feat(core): Introduce BlobStore & IdStore APIs

java/dev/enola/cas/BUILD

@@ -27,6 +27,7 @@ java_binary(
     ),
     visibility = ["//:__subpackages__"],
     deps = [
+        "//java/dev/enola/common",
         "//java/dev/enola/common/context",
         "//java/dev/enola/common/io",
         "@enola_maven//:com_github_ipld_java_cid",

java/dev/enola/cas/BlobStore.java

@@ -0,0 +1,45 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright 2025 The Enola <https://enola.dev> Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package dev.enola.cas;
+
+import com.google.common.io.ByteSource;
+
+import io.ipfs.cid.Cid;
+
+/**
+ * BlobStore stores bytes, which can then be loaded given their CID.
+ *
+ * <p>Note that this interface per-se does not specify anything about how this may be implemented...
+ * just with simple non-distributed local files. Or into a Key Value Store. Or e.g. with <a
+ * href="https://github.com/systemd/casync/">systemd casync</a>. Or may be on <a
+ * href="https://ipfs.tech/>IPFS</a>, either in <a href="https://ipld.io/specs/transport/car/">CAR
+ * files</a>, or it may be distributed (with <a
+ * href="https://docs.ipfs.tech/install/command-line/">IPFS Bitswap with Kubo</a>, or <a
+ * href="https://github.com/Peergos/nabu">Nabu</a>; or perhaps on the <a
+ * href="https://iroh.network/">Iroh Network</a> based on <a
+ * href="https://www.iroh.computer/">Iroh</a> by <a href="https://n0.computer/">number0</a>. Or
+ * something else, maybe based on Consensus with Raft or Paxos.
+ */
+public interface BlobStore {
+
+    Cid store(ByteSource source);
+
+    ByteSource load(Cid cid);
+
+    // TODO void delete(Cid cid)
+}

java/dev/enola/cas/IPFS.java

@@ -0,0 +1,43 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright 2025 The Enola <https://enola.dev> Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package dev.enola.cas;
+
+import static java.util.Objects.requireNonNull;
+
+import com.google.common.io.ByteSource;
+
+import io.ipfs.cid.Cid;
+
+public class IPFS implements BlobStore { // TODO , IdStore
+
+    private final IPFSResource.Provider ipfsResourceProvider;
+
+    public IPFS(IPFSResource.Provider ipfsResourceProvider) {
+        this.ipfsResourceProvider = ipfsResourceProvider;
+    }
+
+    @Override
+    public Cid store(ByteSource source) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public ByteSource load(Cid cid) {
+        return requireNonNull(ipfsResourceProvider.get("ipfs:" + cid)).byteSource();
+    }
+}

java/dev/enola/cas/IdStore.java

@@ -0,0 +1,32 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright 2025 The Enola <https://enola.dev> Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package dev.enola.cas;
+
+import com.google.common.primitives.Bytes;
+
+import dev.enola.common.ByteSeq;
+
+import io.ipfs.cid.Cid;
+
+/** IdStore stores links of IDs of bytes to CIDs. */
+public interface IdStore {
+
+    void link(ByteSeq bytes, Cid cid);
+
+    Cid get(Bytes link);
+}

java/dev/enola/common/io/resource/ResourceProvider.java

@@ -37,8 +37,8 @@ public interface ResourceProvider extends ProviderFromIRI<Resource> {
 
     // TODO Rename all parameters from iri or uri to url - because that's what these are!
 
-    // TODO Change all @Nullable Resource to Optional<Resource>... or, better, throw exception for
-    // unknown schema
+    // TODO Separate @NonNull SPI provider, instead of changing all @Nullable Resource to
+    // Optional<Resource>... or, better, throw exception for unknown schema
 
     // TODO Should this have a Resource getResource(URI uri, MediaType mediaType) ?