1 files changed, 35 insertions, 0 deletions
diff --git a/vendor/zune-inflate/src/crc.rs b/vendor/zune-inflate/src/crc.rs
new file mode 100644
index 0000000..7c01127
--- /dev/null
+++ b/vendor/zune-inflate/src/crc.rs
@@ -0,0 +1,35 @@
+#![cfg(feature = "gzip")]
+
+use crate::crc::crc_tables::{CRC32_SLICE1_TABLE, CRC32_SLICE8_TABLE};
+
+mod crc_tables;
+
+/// Calculate crc for a data and an initial crc value
+#[allow(clippy::identity_op, clippy::zero_prefixed_literal)]
+pub fn crc32(data: &[u8], mut crc: u32) -> u32
+{
+    // main loop
+    for chunk in data.chunks_exact(8)
+    {
+        let chunk_loaded = u64::from_le_bytes(chunk.try_into().unwrap());
+
+        let v1 = (chunk_loaded & u64::from(u32::MAX)) as u32;
+        let v2 = (chunk_loaded >> 32) as u32;
+
+        crc = CRC32_SLICE8_TABLE[0x700 + (((crc ^ v1) >> 00) & 0xFF) as usize]
+            ^ CRC32_SLICE8_TABLE[0x600 + (((crc ^ v1) >> 08) & 0xFF) as usize]
+            ^ CRC32_SLICE8_TABLE[0x500 + (((crc ^ v1) >> 16) & 0xFF) as usize]
+            ^ CRC32_SLICE8_TABLE[0x400 + (((crc ^ v1) >> 24) & 0xFF) as usize]
+            ^ CRC32_SLICE8_TABLE[0x300 + (((v2 >> 00) & 0xFF) as usize)]
+            ^ CRC32_SLICE8_TABLE[0x200 + (((v2 >> 08) & 0xFF) as usize)]
+            ^ CRC32_SLICE8_TABLE[0x100 + (((v2 >> 16) & 0xFF) as usize)]
+            ^ CRC32_SLICE8_TABLE[0x000 + (((v2 >> 24) & 0xFF) as usize)];
+    }
+    // handle remainder
+    for remainder in data.chunks_exact(8).remainder()
+    {
+        crc = (crc >> 8) ^ CRC32_SLICE1_TABLE[((crc & 0xFF) ^ u32::from(*remainder)) as usize];
+    }
+
+    crc
+}