Support cache (#1770)

* feat: port

* fix: use httprouter

* fix: WriteHeader

* fix: bolthold

* fix: bugs

* chore: one less file

* test: test handler

* fix: bug in id

* test: fix cases

* chore: tidy

* fix: use atomic.Int32

* fix: use atomic.Store

* feat: support close

* chore: lint

* fix: cache keys are case insensitive

* fix: options

* fix: use options

* fix: close

* fix: ignore close error

* Revert "fix: close"

This reverts commit d53ea7568ba03908eb153031c435008fd47e7ccb.

* fix: cacheUrlKey

* fix: nil close

* chore: lint code

* fix: test key

* test: case insensitive

* chore: lint

cmd/input.go

@@ -42,6 +42,10 @@ type Input struct {
 	artifactServerPath                 string
 	artifactServerAddr                 string
 	artifactServerPort                 string
+	noCacheServer                      bool
+	cacheServerPath                    string
+	cacheServerAddr                    string
+	cacheServerPort                    uint16
 	jsonLogger                         bool
 	noSkipCheckout                     bool
 	remoteName                         string