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>
This changes the listener signature to accept context and calling
module, so that all possible parameters and results can be logged. This
also changes the logging listener to make parameters visible when
logging results.
This infrastructure supports some helpful use cases, such as logging
WASI result parameters, such as the prestat path, which is only knowable
after the function has been called. The context parameter supposed
reading results of gojs functions, which are stored host-side in a go
context object.
Future pull requests will complete this as well backfill unit tests.
This is raised independently mainly to keep the PR size down of the
upcoming filesystem logger.
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>
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>
This adds host functions that work on dynamic function tables. These are
only used by emscripten, but require some infrastructure to support it.
I added the least possible to due the task. This also only handles i32
and void returns with up to four parameters as that covers the needs of
PDFium. Future integrations may need more parameters or a mix of floats.
Such use cases should be addressed as they come as otherwise it is a lot
of work for the cartesian product of all combinations.
See 1b0d724fd5/test/passes/post-emscripten.wast
See https://github.com/jerbob92/go-pdfium-wasm
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 restores the ability to leave out the initial context parameter
when defining functions with reflection. This is important because some
projects are porting from a different library to wazero, and all the
alternatives are not contextualized.
For example, this project is porting envoy host functions, and the
original definitions (in mosn) don't have a context parameter. By being
lenient, they can migrate easier.
See 6b813482b6/pkg/proxywasm/wazero/imports_v1.go
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>
It is more often the case that projects are enabling a freestanding
target, and that may or may not have an exporting memory depending on
how that's interpreted. This adds the ability to inspect memories
similar to how you can already inspect compiled code prior to
instantiation. For example, you can enforce an ABI constraint that
"memory" must be exported even if WASI is not in use.
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>
