContext as a parameter is more restrictive for users of this API than necessary.
Modifications:
- Add a new method readChunk(ByteBufAllocator)
- Deprecate readChunk(ChannelHandlerContext) and updates all implementations to call readChunk(ByteBufAllocator)
Result:
API that only requires ByteBufAllocator to use ChunkedInput.
Motivation:
HttpHeaderValues.IDENTITY is an AsciiString, but was compared using equals to a String.
Modifications:
Use contentEquals instead.
Result:
Correct comparison.
Motivation:
We have websocket extension support (with compression) in old master. We should port this to 4.1
Modifications:
Backport relevant code.
Result:
websocket extension support (with compression) is now in 4.1.
Motivation:
Consistency in API design
Modifications:
- Deprecate CorsConfig.Builder and its factory methods
- Deprecate CorsConfig.DateValueGenerator
- Add CorsConfigBuilder and its factory methods
- Fix typo (curcuit -> circuit)
Result:
Consistency with other builder APIs such as SslContextBuilder and
Http2ConnectionHandlerBuilder
Motivation:
If a uri contains whitespaces we need to ensure we correctly escape these when creating the request for the handshake.
Modifications:
- Correctly encode path for uri
- Add tests
Result:
Correctly handle whitespaces when doing websocket upgrade requests.
Motivation:
HttpClientUpgradeHandler uses HttpHeaderNames.UPGRADE as the value of
the 'Connection' header, which is incorrect. It should use
HttpHeaderValues.UPGRADE instead (note Names vs Values.)
Also, HttpHeaderValues.UPGRADE should be 'upgrade' rather than
'Upgrade', as defined in:
- https://tools.ietf.org/html/rfc7230#section-6.7
Modifications:
- Use HttpHeaderValues.UPGRADE for a 'Connection' header
- Lowercase the value of HttpHeaderValues.UPGRADE
Result:
- Fixes#4508
- Correct behavior
Motivation:
On a successful protocol upgrade in HTTP, HttpClientUpgradeHandler calls
HttpClientCodec.upgradeFrom(), which removed both the HTTP encoder and
decoder from the pipeline immediately.
However, because the decoder is in the middle of the decode loop,
removing it from the pipeline immediately will cause the cumulation
buffer to be released prematurely.
This often leads to an IllegalReferenceCountException or missing first
response after the upgrade response.
Modifications:
- Remove the decoder *after* the decode loop is done
Result:
Fixes#4504
Motivation:
HttpClientUpgradeHandler currently throws an IllegalStateException when
the server sends a '101 Switching Protocols' response that has no
'Upgrade' header.
Some servers do not send the 'Upgrade' header on a successful protocol
upgrade and we could safely assume that the server accepted the
requested protocol upgrade in such a case, looking from the response
status code (101)
Modifications:
- Do not throw an IllegalStateException when the server responded 101
without a 'Upgrade' header
- Note that we still check the equality of the 'Upgrade' header when it
is present.
Result:
- Fixes#4523
- Better interoperability
Motivation:
- On the client, cookies should be sorted in decreasing order of path
length. From RFC 6265:
5.4.2. The user agent SHOULD sort the cookie-list in the following
order:
* Cookies with longer paths are listed before cookies with
shorter paths.
* Among cookies that have equal-length path fields, cookies with
earlier creation-times are listed before cookies with later
creation-times.
NOTE: Not all user agents sort the cookie-list in this order, but
this order reflects common practice when this document was
written, and, historically, there have been servers that
(erroneously) depended on this order.
Note that the RFC does not define the path length of cookies without a
path. We sort pathless cookies before cookies with the longest path,
since pathless cookies inherit the request path (and setting a path
that is longer than the request path is of limited use, since it cannot
be read from the context in which it is written).
- On the server, if there are multiple cookies of the same name, only one
of them should be encoded. RFC 6265 says:
Servers SHOULD NOT include more than one Set-Cookie header field in
the same response with the same cookie-name.
Note that the RFC does not define which cookie should be set in the case
of multiple cookies with the same name; we arbitrarily pick the last one.
Modifications:
- Changed the visibility of the 'strict' field to 'protected' in
CookieEncoder.
- Modified ClientCookieEncoder to sort cookies in decreasing order of path
length when in strict mode.
- Modified ServerCookieEncoder to return only the last cookie of a given
name when in strict mode.
- Added a fast path for both strict mode in both client and server code
for cases with only one cookie, in order avoid the overhead of sorting
and memory allocation.
- Added unit tests for the new cases.
Result:
- Cookie generation on client and server is now more conformant to RFC 6265.
Motivation:
HttpHeaders already has specific methods for such popular and simple headers like "Host", but if I need to convert POST raw body to string I need to parse complex ContentType header in my code.
Modifications:
Add getCharset and getCharsetAsString methods to parse charset from Content-Length header.
Result:
Easy to use utility method.
Motivation:
FullHttp[Request|Response].hashCode() uses a releasable object and in vulnerable to a IllegalRefCountException if that object has been released.
Modifications:
- Ensure the released object is not used.
Result:
No more IllegalRefCountException.
Motivation:
Headers and groups of headers are frequently copied and the current mechanism is slower than it needs to be.
Modifications:
Skip name validation and hash computation when they are not necessary.
Fix emergent bug in CombinedHttpHeaders identified with better testing
Fix memory leak in DefaultHttp2Headers when clearing
Added benchmarks
Result:
Faster header copying and some collateral bug fixes
Motivation:
Makes the API contract of headers more consistent and simpler.
Modifications:
If self is passed to set then simply return
Result:
set and setAll will be consistent
Motivation:
The HTTP/2 RFC (https://tools.ietf.org/html/rfc7540#section-8.1.2) indicates that header names consist of ASCII characters. We currently use ByteString to represent HTTP/2 header names. The HTTP/2 RFC (https://tools.ietf.org/html/rfc7540#section-10.3) also eludes to header values inheriting the same validity characteristics as HTTP/1.x. Using AsciiString for the value type of HTTP/2 headers would allow for re-use of predefined HTTP/1.x values, and make comparisons more intuitive. The Headers<T> interface could also be expanded to allow for easier use of header types which do not have the same Key and Value type.
Motivation:
- Change Headers<T> to Headers<K, V>
- Change Http2Headers<ByteString> to Http2Headers<CharSequence, CharSequence>
- Remove ByteString. Having AsciiString extend ByteString complicates equality comparisons when the hash code algorithm is no longer shared.
Result:
Http2Header types are more representative of the HTTP/2 RFC, and relationship between HTTP/2 header name/values more directly relates to HTTP/1.x header names/values.
Keep RTSPRequestEncoder, RTSPRequestDecoder, RTSPResponseEncoder and
RTSPResponseDecoder for backwards compatibility but they now just extends
the generic encoder/decoder and are markes as deprecated.
Renamed the decoder test, because the decoder is now generic. Added
testcase for when ANNOUNCE request is received from server.
Created testcases for encoder.
Mark abstract base classes RTSPObjectEncoder and RTSPObjectDecoder as
deprecated, that functionality is now in RTSPEncoder and RTSPDecoder.
Added annotation in RtspHeaders to suppress warnings about deprecation, no need when
whole class is deprecated.
Motivation:
As part of recent efforts to rectify performance and make 4.1 headers more similar to 5.0 some methods were deprecated. Some of these methods were deprecated because they used String instead of CharSequence in the signature, which may require casting at the user level. Some of the deprecated methods have no direct alternatives and were done to inform a user the method will go away in future releases.
Modifications:
- Remove the deprecated qualifier from methods where no direct replacement exists
Result:
Less warnings in user code.
Motivation:
As toString() is often used while logging we need to ensure this produces no exception.
Modifications:
Ensure we never throw an IllegalReferenceCountException.
Result:
Be able to log without produce exceptions.
Motivation:
We should prevent to add/set DefaultHttpHeaders to itself to prevent unexpected side-effects.
Modifications:
Throw IllegalArgumentException if user tries to pass the same instance to set/add.
Result:
No surprising side-effects.
Motivation:
Http2CodecUtils has some static variables which are defined as Strings instead of CharSequence. One of these defines is used as a header name and should be AsciiString.
Modifications:
- Change the String defines in Http2CodecUtils to CharSequence
Result:
Types are more consistently using CharSequence and adding the upgrade header will require less work.
Motivation:
According to the SPDY spec https://www.chromium.org/spdy/spdy-protocol/spdy-protocol-draft3-1#TOC-3.2.1-Request header names must be lowercase. Our predefined SPDY extension headers are not lowercase.
Modifications
- SpdyHttpHeaders should define header names in lower case
Result:
Compliant with SPDY spec, and header validation code does not detect errors for our own header names.
Motivation:
Currently there is a HttpConversionUtil.addHttp2ToHttpHeaders which requires a FullHttpMessage, but this may not always be available. There is no interface that can be used with just Http2Headers and HttpHeaders.
Modifications:
- add an overload for HttpConversionUtil.addHttp2ToHttpHeaders which does not take FullHttpMessage
Result:
An overload for HttpConversionUtil.addHttp2ToHttpHeaders exists which does not require FullHttpMessage.
Motivation:
As we stored the WebSocketServerHandshaker in the ChannelHandlerContext it was always null and so no close frame was send if WebSocketServerProtocolHandler was used.
Modifications:
Store WebSocketServerHAndshaker in the Channel attributes and so make it visibile between different handlers.
Result:
Correctly send close frame.
Motivaion:
The HttpHeaders and DefaultHttpHeaders have methods deprecated due to being removed in future releases, but no replacement method to use in the current release. The deprecation policy should not be so aggressive as to not provide any non-deprecated method to use.
Modifications:
- Remove deprecated annotations and javadocs from methods which are the best we can do in terms of matching the master's api for 4.1
Result:
There should be non-deprecated methods available for HttpHeaders in 4.1.
Motivation:
Related to issue #4185.
HTTP has the option to disable header validation for optimisation purposes. Introduce the same option for SPDY headers.
Also, optimise SpdyHttpEncoder by allowing the user to specify whether or not the encoder needs to convert header names to lowercase.
Modifications:
Added flags for validation and conversion.
Result:
SpdyHeader validation and conversion can be disabled.
Motivation:
When SpdyHttpEncoder attempts to create an SpdyHeadersFrame from a HttpResponse an IllegalArgumentException is thrown if the original HttpResponse contains a header that includes uppercase characters. The IllegalArgumentException is thrown due to the additional validation check introduced by #4047.
Previous versions of the SPDY codec would handle this by converting the HTTP header name to lowercase before adding the header to the SpdyHeadersFrame.
Modifications:
Convert the header name to lowercase before adding it to SpdyHeaders
Result:
SpdyHttpEncoder can now convert a valid HttpResponse into a valid SpdyFrame
Motivation:
As all methods in the ChannelHandler are executed by the same thread there is no need to use synchronized.
Modifications:
Remove synchronized keyword.
Result:
No more unnessary synchronized in SpdySessionHandler.
Motivation:
There currently exists http.HttpUtil, http2.HttpUtil, and http.HttpHeaderUtil. Having 2 HttpUtil methods can be confusing and the utilty methods in the http package could be consolidated.
Modifications:
- Rename http2.HttpUtil to http2.HttpConversionUtil
- Move http.HttpHeaderUtil methods into http.HttpUtil
Result:
Consolidated utilities whose names don't overlap.
Fixes https://github.com/netty/netty/issues/4120
Motivation:
The HttpRequestEncoder.encodeInitialLine can now be consistent with the master branch after 85c79dbbe4
Modifications:
- Use the AsciiString and ByteBufUtil.copy methods
Result:
Consistent behavior/code between 4.1 and master branches.
Motivation:
Whe a 100 Continue response was written an IllegalStateException was produced as soon as the user wrote the following response. This regression was introduced by 41b0080fcc.
Modifications:
- Special handle 100 Continue responses
- Added unit tests
Result:
Fixed regression.
Motivation:
Hixie 76 needs special handling compared to other connection upgrade responses. Our detection code of non websocket responses did actually always use the special handling that only should be used for Hixie 76 responses.
Modifications:
Correctly detect connection upgrade responses which are not for websockets.
Result:
Be able to upgrade connections for other protocols then websockets.
Motivation:
The HTTP schemes defined by https://tools.ietf.org/html/rfc7230 don't have a common representation in Netty.
Modifications:
- Add a class to represent HttpScheme
Result:
The HTTP Scheme is now defined in 1 common location.
Motivation:
The HTTP specification defines specific request-targets in https://tools.ietf.org/html/rfc7230#section-5.3. Netty does not have a way to distinguish between these differnt types, and there is currently no obvious location where these types of methods would live.
Modifications:
- Add methods to distinguish request-targets as defined in https://tools.ietf.org/html/rfc7230#section-5.3
Result:
Common utitlity methods exist to inpsect request-targets.
Motivation:
HttpResponseStatus.reasonPhrase returns an AsciiString, but was compared using equals to a String. Other usages of the reasonPhrase also use the toString() method when not necessary.
Modifications:
- Use the contentEquals method
Result:
Correct comparison, and no toString() when not needed.
Motivation:
The HttpObjectAggregator always responds with a 100-continue response. It should check the Content-Length header to see if the content length is OK, and if not responds with a 417.
Modifications:
- HttpObjectAggregator checks the Content-Length header in the case of a 100-continue.
Result:
HttpObjectAggregator responds with 417 if content is known to be too big.
Motivation:
When attempting to retrieve a SPDY header using an AsciiString key, if the header was inserted using a String based key, the lookup would fail. Similarly, the lookup would fail if the header was inserted with an AsciiString key, and retrieved using a String key. This has been fixed with the header simplification commit (1a43923aa8).
Extra unit tests have been added to protect against this issue occurring in the future. The tests check that a header added using String or AsciiString can be retrieved using AsciiString or String respectively.
Modifications:
Added more unit tests
Result:
Protect against issue #4053 happening again.
Motivation:
A degradation in performance has been observed from the 4.0 branch as documented in https://github.com/netty/netty/issues/3962.
Modifications:
- Simplify Headers class hierarchy.
- Restore the DefaultHeaders to be based upon DefaultHttpHeaders from 4.0.
- Make various other modifications that are causing hot spots.
Result:
Performance is now on par with 4.0.
Motivation:
Due not using a cast we insert 32 and not a whitespace into the String.
Modifications:
Correclty cast to char.
Result:
Correct handling of whitespaces.
Motivation:
In the event an HTTP message does not include either a content-length or a transfer-encoding header [RFC 7230](https://tools.ietf.org/html/rfc7230#section-3.3.3) states the behavior must be treated differently for requests and responses. If the channel is half closed then the HttpObjectDecoder is not invoking decodeLast and thus not checking if messages should be sent up the pipeline.
Modifications:
- Add comments to clarify regular decode default case.
- Handle the ChannelInputShutdownEvent in the HttpObjectDecoder and evaluate if messages need to be generated.
Result:
Messages are generated on half closed, and comments clarify existing logic.
Motivation:
We noticed that the headers implementation in Netty for HTTP/2 uses quite a lot of memory
and that also at least the performance of randomly accessing a header is quite poor. The main
concern however was memory usage, as profiling has shown that a DefaultHttp2Headers
not only use a lot of memory it also wastes a lot due to the underlying hashmaps having
to be resized potentially several times as new headers are being inserted.
This is tracked as issue #3600.
Modifications:
We redesigned the DefaultHeaders to simply take a Map object in its constructor and
reimplemented the class using only the Map primitives. That way the implementation
is very concise and hopefully easy to understand and it allows each concrete headers
implementation to provide its own map or to even use a different headers implementation
for processing requests and writing responses i.e. incoming headers need to provide
fast random access while outgoing headers need fast insertion and fast iteration. The
new implementation can support this with hardly any code changes. It also comes
with the advantage that if the Netty project decides to add a third party collections library
as a dependency, one can simply plug in one of those very fast and memory efficient map
implementations and get faster and smaller headers for free.
For now, we are using the JDK's TreeMap for HTTP and HTTP/2 default headers.
Result:
- Significantly fewer lines of code in the implementation. While the total commit is still
roughly 400 lines less, the actual implementation is a lot less. I just added some more
tests and microbenchmarks.
- Overall performance is up. The current implementation should be significantly faster
for insertion and retrieval. However, it is slower when it comes to iteration. There is simply
no way a TreeMap can have the same iteration performance as a linked list (as used in the
current headers implementation). That's totally fine though, because when looking at the
benchmark results @ejona86 pointed out that the performance of the headers is completely
dominated by insertion, that is insertion is so significantly faster in the new implementation
that it does make up for several times the iteration speed. You can't iterate what you haven't
inserted. I am demonstrating that in this spreadsheet [1]. (Actually, iteration performance is
only down for HTTP, it's significantly improved for HTTP/2).
- Memory is down. The implementation with TreeMap uses on avg ~30% less memory. It also does not
produce any garbage while being resized. In load tests for GRPC we have seen a memory reduction
of up to 1.2KB per RPC. I summarized the memory improvements in this spreadsheet [1]. The data
was generated by [2] using JOL.
- While it was my original intend to only improve the memory usage for HTTP/2, it should be similarly
improved for HTTP, SPDY and STOMP as they all share a common implementation.
[1] https://docs.google.com/spreadsheets/d/1ck3RQklyzEcCLlyJoqDXPCWRGVUuS-ArZf0etSXLVDQ/edit#gid=0
[2] https://gist.github.com/buchgr/4458a8bdb51dd58c82b4
Motivation:
The SPDY spec requires that all header names be lowercase (see https://www.chromium.org/spdy/spdy-protocol/spdy-protocol-draft3-1#TOC-3.2-HTTP-Request-Response). The SPDY codec header name validator does not enforce this requirement.
Modifications:
- SpdyCodecUtil.validateHeaderName should check for upper case characters and throw an error if any are found.
Result:
SPDY codec header validation enforces specification requirement.
Motivation:
The HttpObjectDecoder is on the hot code path for the http codec. There are a few hot methods which can be modified to improve performance.
Modifications:
- Modify AppendableCharSequence to provide unsafe methods which don't need to re-check bounds for every call.
- Update HttpObjectDecoder methods to take advantage of new AppendableCharSequence methods.
Result:
Peformance boost for decoding http objects.
Motivation:
WebSocketServerHandshakerFactory.sendUnsupportedVersionResponse does not
send a LastHttpContent, nor does it flush, and it doesn't send a content
length.
Modifications:
Changed sendUnsupportedVersionResponse to send FullHttpResponse, to
writeAndFlush, and to set a content length of 0. Also added a test for
this method.
Result:
Upstream handlers will be able to determine the end of the response, the
response will actually get written to the client, and the client will be
able to determine the end of the response.
Proposal to fix issue #3636
Motivations:
Currently, while adding the next buffers to the decoder
(`decoder.offer()`), there is no way to access to the current HTTP
object being decoded since it can only be available currently once fully
decoded by `decoder.hasNext()`.
Some could want to know the progression on the overall transfer but also
per HTTP object.
While overall progression could be done using (if available) the global
Content-Length of the request and taking into account each HttpContent
size, the per HttpData object progression is unknown.
Modifications:
1) For HTTP object, `AbstractHttpData` has 2 protected properties named
`definedSize` and `size`, respectively the supposely final size and the
current (decoded until now) size.
This provides a new method `definedSize()` to get the current value for
`definedSize`. The `size` attribute is reachable by the `length()`
method.
Note however there are 2 different ways that currently managed the
`definedSize`:
a) `Attribute`: it is reset each time the value is less than actual
(when a buffer is added, the value is increased) since the final length
is not known (no Content-Length)
b) `FileUpload`: it is set at startup from the lengh provided
So these differences could lead in wrong perception;
a) `Attribute`: definedSize = size always
b) `FileUpload`: definedSize >= size always
Therefore the comment tries to explain clearly the different behaviors.
2) In the InterfaceHttpPostRequestDecoder (and the derived classes), I
add a new method: `decoder.currentPartialHttpData()` which will return a
`InterfaceHttpData` (if any) as the current `Attribute` or `FileUpload`
(the 2 generic types), which will allow then the programmer to check
according to the real type (instance of) the 2 methods `definedSize()`
and `length()`.
This method check if currentFileUpload or currentAttribute are null and
returns the one (only one could be not null) that is not null.
Note that if this method returns null, it might mean 2 situations:
a) the last `HttpData` (whatever attribute or file upload) is already
finished and therefore accessible through `next()`
b) there is not yet any `HttpData` in decoding (body not yet parsed for
instance)
Result:
The developper has more access and therefore control on the current
upload.
The coding from developper side could looks like in the example in
HttpUloadServerHandler.
Related: #3814
Motivation:
To implement the support for an upgrade from cleartext HTTP/1.1
connection to cleartext HTTP/2 (h2c) connection, a user usually uses
HttpServerUpgradeHandler.
It does its job, but it requires a user to instantiate the UpgradeCodecs
for all supported protocols upfront. It means redundancy for the
connections that are not upgraded.
Modifications:
- Change the constructor of HttpServerUpgradeHandler
- Accept UpgraceCodecFactory instead of UpgradeCodecs
- The default constructor of HttpServerUpgradeHandler sets the
maxContentLength to 0 now, which shouldn't be a problem because a
usual upgrade request is a GET.
- Update the examples accordingly
Result:
A user can instantiate Http2ServerUpgradeCodec and its related objects
(Http2Connection, Http2FrameReader/Writer, Http2FrameListener, etc) only
when necessary.
Motivation:
We need to ensure we never allow to have null values set on headers, otherwise we will see a NPE during encoding them.
Modifications:
Add unit test that shows we correctly handle null values.
Result:
Verify correct implementation.
Motivation:
SpdyOrHttpChooser and Http2OrHttpChooser duplicate fair amount code with each other.
Modification:
- Replace SpdyOrHttpChooser and Http2OrHttpChooser with ApplicationProtocolNegotiationHandler
- Add ApplicationProtocolNames to define the known application-level protocol names
Result:
- Less code duplication
- A user can perform dynamic pipeline configuration that follows ALPN/NPN for any protocols.
Related: #3641 and #3813
Motivation:
When setting up an HTTP/1 or HTTP/2 (or SPDY) pipeline, a user usually
ends up with adding arbitrary set of handlers.
Http2OrHttpChooser and SpdyOrHttpChooser have two abstract methods
(create*Handler()) that expect a user to return a single handler, and
also have add*Handlers() methods that add the handler returned by
create*Handler() to the pipeline as well as the pre-defined set of
handlers.
The problem is, some users (read: I) don't need all of them or the
user wants to add more than one handler. For example, take a look at
io.netty.example.http2.tiles.Http2OrHttpHandler, which works around
this issue by overriding addHttp2Handlers() and making
createHttp2RequestHandler() a no-op.
Modifications:
- Replace add*Handlers() and create*Handler() with configure*()
- Rename getProtocol() to selectProtocol() to make what it does clear
- Provide the default implementation of selectProtocol()
- Remove SelectedProtocol.UNKNOWN and use null instead, because
'UNKNOWN' is not a protocol
- Proper exception handling in the *OrHttpChooser so that the
exception is logged and the connection is closed when failed to
select a protocol
- Make SpdyClient example always use SSL. It was always using SSL
anyway.
- Implement SslHandshakeCompletionEvent.toString() for debuggability
- Remove an orphaned class: JettyNpnSslSession
- Add SslHandler.applicationProtocol() to get the name of the
application protocol
- SSLSession.getProtocol() now returns transport-layer protocol name
only, so that it conforms to its contract.
Result:
- *OrHttpChooser have better API.
- *OrHttpChooser handle protocol selection failure properly.
- SSLSession.getProtocol() now conforms to its contract.
- SpdyClient example works with SpdyServer example out of the box
Motivation:
Found a bug in that netty would generate a 20 byte body when returing a response
to an HTTP HEAD. the 20 bytes seems to be related to the compression footer.
RFC2616, section 9.4 states that responses to an HTTP HEAD MUST not return a message
body in the response.
Netty's own client implementation expected an empty response. The extra bytes lead to a
2nd response with an error decoder result:
java.lang.IllegalArgumentException: invalid version format: 14
Modifications:
Track the HTTP request method. When processing the response we determine if the response
is passthru unnchanged. This decision now takes into account the request method and passthru
responses related to HTTP HEAD requests.
Result:
Netty's http client works and better RFC conformance.
Motivation:
* Path attribute should be null, not empty String, if it's passed as "Path=".
* Only extract attribute value when the name is recognized.
* Only extract Expires attribute value String if MaxAge is undefined as it has precedence.
Modification:
Modify ClientCookieDecoder.
Add "testIgnoreEmptyPath" test in ClientCookieDecoderTest.
Result:
More idyomatic Path behavior (like Domain).
Minor performance improvement in some corner cases.
Motivations:
When using HttpPostRequestEncoder and trying to set an attribute if a
charset is defined, currenlty implicit Charset.toStrng() is used, given
wrong format.
As in Android for UTF-16 = "com.ibm.icu4jni.charset.CharsetICU[UTF-16]".
Modifications:
Each time charset is used to be printed as its name, charset.name() is
used to get the canonical name.
Result:
Now get "UTF-16" instead.
(3.10 version)
RFC6265 specifies which characters are allowed in a cookie name and value.
Netty is currently too lax, which can used for HttpOnly escaping.
Modification:
In ServerCookieDecoder: discard cookie key-value pairs that contain invalid characters.
In ClientCookieEncoder: throw an exception when trying to encode cookies with invalid characters.
Result:
The problem described in the motivation section is fixed.
Motivation:
Our automatically handling of non-auto-read failed because it not detected the need of calling read again by itself if nothing was decoded. Beside this handling of non-auto-read never worked for SslHandler as it always triggered a read even if it decoded a message and auto-read was false.
This fixes [#3529] and [#3587].
Modifications:
- Implement handling of calling read when nothing was decoded (with non-auto-read) to ByteToMessageDecoder again
- Correctly respect non-auto-read by SslHandler
Result:
No more stales and correctly respecting of non-auto-read by SslHandler.
Motivation:
Other implementations of FullHttpMessage allow .toString to be called after the Message has been released
This brings AggregatedFullHttpMessage into line with those impls.
Modifications:
- Changed AggregatedFullHttpMessage to no longer be a sub-class of DefaultByteBufHolder
- Changes AggregatedFullHttpMessage to implement ByteBufHolder
- Hold the content buffer internally to AggregatedFullHttpMessage
- Implement the required content() and release() methods that were missing
- Do not check refcnt when accessing content() (similar to DefaultFullHttpMessage)
Result:
A released AggregatedFullHttpMessage can have .toString called without throwing an exception
Motivation:
While forward porting https://github.com/netty/netty/pull/3579 there were a few areas that had not been previously back ported.
Modifications:
Backport the missed areas to ensure consistency.
Result:
More consistent 4.1 and master branches.
Motivation:
The usage and code within AsciiString has exceeded the original design scope for this class. Its usage as a binary string is confusing and on the verge of violating interface assumptions in some spots.
Modifications:
- ByteString will be created as a base class to AsciiString. All of the generic byte handling processing will live in ByteString and all the special character encoding will live in AsciiString.
Results:
The AsciiString interface will be clarified. Users of AsciiString can now be clear of the limitations the class imposes while users of the ByteString class don't have to live with those limitations.
(Ported @luciferous's changes against 3.10)
Motivation:
The current implementation of the encoder writes each character of the
String as a single byte to the buffer, however not all characters are
mappable to a single byte.
Modifications:
If a character is outside the ASCII range, it's converted to '?'.
Result:
A safer encoder for String to ASCII, which substitutes unmappable
characters with'?'.