Remove sleep call in pcfunc tile fetching (#132)

The sleep call did have an effect of spreading out requests over time,
but in an arbitrary and non-efficient manner. The semaphore context
block effectively blocks on a counter-based lock.

pc-funcs.dev.env

@@ -3,10 +3,10 @@ WEBSITE_HOSTNAME=funcs:8083
 
 ANIMATION_OUTPUT_STORAGE_URL="http://azurite:10000/devstoreaccount1/output/animations"
 ANIMATION_OUTPUT_ACCOUNT_KEY="Eby8vdM02xNOcqFlqUwJPLlmEtlCDXJ1OUzFT50uSRZ6IFsuFq2UVErCz4I6tq/K1SZFPTOtr/KBHBeksoGMGw=="
-ANIMATION_API_ROOT_URL="https://planetarycomputer.microsoft.com/api/data/v1"
+ANIMATION_API_ROOT_URL="https://planetarycomputer-staging.microsoft.com/api/data/v1"
 ANIMATION_TILE_REQUEST_CONCURRENCY=2
 
 IMAGE_OUTPUT_STORAGE_URL="http://azurite:10000/devstoreaccount1/output/images"
 IMAGE_OUTPUT_ACCOUNT_KEY="Eby8vdM02xNOcqFlqUwJPLlmEtlCDXJ1OUzFT50uSRZ6IFsuFq2UVErCz4I6tq/K1SZFPTOtr/KBHBeksoGMGw=="
-IMAGE_API_ROOT_URL="https://planetarycomputer.microsoft.com/api/data/v1"
-IMAGE_TILE_REQUEST_CONCURRENCY=2
+IMAGE_API_ROOT_URL="https://planetarycomputer-staging.microsoft.com/api/data/v1"
+IMAGE_TILE_REQUEST_CONCURRENCY=2

pcfuncs/funclib/tiles.py

@@ -162,11 +162,6 @@ async def _f() -> io.BytesIO:
             async with aiohttp.ClientSession() as session:
                 async with self._async_limit:
                     async with session.get(url) as resp:
-                        # Download the image tile, block if exceeding concurrency limits
-                        if self._async_limit.locked():
-                            logger.info("Concurrency limit reached, waiting...")
-                            await asyncio.sleep(1)
-
                         if resp.status == 200:
                             return io.BytesIO(await resp.read())
                         else: