feat: Implement a first draft of the RoutingResourceStore

src/storage/routing/PathRouterRule.ts

@@ -0,0 +1,35 @@
+import type { Representation } from '../../ldp/representation/Representation';
+import type { ResourceIdentifier } from '../../ldp/representation/ResourceIdentifier';
+import { NotFoundHttpError } from '../../util/errors/NotFoundHttpError';
+import { UnsupportedHttpError } from '../../util/errors/UnsupportedHttpError';
+import type { ResourceStore } from '../ResourceStore';
+import type { RouterRule } from './RouterRule';
+
+// TODO:
+export class PathRouterRule implements RouterRule {
+  private readonly pathMap: { [path: string]: ResourceStore };
+
+  public constructor(pathMap: { [path: string]: ResourceStore }) {
+    this.pathMap = pathMap;
+  }
+
+  public async getMatchingResourceStore(identifier: ResourceIdentifier, representation?: Representation):
+  Promise<ResourceStore> {
+    const paths = Object.keys(this.pathMap);
+    const matches = paths.filter((path): boolean => identifier.path.includes(path));
+    if (matches.length !== 1) {
+      // Incoming data, need to reject
+      if (representation) {
+        throw new UnsupportedHttpError(
+          `Identifiers need to have exactly 1 of the following in them: [${paths.join(', ')}]`,
+        );
+
+      // Because of the above requirement, we know this will always be a 404 for requests
+      } else {
+        throw new NotFoundHttpError();
+      }
+    }
+
+    return this.pathMap[matches[0]];
+  }
+}

src/storage/routing/RdfConvertingRouterRule.ts

@@ -0,0 +1,42 @@
+import type { Representation } from '../../ldp/representation/Representation';
+import type { ResourceIdentifier } from '../../ldp/representation/ResourceIdentifier';
+import { INTERNAL_QUADS } from '../../util/ContentTypes';
+import type { RepresentationConverter } from '../conversion/RepresentationConverter';
+import type { ResourceStore } from '../ResourceStore';
+import type { RouterRule } from './RouterRule';
+
+// TODO:
+export class RdfConvertingRouterRule implements RouterRule {
+  private readonly rdfStore: ResourceStore;
+  private readonly binaryStore: ResourceStore;
+  private readonly converter: RepresentationConverter;
+
+  public constructor(rdfStore: ResourceStore, binaryStore: ResourceStore, converter: RepresentationConverter) {
+    this.rdfStore = rdfStore;
+    this.binaryStore = binaryStore;
+    this.converter = converter;
+  }
+
+  public async getMatchingResourceStore(identifier: ResourceIdentifier, representation?: Representation):
+  Promise<ResourceStore> {
+    if (representation) {
+      try {
+        const preferences = { type: [{ value: INTERNAL_QUADS, weight: 1 }]};
+        await this.converter.canHandle({ identifier, representation, preferences });
+        return this.rdfStore;
+      } catch {
+        return this.binaryStore;
+      }
+    } else {
+      // No content-type given so we can only check if one of the stores has data for the identifier
+      // Any of the two stores can be used. Using the binary one here since that one would be faster in current cases.
+      try {
+        const response = await this.binaryStore.getRepresentation(identifier, {});
+        response.data.destroy();
+        return this.binaryStore;
+      } catch {
+        return this.rdfStore;
+      }
+    }
+  }
+}

src/storage/routing/RouterRule.ts

@@ -0,0 +1,20 @@
+import type { Representation } from '../../ldp/representation/Representation';
+import type { ResourceIdentifier } from '../../ldp/representation/ResourceIdentifier';
+import type { ResourceStore } from '../ResourceStore';
+
+/**
+ * A RouterRule represents a rule that decides which instance of a
+ * ResourceStore should be used to handle the incoming request.
+ */
+export interface RouterRule {
+
+  /**
+   * Find the appropriate ResourceStore to which the request should be routed based on the incoming parameters.
+   * @param identifier - Incoming ResourceIdentifier.
+   * @param representation - Optional incoming Representation.
+   */
+  getMatchingResourceStore: (
+    identifier: ResourceIdentifier,
+    representation?: Representation,
+  ) => Promise<ResourceStore>;
+}