This allows users to reduce the memory limit per module below 4 Gi. This
is often needed because Wasm routinely leaves off the max, which implies
spec max (4 Gi). This uses Ki Gi etc in error messages because the spec
chooses to, though we can change to make it less awkward.
This also fixes an issue where we instantiated an engine inside config.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This introduces `SysConfig` to replace `WASIConfig` and formalize documentation around system calls.
The only incompatible change planned after this is to switch from wasi.FS to fs.FS
Implementation Notes:
Defaulting to os.Stdin os.Stdout and os.Stderr doesn't make sense for
the same reasons as why we don't propagate ENV or ARGV: it violates
sand-boxing. Moreover, these are worse as they prevent concurrency and
can also lead to console overload if accidentally not overridden.
This also changes default stdin to read EOF as that is safer than reading
from os.DevNull, which can run the host out of file descriptors.
Finally, this removes "WithPreopens" for "WithFS" and "WithWorkDirFS",
to focus on the intended result. Similar Docker, if the WorkDir isn't set, it
defaults to the same as root.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
Allows users to do the following to enable sign-extension-ops:
```
r := wazero.NewRuntimeWithConfig(wazero.NewRuntimeConfig().WithFeatureSignExtensionOps(true))
```
Resolves#66
Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
Co-authored-by: Adrian Cole <adrian@tetrate.io>
This adds `RuntimeConfig.WithFeatureMutableGlobal(enabled bool)`, which
allows disabling of mutable globals. When disabled, any attempt to add a
mutable global, either explicitly or implicitly via decoding wasm will
fail.
To support this, there's a new `Features` bitflag that can allow up to
63 feature toggles without passing structs.
While here, I fixed a significant performance problem in decoding
binary:
Before
```
BenchmarkCodecExample/binary.DecodeModule-16 184243 5623 ns/op 3848 B/op 184 allocs/op
```
Now
```
BenchmarkCodecExample/binary.DecodeModule-16 294084 3520 ns/op 2176 B/op 91 allocs/op
```
Signed-off-by: Adrian Cole <adrian@tetrate.io>
