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use std::error;
use std::fmt;
use std::io;
use std::str;
use byteorder;
use regex_syntax;
use raw;
use RegexError;
pub type Result<T> = ::std::result::Result<T, Error>;
#[derive(Debug)]
pub enum Error {
Io(io::Error),
Regex(RegexError),
Version { expected: u64, got: u64 },
Format,
Value { got: u64 },
DuplicateKey { got: Vec<u8> },
OutOfOrder { previous: Vec<u8>, got: Vec<u8> },
WrongType { expected: raw::FstType, got: raw::FstType },
}
impl From<io::Error> for Error {
fn from(err: io::Error) -> Error {
Error::Io(err)
}
}
impl From<RegexError> for Error {
fn from(err: RegexError) -> Error {
Error::Regex(err)
}
}
impl From<regex_syntax::Error> for Error {
fn from(err: regex_syntax::Error) -> Error {
Error::Regex(RegexError::Syntax(err))
}
}
impl From<byteorder::Error> for Error {
fn from(err: byteorder::Error) -> Error {
Error::Io(From::from(err))
}
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
use self::Error::*;
match *self {
Io(ref err) => err.fmt(f),
Regex(ref err) => err.fmt(f),
Version { expected, got } => {
write!(f, "\
Error opening FST: expected API version {}, got API version {}.
It looks like the FST you're trying to open is either not an FST file or it
was generated with a different version of the 'fst' crate. You'll either need
to change the version of the 'fst' crate you're using, or re-generate the
FST.", expected, got)
}
Format => write!(f, "\
Error opening FST: An unknown error occurred. This usually means you're trying
to read data that isn't actually an encoded FST."),
Value { got } => write!(f, "\
Invalid value for FST map: {}. The maximum value is `2^64 - 2`. Said
differently, the only invalid value is `2^64 - 1`.", got),
DuplicateKey { ref got } => write!(f, "\
Error inserting duplicate key: {}.", format_bytes(&*got)),
OutOfOrder { ref previous, ref got } => write!(f, "\
Error inserting out-of-order key: {}. (Previous key was {}.) Keys must be
inserted in lexicographic order.",
format_bytes(&*got), format_bytes(&*previous)),
WrongType { expected, got } => write!(f, "\
Error opening FST: expected type {}, got type {}.", expected, got),
}
}
}
impl error::Error for Error {
fn description(&self) -> &str {
use self::Error::*;
match *self {
Io(ref err) => err.description(),
Regex(ref err) => err.description(),
Version { .. } => "incompatible version found when opening FST",
Format => "unknown invalid format found when opening FST",
Value { .. } => "invalid value",
DuplicateKey { .. } => "duplicate key insertion",
OutOfOrder { .. } => "out-of-order key insertion",
WrongType { .. } => "incompatible type found when opening FST",
}
}
fn cause(&self) -> Option<&error::Error> {
match *self {
Error::Io(ref err) => Some(err),
Error::Regex(ref err) => Some(err),
_ => None,
}
}
}
fn format_bytes(bytes: &[u8]) -> String {
match str::from_utf8(bytes) {
Ok(s) => s.to_owned(),
Err(_) => format!("{:?}", bytes),
}
}