Add a few more content addressing methods

Good to round out the library interface.

src/libstore/content-address.cc

@@ -154,38 +154,32 @@ std::string renderContentAddress(std::optional<ContentAddress> ca)
     return ca ? ca->render() : "";
 }
 
-ContentAddressWithReferences ContentAddressWithReferences::fromParts(
-    ContentAddressMethod  method, Hash hash, StoreReferences refs)
+ContentAddress ContentAddress::fromParts(
+    ContentAddressMethod method, Hash hash)
 {
     return std::visit(overloaded {
-        [&](TextIngestionMethod _) -> ContentAddressWithReferences {
-            if (refs.self)
-                throw UsageError("Cannot have a self reference with text hashing scheme");
-            return TextInfo {
-                .hash = { .hash = std::move(hash) },
-                .references = std::move(refs.others),
+        [&](TextIngestionMethod _) -> ContentAddress {
+            return TextHash {
+                .hash = std::move(hash),
             };
         },
-        [&](FileIngestionMethod m2) -> ContentAddressWithReferences {
-            return FixedOutputInfo {
-                .hash = {
-                    .method = m2,
+        [&](FileIngestionMethod m2) -> ContentAddress {
+            return FixedOutputHash {
+                .method = std::move(m2),
                 .hash = std::move(hash),
-                },
-                .references = std::move(refs),
             };
         },
     }, method.raw);
 }
 
-ContentAddressMethod ContentAddressWithReferences::getMethod() const
+ContentAddressMethod ContentAddress::getMethod() const
 {
     return std::visit(overloaded {
-        [](const TextInfo & th) -> ContentAddressMethod {
+        [](const TextHash & th) -> ContentAddressMethod {
             return TextIngestionMethod {};
         },
-        [](const FixedOutputInfo & fsh) -> ContentAddressMethod {
-            return fsh.hash.method;
+        [](const FixedOutputHash & fsh) -> ContentAddressMethod {
+            return fsh.method;
         },
     }, raw);
 }
@@ -229,6 +223,42 @@ ContentAddressWithReferences ContentAddressWithReferences::withoutRefs(const Con
     }, ca.raw);
 }
 
+ContentAddressWithReferences ContentAddressWithReferences::fromParts(
+    ContentAddressMethod method, Hash hash, StoreReferences refs)
+{
+    return std::visit(overloaded {
+        [&](TextIngestionMethod _) -> ContentAddressWithReferences {
+            if (refs.self)
+                throw UsageError("Cannot have a self reference with text hashing scheme");
+            return TextInfo {
+                .hash = { .hash = std::move(hash) },
+                .references = std::move(refs.others),
+            };
+        },
+        [&](FileIngestionMethod m2) -> ContentAddressWithReferences {
+            return FixedOutputInfo {
+                .hash = {
+                    .method = m2,
+                    .hash = std::move(hash),
+                },
+                .references = std::move(refs),
+            };
+        },
+    }, method.raw);
+}
+
+ContentAddressMethod ContentAddressWithReferences::getMethod() const
+{
+    return std::visit(overloaded {
+        [](const TextInfo & th) -> ContentAddressMethod {
+            return TextIngestionMethod {};
+        },
+        [](const FixedOutputInfo & fsh) -> ContentAddressMethod {
+            return fsh.hash.method;
+        },
+    }, raw);
+}
+
 Hash ContentAddressWithReferences::getHash() const
 {
     return std::visit(overloaded {

src/libstore/content-address.hh

@@ -154,8 +154,9 @@ struct ContentAddress
     { }
 
     /**
-     * Compute the content-addressability assertion (ValidPathInfo::ca) for
-     * paths created by Store::makeFixedOutputPath() / Store::addToStore().
+     * Compute the content-addressability assertion
+     * (`ValidPathInfo::ca`) for paths created by
+     * `Store::makeFixedOutputPath()` / `Store::addToStore()`.
      */
     std::string render() const;
 
@@ -163,6 +164,18 @@ struct ContentAddress
 
     static std::optional<ContentAddress> parseOpt(std::string_view rawCaOpt);
 
+    /**
+     * Create a `ContentAddress` from 2 parts:
+     *
+     * @param method Way ingesting the file system data.
+     *
+     * @param hash Hash of ingested file system data.
+     */
+    static ContentAddress fromParts(
+        ContentAddressMethod method, Hash hash);
+
+    ContentAddressMethod getMethod() const;
+
     const Hash & getHash() const;
 };
 
@@ -251,13 +264,13 @@ struct ContentAddressWithReferences
     { }
 
     /**
-     * Create a ContentAddressWithReferences from a mere ContentAddress, by
-     * assuming no references in all cases.
+     * Create a `ContentAddressWithReferences` from a mere
+     * `ContentAddress`, by assuming no references in all cases.
      */
     static ContentAddressWithReferences withoutRefs(const ContentAddress &);
 
     /**
-     * Create a ContentAddressWithReferences from 3 parts:
+     * Create a `ContentAddressWithReferences` from 3 parts:
      *
      * @param method Way ingesting the file system data.
      *