sq3-rs 0.3.0

SQLite reader with no dependencies
Documentation 
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use std::fmt::Display;

use sq3_derive::Name;
use sq3_parser::TypeName;

use crate::{
    field_parsing_error,
    result::{SqliteError, SqliteResult},
    traits::ParseBytes,
};

/// # Text encoding (4 Bytes)
///
///  The 4-byte big-endian integer at offset 56 determines the encoding used for
/// all text strings stored in the database. A value of 1 means UTF-8. A value
/// of 2 means UTF-16le. A value of 3 means UTF-16be. No other values are
/// allowed. The sqlite3.h header file defines C-preprocessor macros
/// SQLITE_UTF8 as 1, SQLITE_UTF16LE as 2, and SQLITE_UTF16BE as 3, to use in
/// place of the numeric codes for the text encoding.
#[derive(Debug, Default, Name)]
pub enum DatabaseTextEncoding {
    #[default]
    Utf8,
    Utf16Le,
    Utf16Be,
}

impl From<&DatabaseTextEncoding> for u32 {
    fn from(value: &DatabaseTextEncoding) -> Self {
        match value {
            DatabaseTextEncoding::Utf8 => 1,
            DatabaseTextEncoding::Utf16Le => 2,
            DatabaseTextEncoding::Utf16Be => 3,
        }
    }
}

impl TryFrom<u32> for DatabaseTextEncoding {
    type Error = SqliteError;

    fn try_from(value: u32) -> Result<Self, Self::Error> {
        match value {
            1 => Ok(Self::Utf8),
            2 => Ok(Self::Utf16Le),
            3 => Ok(Self::Utf16Be),
            _ => Err(field_parsing_error! {Self::NAME.into()}),
        }
    }
}

impl Display for DatabaseTextEncoding {
    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
        let number = u32::from(self);
        let name = match self {
            DatabaseTextEncoding::Utf8 => "utf8",
            DatabaseTextEncoding::Utf16Le => "utf16le",
            DatabaseTextEncoding::Utf16Be => "utf16le",
        };
        write!(f, "{number} ({name})")
    }
}

impl ParseBytes for DatabaseTextEncoding {
    const LENGTH_BYTES: usize = 4;

    fn parsing_handler(bytes: &[u8]) -> SqliteResult<Self> {
        let buf: [u8; Self::LENGTH_BYTES] = bytes.try_into()?;

        let value = u32::from_be_bytes(buf);

        value.try_into()
    }
}