#[rustfmt::skip]
static CRC32_TABLE: [u32; 256] = [
0x00000000, 0x04C11DB7, 0x09823B6E, 0x0D4326D9,
0x130476DC, 0x17C56B6B, 0x1A864DB2, 0x1E475005,
0x2608EDB8, 0x22C9F00F, 0x2F8AD6D6, 0x2B4BCB61,
0x350C9B64, 0x31CD86D3, 0x3C8EA00A, 0x384FBDBD,
0x4C11DB70, 0x48D0C6C7, 0x4593E01E, 0x4152FDA9,
0x5F15ADAC, 0x5BD4B01B, 0x569796C2, 0x52568B75,
0x6A1936C8, 0x6ED82B7F, 0x639B0DA6, 0x675A1011,
0x791D4014, 0x7DDC5DA3, 0x709F7B7A, 0x745E66CD,
0x9823B6E0, 0x9CE2AB57, 0x91A18D8E, 0x95609039,
0x8B27C03C, 0x8FE6DD8B, 0x82A5FB52, 0x8664E6E5,
0xBE2B5B58, 0xBAEA46EF, 0xB7A96036, 0xB3687D81,
0xAD2F2D84, 0xA9EE3033, 0xA4AD16EA, 0xA06C0B5D,
0xD4326D90, 0xD0F37027, 0xDDB056FE, 0xD9714B49,
0xC7361B4C, 0xC3F706FB, 0xCEB42022, 0xCA753D95,
0xF23A8028, 0xF6FB9D9F, 0xFBB8BB46, 0xFF79A6F1,
0xE13EF6F4, 0xE5FFEB43, 0xE8BCCD9A, 0xEC7DD02D,
0x34867077, 0x30476DC0, 0x3D044B19, 0x39C556AE,
0x278206AB, 0x23431B1C, 0x2E003DC5, 0x2AC12072,
0x128E9DCF, 0x164F8078, 0x1B0CA6A1, 0x1FCDBB16,
0x018AEB13, 0x054BF6A4, 0x0808D07D, 0x0CC9CDCA,
0x7897AB07, 0x7C56B6B0, 0x71159069, 0x75D48DDE,
0x6B93DDDB, 0x6F52C06C, 0x6211E6B5, 0x66D0FB02,
0x5E9F46BF, 0x5A5E5B08, 0x571D7DD1, 0x53DC6066,
0x4D9B3063, 0x495A2DD4, 0x44190B0D, 0x40D816BA,
0xACA5C697, 0xA864DB20, 0xA527FDF9, 0xA1E6E04E,
0xBFA1B04B, 0xBB60ADFC, 0xB6238B25, 0xB2E29692,
0x8AAD2B2F, 0x8E6C3698, 0x832F1041, 0x87EE0DF6,
0x99A95DF3, 0x9D684044, 0x902B669D, 0x94EA7B2A,
0xE0B41DE7, 0xE4750050, 0xE9362689, 0xEDF73B3E,
0xF3B06B3B, 0xF771768C, 0xFA325055, 0xFEF34DE2,
0xC6BCF05F, 0xC27DEDE8, 0xCF3ECB31, 0xCBFFD686,
0xD5B88683, 0xD1799B34, 0xDC3ABDED, 0xD8FBA05A,
0x690CE0EE, 0x6DCDFD59, 0x608EDB80, 0x644FC637,
0x7A089632, 0x7EC98B85, 0x738AAD5C, 0x774BB0EB,
0x4F040D56, 0x4BC510E1, 0x46863638, 0x42472B8F,
0x5C007B8A, 0x58C1663D, 0x558240E4, 0x51435D53,
0x251D3B9E, 0x21DC2629, 0x2C9F00F0, 0x285E1D47,
0x36194D42, 0x32D850F5, 0x3F9B762C, 0x3B5A6B9B,
0x0315D626, 0x07D4CB91, 0x0A97ED48, 0x0E56F0FF,
0x1011A0FA, 0x14D0BD4D, 0x19939B94, 0x1D528623,
0xF12F560E, 0xF5EE4BB9, 0xF8AD6D60, 0xFC6C70D7,
0xE22B20D2, 0xE6EA3D65, 0xEBA91BBC, 0xEF68060B,
0xD727BBB6, 0xD3E6A601, 0xDEA580D8, 0xDA649D6F,
0xC423CD6A, 0xC0E2D0DD, 0xCDA1F604, 0xC960EBB3,
0xBD3E8D7E, 0xB9FF90C9, 0xB4BCB610, 0xB07DABA7,
0xAE3AFBA2, 0xAAFBE615, 0xA7B8C0CC, 0xA379DD7B,
0x9B3660C6, 0x9FF77D71, 0x92B45BA8, 0x9675461F,
0x8832161A, 0x8CF30BAD, 0x81B02D74, 0x857130C3,
0x5D8A9099, 0x594B8D2E, 0x5408ABF7, 0x50C9B640,
0x4E8EE645, 0x4A4FFBF2, 0x470CDD2B, 0x43CDC09C,
0x7B827D21, 0x7F436096, 0x7200464F, 0x76C15BF8,
0x68860BFD, 0x6C47164A, 0x61043093, 0x65C52D24,
0x119B4BE9, 0x155A565E, 0x18197087, 0x1CD86D30,
0x029F3D35, 0x065E2082, 0x0B1D065B, 0x0FDC1BEC,
0x3793A651, 0x3352BBE6, 0x3E119D3F, 0x3AD08088,
0x2497D08D, 0x2056CD3A, 0x2D15EBE3, 0x29D4F654,
0xC5A92679, 0xC1683BCE, 0xCC2B1D17, 0xC8EA00A0,
0xD6AD50A5, 0xD26C4D12, 0xDF2F6BCB, 0xDBEE767C,
0xE3A1CBC1, 0xE760D676, 0xEA23F0AF, 0xEEE2ED18,
0xF0A5BD1D, 0xF464A0AA, 0xF9278673, 0xFDE69BC4,
0x89B8FD09, 0x8D79E0BE, 0x803AC667, 0x84FBDBD0,
0x9ABC8BD5, 0x9E7D9662, 0x933EB0BB, 0x97FFAD0C,
0xAFB010B1, 0xAB710D06, 0xA6322BDF, 0xA2F33668,
0xBCB4666D, 0xB8757BDA, 0xB5365D03, 0xB1F740B4,
];
pub fn crc32(data: &[u8]) -> u32 {
crc32_with_init(data, 0)
}
pub fn crc32_with_init(data: &[u8], initial: u32) -> u32 {
let mut crc = initial;
for &byte in data {
let idx = ((crc >> 24) ^ (byte as u32)) & 0xFF;
crc = CRC32_TABLE[idx as usize] ^ (crc << 8);
}
crc
}
fn crc32_typed(bytes: &[u8], initial: u32, xor_initial: bool) -> u32 {
let init = if xor_initial {
initial ^ (bytes.as_ptr() as u32)
} else {
initial
};
crc32_with_init(bytes, init)
}
pub fn crc32_int(value: i32, initial: u32, xor_initial: bool) -> u32 {
crc32_typed(&value.to_le_bytes(), initial, xor_initial)
}
pub fn crc32_long(value: i64, initial: u32, xor_initial: bool) -> u32 {
crc32_typed(&value.to_le_bytes(), initial, xor_initial)
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_crc32_empty() {
assert_eq!(crc32(&[]), 0);
}
#[test]
fn test_crc32_deterministic() {
let data = b"MapleStory";
let a = crc32(data);
let b = crc32(data);
assert_eq!(a, b);
}
#[test]
fn test_crc32_pkg1_nonzero() {
let val = crc32(b"PKG1");
assert_ne!(val, 0);
assert_eq!(val, crc32(b"PKG1")); }
#[test]
fn test_crc32_different_inputs_differ() {
assert_ne!(crc32(b"hello"), crc32(b"world"));
}
#[test]
fn test_crc32_with_init_nonzero() {
let a = crc32(b"test");
let b = crc32_with_init(b"test", 0x12345678);
assert_ne!(a, b);
}
#[test]
fn test_crc32_int_no_xor() {
let value: i32 = 42;
let initial: u32 = 0;
let result = crc32_int(value, initial, false);
assert_eq!(result, crc32_with_init(&value.to_le_bytes(), initial));
}
#[test]
fn test_crc32_int_no_xor_with_initial() {
let value: i32 = -1;
let initial: u32 = 0xDEADBEEF;
let result = crc32_int(value, initial, false);
assert_eq!(result, crc32_with_init(&value.to_le_bytes(), initial));
}
#[test]
fn test_crc32_int_zero_value() {
let result = crc32_int(0, 0, false);
assert_eq!(result, crc32_with_init(&0i32.to_le_bytes(), 0));
}
#[test]
fn test_crc32_int_xor_differs_from_no_xor() {
let value: i32 = 42;
let initial: u32 = 0;
let no_xor = crc32_int(value, initial, false);
let with_xor = crc32_int(value, initial, true);
assert_ne!(no_xor, with_xor);
}
#[test]
fn test_crc32_int_deterministic() {
let a = crc32_int(100, 0, false);
let b = crc32_int(100, 0, false);
assert_eq!(a, b);
}
#[test]
fn test_crc32_int_different_values_differ() {
assert_ne!(crc32_int(1, 0, false), crc32_int(2, 0, false));
}
#[test]
fn test_crc32_long_no_xor() {
let value: i64 = 123456789;
let initial: u32 = 0;
let result = crc32_long(value, initial, false);
assert_eq!(result, crc32_with_init(&value.to_le_bytes(), initial));
}
#[test]
fn test_crc32_long_no_xor_with_initial() {
let value: i64 = -1;
let initial: u32 = 0xCAFEBABE;
let result = crc32_long(value, initial, false);
assert_eq!(result, crc32_with_init(&value.to_le_bytes(), initial));
}
#[test]
fn test_crc32_long_zero_value() {
let result = crc32_long(0, 0, false);
assert_eq!(result, crc32_with_init(&0i64.to_le_bytes(), 0));
}
#[test]
fn test_crc32_long_xor_differs_from_no_xor() {
let value: i64 = 42;
let initial: u32 = 0;
let no_xor = crc32_long(value, initial, false);
let with_xor = crc32_long(value, initial, true);
assert_ne!(no_xor, with_xor);
}
#[test]
fn test_crc32_long_deterministic() {
let a = crc32_long(999, 0, false);
let b = crc32_long(999, 0, false);
assert_eq!(a, b);
}
#[test]
fn test_crc32_long_different_values_differ() {
assert_ne!(crc32_long(1, 0, false), crc32_long(2, 0, false));
}
#[test]
fn test_crc32_long_nonzero_result() {
assert_ne!(crc32_long(i64::MAX, 0, false), 0);
}
}