With the latest sbt snapshot, the ui would get stuck if the user entered
an empty command. They would be presented with an empty prompt and could
not input any commands. This was caused by the change in
d569abe70a that reset the prompt after a
line was read. I had tried to optimize line reading by ignoring empty
commands in UITask.readline so we wouldn't have to make a new thread.
This optimization wasn't really buying much since it only affects how
quickly the user is reprompted after entering an empty command. Unless a
user is spamming the <enter> key, they shouldn't notice a difference.
It was a bit tricky to reason about the state of the prompt for a
terminal. To help make things more clear, I reworked things so that the
LineReader always sets the prompt to Pending after it reads a command.
In MainLoop, we cache the prompt value and temporarily set it to Running
while the command is running, which is really how it should have always
been.
JLine 3 automatically appends a space character to the completion
candidate unless you tell it not to by setting its 'complete' parameter.
This behavior is generally nice because it will automatically complete
something like 'foo/testO<TAB>' to 'foo/testOnly ' which allows the user
to start typing the testname without having to enter space. It does,
however, break scripted completions because it will complete
'scripted wat<TAB>' to 'scripted watch/ '
This commit updates the custom completer to append a " " to the initial
completions and check if there are any additional completions available.
If so, we set the complete flag to true and jline will append a space to
the input when the user presses <TAB> or <ENTER>. Otherwise the old
jline2 behavior where no spaces are ever appended is preserved.
This commit upgrades sbt to using jline3. The advantage to jline3 is
that it has a significantly better tab completion engine that is more
similar to what you get from zsh or fish.
The diff is bigger than I'd hoped because there are a number of
behaviors that are different in jline3 vs jline2 in how the library
consumes input streams and implements various features. I also was
unable to remove jline2 because we need it for older versions of the
scala console to work correctly with the thin client. As a result, the
changes are largely additive.
A good amount of this commit was in adding more protocol so that the
remote client can forward its jline3 terminal information to the server.
There were a number of minor changes that I made that either fixed
outstanding ui bugs from #5620 or regressions due to differences between
jline3 and jline2.
The number one thing that caused problems is that the jline3 LineReader
insists on using a NonBlockingInputStream. The implementation ofo
NonBlockingInputStream seems buggy. Moreover, sbt internally uses a
non blocking input stream for system in so jline is adding non blocking
to an already non blocking stream, which is frustrating.
A long term solution might be to consider insourcing LineReader.java
from jline3 and just adapting it to use an sbt terminal rather than
fighting with the jline3 api. This would also have the advantage of not
conflicting with other versions of jline3. Even if we don't, we may want to
shade jline3 if that is possible.
In order to support a multi-client sbt server ux, we need to factor
`Terminal` out into a class instead of a singleton. Each terminal provides
and outputstream and inputstream. In all of the places where we were
previously relying on the `Terminal` singleton we need to update the
code to use `Terminal.get`, which will redirect io to the terminal whose
command is currently running.
This commit does not implement the server side ui for network clients.
It is just preparatory work for the multi-client ui.
The Terminal implementations have thread safe access to the output
stream. For this reason, I had to remove the sychronization on the
ConsoleOut lockObject. There were code paths that led to deadlock when
synchronizing on the lockObject.
It is better that sbt not expose the implementation detail that
LineReader is implemented by JLine. Other terminal related apis should
be handled by sbt.internal.util.Terminal.
Presently if a server command comes in while in the shell, the client
output can appear on the same line as the command prompt and the command
prompt will not appear again until the user hits enter. This is a
confusing ux. For example, if I start an sbt server and type
the partial command "comp" and then start up a client and run the clean
command followed by a compile, the output looks like:
[info] sbt server started at local:///Users/ethanatkins/.sbt/1.0/server/51cfad3281b3a8a1820a/sock
sbt:scala-compile> comp[info] new client connected: network-1
[success] Total time: 0 s, completed Dec 12, 2019, 7:23:24 PM
[success] Total time: 0 s, completed Dec 12, 2019, 7:23:27 PM
[success] Total time: 2 s, completed Dec 12, 2019, 7:23:31 PM
Now, if I type "ile\n", I get:
[info] sbt server started at local:///Users/ethanatkins/.sbt/1.0/server/51cfad3281b3a8a1820a/sock
ile
[success] Total time: 0 s, completed Dec 12, 2019, 7:23:34 PM
sbt:scala-compile>
Following the same set of inputs after this change, I get:
[info] sbt server started at local:///Users/ethanatkins/.sbt/1.0/server/51cfad3281b3a8a1820a/sock
sbt:scala-compile> comp
[info] new client connected: network-1
[success] Total time: 0 s, completed Dec 12, 2019, 7:25:58 PM
sbt:scala-compile> comp
[success] Total time: 0 s, completed Dec 12, 2019, 7:26:14 PM
sbt:scala-compile> comp
[success] Total time: 1 s, completed Dec 12, 2019, 7:26:17 PM
sbt:scala-compile> compile
[success] Total time: 0 s, completed Dec 12, 2019, 7:26:19 PM
sbt:scala-compile>
To implement this change, I added the redraw() method to LineReader
which is a wrapper around ConsoleReader.drawLine; ConsoleReader.flush().
We invoke LineReader.redraw whenever the ConsoleChannel receives a
ConsolePromptEvent and there is a running thread.
To prevent log lines from being appended to the prompt line, in the
CommandExchange we print a newline character whenever a new command is
received from the network or a network client connects and we believe
that there is an active prompt.
The ask user thread is a background thread so it's fine for it to block
on System.in. By blocking rather than polling, the cpu utilization of
sbt drops to 0 on idle. We have to explicitly handle <ctrl+d> if we
block though because the JLine console reader will return null both if
the input stream returns -1
This commit aims to centralize all of the terminal interactions
throughout sbt. It also seeks to hide the jline implementation details
and only expose the apis that sbt needs for interacting with the
terminal.
In general, we should be able to assume that the terminal is in
canonical (line buffered) mode with echo enabled. To switch to raw mode
or to enable/disable echo, there are apis: Terminal.withRawSystemIn and
Terminal.withEcho that take a thunk as parameter to ensure that the
terminal is reset back to the canonical mode afterwards.
To demonstrate [-Yno-lub](http://eed3si9n.com/stricter-scala-with-ynolub), this shows the code changes that removes lubing (Not all subprojects are done).
After I made the changes, I switched the Scala back to normal 2.12.10.
At the suggestion of @eed3si9n, instead of specifying the file cache
size in bytes, we now specify it in a formatted string. For example,
instead of specifying 128 megabytes in bytes (134217728), we can specify
it with the string "128M".
In some cases, comp.append could be an empty string. This would happen
if a parser was something like `(token(foo) <~ ;).+ <~ fo.?` because there were
no completions for the `fo` available anchor. The effect of this was
that tab would never complete foo;f to foo;foo, even though that was the
only possible completion. It would, _display_, foo as a possible
completion though.
This came up because the multi parser has a similar parser to that
described above and it broke tab completion to the right of a semi
colon.
We run into issues if we naively split the command input on ';' and
treat each part as a separate command unless the ';' is inside of a
string because it is also valid to have ';'s inside of braced
expressions, e.g. `set foo := { val x = 1; x + 1 }`. There was no parser
for expressions enclosed in braces. I add one that should parse any
expression wrapped in braces so long as each opening brace is matched by a
closing brace. The parser returns the original expression. This allows
the multi parser to ignore ';' inside of '{...}'.
I had to rework the scripted tests to individually run 'reload' and
'setUpScripted' because the new parser rejects setUpScripted because it
isn't a valid command until reload has run.
In my recent changes to watch, I have been moving towards a world in
which sbt manages the file inputs and outputs at the task level. The
main idea is that we want to enable a user to specify the inputs and
outputs of a task and have sbt able to track those inputs across
multiple task evaluations. Sbt should be able to automatically trigger a
build when the inputs change and it also should be able to avoid task
evaluation if non of the inputs have changed.
The former case of having sbt automatically watch the file inputs of a
task has been present since watch was refactored. In this commit, I
make it possible for the user to retrieve the lists of new, modified and
deleted files. The user can then avoid task evaluation if none of the
inputs have changed.
To implement this, I inject a number of new settings during project
load if the fileInputs setting is defined for a task. The injected
settings are:
allPathsAndAttributes -- this retrieves all of the paths described by
the fileInputs for the task along with their attributes
fileStamps -- this retrieves all of the file stamps for the files
returned by allPathsAndAttributes
Using these two injected tasks, I also inject a number of derived tasks,
such as allFiles, which returns all of the regular files returned by
allPathsAndAttributes and changedFiles, which returns all of the regular
files that have been modified since the last run.
Using these injected settings, the user is able to write tasks that
avoid evaluation if the inputs haven't changed.
foo / fileInputs += baseDirectory.value.toGlob / ** / "*.scala"
foo := {
foo.previous match {
case Some(p) if (foo / changedFiles).value.isEmpty => p
case _ => fooImpl((foo / allFiles).value
}
}
To make this whole mechanism work, I add a private task key:
val fileAttributeMap = taskKey[java.util.HashMap[Path, Stamp]]("...")
This keeps track of the stamps for all of the files that are managed by
sbt. The fileStamps task will first look for the stamp in the attribute
map and, only if it is not present, it will update the cache. This
allows us to ensure that a given file will only be stamped once per task
evaluation run no matter how the file inputs are specified. Moreover, in
a continuous build, I'm able to reuse the attribute map which can
significantly reduce latency because the default file stamping
implementation used by zinc is fairly expensive (it can take anywhere
between 300-1500ms to stamp 5000 8kb source files on my mac).
I also renamed some of the watch related keys to be a bit more clear.
The usingTerminal method synchronizes the JLine object which can lead to
deadlock if multiple threads call it. When we just to want to read the
attributes of the terminal, but not modify it, there doesn't seem to be
any reason to use a lock.
Although this is technically in the internal package, it is exposed to
users when they write a custom input task. I do not think that we should
prevent users/plugin authors from writing their own parser
implementations if there is a different library they prefer. By my
count, there are 21 implementations of this interface in sbt, so it's
unlikely that there is much benefit from a pattern matching perspective.
Make sure that we generate valid ID (according to matches(ID, s)) so
that we properly test the new validID implementation.
And that's what led to the bug fix. :)
It turned up in profiling sessions. Previously, it used parser combinators
which are somewhat slow especially when the JVM is still cold.
The grammar for ID is simple enough to afford this handwritten parser.
Fixessbt/sbt#1812
This adds unified slash syntax for both sbt shell and the build.sbt DSL.
Instead of the current `<project-id>/config:intask::key`,
this adds `<project-id>/<config-ident>/intask/key` where <config-ident> is the Scala identifier notation for the configurations like `Compile` and `Test`.
This also adds a series of implicits called `SlashSyntax` that adds `/` operators to project refererences, configuration, and keys such that the same syntax works in build.sbt.
These examples work for both from the shell and in build.sbt.
Global / cancelable
ThisBuild / scalaVersion
Test / test
root / Compile / compile / scalacOptions
ProjectRef(uri("file:/xxx/helloworld/"),"root")/Compile/scalacOptions
Zero / Zero / name
The inspect command now outputs something that can be copy-pasted:
> inspect compile
[info] Task: sbt.inc.Analysis
[info] Description:
[info] Compiles sources.
[info] Provided by:
[info] ProjectRef(uri("file:/xxx/helloworld/"),"root")/Compile/compile
[info] Defined at:
[info] (sbt.Defaults) Defaults.scala:326
[info] Dependencies:
[info] Compile/manipulateBytecode
[info] Compile/incCompileSetup
[info] Reverse dependencies:
[info] Compile/printWarnings
[info] Compile/products
[info] Compile/discoveredSbtPlugins
[info] Compile/discoveredMainClasses
[info] Delegates:
[info] Compile/compile
[info] compile
[info] ThisBuild/Compile/compile
[info] ThisBuild/compile
[info] Zero/Compile/compile
[info] Global/compile
[info] Related:
[info] Test/compile
Ref #3282
We used to wrap InputStream so it will inject Thread.sleep, which then allows the thread to be cancelled, emulating a non-blocking readLine. This trick doesn't seem to work for Windows.
For non-Cygwin, actually just removing the wrapping does the job, but I couldn't get it to work for Cygwin.
To test, run some command via network, and then type `show name` into the terminal. On Cygwin, it will not respond.
Eugene Yokota
Ethan Atkins
xuwei-k
Ethan Atkins
Kazuhiro Sera
Jason Pickens
Dale Wijnand
Johannes Rudolph
Simon Schäfer
kczulko