1 files changed, 46 insertions, 0 deletions
diff --git a/third_party/rust/flate2/src/ffi/mod.rs b/third_party/rust/flate2/src/ffi/mod.rs
new file mode 100644
index 0000000000..4135e1143a
--- /dev/null
+++ b/third_party/rust/flate2/src/ffi/mod.rs
@@ -0,0 +1,46 @@
+//! This module contains backend-specific code.
+
+use crate::mem::{CompressError, DecompressError, FlushCompress, FlushDecompress, Status};
+use crate::Compression;
+
+/// Traits specifying the interface of the backends.
+///
+/// Sync + Send are added as a condition to ensure they are available
+/// for the frontend.
+pub trait Backend: Sync + Send {
+    fn total_in(&self) -> u64;
+    fn total_out(&self) -> u64;
+}
+
+pub trait InflateBackend: Backend {
+    fn make(zlib_header: bool, window_bits: u8) -> Self;
+    fn decompress(
+        &mut self,
+        input: &[u8],
+        output: &mut [u8],
+        flush: FlushDecompress,
+    ) -> Result<Status, DecompressError>;
+    fn reset(&mut self, zlib_header: bool);
+}
+
+pub trait DeflateBackend: Backend {
+    fn make(level: Compression, zlib_header: bool, window_bits: u8) -> Self;
+    fn compress(
+        &mut self,
+        input: &[u8],
+        output: &mut [u8],
+        flush: FlushCompress,
+    ) -> Result<Status, CompressError>;
+    fn reset(&mut self);
+}
+
+// Default to Rust implementation unless explicitly opted in to a different backend.
+cfg_if::cfg_if! {
+    if #[cfg(any(feature = "miniz-sys", feature = "any_zlib"))] {
+        mod c;
+        pub use self::c::*;
+    } else {
+        mod rust;
+        pub use self::rust::*;
+    }
+}