Added support for COD metadata v2.0

Author: Adithyan-Dinesh-Trenser

package.json

@@ -1,7 +1,7 @@
 {
   "name": "cod-dicomweb-server",
   "title": "COD Dicomweb server",
-  "version": "1.3.17",
+  "version": "1.3.18",
   "private": false,
   "description": "A wadors server proxy that get data from a Cloud Optimized Dicom format.",
   "main": "dist/umd/main.js",
@@ -93,6 +93,7 @@
   "dependencies": {
     "comlink": "4.4.2",
     "dicom-parser": "1.8.21",
-    "idb-keyval": "6.2.2"
+    "idb-keyval": "6.2.2",
+    "zstddec": "^0.1.0"
   }
 }

src/classes/CodDicomWebServer.ts

@@ -451,9 +451,10 @@ class CodDicomWebServer {
     sopInstanceUID: string
   ): InstanceMetadata | SeriesMetadata {
     if (type === Enums.RequestType.INSTANCE_METADATA) {
-      return Object.entries(metadata.cod.instances).find(([key, instance]) => key === sopInstanceUID)?.[1].metadata;
+      return Object.entries(metadata.cod.instances).find(([key, instance]) => key === sopInstanceUID)?.[1]
+        .metadata as InstanceMetadata;
     } else {
-      return Object.values(metadata.cod.instances).map((instance) => instance.metadata);
+      return Object.values(metadata.cod.instances).map((instance) => instance.metadata as InstanceMetadata);
     }
   }
 }

src/constants/index.ts

@@ -1,8 +1,9 @@
 import * as Enums from './enums';
 import * as url from './url';
 import * as dataRetrieval from './dataRetrieval';
+import * as medatata from './metadata';
 
-const constants = { Enums, url, dataRetrieval };
+const constants = { Enums, url, dataRetrieval, medatata };
 
-export { Enums, url, dataRetrieval };
+export { Enums, url, dataRetrieval, medatata };
 export default constants;

src/constants/metadata.ts

@@ -0,0 +1,8 @@
+/**
+ * * V1 (1.0) - The metadata is in the type `InstanceMetadata`( Deprecated since cod-dicomweb-server@v1.3.18 ).
+ * * V2 (2.0) - The metadata is in the type `string`.
+ */
+export const METADATA_VERSION = {
+  V1: '1.0',
+  V2: '2.0'
+};

src/metadataManager.ts

@@ -1,14 +1,33 @@
+import { ZSTDDecoder } from 'zstddec';
+
 import { CustomError } from './classes/customClasses';
 import { createMetadataJsonUrl } from './classes/utils';
+import { medatata } from './constants';
 import { createMetadataFileName, getDirectoryHandle, readFile, writeFile } from './fileAccessSystemUtils';
-import type { JsonMetadata, MetadataUrlCreationParams } from './types';
+import type { InstanceMetadata, JsonMetadata, MetadataUrlCreationParams } from './types';
 
 class MetadataManager {
   private metadataPromises: Record<string, Promise<JsonMetadata>> = {};
+  private decoder?: ZSTDDecoder;
+  private decoderInitPromise: Promise<boolean>;
+
+  constructor() {
+    this.decoder = null;
+    const decoder = new ZSTDDecoder();
 
-  constructor() {}
+    this.decoderInitPromise = decoder
+      .init()
+      .then(() => {
+        this.decoder = decoder;
+        return true;
+      })
+      .catch((error) => {
+        console.error('Failed to initialize ZSTD WASM module:', error);
+        return false;
+      });
+  }
 
-  public addDeidMetadata(jsonMetadata: JsonMetadata, url: string): void {
+  public async addDeidMetadata(jsonMetadata: JsonMetadata, url: string): Promise<void> {
     const { cod } = jsonMetadata;
     const [studyUID, _, seriesUID] = url.match(/studies\/(.*?)\/metadata/)?.[1].split('/') || [];
 
@@ -19,9 +38,22 @@ class MetadataManager {
 
     for (const sopUID in cod.instances) {
       const instance = cod.instances[sopUID];
-      instance.metadata.DeidStudyInstanceUID = { Value: [studyUID] };
-      instance.metadata.DeidSeriesInstanceUID = { Value: [seriesUID] };
-      instance.metadata.DeidSopInstanceUID = { Value: [sopUID] };
+
+      // For V2, convert the metadata to InstanceMetadata format.
+      if (instance.version === medatata.METADATA_VERSION.V2 && typeof instance.metadata === 'string') {
+        const parsedMetadata = await this.decodeDecompressAndParse(instance.metadata);
+
+        if (!parsedMetadata) {
+          throw new Error('Failed to decode, decompress, or parse JSON');
+        }
+
+        instance.metadata = parsedMetadata;
+      }
+
+      const instanceMetadata = instance.metadata as InstanceMetadata;
+      instanceMetadata.DeidStudyInstanceUID = { Value: [studyUID] };
+      instanceMetadata.DeidSeriesInstanceUID = { Value: [seriesUID] };
+      instanceMetadata.DeidSopInstanceUID = { Value: [sopUID] };
     }
   }
 
@@ -56,9 +88,10 @@ class MetadataManager {
           }
           return response.json();
         })
-        .then((data) => {
-          this.addDeidMetadata(data, url);
-          return writeFile(directoryHandle, fileName, data, true).then(() => data);
+        .then(async (data) => {
+          await this.addDeidMetadata(data, url);
+          await writeFile(directoryHandle, fileName, data, true);
+          return data;
         });
 
       return await this.metadataPromises[url];
@@ -67,6 +100,26 @@ class MetadataManager {
       throw error;
     }
   }
+
+  private async decodeDecompressAndParse(base64String: string): Promise<InstanceMetadata> {
+    if (!base64String) {
+      return null;
+    }
+
+    try {
+      if (!(await this.decoderInitPromise)) {
+        throw new Error('WASM Decoder is not initialized. Cannot decompress data.');
+      }
+
+      const compressedBytes = Uint8Array.from(atob(base64String), (c) => c.charCodeAt(0));
+      const decompressedBytes = this.decoder.decode(compressedBytes);
+      const jsonString = new TextDecoder().decode(decompressedBytes);
+      return JSON.parse(jsonString);
+    } catch (error) {
+      console.error('Failed to decode, decompress, or parse JSON:', error);
+      return null;
+    }
+  }
 }
 
 export default MetadataManager;

src/types/metadata.ts

@@ -8,7 +8,7 @@ type JsonMetadata = {
     instances: Record<
       string,
       {
-        metadata: InstanceMetadata;
+        metadata: InstanceMetadata | string;
         // The metadata will either have url or uri
         uri: string;
         url: string;
@@ -22,7 +22,7 @@ type JsonMetadata = {
         original_path: string;
         dependencies: string[];
         diff_hash_dupe_paths: [string];
-        version: string;
+        version: '1.0' | '2.0';
         modified_datetime: string;
       }
     >;

yarn.lock

@@ -5864,3 +5864,8 @@ yocto-queue@^1.0.0:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/yocto-queue/-/yocto-queue-1.1.1.tgz#fef65ce3ac9f8a32ceac5a634f74e17e5b232110"
   integrity sha512-b4JR1PFR10y1mKjhHY9LaGo6tmrgjit7hxVIeAmyMw3jegXR4dhYqLaQF5zMXZxY7tLpMyJeLjr1C4rLmkVe8g==
+
+zstddec@^0.1.0:
+  version "0.1.0"
+  resolved "https://registry.yarnpkg.com/zstddec/-/zstddec-0.1.0.tgz#7050f3f0e0c3978562d0c566b3e5a427d2bad7ec"
+  integrity sha512-w2NTI8+3l3eeltKAdK8QpiLo/flRAr2p8AGeakfMZOXBxOg9HIu4LVDxBi81sYgVhFhdJjv1OrB5ssI8uFPoLg==