increase max message size and implement (lossy) compression

python/lsst/rubintv/analysis/service/commands/butler.py

@@ -141,12 +141,15 @@ class GetFitsImageCommand(BaseCommand):
     data_id : dict
         The data ID of the image. Depending on the type of image this could
         include things like "band" or "visit" or "detector".
+    compress : bool
+        Compress the image before sending.
     """
 
     repo: str
     image_name: str
     collection: dict
     data_id: dict
+    compress: bool
     response_type: str = "fits"
 
     def build_contents(self, data_center: DataCenter) -> dict:
@@ -161,9 +164,20 @@ def build_contents(self, data_center: DataCenter) -> dict:
         logger.info("Received exposure.")
 
         manager = MemFileManager()
-        exposure.writeFits(manager)
-        content = base64.b64encode(manager.getData()).decode('utf-8')
-        logger.info("Encoded exposure.")
+        opts = dict()
+        if self.compress:
+            from lsst.afw.fits import ImageCompressionOptions, ImageWriteOptions, ImageScalingOptions
+            logger.info("Configuring compression.")
+            quantize = 10.0
+            compression = ImageCompressionOptions(ImageCompressionOptions.RICE, True, 0.0)
+            scaling = ImageScalingOptions(ImageScalingOptions.STDEV_BOTH, 32, quantizeLevel=quantize)
+            opts['imageOptions'] = ImageWriteOptions(compression, scaling)
+            opts['maskOptions'] = ImageWriteOptions(compression)
+            opts['varianceOptions'] = opts['imageOptions']
+        exposure.writeFits(manager, **opts)
+
+        logger.info("Encoding exposure...")
+        content = base64.b64encode(manager.getData()).decode('ascii')
 
         return {
             "fits": content,

scripts/mock_server.py

@@ -51,6 +51,7 @@ class WebSocketHandler(tornado.websocket.WebSocketHandler):
     workers: dict[str, WorkerPod] = dict()  # Keep track of connected worker pods
     clients: dict[str, WebSocketHandler] = dict()  # Keep track of connected clients
     queue: list[QueueItem] = list()  # Queue of messages to be processed
+    max_message_size: int = 100 * 1024 * 1024 # Maximum message size
 
     @classmethod
     def urls(cls) -> list[tuple[str, type[tornado.web.RequestHandler], dict[str, str]]]: