sqlite_dbhash

A Rust port of dbhash utility from sqlite repository so that it can be used as a library function instead of a standalone program.

Ported directly from dbhash.c.

Usage

use sqlite_dbhash::{dbhash, Selection};
use rusqlite::{Connection, Result};
fn main() -> Result<()> {
    let conn = Connection::open("my_db.db")?;
    // Equivalent to `dbhash my_db.db` (except for the output mat)
    println!("{:02x?}", dbhash(&conn, None, Selection::SchemaAndContent)?);
    // Equivalent to `dbhash --like "prefix% --schema-only my_db.db"
    println!("{:02x?}", dbhash(&conn, Some("prefix%"), Selection::SchemaOnly)?);
    // Equivalent to `dbhash --without-schema my_db.db`
    println!("{:02x?}", dbhash(&conn, None, Selection::ContentOnly)?);
    Ok(())
}

Intentional Breakage

For the vast majority of the scenarios, the hash produced by this library agrees with the dbhash program from sqlite. However, the hash can be different when the table_pattern/--like parameter contains non-ASCII characters.

I consider it a bug in the sqlite implementation. Since the encoding of the arguments passed from the console is platform-dependent, and the sqlite dbhash implementation simply used sqlite3_vmprintf to interpolate the SQL statement using the raw argv, it could be the case that the argument is not in UTF-8 (on Windows for example), and thus dbhash matches no table with the pattern while it is a false negative.

License

Inheriting sqlite blessing license as follows

The author disclaims copyright to this source code. In place of a legal notice, here is a blessing:

    May you do good and not evil.
    May you find forgiveness for yourself and forgive others.
    May you share freely, never taking more than you give.