swarm/api: url scheme bzz-hash to get hashes of swarm content (#15238) (#15715)

* swarm/api: url scheme bzz-hash to get hashes of swarm content (#15238)

Update URI to support bzz-hash scheme and handle such HTTP requests by
responding with hash of the content as a text/plain response.

* swarm/api: return hash of the content for bzz-hash:// requests

* swarm/api: revert "return hash of the content for bzz-hash:// requests"

Return hashes of the content that would be returned by bzz-raw
request.

* swarm/api/http: handle error in TestBzzGetPath

* swarm/api: remove extra blank line in comment

1 files changed, 8 insertions, 2 deletions

diff --git a/swarm/api/uri.go b/swarm/api/uri.go
index af1dc7445..d8aafedf4 100644
--- a/swarm/api/uri.go
+++ b/swarm/api/uri.go
@@ -36,6 +36,8 @@ type URI struct {
 	// * bzzr - raw swarm content
 	// * bzzi - immutable URI of an entry in a swarm manifest
 	//          (address is not resolved)
+	// * bzz-hash - hash of swarm content
+	//
 	Scheme string
 
 	// Addr is either a hexadecimal storage key or it an address which
@@ -56,7 +58,7 @@ type URI struct {
 // * <scheme>://<addr>
 // * <scheme>://<addr>/<path>
 //
-// with scheme one of bzz, bzz-raw, bzz-immutable or bzz-list
+// with scheme one of bzz, bzz-raw, bzz-immutable, bzz-list or bzz-hash
 // or deprecated ones bzzr and bzzi
 func Parse(rawuri string) (*URI, error) {
 	u, err := url.Parse(rawuri)
@@ -67,7 +69,7 @@ func Parse(rawuri string) (*URI, error) {
 
 	// check the scheme is valid
 	switch uri.Scheme {
-	case "bzz", "bzz-raw", "bzz-immutable", "bzz-list", "bzzr", "bzzi":
+	case "bzz", "bzz-raw", "bzz-immutable", "bzz-list", "bzz-hash", "bzzr", "bzzi":
 	default:
 		return nil, fmt.Errorf("unknown scheme %q", u.Scheme)
 	}
@@ -110,6 +112,10 @@ func (u *URI) DeprecatedImmutable() bool {
 	return u.Scheme == "bzzi"
 }
 
+func (u *URI) Hash() bool {
+	return u.Scheme == "bzz-hash"
+}
+
 func (u *URI) String() string {
 	return u.Scheme + ":/" + u.Addr + "/" + u.Path
 }