internal/pkg: compute http identifier from url

The previous implementation exposes arbitrary user input to the cache as an identifier, which is highly error-prone and can cause the cache to enter an inconsistent state if the user is not careful. This change replaces the implementation to compute identifier late, using url string as params.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/pkg/pkg_test.go

@@ -279,28 +279,28 @@ func TestCache(t *testing.T) {
 
 			cureMany(t, c, []cureStep{
 				{"initial file", newStubFile(
-					pkg.KindHTTP,
+					pkg.KindHTTPGet,
 					identifier,
 					&testdataChecksum,
 					[]byte(testdata), nil,
 				), wantPathname, testdataChecksum, nil},
 
 				{"identical content", newStubFile(
-					pkg.KindHTTP,
+					pkg.KindHTTPGet,
 					identifier0,
 					&testdataChecksum,
 					[]byte(testdata), nil,
 				), wantPathname0, testdataChecksum, nil},
 
 				{"existing entry", newStubFile(
-					pkg.KindHTTP,
+					pkg.KindHTTPGet,
 					identifier,
 					&testdataChecksum,
 					[]byte(testdata), nil,
 				), wantPathname, testdataChecksum, nil},
 
 				{"checksum mismatch", newStubFile(
-					pkg.KindHTTP,
+					pkg.KindHTTPGet,
 					pkg.ID{0xff, 0},
 					new(pkg.Checksum),
 					[]byte(testdata), nil,
@@ -309,7 +309,7 @@ func TestCache(t *testing.T) {
 				}},
 
 				{"store without validation", newStubFile(
-					pkg.KindHTTP,
+					pkg.KindHTTPGet,
 					pkg.MustDecode("vsAhtPNo4waRNOASwrQwcIPTqb3SBuJOXw2G4T1mNmVZM-wrQTRllmgXqcIIoRcX"),
 					nil,
 					[]byte{0}, nil,
@@ -328,14 +328,14 @@ func TestCache(t *testing.T) {
 				}, nil},
 
 				{"error passthrough", newStubFile(
-					pkg.KindHTTP,
+					pkg.KindHTTPGet,
 					pkg.ID{0xff, 1},
 					nil,
 					nil, stub.UniqueError(0xcafe),
 				), nil, pkg.Checksum{}, stub.UniqueError(0xcafe)},
 
 				{"error caching", newStubFile(
-					pkg.KindHTTP,
+					pkg.KindHTTPGet,
 					pkg.ID{0xff, 1},
 					nil,
 					nil, nil,
@@ -357,7 +357,7 @@ func TestCache(t *testing.T) {
 					}, wantPathname, testdataChecksum, nil},
 
 					{"cache miss checksum match", newStubFile(
-						pkg.KindHTTP,
+						pkg.KindHTTPGet,
 						testdataChecksum,
 						nil,
 						[]byte(testdata),
@@ -493,7 +493,7 @@ func TestCache(t *testing.T) {
 				}},
 
 				{"cache hit bad type", newStubFile(
-					pkg.KindHTTP,
+					pkg.KindHTTPGet,
 					pkg.ID{0xff, 2},
 					&wantChecksum,
 					[]byte(testdata), nil,
@@ -571,7 +571,7 @@ func TestCache(t *testing.T) {
 			// check cache activity while a cure is blocking
 			cureMany(t, c, []cureStep{
 				{"error passthrough", newStubFile(
-					pkg.KindHTTP,
+					pkg.KindHTTPGet,
 					pkg.ID{0xff, 1},
 					nil,
 					nil, stub.UniqueError(0xbad),