Concurrent table scans (apache#373)

* feat: concurrent table scans

* refactor: remove TableScanConfig.

Author: sdd

Cargo.toml

@@ -66,6 +66,7 @@ itertools = "0.13"
 log = "^0.4"
 mockito = "^1"
 murmur3 = "0.5.2"
+num_cpus = "1"
 once_cell = "1"
 opendal = "0.48"
 ordered-float = "4.0.0"

crates/iceberg/Cargo.toml

@@ -61,6 +61,7 @@ fnv = { workspace = true }
 futures = { workspace = true }
 itertools = { workspace = true }
 murmur3 = { workspace = true }
+num_cpus = { workspace = true }
 once_cell = { workspace = true }
 opendal = { workspace = true }
 ordered-float = { workspace = true }

crates/iceberg/src/error.rs

@@ -331,6 +331,12 @@ define_from_err!(
     "Failed to read a Parquet file"
 );
 
+define_from_err!(
+    futures::channel::mpsc::SendError,
+    ErrorKind::Unexpected,
+    "Failed to send a message to a channel"
+);
+
 define_from_err!(std::io::Error, ErrorKind::Unexpected, "IO Operation failed");
 
 /// Converts a timestamp in milliseconds to `DateTime<Utc>`, handling errors.