feat(ref-imp): changed IPFS CAS adaptor to use IPFS HTTP API directly

lib/common/ReadableStream.ts

@@ -1,22 +1,43 @@
+import SidetreeError from './SidetreeError';
+import ErrorCode from '../common/SharedErrorCode';
+
 /**
  * ReadableStream utilities
  */
 export default class ReadableStream {
 
   /**
-   * Given a readable stream, reads all data until end or error
-   * @param stream Fetch readable stream to read
+   * Given a readable stream, reads all data only if the content does not exceed given max size.
+   * Throws error if content exceeds give max size.
+   * @param stream Readable stream to read.
+   * @param maxAllowedSizeInBytes The maximum allowed size limit of the content.
    * @returns a Buffer of the readable stream data
    */
-  public static async readAll (stream: NodeJS.ReadableStream): Promise<Buffer> {
+  public static async readAll (stream: NodeJS.ReadableStream, maxAllowedSizeInBytes?: number): Promise<Buffer> {
     // Set callback for the 'readable' event to concatenate chunks of the readable stream.
     let content: Buffer = Buffer.alloc(0);
+    let currentSizeInBytes = 0;
 
     stream.on('readable', () => {
       // NOTE: Cast to any is to work-around incorrect TS definition for read() where
       // `null` should be a possible return type but is not defined in @types/node: 10.12.18.
       let chunk = stream.read() as any;
       while (chunk !== null) {
+        currentSizeInBytes += chunk.length;
+
+        // Monitor on read size only if `maxAllowedSizeInBytes` is set.
+        if (maxAllowedSizeInBytes !== undefined &&
+            currentSizeInBytes > maxAllowedSizeInBytes) {
+
+          const error = new SidetreeError(
+            ErrorCode.ReadableStreamMaxAllowedDataSizeExceeded,
+            `Max data size allowed: ${maxAllowedSizeInBytes} bytes, aborted reading at ${currentSizeInBytes} bytes.`
+          );
+
+          // NOTE: Cast to any is to work-around incorrect TS definition where `destroy()` is missing.
+          (stream as any).destroy(error);
+        }
+
         content = Buffer.concat([content, chunk]);
         chunk = stream.read();
       }

lib/common/SharedErrorCode.ts

@@ -4,7 +4,8 @@
 export default {
   BlockchainTimeOutOfRange: 'blockchain_time_out_of_range',
   InvalidTransactionNumberOrTimeHash: 'invalid_transaction_number_or_time_hash',
-  NotEnoughBalanceForWrite: 'not_enough_balace_for_write',
+  NotEnoughBalanceForWrite: 'not_enough_balance_for_write',
+  ReadableStreamMaxAllowedDataSizeExceeded: 'readable_stream_max_allowed_data_size_exceeded',
   SpendingCapPerPeriodReached: 'spending_cap_per_period_reached',
   ValueTimeLockNotFound: 'value_time_lock_not_found'
 };

lib/common/enums/FetchResultCode.ts

@@ -5,7 +5,6 @@ enum FetchResultCode {
   CasNotReachable = 'cas_not_reachable',
   InvalidHash = 'content_hash_invalid',
   MaxSizeExceeded = 'content_exceeds_maximum_allowed_size',
-  MaxSizeNotSpecified = 'content_max_size_not_specified',
   NotAFile = 'content_not_a_file',
   NotFound = 'content_not_found',
   Success = 'success'

lib/core/Core.ts

@@ -1,8 +1,8 @@
 import BatchScheduler from './BatchScheduler';
 import Blockchain from './Blockchain';
-import Cas from './Cas';
-import DownloadManager from './DownloadManager';
 import Config from './models/Config';
+import DownloadManager from './DownloadManager';
+import ICas from './interfaces/ICas';
 import MongoDbOperationStore from './MongoDbOperationStore';
 import MongoDbTransactionStore from '../common/MongoDbTransactionStore';
 import MongoDbUnresolvableTransactionStore from './MongoDbUnresolvableTransactionStore';
@@ -23,7 +23,6 @@ export default class Core {
   private operationStore: MongoDbOperationStore;
   private versionManager: VersionManager;
   private blockchain: Blockchain;
-  private cas: Cas;
   private downloadManager: DownloadManager;
   private observer: Observer;
   private batchScheduler: BatchScheduler;
@@ -33,12 +32,11 @@ export default class Core {
   /**
    * Core constructor.
    */
-  public constructor (config: Config, versionModels: VersionModel[]) {
+  public constructor (config: Config, versionModels: VersionModel[], private cas: ICas) {
     // Component dependency construction & injection.
     this.versionManager = new VersionManager(config, versionModels); // `VersionManager` is first constructed component.
     this.operationStore = new MongoDbOperationStore(config.mongoDbConnectionString, config.databaseName);
     this.blockchain = new Blockchain(config.blockchainServiceUri);
-    this.cas = new Cas(config.contentAddressableStoreServiceUri);
     this.downloadManager = new DownloadManager(config.maxConcurrentDownloads, this.cas);
     this.resolver = new Resolver(this.versionManager, this.operationStore);
     this.batchScheduler = new BatchScheduler(this.versionManager, this.blockchain, config.batchingIntervalInSeconds);
@@ -112,8 +110,7 @@ export default class Core {
   public async handleGetVersionRequest (): Promise<ResponseModel> {
     const responses = [
       this.serviceInfo.getServiceVersion(),
-      await this.blockchain.getServiceVersion(),
-      await this.cas.getServiceVersion()
+      await this.blockchain.getServiceVersion()
     ];
 
     return {

lib/core/models/Config.ts

@@ -4,7 +4,6 @@
 export default interface Config {
   batchingIntervalInSeconds: number;
   blockchainServiceUri: string;
-  contentAddressableStoreServiceUri: string;
   didMethodName: string;
   maxConcurrentDownloads: number;
   observingIntervalInSeconds: number;

lib/index.ts

@@ -1,13 +1,15 @@
 // NOTE: Aliases to classes and interfaces are used for external consumption.
 
 // Core service exports.
+import ISidetreeCas from './core/interfaces/ICas';
 import SidetreeCore from './core/Core';
 import SidetreeConfig from './core/models/Config';
 import SidetreeResponse from './common/Response';
 import SidetreeResponseModel from './common/models/ResponseModel';
 import SidetreeVersionModel from './common/models/VersionModel';
 
 export {
+  ISidetreeCas,
   SidetreeConfig,
   SidetreeCore,
   SidetreeResponse,
@@ -25,10 +27,3 @@ export {
   ISidetreeBitcoinWallet,
   SidetreeBitcoinProcessor
 };
-
-// IPFS service exports.
-import SidetreeIpfsService from './ipfs/RequestHandler';
-
-export {
-  SidetreeIpfsService
-};