Interface

The method [Database]::run (or alternatively Database::run_timed) is called to execute an SQL query. This takes a [Transaction] parameter which accumulates SELECT results and which also has methods for accessing the environment and controlling output. Custom builtin functions implement [CExp] and have access to the query via an [EvalEnv] parameter, which can be downcast if necessary.

Examples

use rustdb::{Database, SharedPagedData, SimpleFileStorage, WebTransaction, INITSQL};
use std::net::TcpListener;
use std::sync::Arc;

let sfs = Box::new(SimpleFileStorage::new(
"c:\\Users\\pc\\rust\\sftest01.rustdb",
));
let spd = Arc::new(SharedPagedData::new(sfs));
let apd = spd.open_write();
let db = Database::new(apd, INITSQL);

let listener = TcpListener::bind("127.0.0.1:3000").unwrap();
for tcps in listener.incoming() {
if let Ok(mut tcps) = tcps {
if let Ok(mut tr) = WebTransaction::new(&tcps) {
// tr.trace();
let sql = "EXEC web.Main()";
// Execute SQL. http response, SQL output, (status,headers,content) is accumulated in wq.
db.run_timed(&sql, &mut tr);
// Write the http response to the TCP stream.
let _err = tr.write(&mut tcps);
// Save database changes to disk.
db.save();
}
}
}

See here for more advanced example ( Axum webserver with ARGON hash function and query logging ).

Features

This crate supports two cargo features.

• builtin : Allows extra SQL builtin functions to be defined.
• max : Exposes maximal interface, including all internal modules (default).

General Design of Database

SortedFile stores fixed size Records in a tree of Pages. SortedFile is used to implement:

• Variable length values ( which are split into fragments - see bytes module - although up to 15 bytes can be stored directly. ).

• Database Table storage. Each record has a 64-bit Id.

• Index storage ( an index record refers back to the main table ).

When a page becomes too big, it is split into two pages.

Each page is implemented as a binary tree ( so there is a tree of trees ).

[SharedPagedData] allows logical database pages to be shared to allow concurrent readers.

ToDo List

Implement DROP INDEX, ALTER TABLE, fully implement CREATE INDEX.

Consider replication/backup/durability issues Here

Implement email in example program. Replication of log files. Server status.

Sort out error handling for PARSEINT etc.

Work on improving/testing SQL code, browse schema, float I/O. Login.