This adds FS.Path which holds the pre-open path currently only used in
WASI. It also fixes a TODO where we didn't know for sure if the FD
parameter for `path_` functions must always be a pre-open. The TL;DR; is
that usually it is, but it may not be (e.g. in our zig-cc example we can
see any directory FD, not just pre-opens).
Finally, this fixes a bug in our path resolution where we mistook paths
like "foo/foo" for "foo" because we only considered basenames instead of
the full path from the pre-open root.
This also makes pre-open directory lookup lazy because I noticed in
Trivy specifically, this is unnecessary for us to do eagerly, as they
change the FS at runtime per-call. In other words, any value from init
time is invalid later.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This avoids logging activity on stdio file descriptors, in order to help
make troubleshooting easier. Usually, there isn't an issue in these, yet
wasm panics are harder to read if there is also logging of the ..
logging.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This consolidates internal code to syscallfs, which removes the fs.FS
specific path rules, except when adapting one to syscallfs. For example,
this allows the underlying filesystem to decide if relative paths are
supported or not, as well any EINVAL related concerns.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This stubs all remaining syscalls for `GOARCH=wasm GOOS=js` to return
ENOSYS, instead of panic'ing. This allows us to see the parameters it
receives.
For example:
```
==> go.syscall/js.valueCall(fs.truncate(path=/tmp/_Go_TestTruncate135754730,length=0))
<== (err=function not implemented,ok=false)
```
Signed-off-by: Adrian Cole <adrian@tetrate.io>
As noted in slack, we are unlikley to long term use fs.FS internally.
This ensures we attempt to cast to syscallfs.FS for all I/O by panicing
on fs.Open.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This renames the internal writefs package to syscallfs as it is largely
dependent on syscall signatures. This also implements utimes in gojs.
WASI will be a follow-up change as it requires more infrastructure.
Notably, we also need non-TinyGo tests because TinyGo doesn't yet
support os.Chtimes or corresponding syscalls.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This splits unlink and rmdir from remove, as it is not only more precise
in GOOS=js, but it is also needed to implement wasi. I verified this
works by running go unit tests with logging.
```
==> go.syscall/js.valueCall(fs.open(name=/tmp/TestErrIsNotExist1062486353,flags=,perm=----------))
<== (err=<nil>,fd=10)
==> go.syscall/js.valueCall(fs.fstat(fd=10))
<== (err=<nil>,stat={isDir=true,mode=-rwx------,size=96,mtimeMs=1672285985206})
==> go.syscall/js.valueCall(fs.readdir(name=/tmp/TestErrIsNotExist1062486353))
<== (err=<nil>,dirents=&{[001]})
==> go.syscall/js.valueCall(fs.unlink(path=/tmp/TestErrIsNotExist1062486353/001))
<== (err=is a directory,ok=true)
==> go.syscall/js.valueCall(fs.rmdir(path=/tmp/TestErrIsNotExist1062486353/001))
<== (err=<nil>,ok=false)
```
Signed-off-by: Adrian Cole <adrian@tetrate.io>
The type we use to expose write operations is still evolving. It might
be a single writefs.FS interface, or similar to go where we have an
interface per feature (e.g. writefs.MkdirFS). These choices are all
implementation details for DirFS and won't be settled before the end of
the month version cutoff. Instead, this only exposes the ability to
create a DirFS, not an arbitrary implementation of writefs.FS. This does
so by making `writefs.FS` an internal type.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This adds writefs.FS, allowing functions to create and delete files.
This begins by implementing them on `GOARCH=js GOOS=wasm`. The current
status is a lot farther than before, even if completing write on WASI is
left for a later PR (possibly by another volunteer).
Signed-off-by: Adrian Cole <adrian@tetrate.io>
`GOARCH=wasm GOOS=js` defines parameter names in go source, and they are
indirectly related to the wasm parameter "sp". This creates a pseudo
name section so that we can access the parameter names. The alternative
would be adding a hack to normal FunctionDefinition, only used for gojs.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This refactors GOOS and GOARCH specific code into their own packages.
This allows logging interceptors to be built without cyclic package
dependencies.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This separate host from guest instantiation in ways similar to other
imports such as emscripten. Doing so allows parallel use of gojs.Run,
provided the ModuleConfig has been assigned a unique name (e.g. via an
atomic number).
Fixes#939
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This removes ProxyFunc, which was an internal experiment to make
functions that use memory to store parameters or results easier to see.
The main issue with the approach was instantiation performance, as it
needs to dynamically generate functions. Another approach to visibility
can happen later, for example via internal logging hooks.
Notably, this fixed the performance regression after switching WASI to ProxyFunc:
```
name old time/op new time/op delta
Allocation/Compile-16 39.8ms ± 0% 39.5ms ± 0% -0.62% (p=0.016 n=4+5)
Allocation/Instantiate-16 1.74ms ± 4% 0.86ms ± 1% -50.19% (p=0.008 n=5+5)
Allocation/Call-16 4.25µs ± 1% 4.21µs ± 2% ~ (p=0.151 n=5+5)
name old alloc/op new alloc/op delta
Allocation/Compile-16 20.3MB ± 0% 20.3MB ± 0% ~ (p=0.841 n=5+5)
Allocation/Instantiate-16 1.04MB ± 0% 0.56MB ± 0% -45.88% (p=0.008 n=5+5)
Allocation/Call-16 48.0B ± 0% 48.0B ± 0% ~ (all equal)
name old allocs/op new allocs/op delta
Allocation/Compile-16 432k ± 0% 432k ± 0% ~ (p=0.833 n=5+5)
Allocation/Instantiate-16 16.6k ± 0% 6.7k ± 0% -59.34% (p=0.008 n=5+5)
Allocation/Call-16 5.00 ± 0% 5.00 ± 0% ~ (all equal)
```
Since we also removed it from `GOARCH=wasm GOOS=js`, we experienced a performance
benefit there as well:
```
name old time/op new time/op delta
_main/gojs.Run-16 13.7ms ± 1% 12.2ms ± 3% -10.76% (p=0.008 n=5+5)
name old alloc/op new alloc/op delta
_main/gojs.Run-16 25.4MB ± 0% 25.0MB ± 0% -1.66% (p=0.008 n=5+5)
name old allocs/op new allocs/op delta
_main/gojs.Run-16 166k ± 0% 158k ± 0% -4.79% (p=0.016 n=4+5)
```
Signed-off-by: Adrian Cole <adrian@tetrate.io>
We originally had a `context.Context` for anything that might be
traced, but it turned out to be only useful for lifecycle and host functions.
For instruction-scoped aspects like memory updates, a context parameter is too
fine-grained and also invisible in practice. For example, most users will use
the compiler engine, and its memory, global or table access will never use go's
context.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This removes the ability to override the current file system with Go
context, allowing us to simplify common paths and improve performance.
The context override was only used once in GitHub, in Trivy, and we
found another way to do that without it.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
`os.DirFS` ironically doesn't implement `fs.ReadDirFS`, so we cannot
open a directory this way. This blindly attempts to open "." regardless
of if the `fs.FS` implementation is a `fs.ReadDirFS` or not, and if
successful, enforces that the file returned is a directory. If not, a
fake directory is returned.
Doing so allows real stat to be returned for root, and also a chance to
know if a filesystem configured is real or not. Later, we'll need this
to implement open flags.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This adds ResultNames to HostFunctionBuilder and FunctionDefinition
which helps for multi-results or special-cased ones.
End users can access result names in `FunctionDefinition.ResultNames` or
set for their own host functions via
`HostFunctionBuilder.WithResultNames`. This change adds them for all
built-in functions where result names help.
Most notably, GOOS=js uses `ProxyFunc` to allow logging when a function
returns multiple results. Before, the results were returned without
names: e.g. `11231,1` and now they are named like `n=11231,ok=1`.
We soon plan to allow more visibility in WASI, for example, logging
results that will write to memory offsets. This infrastructure makes it
possible to do that.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
While most compilers will only read args/environ once, tools like WAGI
make heavy use of environment, possibly dozens of long variables. This
optimizes both args and environ for this reason and also to setup for
optimizing other functions.
Here are the notable changes:
* eagerly coerce to byte slices instead of strings
* re-use null terminated length for writing values
* avoid loops that call mem.WriteXXX internally
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This switches to gofumpt and applies changes, as I've noticed working
in dapr (who uses this) that it finds some things that are annoying,
such as inconsistent block formatting in test tables.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This PR follows @hafeidejiangyou advice to not only enable end users to
avoid reflection when calling host functions, but also use that approach
ourselves internally. The performance results are staggering and will be
noticable in high performance applications.
Before
```
BenchmarkHostCall/Call
BenchmarkHostCall/Call-16 1000000 1050 ns/op
Benchmark_EnvironGet/environGet
Benchmark_EnvironGet/environGet-16 525492 2224 ns/op
```
Now
```
BenchmarkHostCall/Call
BenchmarkHostCall/Call-16 14807203 83.22 ns/op
Benchmark_EnvironGet/environGet
Benchmark_EnvironGet/environGet-16 951690 1054 ns/op
```
To accomplish this, this PR consolidates code around host function
definition and enables a fast path for functions where the user takes
responsibility for defining its WebAssembly mappings. Existing users
will need to change their code a bit, as signatures have changed.
For example, we are now more strict that all host functions require a
context parameter zero. Also, we've replaced
`HostModuleBuilder.ExportFunction` and `ExportFunctions` with a new type
`HostFunctionBuilder` that consolidates the responsibility and the
documentation.
```diff
ctx := context.Background()
-hello := func() {
+hello := func(context.Context) {
fmt.Fprintln(stdout, "hello!")
}
-_, err := r.NewHostModuleBuilder("env").ExportFunction("hello", hello).Instantiate(ctx, r)
+_, err := r.NewHostModuleBuilder("env").
+ NewFunctionBuilder().WithFunc(hello).Export("hello").
+ Instantiate(ctx, r)
```
Power users can now use `HostFunctionBuilder` to define functions that
won't use reflection. There are two choices of interfaces to use
depending on if that function needs access to the calling module or not:
`api.GoFunction` and `api.GoModuleFunction`. Here's an example defining
one.
```go
builder.WithGoFunction(api.GoFunc(func(ctx context.Context, params []uint64) []uint64 {
x, y := uint32(params[0]), uint32(params[1])
sum := x + y
return []uint64{sum}
}, []api.ValueType{api.ValueTypeI32, api.ValueTypeI32}, []api.ValueType{api.ValueTypeI32})
```
As you'll notice and as documented, this approach is more verbose and
not for everyone. If you aren't making a low-level library, you are
likely able to afford the 1us penalty for the convenience of reflection.
However, we are happy to enable this option for foundational libraries
and those with high performance requirements (like ourselves)!
Fixes#825
Signed-off-by: Adrian Cole <adrian@tetrate.io>
We formerly introduced `MemorySizer` as a way to control capacity independently of size. This was the first and only feature in `CompileConfig`. While possibly used privately, `MemorySizer` has never been used in public GitHub code.
These APIs interfere with how we do caching of compiled modules. Notably, they can change the min or max defined in wasm, which invalidates some constants. This has also had a bad experience, forcing everyone to boilerplate`wazero.NewCompileConfig()` despite that API never being used in open source.
This addresses the use cases in a different way, by moving configuration to `RuntimeConfig` instead. This allows us to remove `MemorySizer` and `CompileConfig`, and the problems with them, yet still retaining functionality in case someone uses it.
* `RuntimeConfig.WithMemoryLimitPages(uint32)`: Prevents memory from growing to 4GB (spec limit) per instance.
* This works regardless of whether the wasm encodes max or not. If there is no max, it becomes effectively this value.
* `RuntimeConfig.WithMemoryCapacityFromMax(bool)`: Prevents reallocations (when growing).
* Wasm that never sets max will grow from min to the limit above.
Note: Those who want to change their wasm (ex insert a max where there was none), have to do that externally, ex via compiler settings or post-build transformations such as [wabin](https://github.com/tetratelabs/wabin)
Signed-off-by: Adrian Cole <adrian@tetrate.io>
We at one point considered making `ModuleBuilder` create complete
WebAssembly binaries. However, we recently spun out
[wabin](https://github.com/tetratelabs/wabin), which allows this.
Meanwhile, the features in `ModuleBuilder` were confusing and misused.
For example, the only two cases memory was exported on GitHub were done
by accident. This is because host functions act on the guest's memory,
not their own.
Hence, this removes memory and globals from host side definitions, and
renames the type to HostModuleBuilder to clarify this is not ever going
to be used to construct normal Wasm binaries.
Most importantly, this simplifies the API and reduces a lot of code. It
is important to make changes like this, particularly deleting any
experimental things that didn't end up useful.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
Co-authored-by: Anuraag Agrawal <anuraaga@gmail.com>
While compilers should be conservative when targeting WebAssembly Core
features, runtimes should be lenient as otherwise people need to
constantly turn on all features. Currently, most examples have to turn
on 2.0 features because compilers such as AssemblyScript and TinyGo use
them by default. This matches the policy with the reality, and should
make first time use easier.
This top-levels an internal type as `api.CoreFeatures` and defaults to
2.0 as opposed to 1.0, our previous default. This is less cluttered than
the excess of `WithXXX` methods we had prior to implementing all
planned WebAssembly Core Specification 1.0 features.
Finally, this backfills rationale as flat config types were a distinct
decision even if feature set selection muddied the topic.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
Our root directory is getting crowded and it is also difficult to
organize the "host imports" concept due to this.
This moves common and language-specific imports into their own
directory. This will break go import signatures on the next release, but
is more sustainable overall.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This adds an experimental package gojs which implements the host side of Wasm compiled by GOARCH=wasm GOOS=js go build -o X.wasm X.go
This includes heavy disclaimers, in part inherited by Go's comments https://github.com/golang/go/blob/go1.19/src/syscall/js/js.go#L10-L11
Due to this many will still use TinyGo instead.
That said, this is frequently asked for and has interesting features including reflection and HTTP client support.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
