PE-5029: adds a parameter to by pass the download verification

lib/src/streams/download.dart

@@ -1,39 +1,13 @@
 import 'dart:async';
 import 'dart:convert';
 import 'dart:typed_data';
+
 import 'package:arweave/arweave.dart';
+import 'package:arweave/src/utils/graph_ql_utils.dart';
 import 'package:async/async.dart';
 import 'package:http/http.dart';
-import 'http_client/io.dart' if (dart.library.js) 'http_client/browsers.dart';
 
-String gqlGetTxInfo(String txId) => '''
-{
-  transaction(id: "$txId") {
-    owner {
-      key
-    }
-    data {
-      size
-    }
-    quantity {
-      winston
-    }
-    fee {
-      winston
-    }
-    anchor
-    signature
-    recipient
-    tags {
-      name
-      value
-    }
-    bundledIn {
-      id
-    }
-  }
-}
-''';
+import 'http_client/io.dart' if (dart.library.js) 'http_client/browsers.dart';
 
 Future<
     (
@@ -43,47 +17,26 @@ Future<
   required String txId,
   String? gatewayHost = 'arweave.net',
   Function(double progress, int speed)? onProgress,
+  bool verifyDownload = true,
 }) async {
   final downloadUrl = "https://$gatewayHost/$txId";
-  final gqlUrl = "https://$gatewayHost/graphql";
-
-  final gqlResponse = await post(
-    Uri.parse(gqlUrl),
-    headers: {'Content-Type': 'application/json'},
-    body: jsonEncode({'query': gqlGetTxInfo(txId)}),
-  );
-
-  if (gqlResponse.statusCode != 200) {
-    throw Exception('Failed to download $txId');
-  }
-
-  var txData = jsonDecode(gqlResponse.body)['data']['transaction'];
-
-  final txAnchor = txData['anchor'];
-  final txOwner = txData['owner']['key'];
-  final txTarget = txData['recipient'];
-  final txSignature = txData['signature'];
-  final txDataSize = int.parse(txData['data']['size']);
-  final isDataItem = txData['bundledIn'] != null;
-  final txQuantity = int.parse(txData['quantity']['winston']);
-  final txReward = int.parse(txData['fee']['winston']);
-  final downloadedTags = txData['tags'];
-  final List<Tag> txTags = [];
-  for (var tag in downloadedTags) {
-    txTags.add(createTag(tag['name'], tag['value']));
-  }
 
   int bytesDownloaded = 0;
   StreamSubscription<List<int>>? subscription;
   final controller = StreamController<List<int>>();
 
+  final txData = await _getTransactionData(
+    txId: txId,
+    gatewayHost: gatewayHost!,
+  );
+
   // keep track of progress and download speed
   int lastBytes = 0;
   setProgressTimer(onProgress) => Timer.periodic(
         Duration(milliseconds: 500),
         (Timer timer) {
-          double progress =
-              double.parse((bytesDownloaded / txDataSize).toStringAsFixed(2));
+          double progress = double.parse(
+              (bytesDownloaded / txData.dataSize).toStringAsFixed(2));
           int speed = bytesDownloaded - lastBytes;
 
           onProgress(
@@ -106,46 +59,62 @@ Future<
     final client = getClient();
     final streamResponse = await client.send(request);
 
-    final splitStream = StreamSplitter(streamResponse.stream);
-    final downloadStream = splitStream.split();
-    final verificationStream = splitStream.split();
-
-    // Calling `close()` indicates that no further streams will be created,
-    // causing splitStream to function without an internal buffer.
-    // The future will be completed when both streams are consumed, so we
-    // shouldn't await it here.
-    unawaited(splitStream.close());
-
-    _verify(
-      isDataItem: isDataItem,
-      id: txId,
-      owner: txOwner,
-      signature: txSignature,
-      target: txTarget,
-      anchor: txAnchor,
-      tags: txTags,
-      dataStream: verificationStream.map((list) => Uint8List.fromList(list)),
-      reward: txReward,
-      quantity: txQuantity,
-      dataSize: txDataSize,
-    ).then((isVerified) {
-      if (!isVerified) {
-        controller.addError('failed to verify transaction');
-      }
-
-      subscription?.cancel();
-      controller.close();
-      if (onProgress != null) {
-        progressTimer.cancel();
-      }
-    });
+    Stream<List<int>> downloadStream;
+
+    if (verifyDownload) {
+      final splitStream = StreamSplitter(streamResponse.stream);
+
+      downloadStream = splitStream.split();
+      final verificationStream = splitStream.split();
+
+      // Calling `close()` indicates that no further streams will be created,
+      // causing splitStream to function without an internal buffer.
+      // The future will be completed when both streams are consumed, so we
+      // shouldn't await it here.
+      unawaited(splitStream.close());
+
+      _verify(
+        dataStream: verificationStream,
+        txData: txData,
+        txId: txId,
+      ).then((isVerified) {
+        if (!isVerified) {
+          // TODO: maybe using a custom Exception here would be better? e.g. ValidationException
+          controller.addError('failed to verify transaction');
+        }
+
+        controller.close();
+        subscription?.cancel();
+      });
+    } else {
+      /// If we don't need to verify the download, we can just return the
+      /// stream directly.
+      downloadStream = streamResponse.stream;
+    }
 
     subscription = downloadStream.listen(
       (List<int> chunk) {
         bytesDownloaded += chunk.length;
         controller.sink.add(chunk);
       },
       cancelOnError: true,
+      onError: (e) {
+        print('[arweave]: Error downloading $txId');
+
+        controller.addError(e);
+        controller.close();
+
+        if (onProgress != null) {
+          progressTimer.cancel();
+        }
+      },
+      onDone: () {
+        if (onProgress != null) {
+          progressTimer.cancel();
+        }
+
+        controller.close();
+      },
     );
   }
 
@@ -175,40 +144,89 @@ Future<
   return (controller.stream, cancelDownload);
 }
 
-_verify({
-  required bool isDataItem,
-  required String id,
-  required String owner,
-  required String signature,
-  required String target,
-  required String anchor,
-  required List<Tag> tags,
+// TODO: maybe move this to a separate file? An utils file maybe?
+// We problably have the same logic on ardrive-app project. Maybe we can
+// create a package with this logic and use it on both projects.
+Future<TransactionData> _getTransactionData({
+  required String txId,
+  required String gatewayHost,
+}) async {
+  final gqlUrl = "https://$gatewayHost/graphql";
+
+  final gqlResponse = await post(
+    Uri.parse(gqlUrl),
+    headers: {'Content-Type': 'application/json'},
+    body: jsonEncode({'query': gqlGetTxInfo(txId)}),
+  );
+
+  if (gqlResponse.statusCode != 200) {
+    throw Exception('Failed to download $txId');
+  }
+
+  var txDataJson = jsonDecode(gqlResponse.body)['data']['transaction'];
+
+  return TransactionData.fromJson(txDataJson);
+}
+
+Future<bool> _verify({
+  required TransactionData txData,
+  required String txId,
   required Stream<List<int>> dataStream,
-  required int reward,
-  required int quantity,
-  required int dataSize,
 }) {
-  if (isDataItem) {
+  if (txData.isDataItem) {
     return verifyDataItem(
-        id: id,
-        owner: owner,
-        signature: signature,
-        target: target,
-        anchor: anchor,
-        tags: tags,
+        id: txId,
+        owner: txData.owner,
+        signature: txData.signature,
+        target: txData.target,
+        anchor: txData.anchor,
+        tags: txData.tags,
         dataStream: dataStream.map((list) => Uint8List.fromList(list)));
   } else {
     return verifyTransaction(
-      id: id,
-      owner: owner,
-      signature: signature,
-      target: target,
-      anchor: anchor,
-      tags: tags,
-      reward: reward,
-      quantity: quantity,
-      dataSize: dataSize,
+      id: txId,
+      owner: txData.owner,
+      signature: txData.signature,
+      target: txData.target,
+      anchor: txData.anchor,
+      tags: txData.tags,
+      reward: txData.reward,
+      quantity: txData.quantity,
+      dataSize: txData.dataSize,
       dataStream: dataStream.map((list) => Uint8List.fromList(list)),
     );
   }
 }
+
+class TransactionData {
+  late String anchor;
+  late String owner;
+  late String target;
+  late String signature;
+  late int dataSize;
+  late bool isDataItem;
+  late int quantity;
+  late int reward;
+  late List<Tag> tags;
+
+  TransactionData.fromJson(Map<String, dynamic> json) {
+    parseData(json);
+  }
+
+  void parseData(Map<String, dynamic> jsonData) {
+    anchor = jsonData['anchor'];
+    owner = jsonData['owner']['key'];
+    target = jsonData['recipient'];
+    signature = jsonData['signature'];
+    dataSize = int.parse(jsonData['data']['size']);
+    isDataItem = jsonData['bundledIn'] != null;
+    quantity = int.parse(jsonData['quantity']['winston']);
+    reward = int.parse(jsonData['fee']['winston']);
+
+    var downloadedTags = jsonData['tags'];
+    tags = [];
+    for (var tag in downloadedTags) {
+      tags.add(createTag(tag['name'], tag['value']));
+    }
+  }
+}

lib/src/utils/graph_ql_utils.dart

@@ -0,0 +1,28 @@
+String gqlGetTxInfo(String txId) => '''
+{
+  transaction(id: "$txId") {
+    owner {
+      key
+    }
+    data {
+      size
+    }
+    quantity {
+      winston
+    }
+    fee {
+      winston
+    }
+    anchor
+    signature
+    recipient
+    tags {
+      name
+      value
+    }
+    bundledIn {
+      id
+    }
+  }
+}
+''';

pubspec.yaml

@@ -1,6 +1,6 @@
 name: arweave
 description: ""
-version: 3.8.2
+version: 3.8.3
 environment:
   sdk: ">=3.0.0 <4.0.0"
 publish_to: none