From 249291bc31ecf4947327f659d1db01bb2b2c6bbd Mon Sep 17 00:00:00 2001
From: liamfallon <liam.fallon@est.tech>
Date: Tue, 11 Feb 2025 11:20:05 +0000
Subject: [PATCH] Restore cache.go

---
 pkg/cache/memorycache/cache.go | 134 ---------------------------------
 1 file changed, 134 deletions(-)
 delete mode 100644 pkg/cache/memorycache/cache.go

diff --git a/pkg/cache/memorycache/cache.go b/pkg/cache/memorycache/cache.go
deleted file mode 100644
index aa94d1ef..00000000
--- a/pkg/cache/memorycache/cache.go
+++ /dev/null
@@ -1,134 +0,0 @@
-// Copyright 2022, 2024 The kpt and Nephio Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package memorycache
-
-import (
-	"context"
-	"errors"
-	"sync"
-
-	configapi "github.com/nephio-project/porch/api/porchconfig/v1alpha1"
-	cachetypes "github.com/nephio-project/porch/pkg/cache/types"
-	"github.com/nephio-project/porch/pkg/externalrepo"
-	"github.com/nephio-project/porch/pkg/repository"
-	"go.opentelemetry.io/otel"
-	"go.opentelemetry.io/otel/trace"
-)
-
-var tracer = otel.Tracer("memorycache")
-
-// Cache allows us to keep state for repositories, rather than querying them every time.
-//
-// Cache Structure:
-// <cacheDir>/git/
-// * Caches bare git repositories in directories named based on the repository address.
-// <cacheDir>/oci/
-// * Caches oci images with further hierarchy underneath
-// * We Cache image layers in <cacheDir>/oci/layers/ (this might be obsolete with the flattened Cache)
-// * We Cache flattened tar files in <cacheDir>/oci/ (so we don't need to pull to read resources)
-// * We poll the repositories periodically (configurable) and cache the discovered images in memory.
-type Cache struct {
-	mutex        sync.Mutex
-	repositories map[string]*cachedRepository
-	options      cachetypes.CacheOptions
-}
-
-var _ cachetypes.Cache = &Cache{}
-
-func (c *Cache) OpenRepository(ctx context.Context, repositorySpec *configapi.Repository) (repository.Repository, error) {
-	ctx, span := tracer.Start(ctx, "Cache::OpenRepository", trace.WithAttributes())
-	defer span.End()
-
-	key, err := externalrepo.RepositoryKey(repositorySpec)
-	if err != nil {
-		return nil, err
-	}
-
-	c.mutex.Lock()
-	defer c.mutex.Unlock()
-
-	if cachedRepo := c.repositories[key]; cachedRepo != nil {
-		// If there is an error from the background refresh goroutine, return it.
-		if err := cachedRepo.getRefreshError(); err == nil {
-			return cachedRepo, nil
-		} else {
-			return nil, err
-		}
-	}
-
-	externalRepo, err := externalrepo.CreateRepositoryImpl(ctx, repositorySpec, c.options.ExternalRepoOptions)
-	if err != nil {
-		return nil, err
-	}
-
-	cachedRepo := newRepository(key, repositorySpec, externalRepo, c.options)
-	c.repositories[key] = cachedRepo
-
-	return cachedRepo, nil
-}
-
-func (c *Cache) UpdateRepository(ctx context.Context, repositorySpec *configapi.Repository) error {
-	return errors.New("update on memory cached repositories is not supported")
-}
-
-func (c *Cache) CloseRepository(ctx context.Context, repositorySpec *configapi.Repository, allRepos []configapi.Repository) error {
-	_, span := tracer.Start(ctx, "Cache::CloseRepository", trace.WithAttributes())
-	defer span.End()
-
-	key, err := externalrepo.RepositoryKey(repositorySpec)
-	if err != nil {
-		return err
-	}
-
-	// check if repositorySpec shares the underlying cached repo with another repository
-	for _, r := range allRepos {
-		if r.Name == repositorySpec.Name && r.Namespace == repositorySpec.Namespace {
-			continue
-		}
-		otherKey, err := externalrepo.RepositoryKey(&r)
-		if err != nil {
-			return err
-		}
-		if otherKey == key {
-			// do not close cached repo if it is shared
-			return nil
-		}
-	}
-
-	var repository *cachedRepository
-	{
-		c.mutex.Lock()
-		if r, ok := c.repositories[key]; ok {
-			delete(c.repositories, key)
-			repository = r
-		}
-		c.mutex.Unlock()
-	}
-
-	if repository != nil {
-		return repository.Close()
-	} else {
-		return nil
-	}
-}
-
-func (c *Cache) GetRepositories(ctx context.Context) []configapi.Repository {
-	repoSlice := []configapi.Repository{}
-
-	for _, repo := range c.repositories {
-		repoSlice = append(repoSlice, *repo.repoSpec)
-	}
-	return repoSlice
-}