aioredis-rpc 1.1.0
An RPC library based on aioredis, msgpack, and pydantic.
License: MIT
Requires Python: >=3.6.1
Keywords: aioredis msgpack python redis rpc

# aioredis-rpc

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A RPC interface using [aioredis](https://github.com/aio-libs/aioredis-py)
and [pydantic](https://github.com/samuelcolvin/pydantic).

## Usage

```bash
pip install aioredis-rpc
```

`pydantic` is used to model complex objects which are transparently serialized
and packed into messages using `msgpack`.

```python
# Define Pydantic models
class FileData(BaseModel):
  filename: str
  data: bytes
```

Define a class using the `@endpoint` decorator to specify which methods will be
accessible via rpc.

```python
from redisrpc import endpoint

# Define an RPC class
class Dropbox:
  files: Dict[str, FileData]
  max_files: int

  def __init__(self, max_files: int = 1000):
    self.files = dict()
    self.max_files = max_files

  @endpoint
  async def upload_file(self, file: FileData) -> int:
    if len(self.files) >= self.max_files:
      # Errors are propagated to the client-side
      raise Exception('too many files')
    self.files[file.name] = file
    return len(file.data)

  @endpoint
  def get_file_names(self) -> List[str]:
    return list(self.files.keys())

  @endpoint
  async def download_file(self, name: str) -> FileData:
    return self.files[name]
```

Use the `create_server` function to make an instance of your server-side rpc
class. The server instance will be assigned an `rpc` attribute to access server
functions like `connect` and `disconnect`. Once `connect` is called methods
decorated with `@endpoint` will be invoked automatically by remote calls from
the client.

> _NOTE: The `RpcProvider.connect` method is non-blocking._

```python
server = create_server(Dropbox, max_files=2)
# Returns once connected to redis
await server.rpc.connect(dsn="redis://localhost")
# Wait forever
while True:
  await asyncio.sleep(1)
```

The `create_client` function create a faux instance of the rpc class with only
the methods decorated by `@endpoint` present. When these methods are called by
the client the function arguments are serialized and published to redis.

> _NOTE: If there are no subscribers to the redis channel then the client will
> throw a `RpcNotConnectedError`._

```python
client = create_client(Dropbox)
await client.rpc.connect(dsn="redis://localhost")
```

Now that both ends are connected the `@endpoint` decorated methods may be called
like they are accessing the actual class passed to `create_client`.

```python
file1 = FileData(name='file1', data=b'1234')
size = await client.upload_file(file1)
```