From 3c6dffa5ccfc72804a76f2090738721b90b10ce8 Mon Sep 17 00:00:00 2001
From: Igor Tolmachev <me@igorek.dev>
Date: Tue, 25 Jun 2024 23:23:19 +0900
Subject: Add bit flag logic

---
 src/zip/file.rs | 94 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)

(limited to 'src/zip/file.rs')

diff --git a/src/zip/file.rs b/src/zip/file.rs
index f735d65..b4f2d7c 100644
--- a/src/zip/file.rs
+++ b/src/zip/file.rs
@@ -28,8 +28,100 @@ impl CompressionMethod {
     }
 }
 
+pub struct BitFlag {
+    pub flag: u16,
+}
+
+pub mod bit {
+    #[derive(Debug, PartialEq, Eq)]
+    pub enum DeflateMode {
+        Normal,
+        Maximum,
+        Fast,
+        SuperFast,
+    }
+}
+
+macro_rules! get_set_bit_flag {
+    {$($get:ident $set:ident $bit:expr)+} => {
+        $(
+            pub fn $get(&self) -> bool {
+                self.get_bit($bit)
+            }
+
+            pub fn $set(&mut self, enable: bool) {
+                self.set_bit($bit, enable);
+            }
+        )*
+    };
+}
+
+impl BitFlag {
+    pub fn new(flag: u16) -> Self {
+        Self { flag }
+    }
+
+    #[inline]
+    fn get_bit(&self, bit: u32) -> bool {
+        (self.flag & 2u16.pow(bit)) > 0
+    }
+
+    #[inline]
+    fn set_bit(&mut self, bit: u32, enable: bool) {
+        if enable {
+            self.flag |= 2u16.pow(bit);
+        } else {
+            self.flag &= !2u16.pow(bit);
+        }
+    }
+
+    pub fn deflate_mode(&self) -> bit::DeflateMode {
+        match self.flag & 6 {
+            0 => bit::DeflateMode::Normal,
+            2 => bit::DeflateMode::Maximum,
+            4 => bit::DeflateMode::Fast,
+            6 => bit::DeflateMode::SuperFast,
+            _ => panic!("impossible"),
+        }
+    }
+
+    pub fn set_deflate_mode(&mut self, mode: bit::DeflateMode) {
+        match mode {
+            bit::DeflateMode::Normal => {
+                self.set_bit(1, false);
+                self.set_bit(2, false);
+            }
+            bit::DeflateMode::Maximum => {
+                self.set_bit(1, true);
+                self.set_bit(2, false);
+            }
+            bit::DeflateMode::Fast => {
+                self.set_bit(1, false);
+                self.set_bit(2, true);
+            }
+            bit::DeflateMode::SuperFast => {
+                self.set_bit(1, true);
+                self.set_bit(2, true);
+            }
+        }
+    }
+
+    get_set_bit_flag! {
+        is_encrypted           set_encrypted           0
+        is_imploding_8k        set_imploding_8k        1
+        is_imploding_3sf_trees set_imploding_3sf_trees 2
+        is_lzma_has_eos_marker set_lzma_has_eos_marker 1
+        is_has_data_descriptor set_has_data_descriptor 3
+        is_patched_data        set_patched_data        5
+        is_strong_encryption   set_strong_encryption   6
+        is_utf8                set_utf8                11
+        is_cd_encryption       set_cd_encryption       13
+    }
+}
+
 pub struct ZipFile {
     pub compression_method: CompressionMethod,
+    pub bit_flag: BitFlag,
     pub datetime: DateTime<Local>,
     pub crc: u32,
     pub compressed_size: u64,
@@ -42,6 +134,7 @@ pub struct ZipFile {
 impl ZipFile {
     pub fn new(
         compression_method: CompressionMethod,
+        bit_flag: BitFlag,
         datetime: DateTime<Local>,
         crc: u32,
         compressed_size: u64,
@@ -52,6 +145,7 @@ impl ZipFile {
     ) -> Self {
         Self {
             compression_method,
+            bit_flag,
             datetime,
             crc,
             compressed_size,
-- 
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