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use super::{clear_ends_with_cases, contains_cases, ends_with_cases};
use crate::integer::{
BooleanBlock, IntegerRadixCiphertext, RadixCiphertext, ServerKey as IntegerServerKey,
};
use crate::strings::char_iter::CharIter;
use crate::strings::ciphertext::{FheAsciiChar, FheString, GenericPatternRef};
use crate::strings::server_key::pattern::IsMatch;
use crate::strings::server_key::ServerKey;
use itertools::Itertools;
use rayon::prelude::*;
use rayon::range::Iter;
use std::borrow::Borrow;
impl<T: Borrow<IntegerServerKey> + Sync> ServerKey<T> {
// Compare pat with str, with pat shifted right (in relation to str) the number given by iter
fn compare_shifted(
&self,
str_pat: (CharIter, CharIter),
par_iter: Iter<usize>,
ignore_pat_pad: bool,
) -> BooleanBlock {
let sk = self.inner();
let (str, pat) = str_pat;
let matched: Vec<_> = par_iter
.map(|start| {
if ignore_pat_pad {
let str_chars = str.par_iter().skip(start).zip(pat.par_iter());
self.asciis_eq_ignore_pat_pad(str_chars)
} else {
self.asciis_eq(str.into_iter().skip(start), pat.into_iter())
}
})
.collect();
let block_vec: Vec<_> = matched
.into_iter()
.map(|bool| {
let radix: RadixCiphertext = bool.into_radix(1, sk);
radix.into_blocks()[0].clone()
})
.collect();
// This will be 0 if there was no match, non-zero otherwise
let combined_radix = RadixCiphertext::from(block_vec);
sk.scalar_ne_parallelized(&combined_radix, 0)
}
fn clear_compare_shifted(
&self,
str_pat: (CharIter, &str),
par_iter: Iter<usize>,
) -> BooleanBlock {
let sk = self.inner();
let (str, pat) = str_pat;
let matched: Vec<_> = par_iter
.map(|start| self.clear_asciis_eq(str.into_iter().skip(start), pat))
.collect();
let block_vec: Vec<_> = matched
.into_iter()
.map(|bool| {
let radix: RadixCiphertext = bool.into_radix(1, sk);
radix.into_blocks()[0].clone()
})
.collect();
// This will be 0 if there was no match, non-zero otherwise
let combined_radix = RadixCiphertext::from(block_vec);
sk.scalar_ne_parallelized(&combined_radix, 0)
}
/// Returns `true` if the given pattern (either encrypted or clear) matches a substring of this
/// encrypted string.
///
/// Returns `false` if the pattern does not match any substring.
///
/// The pattern to search for can be specified as either `GenericPatternRef::Clear` for a clear
/// string or `GenericPatternRef::Enc` for an encrypted string.
///
/// # Examples
///
/// ```rust
/// use tfhe::integer::{ClientKey, ServerKey};
/// use tfhe::shortint::parameters::PARAM_MESSAGE_2_CARRY_2_KS_PBS_TUNIFORM_2M128;
/// use tfhe::strings::ciphertext::{ClearString, FheString, GenericPattern};
///
/// let ck = ClientKey::new(PARAM_MESSAGE_2_CARRY_2_KS_PBS_TUNIFORM_2M128);
/// let sk = ServerKey::new_radix_server_key(&ck);
/// let ck = tfhe::strings::ClientKey::new(ck);
/// let sk = tfhe::strings::ServerKey::new(sk);
/// let (bananas, nana, apples) = ("bananas", "nana", "apples");
///
/// let enc_bananas = FheString::new(&ck, bananas, None);
/// let enc_nana = GenericPattern::Enc(FheString::new(&ck, nana, None));
/// let clear_apples = GenericPattern::Clear(ClearString::new(apples.to_string()));
///
/// let result1 = sk.contains(&enc_bananas, enc_nana.as_ref());
/// let result2 = sk.contains(&enc_bananas, clear_apples.as_ref());
///
/// let should_be_true = ck.inner().decrypt_bool(&result1);
/// let should_be_false = ck.inner().decrypt_bool(&result2);
///
/// assert!(should_be_true);
/// assert!(!should_be_false);
/// ```
pub fn contains(&self, str: &FheString, pat: GenericPatternRef<'_>) -> BooleanBlock {
let sk = self.inner();
let trivial_or_enc_pat = match pat {
GenericPatternRef::Clear(pat) => FheString::trivial(self, pat.str()),
GenericPatternRef::Enc(pat) => pat.clone(),
};
match self.length_checks(str, &trivial_or_enc_pat) {
IsMatch::Clear(val) => return sk.create_trivial_boolean_block(val),
IsMatch::Cipher(val) => return val,
IsMatch::None => (),
}
let ignore_pat_pad = trivial_or_enc_pat.is_padded();
let null = (!str.is_padded() && trivial_or_enc_pat.is_padded())
.then_some(FheAsciiChar::null(self));
let (str_iter, pat_iter, iter) = contains_cases(str, &trivial_or_enc_pat, null.as_ref());
match pat {
GenericPatternRef::Clear(pat) => {
self.clear_compare_shifted((str_iter, pat.str()), iter.into_par_iter())
}
GenericPatternRef::Enc(_) => {
self.compare_shifted((str_iter, pat_iter), iter.into_par_iter(), ignore_pat_pad)
}
}
}
/// Returns `true` if the given pattern (either encrypted or clear) matches a prefix of this
/// encrypted string.
///
/// Returns `false` if the pattern does not match the prefix.
///
/// The pattern to search for can be specified as either `GenericPatternRef::Clear` for a clear
/// string or `GenericPatternRef::Enc` for an encrypted string.
///
/// # Examples
///
/// ```rust
/// use tfhe::integer::{ClientKey, ServerKey};
/// use tfhe::shortint::parameters::PARAM_MESSAGE_2_CARRY_2_KS_PBS_TUNIFORM_2M128;
/// use tfhe::strings::ciphertext::{ClearString, FheString, GenericPattern};
///
/// let ck = ClientKey::new(PARAM_MESSAGE_2_CARRY_2_KS_PBS_TUNIFORM_2M128);
/// let sk = ServerKey::new_radix_server_key(&ck);
/// let ck = tfhe::strings::ClientKey::new(ck);
/// let sk = tfhe::strings::ServerKey::new(sk);
/// let (bananas, ba, nan) = ("bananas", "ba", "nan");
///
/// let enc_bananas = FheString::new(&ck, bananas, None);
/// let enc_ba = GenericPattern::Enc(FheString::new(&ck, ba, None));
/// let clear_nan = GenericPattern::Clear(ClearString::new(nan.to_string()));
///
/// let result1 = sk.starts_with(&enc_bananas, enc_ba.as_ref());
/// let result2 = sk.starts_with(&enc_bananas, clear_nan.as_ref());
///
/// let should_be_true = ck.inner().decrypt_bool(&result1);
/// let should_be_false = ck.inner().decrypt_bool(&result2);
///
/// assert!(should_be_true);
/// assert!(!should_be_false);
/// ```
pub fn starts_with(&self, str: &FheString, pat: GenericPatternRef<'_>) -> BooleanBlock {
let sk = self.inner();
let trivial_or_enc_pat = match pat {
GenericPatternRef::Clear(pat) => FheString::trivial(self, pat.str()),
GenericPatternRef::Enc(pat) => pat.clone(),
};
match self.length_checks(str, &trivial_or_enc_pat) {
IsMatch::Clear(val) => return sk.create_trivial_boolean_block(val),
IsMatch::Cipher(val) => return val,
IsMatch::None => (),
}
if !trivial_or_enc_pat.is_padded() {
return match pat {
GenericPatternRef::Clear(pat) => {
self.clear_asciis_eq(str.chars().iter(), pat.str())
}
GenericPatternRef::Enc(pat) => {
self.asciis_eq(str.chars().iter(), pat.chars().iter())
}
};
}
let str_len = str.len();
let pat_len = trivial_or_enc_pat.len();
// In the padded pattern case we can remove the last char (as it's always null)
let pat_chars = &trivial_or_enc_pat.chars()[..pat_len - 1];
let null = FheAsciiChar::null(self);
let str_chars = if !str.is_padded() && (str_len < pat_len - 1) {
// If str = "xy" and pat = "xyz\0", then str[..] == pat[..2], but instead we have
// to check if "xy\0" == pat[..3] (i.e. check that the actual pattern isn't longer)
str.chars()
.iter()
.chain(std::iter::once(&null))
.collect_vec()
} else {
str.chars().iter().collect_vec()
};
let str_pat = str_chars.par_iter().copied().zip(pat_chars.par_iter());
self.asciis_eq_ignore_pat_pad(str_pat)
}
/// Returns `true` if the given pattern (either encrypted or clear) matches a suffix of this
/// encrypted string.
///
/// Returns `false` if the pattern does not match the suffix.
///
/// The pattern to search for can be specified as either `GenericPatternRef::Clear` for a clear
/// string or `GenericPatternRef::Enc` for an encrypted string.
///
/// # Examples
///
/// ```rust
/// use tfhe::integer::{ClientKey, ServerKey};
/// use tfhe::shortint::parameters::PARAM_MESSAGE_2_CARRY_2_KS_PBS_TUNIFORM_2M128;
/// use tfhe::strings::ciphertext::{ClearString, FheString, GenericPattern};
///
/// let ck = ClientKey::new(PARAM_MESSAGE_2_CARRY_2_KS_PBS_TUNIFORM_2M128);
/// let sk = ServerKey::new_radix_server_key(&ck);
/// let ck = tfhe::strings::ClientKey::new(ck);
/// let sk = tfhe::strings::ServerKey::new(sk);
/// let (bananas, anas, nana) = ("bananas", "anas", "nana");
///
/// let enc_bananas = FheString::new(&ck, bananas, None);
/// let enc_anas = GenericPattern::Enc(FheString::new(&ck, anas, None));
/// let clear_nana = GenericPattern::Clear(ClearString::new(nana.to_string()));
///
/// let result1 = sk.ends_with(&enc_bananas, enc_anas.as_ref());
/// let result2 = sk.ends_with(&enc_bananas, clear_nana.as_ref());
///
/// let should_be_true = ck.inner().decrypt_bool(&result1);
/// let should_be_false = ck.inner().decrypt_bool(&result2);
///
/// assert!(should_be_true);
/// assert!(!should_be_false);
/// ```
pub fn ends_with(&self, str: &FheString, pat: GenericPatternRef<'_>) -> BooleanBlock {
let sk = self.inner();
let trivial_or_enc_pat = match pat {
GenericPatternRef::Clear(pat) => FheString::trivial(self, pat.str()),
GenericPatternRef::Enc(pat) => pat.clone(),
};
match self.length_checks(str, &trivial_or_enc_pat) {
IsMatch::Clear(val) => return sk.create_trivial_boolean_block(val),
IsMatch::Cipher(val) => return val,
IsMatch::None => (),
}
match pat {
GenericPatternRef::Clear(pat) => {
let (str_iter, clear_pat, iter) = clear_ends_with_cases(str, pat.str());
self.clear_compare_shifted((str_iter, &clear_pat), iter.into_par_iter())
}
GenericPatternRef::Enc(pat) => {
let null = (str.is_padded() ^ pat.is_padded()).then_some(FheAsciiChar::null(self));
let (str_iter, pat_iter, iter) = ends_with_cases(str, pat, null.as_ref());
self.compare_shifted((str_iter, pat_iter), iter.into_par_iter(), false)
}
}
}
}