brz-memcache 0.0.8

use super::{DebugName, Hash};
use std::fmt::Display;

/// 当前crc32相关hash算法目前有两类，基于i64提升的非负crc32，基于i32的crc32abs:：
///   ================  基于i64版本  ================
///   1 crc32: java版本的i64/long版本的crc32，对整个key做crc32算法；
///   2 crc32-num: 对偏移N个字节后的数字进行crc32计算, eg: crc32-num-5, crc32-num；
///   3 crc32-short: 对crc32计算后，再转为short，适配java mc访问；
///   4 crc32-delimiter: 目前有3种，crc32-point, crc32-pound, crc32-underscore，表示对特殊字符前的内容做crc32，后面可以再跟一个数字表示偏移；
///   5 crc32-mixnum:key中所有num拼接成一个字串num做hashkey，like a_123_456_bc的hashkey是123456；
///   6 crc32-smartnum: 第一串长度大于等于5的数字做为hashkey;
///   ================  基于i32版本  ================
///     备注：不取名crc32-abs，是为了区分i32/i63的base，及为后续扩展做准备 fishermen
///   7 crc32abs: 转为i32，然后进行abs操作
///   8 后续可能会有crc32abs-delimiter，基于point/pound/underscore之前的部分key，先转为i32，然后进行abs操作；
///

pub(super) const CRC32TAB: [i64; 256] = [
    0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,
    0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,
    0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
    0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,
    0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,
    0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
    0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,
    0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,
    0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
    0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,
    0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,
    0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
    0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,
    0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,
    0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
    0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,
    0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,
    0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
    0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,
    0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,
    0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
    0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,
    0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,
    0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
    0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,
    0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,
    0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
    0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,
    0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,
    0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
    0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,
    0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D,
];

pub(super) const CRC_SEED: i64 = 0xFFFFFFFF;

// 用于兼容jdk版本crc32算法
#[derive(Default, Clone, Debug)]
pub struct Crc32;

// 用于mc crc32 short hash变种
#[derive(Default, Clone, Debug)]
pub struct Crc32Short;

// crc32算法，hash key只支持start_pos之后的所有数字，用于兼容混合"."、"_"分割的hash key
#[derive(Default, Clone, Debug)]
pub struct Crc32Num {
    start_pos: usize,
}

// Crc32算法，hash key是开始位置之后、分隔符之前的字符串
#[derive(Default, Clone, Debug)]
pub struct Crc32Delimiter {
    start_pos: usize,
    delimiter: u8,
    name: DebugName,
}

// 第一串长度大于等于5的数字做为hashkey
#[derive(Default, Clone, Debug)]
pub struct Crc32SmartNum {}

// mixnum: key中所有num拼接成一个字串num做hashkey，like a_123_456_bc的hashkey是123456
#[derive(Default, Clone, Debug)]
pub struct Crc32MixNum {}

/// 遵从i32进行crc32计算，并进行abs操作;
#[derive(Debug, Clone, Default)]
pub struct Crc32Abs;

/// 遵从i32进行crc32计算，并进行abs操作，且只计算startpos之后、delimiter之前的字符，格式：$start+$hashkey+$delimiter$
#[derive(Default, Clone, Debug)]
pub struct Crc32AbsDelimiter {
    start_pos: usize,
    delimiter: u8,
    name: DebugName,
}

// 对全key做crc32
impl super::Hash for Crc32 {
    #[inline]
    fn hash<K: super::HashKey>(&self, key: &K) -> i64 {
        let mut crc: i64 = CRC_SEED;

        for i in 0..key.len() {
            let c = key.at(i);
            crc = ((crc >> 8) & 0x00FFFFFF) ^ CRC32TAB[((crc ^ (c as i64)) & 0xff) as usize];
        }

        crc ^= CRC_SEED;
        crc &= CRC_SEED;
        if crc <= 0 {
            // 理论上不会有负数hash
            tracing::warn!("crc32 - negative hash/{} for key/{:?}", crc, key);
        }
        crc
    }
}

// 兼容reference-library中mc crc32 hash算法调整，手动测试各种长度key，hash一致；
// 核心算法同crc32，但要多做一次做移位及截断
impl super::Hash for Crc32Short {
    #[inline]
    fn hash<K: super::HashKey>(&self, key: &K) -> i64 {
        let crc = Crc32.hash(key);
        let mut rs = (crc >> 16) & 0x7fff;
        // crc32-short由于存在移位及截断，存在很多hash为0的情况
        if rs < 0 {
            tracing::debug!("found negative crc32-short/{} for key:{:?}", rs, key);
            rs = rs.wrapping_mul(-1);
        }

        rs
    }
}

impl Crc32Num {
    pub fn from(alg: &str) -> Self {
        let alg_parts: Vec<&str> = alg.split("-").collect();

        debug_assert!(alg_parts.len() >= 2);
        debug_assert_eq!(alg_parts[0], "crc32");
        debug_assert_eq!(alg_parts[1], "num");

        if alg_parts.len() == 2 {
            return Self { start_pos: 0 };
        }

        debug_assert_eq!(alg_parts.len(), 3);
        if let Ok(prefix_len) = alg_parts[2].parse::<usize>() {
            return Self {
                start_pos: prefix_len,
            };
        } else {
            tracing::debug!("use crc32-num for unknown hash: {:?}", alg_parts);
            return Self { start_pos: 0 };
        }
    }
}

impl super::Hash for Crc32Num {
    fn hash<S: super::HashKey>(&self, key: &S) -> i64 {
        debug_assert!(self.start_pos < key.len());

        let mut crc: i64 = CRC_SEED;
        for i in self.start_pos..key.len() {
            let c = key.at(i);
            // 对于用数字类型做hash，则遇到非数字结束
            if !c.is_ascii_digit() {
                break;
            }
            crc = ((crc >> 8) & 0x00FFFFFF) ^ CRC32TAB[((crc ^ (c as i64)) & 0xff) as usize];
        }

        crc ^= CRC_SEED;
        crc &= CRC_SEED;
        if crc <= 0 {
            tracing::debug!(
                "crc32-num-{} key:{:?}, malform hash:{}",
                self.start_pos,
                key,
                crc
            );
        }
        crc
    }
}

impl Display for Crc32Num {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        if self.start_pos == 0 {
            return write!(f, "{}", "crc32-num");
        }

        write!(f, "crc32-num-{}", self.start_pos)
    }
}

impl Crc32Delimiter {
    pub fn from(alg: &str) -> Self {
        let alg_parts: Vec<&str> = alg.split(super::HASHER_NAME_DELIMITER).collect();

        debug_assert!(alg_parts.len() >= 2);
        debug_assert_eq!(alg_parts[0], "crc32");

        let delimiter = super::key_delimiter_name_2u8(alg, alg_parts[1]);

        if alg_parts.len() == 2 {
            return Self {
                start_pos: 0,
                delimiter,
                name: alg.into(),
            };
        }

        debug_assert!(alg_parts.len() == 3);
        if let Ok(prefix_len) = alg_parts[2].parse::<usize>() {
            return Self {
                start_pos: prefix_len,
                delimiter,
                name: alg.into(),
            };
        } else {
            tracing::debug!("found unknown hash/{}, ignore prefix instead", alg);
            return Self {
                start_pos: 0,
                delimiter,
                name: alg.into(),
            };
        }
    }
}

impl super::Hash for Crc32Delimiter {
    fn hash<S: super::HashKey>(&self, key: &S) -> i64 {
        let mut crc: i64 = CRC_SEED;
        debug_assert!(self.start_pos < key.len());

        // 对于用“.”、“_”、“#”做分割的hash key，遇到分隔符停止
        let check_delimiter = self.delimiter != super::KEY_DELIMITER_NONE;
        for i in self.start_pos..key.len() {
            let c = key.at(i);
            if check_delimiter && (c == self.delimiter) {
                break;
            }
            crc = ((crc >> 8) & 0x00FFFFFF) ^ CRC32TAB[((crc ^ (c as i64)) & 0xff) as usize];
        }

        crc ^= CRC_SEED;
        crc &= CRC_SEED;
        if crc <= 0 {
            tracing::debug!("{:?} - malform hash/{} for key/{:?}", self.name, crc, key);
        }
        crc
    }
}

impl Display for Crc32Delimiter {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "{:?}", self.name)
    }
}

impl super::Hash for Crc32SmartNum {
    fn hash<S: super::HashKey>(&self, key: &S) -> i64 {
        // 解析出smartnum hashkey的位置
        let (start, end) = parse_smartnum_hashkey(key);

        let mut crc: i64 = CRC_SEED;
        for i in start..end {
            let c = key.at(i);
            // smartnum hash，理论上必须是全部数字，但非法请求可能包含非数字（或者配置错误）
            //debug_assert!(c.is_ascii_digit(), "malfromed smart key:{:?}", key);
            crc = ((crc >> 8) & 0x00FFFFFF) ^ CRC32TAB[((crc ^ (c as i64)) & 0xff) as usize];
        }

        crc ^= CRC_SEED;
        crc &= CRC_SEED;
        if crc <= 0 {
            tracing::warn!("+++ crc32-smartnum key:{:?}, hash:{}", key, crc);
        }
        crc
    }
}

// 解析smartnum key中hashkey
pub(crate) fn parse_smartnum_hashkey<S: super::HashKey>(key: &S) -> (usize, usize) {
    // 找到真正hashkey的起始位置，要求：连续的数字，数字位数大于等于4
    let mut start = usize::MAX;
    let mut end = usize::MAX;
    for i in 0..key.len() {
        let c = key.at(i);
        if c.is_ascii_digit() && start == usize::MAX {
            // 第一次发现数字，设置start
            start = i;
        } else if start != usize::MAX && !c.is_ascii_digit() {
            // 发现数字后，第一次发现非数字
            end = i;
            // 第一串长度大于等于5的数字做为hashkey
            if end - start >= super::SMARTNUM_MIN_LEN {
                break;
            } else {
                // 长度小于uid最小长度，重置
                start = usize::MAX;
                end = usize::MAX;
            }
        }
    }
    // 处理结尾仍然是数字的场景
    if start != usize::MAX && end == usize::MAX {
        end = key.len();
    }

    // 异常请求场景: 非法key，先只打印日志
    if start == usize::MAX || (end - start) < super::SMARTNUM_MIN_LEN {
        start = 0;
        end = key.len();
        tracing::error!("+++ malformed smartnum key:{:?}", key);
    }

    (start, end)
}

// 将key中非数字分开的所有num合并到一起来计算hash，如abc_123_45_cde6、123_456_xx的hashkey都是: 123456
impl super::Hash for Crc32MixNum {
    fn hash<S: super::HashKey>(&self, key: &S) -> i64 {
        let mut crc: i64 = CRC_SEED;
        // 找出所有num来作为hashkey
        for i in 0..key.len() {
            let c = key.at(i);
            if c.is_ascii_digit() {
                tracing::debug!("+++ crc32-mixnum:{}", c as char);

                // 进行crc32计算
                crc = ((crc >> 8) & 0x00FFFFFF) ^ CRC32TAB[((crc ^ (c as i64)) & 0xff) as usize];
            }
        }

        crc ^= CRC_SEED;
        crc &= CRC_SEED;
        if crc <= 0 {
            tracing::warn!("+++ crc32-smartnum key:{:?}, hash:{}", key, crc);
        }
        crc
    }
}

impl Hash for Crc32Abs {
    fn hash<S: super::HashKey>(&self, key: &S) -> i64 {
        let mut crc: i64 = CRC_SEED;

        for i in 0..key.len() {
            let c = key.at(i);
            crc = ((crc >> 8) & 0x00FFFFFF) ^ CRC32TAB[((crc ^ (c as i64)) & 0xff) as usize];
        }

        crc ^= CRC_SEED;
        crc &= CRC_SEED;

        let mut crc = crc as i32;
        if crc <= 0 {
            // 理论上会有大量负数hash
            tracing::debug!("crc32abs - negative hash/{} for key/{:?}", crc, key);
            crc = crc.abs();
        }
        crc as i64
    }
}

/// --- Crc32AbsDelimiter impl: crc32abs-point/underscore/pound ---
impl Crc32AbsDelimiter {
    pub fn from(alg: &str) -> Self {
        let alg_parts: Vec<&str> = alg.split(super::HASHER_NAME_DELIMITER).collect();

        debug_assert!(alg_parts.len() >= 2);
        debug_assert_eq!(alg_parts[0], "crc32abs");

        let delimiter = super::key_delimiter_name_2u8(alg, alg_parts[1]);

        if alg_parts.len() == 2 {
            return Self {
                start_pos: 0,
                delimiter,
                name: alg.into(),
            };
        }

        debug_assert!(alg_parts.len() == 3);
        if let Ok(prefix_len) = alg_parts[2].parse::<usize>() {
            return Self {
                start_pos: prefix_len,
                delimiter,
                name: alg.into(),
            };
        } else {
            tracing::debug!("found unknown hash/{}, ignore prefix instead", alg);
            return Self {
                start_pos: 0,
                delimiter,
                name: alg.into(),
            };
        }
    }
}

impl super::Hash for Crc32AbsDelimiter {
    fn hash<S: super::HashKey>(&self, key: &S) -> i64 {
        let mut crc: i64 = CRC_SEED;
        debug_assert!(self.start_pos < key.len());

        let check_delimiter = self.delimiter != super::KEY_DELIMITER_NONE;
        for i in self.start_pos..key.len() {
            let c = key.at(i);
            if check_delimiter && (c == self.delimiter) {
                break;
            }
            crc = ((crc >> 8) & 0x00FFFFFF) ^ CRC32TAB[((crc ^ (c as i64)) & 0xff) as usize];
        }

        crc ^= CRC_SEED;
        crc &= CRC_SEED;

        let mut crc = crc as i32;
        if crc <= 0 {
            tracing::debug!("{:?} - negative hash/{} for key/{:?}", self.name, crc, key);
            crc = crc.abs();
        }
        crc as i64
    }
}

impl Display for Crc32AbsDelimiter {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "{:?}", self.name)
    }
}