internal/fetch: remove ZipSize from getters

A ModuleGetter no longer needs the ZipSize method, because
load-shedding has been moved into the worker, where it uses the proxy
client directly.

For golang/go#48010

Change-Id: I01eb0b88ac758e83be20333b73b4315985fc9d8e
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/346751
Trust: Jonathan Amsterdam <jba@google.com>
Run-TryBot: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Julie Qiu <julie@golang.org>
diff --git a/internal/fetch/getters.go b/internal/fetch/getters.go
index 4a78b25..2d76deb 100644
--- a/internal/fetch/getters.go
+++ b/internal/fetch/getters.go
@@ -41,10 +41,6 @@
 	// to have according to the zip archive layout specification at
 	// https://golang.org/ref/mod#zip-files.
 	ContentDir(ctx context.Context, path, version string) (fs.FS, error)
-
-	// ZipSize returns the approximate size of the zip file in bytes.
-	// It is used only for load-shedding.
-	ZipSize(ctx context.Context, path, version string) (int64, error)
 }
 
 type proxyModuleGetter struct {
@@ -75,12 +71,6 @@
 	return fs.Sub(zr, path+"@"+version)
 }
 
-// ZipSize returns the approximate size of the zip file in bytes.
-// It is used only for load-shedding.
-func (g *proxyModuleGetter) ZipSize(ctx context.Context, path, version string) (int64, error) {
-	return g.prox.ZipSize(ctx, path, version)
-}
-
 // Version and commit time are pre specified when fetching a local module, as these
 // fields are normally obtained from a proxy.
 var (
@@ -153,11 +143,6 @@
 	return os.DirFS(g.dir), nil
 }
 
-// ZipSize returns the approximate size of the zip file in bytes.
-func (g *directoryModuleGetter) ZipSize(ctx context.Context, path, version string) (int64, error) {
-	return 0, errors.New("directoryModuleGetter.ZipSize unimplemented")
-}
-
 // An fsProxyModuleGetter gets modules from a directory in the filesystem
 // that is organized like the proxy, with paths that correspond to proxy
 // URLs. An example of such a directory is $(go env GOMODCACHE)/cache/download.
@@ -240,11 +225,6 @@
 	return fs.Sub(zr, path+"@"+vers)
 }
 
-// ZipSize returns the approximate size of the zip file in bytes.
-func (g *fsProxyModuleGetter) ZipSize(ctx context.Context, path, version string) (int64, error) {
-	return 0, errors.New("fsProxyModuleGetter.ZipSize unimplemented")
-}
-
 // latestVersion gets the latest version that is in the directory.
 func (g *fsProxyModuleGetter) latestVersion(modulePath string) (_ string, err error) {
 	defer derrors.Wrap(&err, "fsProxyModuleGetter.latestVersion(%q)", modulePath)