Feature: download on ipfs client

src/aleph/sdk/client.py

@@ -23,6 +23,8 @@
     TypeVar,
     Union,
 )
+from io import BytesIO
+from typing import BinaryIO
 
 import aiohttp
 from aleph_message.models import (
@@ -31,6 +33,7 @@
     AlephMessage,
     ForgetContent,
     ForgetMessage,
+    ItemHash,
     ItemType,
     Message,
     MessageType,
@@ -42,7 +45,7 @@
 )
 from aleph_message.models.program import Encoding, ProgramContent
 from aleph_message.status import MessageStatus
-from pydantic import ValidationError
+from pydantic import ValidationError, BaseModel
 
 from aleph.sdk.types import Account, GenericMessage, StorageEnum
 
@@ -225,8 +228,17 @@ def get_posts(
             end_date=end_date,
         )
 
-    def download_file(self, file_hash: str) -> bytes:
-        return self._wrap(self.async_session.download_file, file_hash=file_hash)
+    def download_file(self, file_hash: str, chunk_size: int = 16 * 1024) -> bytes:
+        return self._wrap(
+            self.async_session.download_file, file_hash=file_hash, chunk_size=chunk_size
+        )
+
+    def download_file_ipfs(self, file_hash: str, chunk_size: int = 16 * 1024) -> bytes:
+        return self._wrap(
+            self.async_session.download_file_ipfs,
+            file_hash=file_hash,
+            chunk_size=chunk_size,
+        )
 
     def watch_messages(
         self,
@@ -608,22 +620,100 @@ async def get_posts(
             resp.raise_for_status()
             return await resp.json()
 
+    async def download_file_to_buffer(
+        self,
+        file_hash: str,
+        output_buffer: BinaryIO,
+        chunk_size: int,
+    ) -> None:
+        """
+        Download a file from the storage engine and write it to the specified output buffer.
+        :param file_hash: The hash of the file to retrieve.
+        :param output_buffer: Writable binary buffer. The file will be written to this buffer.
+        :param chunk_size: Size of the chunk to download.
+        """
+        IPFS_HASH = ItemHash(file_hash)
+
+        async with aiohttp.ClientSession() as session:
+            async with self.http_session.get(
+                f"/api/v0/storage/raw/{file_hash}"
+            ) as response:
+                if response.status == 200:
+                    response.raise_for_status()
+                    while True:
+                        chunk = await response.content.read(chunk_size)
+                        if not chunk:
+                            break
+                        output_buffer.write(chunk)
+                if response.status == 413:
+                    if ItemType.from_hash(IPFS_HASH) == ItemType.ipfs:
+                        return await self.download_file_ipfs_to_buffer(
+                            file_hash, output_buffer, chunk_size
+                        )
+                    else:
+                        raise Exception("Unsupported file hash")
+
+    async def download_file_ipfs_to_buffer(
+        self,
+        file_hash: str,
+        output_buffer: BinaryIO,
+        chunk_size: int,
+    ) -> None:
+        """
+        Download a file from the storage engine and write it to the specified output buffer.
+
+        :param file_hash: The hash of the file to retrieve.
+        :param output_buffer: The binary output buffer to write the file data to.
+        :param chunk_size: Size of chunk we download.
+        """
+        async with aiohttp.ClientSession() as session:
+            async with session.get(
+                f"https://ipfs.aleph.im/ipfs/{file_hash}"
+            ) as response:
+                response.raise_for_status()
+                while True:
+                    chunk = await response.content.read(chunk_size)
+                    if not chunk:
+                        break
+                    output_buffer.write(chunk)
+
     async def download_file(
         self,
         file_hash: str,
+        chunk_size: int = 16 * 1024,
     ) -> bytes:
         """
         Get a file from the storage engine as raw bytes.
 
         Warning: Downloading large files can be slow and memory intensive.
 
         :param file_hash: The hash of the file to retrieve.
+        :param chunk_size: The size of each chunk to read from the response.
         """
-        async with self.http_session.get(
-            f"/api/v0/storage/raw/{file_hash}"
-        ) as response:
-            response.raise_for_status()
-            return await response.read()
+        buffer = BytesIO()
+        await self.download_file_to_buffer(
+            file_hash, output_buffer=buffer, chunk_size=chunk_size
+        )
+        return buffer.getvalue()
+
+    async def download_file_ipfs(
+        self,
+        file_hash: str,
+        chunk_size: int = 16 * 1024,
+    ) -> bytes:
+        """
+        Get a file from the ipfs storage engine as raw bytes.
+
+        Warning: Downloading large files can be slow.
+
+        :param file_hash: The hash of the file to retrieve.
+        :param chunk_size: The size of each chunk to read from the response.
+        """
+        buffer = BytesIO()
+        await self.download_file_ipfs_to_buffer(
+            file_hash, output_buffer=buffer, chunk_size=chunk_size
+        )
+        return buffer.getvalue()
 
     async def get_messages(
         self,

tests/unit/test_download.py

@@ -0,0 +1,33 @@
+import pytest
+from aleph.sdk import AlephClient
+from aleph.sdk.conf import settings as sdk_settings
+
+
+@pytest.mark.parametrize(
+    "file_hash,expected_size",
+    [
+        ("QmeomffUNfmQy76CQGy9NdmqEnnHU9soCexBnGU3ezPHVH", 5),
+        ("Qmdy5LaAL4eghxE7JD6Ah5o4PJGarjAV9st8az2k52i1vq", 5817703),
+    ],
+)
+@pytest.mark.asyncio
+async def test_download(file_hash: str, expected_size: int):
+    async with AlephClient(api_server=sdk_settings.API_HOST) as client:
+        file_content = await client.download_file(file_hash)  # File is 5B
+        file_size = len(file_content)
+        assert file_size == expected_size
+
+
+@pytest.mark.parametrize(
+    "file_hash,expected_size",
+    [
+        ("QmeomffUNfmQy76CQGy9NdmqEnnHU9soCexBnGU3ezPHVH", 5),
+        ("Qmdy5LaAL4eghxE7JD6Ah5o4PJGarjAV9st8az2k52i1vq", 5817703),
+    ],
+)
+@pytest.mark.asyncio
+async def test_download_ipfs(file_hash: str, expected_size: int):
+    async with AlephClient(api_server=sdk_settings.API_HOST) as client:
+        file_content = await client.download_file_ipfs(file_hash)  ## 5817703 B FILE
+        file_size = len(file_content)
+        assert file_size == expected_size