Update python bindings

Author: kylebarron

python/Cargo.lock

@@ -21,7 +21,7 @@ from async_tiff.store import S3Store
 store = S3Store("naip-visualization", region="us-west-2", request_payer=True)
 path = "ny/2022/60cm/rgb/40073/m_4007307_sw_18_060_20220803.tif"
 
-tiff = await TIFF.open(path, store=store, prefetch=32768)
+tiff = await TIFF.open(path, store=store)
 primary_ifd = tiff.ifds[0]
 
 primary_ifd.geo_key_directory.citation
@@ -68,7 +68,7 @@ from async_tiff.store import S3Store
 store = S3Store("sentinel-cogs", region="us-west-2", skip_signature=True)
 path = "sentinel-s2-l2a-cogs/12/S/UF/2022/6/S2B_12SUF_20220609_0_L2A/B04.tif"
 
-tiff = await TIFF.open(path, store=store, prefetch=32768)
+tiff = await TIFF.open(path, store=store)
 primary_ifd = tiff.ifds[0]
 # Text readable citation
 primary_ifd.geo_key_directory.citation

python/README.md

@@ -17,13 +17,18 @@ class TIFF:
         *,
         store: ObjectStore | ObspecInput,
         prefetch: int = 32768,
+        multiplier: int | float = 2.0,
     ) -> TIFF:
         """Open a new TIFF.
 
         Args:
             path: The path within the store to read from.
             store: The backend to use for data fetching.
             prefetch: The number of initial bytes to read up front.
+            multiplier: The multiplier to use for readahead size growth. Must be
+                greater than 1.0. For example, for a value of `2.0`, the first metadata
+                read will be of size `prefetch`, and then the next read will be of size
+                `prefetch * 2`.
 
         Returns:
             A TIFF instance.

python/python/async_tiff/_tiff.pyi

@@ -1,9 +1,10 @@
 use std::sync::Arc;
 
-use async_tiff::metadata::{PrefetchBuffer, TiffMetadataReader};
+use async_tiff::metadata::cache::ReadaheadMetadataCache;
+use async_tiff::metadata::TiffMetadataReader;
 use async_tiff::reader::AsyncFileReader;
 use async_tiff::TIFF;
-use pyo3::exceptions::{PyFileNotFoundError, PyIndexError, PyTypeError};
+use pyo3::exceptions::{PyIndexError, PyTypeError};
 use pyo3::prelude::*;
 use pyo3::types::PyType;
 use pyo3_async_runtimes::tokio::future_into_py;
@@ -21,20 +22,21 @@ pub(crate) struct PyTIFF {
 #[pymethods]
 impl PyTIFF {
     #[classmethod]
-    #[pyo3(signature = (path, *, store, prefetch=32768))]
+    #[pyo3(signature = (path, *, store, prefetch=32768, multiplier=2.0))]
     fn open<'py>(
         _cls: &'py Bound<PyType>,
         py: Python<'py>,
         path: String,
         store: StoreInput,
         prefetch: u64,
+        multiplier: f64,
     ) -> PyResult<Bound<'py, PyAny>> {
         let reader = store.into_async_file_reader(path);
 
         let cog_reader = future_into_py(py, async move {
-            let metadata_fetch = PrefetchBuffer::new(reader.clone(), prefetch)
-                .await
-                .map_err(|err| PyFileNotFoundError::new_err(err.to_string()))?;
+            let metadata_fetch = ReadaheadMetadataCache::new(reader.clone())
+                .with_initial_size(prefetch)
+                .with_multiplier(multiplier);
             let mut metadata_reader = TiffMetadataReader::try_open(&metadata_fetch).await.unwrap();
             let ifds = metadata_reader
                 .read_all_ifds(&metadata_fetch)

python/src/tiff.rs

@@ -11,7 +11,7 @@ async def test_cog_s3():
     """
     path = "sentinel-s2-l2a-cogs/12/S/UF/2022/6/S2B_12SUF_20220609_0_L2A/B04.tif"
     store = S3Store("sentinel-cogs", region="us-west-2", skip_signature=True)
-    tiff = await TIFF.open(path=path, store=store, prefetch=32768)
+    tiff = await TIFF.open(path=path, store=store)
 
     ifds = tiff.ifds
     assert len(ifds) == 5