Fixes https://github.com/pulumi/pulumi/issues/12738https://github.com/pulumi/pulumi/pull/11834 turned on the prealloc
linter and changed a load of slice uses from just `var x T[]` to `x :=
make([]T, 0, preallocSize)`. This was good for performance but it turns
out there are a number of places in the codebase that treat a `nil`
slice as semnatically different to an empty slice.
Trying to test that, or even reason that through for every callsite is
untractable, so this PR replaces all expressions of the form `make([]T,
0, size)` with a call to `slice.Prealloc[T](size)`. When size is 0 that
returns a nil array, rather than an empty array.
We're going to use convert for more data sources than just YAML (e.g.
hcl, arm, etc). So we don't want the PCL output option to be YAML
specific given it should be usable for any input source.
These changes extend the public API of `pkg/codegen/schema` to support
on-demand binding of package members. On-demand binding is appropriate for
scenarios that do not require the entire package, especially those such as
program code generation or the YAML LSP server that require only specific
types/functions/etc.
The extensions to the public API consist of two new types and several new
methods. The most notable of these are `PackageReference` and
`Loader.LoadPackageReference`. The former provides the on-demand binding
interface, while the latter creates instances of the former (n.b. it was
my intent to make a breaking change to the signature of `Loader.LoadPackage`
s.t. it returns a `PackageReference`, but the circular dependency between
this Go module and those for YAML and Java prevented that change).
These changes _dramatically_ reduce the memory required to interace with
Pulumi Packages, and only require memory proportional to the number of
accessed package members. We may be able to improve on this in the future
by removing type/resource/function interning, which would allow those
values to be garbage collected at a granaular level rather than at a
package level. That is a more radical change, though, as it requires new
equality semantics for each of the affected types (some of which are
currently used as map keys).