openigtlink-rust 0.4.1

//! CRC64 checksum calculation for OpenIGTLink messages
//!
//! This implementation uses the exact lookup table from the official
//! C++ OpenIGTLink library to ensure byte-level compatibility.

/// CRC64 lookup table from OpenIGTLink C++ implementation (igtl_util.c)
///
/// This table must match exactly with the official implementation for
/// compatibility with other OpenIGTLink implementations.
const CRC64_TABLE: [u64; 256] = [
    0x0000000000000000,
    0x42F0E1EBA9EA3693,
    0x85E1C3D753D46D26,
    0xC711223CFA3E5BB5,
    0x493366450E42ECDF,
    0x0BC387AEA7A8DA4C,
    0xCCD2A5925D9681F9,
    0x8E224479F47CB76A,
    0x9266CC8A1C85D9BE,
    0xD0962D61B56FEF2D,
    0x17870F5D4F51B498,
    0x5577EEB6E6BB820B,
    0xDB55AACF12C73561,
    0x99A54B24BB2D03F2,
    0x5EB4691841135847,
    0x1C4488F3E8F96ED4,
    0x663D78FF90E185EF,
    0x24CD9914390BB37C,
    0xE3DCBB28C335E8C9,
    0xA12C5AC36ADFDE5A,
    0x2F0E1EBA9EA36930,
    0x6DFEFF5137495FA3,
    0xAAEFDD6DCD770416,
    0xE81F3C86649D3285,
    0xF45BB4758C645C51,
    0xB6AB559E258E6AC2,
    0x71BA77A2DFB03177,
    0x334A9649765A07E4,
    0xBD68D2308226B08E,
    0xFF9833DB2BCC861D,
    0x388911E7D1F2DDA8,
    0x7A79F00C7818EB3B,
    0xCC7AF1FF21C30BDE,
    0x8E8A101488293D4D,
    0x499B3228721766F8,
    0x0B6BD3C3DBFD506B,
    0x854997BA2F81E701,
    0xC7B97651866BD192,
    0x00A8546D7C558A27,
    0x4258B586D5BFBCB4,
    0x5E1C3D753D46D260,
    0x1CECDC9E94ACE4F3,
    0xDBFDFEA26E92BF46,
    0x990D1F49C77889D5,
    0x172F5B3033043EBF,
    0x55DFBADB9AEE082C,
    0x92CE98E760D05399,
    0xD03E790CC93A650A,
    0xAA478900B1228E31,
    0xE8B768EB18C8B8A2,
    0x2FA64AD7E2F6E317,
    0x6D56AB3C4B1CD584,
    0xE374EF45BF6062EE,
    0xA1840EAE168A547D,
    0x66952C92ECB40FC8,
    0x2465CD79455E395B,
    0x3821458AADA7578F,
    0x7AD1A461044D611C,
    0xBDC0865DFE733AA9,
    0xFF3067B657990C3A,
    0x711223CFA3E5BB50,
    0x33E2C2240A0F8DC3,
    0xF4F3E018F031D676,
    0xB60301F359DBE0E5,
    0xDA050215EA6C212F,
    0x98F5E3FE438617BC,
    0x5FE4C1C2B9B84C09,
    0x1D14202910527A9A,
    0x93366450E42ECDF0,
    0xD1C685BB4DC4FB63,
    0x16D7A787B7FAA0D6,
    0x5427466C1E109645,
    0x4863CE9FF6E9F891,
    0x0A932F745F03CE02,
    0xCD820D48A53D95B7,
    0x8F72ECA30CD7A324,
    0x0150A8DAF8AB144E,
    0x43A04931514122DD,
    0x84B16B0DAB7F7968,
    0xC6418AE602954FFB,
    0xBC387AEA7A8DA4C0,
    0xFEC89B01D3679253,
    0x39D9B93D2959C9E6,
    0x7B2958D680B3FF75,
    0xF50B1CAF74CF481F,
    0xB7FBFD44DD257E8C,
    0x70EADF78271B2539,
    0x321A3E938EF113AA,
    0x2E5EB66066087D7E,
    0x6CAE578BCFE24BED,
    0xABBF75B735DC1058,
    0xE94F945C9C3626CB,
    0x676DD025684A91A1,
    0x259D31CEC1A0A732,
    0xE28C13F23B9EFC87,
    0xA07CF2199274CA14,
    0x167FF3EACBAF2AF1,
    0x548F120162451C62,
    0x939E303D987B47D7,
    0xD16ED1D631917144,
    0x5F4C95AFC5EDC62E,
    0x1DBC74446C07F0BD,
    0xDAAD56789639AB08,
    0x985DB7933FD39D9B,
    0x84193F60D72AF34F,
    0xC6E9DE8B7EC0C5DC,
    0x01F8FCB784FE9E69,
    0x43081D5C2D14A8FA,
    0xCD2A5925D9681F90,
    0x8FDAB8CE70822903,
    0x48CB9AF28ABC72B6,
    0x0A3B7B1923564425,
    0x70428B155B4EAF1E,
    0x32B26AFEF2A4998D,
    0xF5A348C2089AC238,
    0xB753A929A170F4AB,
    0x3971ED50550C43C1,
    0x7B810CBBFCE67552,
    0xBC902E8706D82EE7,
    0xFE60CF6CAF321874,
    0xE224479F47CB76A0,
    0xA0D4A674EE214033,
    0x67C58448141F1B86,
    0x253565A3BDF52D15,
    0xAB1721DA49899A7F,
    0xE9E7C031E063ACEC,
    0x2EF6E20D1A5DF759,
    0x6C0603E6B3B7C1CA,
    0xF6FAE5C07D3274CD,
    0xB40A042BD4D8425E,
    0x731B26172EE619EB,
    0x31EBC7FC870C2F78,
    0xBFC9838573709812,
    0xFD39626EDA9AAE81,
    0x3A28405220A4F534,
    0x78D8A1B9894EC3A7,
    0x649C294A61B7AD73,
    0x266CC8A1C85D9BE0,
    0xE17DEA9D3263C055,
    0xA38D0B769B89F6C6,
    0x2DAF4F0F6FF541AC,
    0x6F5FAEE4C61F773F,
    0xA84E8CD83C212C8A,
    0xEABE6D3395CB1A19,
    0x90C79D3FEDD3F122,
    0xD2377CD44439C7B1,
    0x15265EE8BE079C04,
    0x57D6BF0317EDAA97,
    0xD9F4FB7AE3911DFD,
    0x9B041A914A7B2B6E,
    0x5C1538ADB04570DB,
    0x1EE5D94619AF4648,
    0x02A151B5F156289C,
    0x4051B05E58BC1E0F,
    0x87409262A28245BA,
    0xC5B073890B687329,
    0x4B9237F0FF14C443,
    0x0962D61B56FEF2D0,
    0xCE73F427ACC0A965,
    0x8C8315CC052A9FF6,
    0x3A80143F5CF17F13,
    0x7870F5D4F51B4980,
    0xBF61D7E80F251235,
    0xFD913603A6CF24A6,
    0x73B3727A52B393CC,
    0x31439391FB59A55F,
    0xF652B1AD0167FEEA,
    0xB4A25046A88DC879,
    0xA8E6D8B54074A6AD,
    0xEA16395EE99E903E,
    0x2D071B6213A0CB8B,
    0x6FF7FA89BA4AFD18,
    0xE1D5BEF04E364A72,
    0xA3255F1BE7DC7CE1,
    0x64347D271DE22754,
    0x26C49CCCB40811C7,
    0x5CBD6CC0CC10FAFC,
    0x1E4D8D2B65FACC6F,
    0xD95CAF179FC497DA,
    0x9BAC4EFC362EA149,
    0x158E0A85C2521623,
    0x577EEB6E6BB820B0,
    0x906FC95291867B05,
    0xD29F28B9386C4D96,
    0xCEDBA04AD0952342,
    0x8C2B41A1797F15D1,
    0x4B3A639D83414E64,
    0x09CA82762AAB78F7,
    0x87E8C60FDED7CF9D,
    0xC51827E4773DF90E,
    0x020905D88D03A2BB,
    0x40F9E43324E99428,
    0x2CFFE7D5975E55E2,
    0x6E0F063E3EB46371,
    0xA91E2402C48A38C4,
    0xEBEEC5E96D600E57,
    0x65CC8190991CB93D,
    0x273C607B30F68FAE,
    0xE02D4247CAC8D41B,
    0xA2DDA3AC6322E288,
    0xBE992B5F8BDB8C5C,
    0xFC69CAB42231BACF,
    0x3B78E888D80FE17A,
    0x7988096371E5D7E9,
    0xF7AA4D1A85996083,
    0xB55AACF12C735610,
    0x724B8ECDD64D0DA5,
    0x30BB6F267FA73B36,
    0x4AC29F2A07BFD00D,
    0x08327EC1AE55E69E,
    0xCF235CFD546BBD2B,
    0x8DD3BD16FD818BB8,
    0x03F1F96F09FD3CD2,
    0x41011884A0170A41,
    0x86103AB85A2951F4,
    0xC4E0DB53F3C36767,
    0xD8A453A01B3A09B3,
    0x9A54B24BB2D03F20,
    0x5D45907748EE6495,
    0x1FB5719CE1045206,
    0x919735E51578E56C,
    0xD367D40EBC92D3FF,
    0x1476F63246AC884A,
    0x568617D9EF46BED9,
    0xE085162AB69D5E3C,
    0xA275F7C11F7768AF,
    0x6564D5FDE549331A,
    0x279434164CA30589,
    0xA9B6706FB8DFB2E3,
    0xEB46918411358470,
    0x2C57B3B8EB0BDFC5,
    0x6EA7525342E1E956,
    0x72E3DAA0AA188782,
    0x30133B4B03F2B111,
    0xF7021977F9CCEAA4,
    0xB5F2F89C5026DC37,
    0x3BD0BCE5A45A6B5D,
    0x79205D0E0DB05DCE,
    0xBE317F32F78E067B,
    0xFCC19ED95E6430E8,
    0x86B86ED5267CDBD3,
    0xC4488F3E8F96ED40,
    0x0359AD0275A8B6F5,
    0x41A94CE9DC428066,
    0xCF8B0890283E370C,
    0x8D7BE97B81D4019F,
    0x4A6ACB477BEA5A2A,
    0x089A2AACD2006CB9,
    0x14DEA25F3AF9026D,
    0x562E43B4931334FE,
    0x913F6188692D6F4B,
    0xD3CF8063C0C759D8,
    0x5DEDC41A34BBEEB2,
    0x1F1D25F19D51D821,
    0xD80C07CD676F8394,
    0x9AFCE626CE85B507,
];

/// Calculate CRC64 checksum for data
///
/// This is compatible with the OpenIGTLink C++ implementation.
///
/// # Arguments
/// * `data` - Byte slice to calculate CRC for
///
/// # Returns
/// 64-bit CRC checksum
pub fn calculate_crc(data: &[u8]) -> u64 {
    calculate_crc_with_initial(data, 0)
}

/// Calculate CRC64 checksum with an initial CRC value
///
/// This allows for incremental CRC calculation.
///
/// # Arguments
/// * `data` - Byte slice to calculate CRC for
/// * `initial_crc` - Initial CRC value (use 0 for new calculation)
///
/// # Returns
/// 64-bit CRC checksum
pub fn calculate_crc_with_initial(data: &[u8], initial_crc: u64) -> u64 {
    let mut crc = initial_crc;
    for &byte in data {
        let index = (byte ^ (crc >> 56) as u8) as usize;
        crc = CRC64_TABLE[index] ^ (crc << 8);
    }
    crc
}

/// Verify CRC64 checksum
///
/// # Arguments
/// * `data` - Byte slice to verify
/// * `expected_crc` - Expected CRC value
///
/// # Returns
/// `true` if CRC matches, `false` otherwise
pub fn verify_crc(data: &[u8], expected_crc: u64) -> bool {
    calculate_crc(data) == expected_crc
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_crc_deterministic() {
        // CRC should be deterministic
        let data = b"test data";
        let crc1 = calculate_crc(data);
        let crc2 = calculate_crc(data);
        assert_eq!(crc1, crc2);
    }

    #[test]
    fn test_crc_with_initial_value() {
        let data = b"hello";
        let initial = 0x1234567890ABCDEF;
        let crc_with_initial = calculate_crc_with_initial(data, initial);
        let crc_from_zero = calculate_crc(data);
        assert_ne!(crc_with_initial, crc_from_zero);
    }

    #[test]
    fn test_empty_data() {
        let empty: &[u8] = &[];
        let crc = calculate_crc(empty);
        assert_eq!(crc, 0);
    }

    #[test]
    fn test_verify_crc_valid() {
        let data = b"OpenIGTLink";
        let crc = calculate_crc(data);
        assert!(verify_crc(data, crc));
    }

    #[test]
    fn test_verify_crc_invalid() {
        let data = b"OpenIGTLink";
        let crc = calculate_crc(data);
        assert!(!verify_crc(data, crc + 1));
    }

    #[test]
    fn test_different_data_different_crc() {
        let data1 = b"test1";
        let data2 = b"test2";
        let crc1 = calculate_crc(data1);
        let crc2 = calculate_crc(data2);
        assert_ne!(crc1, crc2);
    }

    #[test]
    fn test_single_byte() {
        let data = b"A";
        let crc = calculate_crc(data);
        // CRC should not be zero for non-empty data (in most cases)
        assert_ne!(crc, 0);
    }

    #[test]
    fn test_incremental_crc() {
        let data = b"hello world";
        let full_crc = calculate_crc(data);

        // Calculate incrementally
        let part1_crc = calculate_crc_with_initial(&data[0..5], 0);
        let full_incremental_crc = calculate_crc_with_initial(&data[5..], part1_crc);

        assert_eq!(full_crc, full_incremental_crc);
    }
}