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mod serialize;
mod timer;
mod vint;
pub mod bitpacker;
pub use self::serialize::BinarySerializable;
pub use self::timer::Timing;
pub use self::timer::TimerTree;
pub use self::timer::OpenTimer;
pub use self::vint::VInt;
use std::io;
/// Create a default io error given a string.
pub fn make_io_err(msg: String) -> io::Error {
io::Error::new(io::ErrorKind::Other, msg)
}
/// Has length trait
pub trait HasLen {
/// Return length
fn len(&self) -> usize;
/// Returns true iff empty.
fn is_empty(&self) -> bool {
self.len() == 0
}
}
const HIGHEST_BIT: u64 = 1 << 63;
/// Maps a `i64` to `u64`
///
/// For simplicity, tantivy internally handles `i64` as `u64`.
/// The mapping is defined by this function.
///
/// Maps `i64` to `u64` so that
/// `-2^63 .. 2^63-1` is mapped
/// to
/// `0 .. 2^64-1`
/// in that order.
///
/// This is more suited than simply casting (`val as u64`)
/// because of bitpacking.
///
/// Imagine a list of `i64` ranging from -10 to 10.
/// When casting negative values, the negative values are projected
/// to values over 2^63, and all values end up requiring 64 bits.
///
/// # See also
/// The [reverse mapping is `u64_to_i64`](./fn.u64_to_i64.html).
#[inline(always)]
pub fn i64_to_u64(val: i64) -> u64 {
(val as u64) ^ HIGHEST_BIT
}
/// Reverse the mapping given by [`i64_to_u64`](./fn.i64_to_u64.html).
#[inline(always)]
pub fn u64_to_i64(val: u64) -> i64 {
(val ^ HIGHEST_BIT) as i64
}
#[cfg(test)]
mod test {
use super::{i64_to_u64, u64_to_i64};
fn test_i64_converter_helper(val: i64) {
assert_eq!(u64_to_i64(i64_to_u64(val)), val);
}
#[test]
fn test_i64_converter() {
assert_eq!(i64_to_u64(i64::min_value()), u64::min_value());
assert_eq!(i64_to_u64(i64::max_value()), u64::max_value());
test_i64_converter_helper(0i64);
test_i64_converter_helper(i64::min_value());
test_i64_converter_helper(i64::max_value());
for i in -1000i64..1000i64 {
test_i64_converter_helper(i);
}
}
}
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