1 files changed, 0 insertions, 129 deletions
diff --git a/cache.go b/cache.go
deleted file mode 100644
index d43fa77..0000000
--- a/cache.go
+++ /dev/null
@@ -1,129 +0,0 @@
-package main
-
-import (
-	"context"
-	"log"
-	"path"
-	"sync"
-	"time"
-)
-
-// A PackageCache holds information about Go packages and their upstream
-// repositories.
-//
-// Given a package name, it looks for a similarly named repository in one of
-// the upstream hosts and holds on to the result for quicker subsequent access.
-type PackageCache struct {
-	// ExpireAfter is how long to consider a found repository valid for. As
-	// repositories do not frequently move around, this could be rather long,
-	// though it also determines how long a user might have to wait for a new
-	// repository to become available if they previously got a 404.
-	ExpireAfter time.Duration
-
-	// UpstreamTimeout is how long we should allow HTTP requests to upstream
-	// hosts to carry on before they are canceled.
-	UpstreamTimeout time.Duration
-
-	// Hosts are the RepoHosts which should be checked for a repository matching
-	// the package name. Hosts are checked in order; if two hosts both have a
-	// repo with the desired name, the repo host which is listed first will
-	// "win".
-	Hosts []RepoHost
-
-	// Logger is a logger for diagnostics
-	Logger *log.Logger
-
-	// CanonicalPrefix is the package prefix to use when naming packages. E.g.,
-	// when looking for a package named "conf", we'll treat the package name as
-	// CanonicalPrefix + "/conf", e.g. burwell.io/conf.
-	CanonicalPrefix string
-
-	entries sync.Map // concurrency-safe map[string]entry
-}
-
-type entry struct {
-	t   time.Time
-	pkg *Package
-}
-
-// A Package represents a Go package's canonical name and its source git
-// repository.
-type Package struct {
-	Name string
-	Repo string
-}
-
-// Get loads package name from the cache, consulting upstream repositories to
-// find a matching repo if not present. As this method is meant to be called in
-// the critical path of an incoming HTTP request, it can also be cancelled with
-// the supplied context.
-func (c *PackageCache) Get(ctx context.Context, name string) (Package, bool) {
-	val, ok := c.entries.Load(name)
-	if !ok {
-		return c.load(ctx, name)
-	}
-	ent := val.(entry)
-
-	if time.Now().After(ent.t.Add(c.ExpireAfter)) {
-		return c.load(ctx, name)
-	}
-
-	if ent.pkg == nil {
-		return Package{}, false
-	}
-
-	return *ent.pkg, true
-}
-
-// load looks for a package in the upstream repos, and if found, stores it in
-// the cache. If no matching repo is found, a nil entry is stored in the map so
-// we don't immediately re-check the upstreams for subsequent requests.
-func (c *PackageCache) load(ctx context.Context, name string) (Package, bool) {
-	pkg, ok := c.find(ctx, name)
-	if !ok {
-		c.entries.Store(name, entry{t: time.Now()})
-		return Package{}, false
-	}
-	c.entries.Store(name, entry{t: time.Now(), pkg: &pkg})
-	return pkg, true
-}
-
-// requestContext creates a context for making HTTP requests to upstream hosts.
-func (c *PackageCache) requestContext(ctx context.Context) (context.Context, context.CancelFunc) {
-	if c.UpstreamTimeout == 0 {
-		return ctx, func() {}
-	}
-	return context.WithTimeout(ctx, c.UpstreamTimeout)
-}
-
-// logf logs a message using the configured logger, if any.
-func (c *PackageCache) logf(msg string, args ...interface{}) {
-	if c.Logger == nil {
-		return
-	}
-	c.Logger.Printf(msg, args...)
-}
-
-// find consults the configured upstream hosts to try to find a matching repo
-// for package name.
-func (c *PackageCache) find(ctx context.Context, name string) (Package, bool) {
-	c.logf("loading %s", name)
-	for _, h := range c.Hosts {
-		reqCtx, cancel := c.requestContext(ctx)
-		defer cancel()
-		repo, ok, err := h.HostsRepo(reqCtx, name)
-		if err != nil {
-			c.logf("error checking upstream for repo %s: %v", name, err)
-			return Package{}, false
-		}
-		if ok {
-			c.logf("found repo %s: %s", name, repo)
-			return Package{
-				Name: path.Join(c.CanonicalPrefix, name),
-				Repo: repo,
-			}, true
-		}
-	}
-	c.logf("could not find repo %s on any host", name)
-	return Package{}, false
-}