1 files changed, 58 insertions, 0 deletions
diff --git a/third_party/rust/miniz_oxide/src/deflate/buffer.rs b/third_party/rust/miniz_oxide/src/deflate/buffer.rs
new file mode 100644
index 0000000000..f246c07dfb
--- /dev/null
+++ b/third_party/rust/miniz_oxide/src/deflate/buffer.rs
@@ -0,0 +1,58 @@
+//! Buffer wrappers implementing default so we can allocate the buffers with `Box::default()`
+//! to avoid stack copies. Box::new() doesn't at the moment, and using a vec means we would lose
+//! static length info.
+
+use crate::deflate::core::{LZ_DICT_SIZE, MAX_MATCH_LEN};
+
+/// Size of the buffer of lz77 encoded data.
+pub const LZ_CODE_BUF_SIZE: usize = 64 * 1024;
+/// Size of the output buffer.
+pub const OUT_BUF_SIZE: usize = (LZ_CODE_BUF_SIZE * 13) / 10;
+pub const LZ_DICT_FULL_SIZE: usize = LZ_DICT_SIZE + MAX_MATCH_LEN - 1 + 1;
+
+/// Size of hash values in the hash chains.
+pub const LZ_HASH_BITS: i32 = 15;
+/// How many bits to shift when updating the current hash value.
+pub const LZ_HASH_SHIFT: i32 = (LZ_HASH_BITS + 2) / 3;
+/// Size of the chained hash tables.
+pub const LZ_HASH_SIZE: usize = 1 << LZ_HASH_BITS;
+
+#[inline]
+pub fn update_hash(current_hash: u16, byte: u8) -> u16 {
+    ((current_hash << LZ_HASH_SHIFT) ^ u16::from(byte)) & (LZ_HASH_SIZE as u16 - 1)
+}
+
+pub struct HashBuffers {
+    pub dict: [u8; LZ_DICT_FULL_SIZE],
+    pub next: [u16; LZ_DICT_SIZE],
+    pub hash: [u16; LZ_DICT_SIZE],
+}
+
+impl HashBuffers {
+    #[inline]
+    pub fn reset(&mut self) {
+        *self = HashBuffers::default();
+    }
+}
+
+impl Default for HashBuffers {
+    fn default() -> HashBuffers {
+        HashBuffers {
+            dict: [0; LZ_DICT_FULL_SIZE],
+            next: [0; LZ_DICT_SIZE],
+            hash: [0; LZ_DICT_SIZE],
+        }
+    }
+}
+
+pub struct LocalBuf {
+    pub b: [u8; OUT_BUF_SIZE],
+}
+
+impl Default for LocalBuf {
+    fn default() -> LocalBuf {
+        LocalBuf {
+            b: [0; OUT_BUF_SIZE],
+        }
+    }
+}