;;======================================================================
;; Copyright 2006-2013, Matthew Welland.
;;
;; This program is made available under the GNU GPL version 2.0 or
;; greater. See the accompanying file COPYING for details.
;;
;; This program is distributed WITHOUT ANY WARRANTY; without even the
;; implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
;; PURPOSE.
;;======================================================================
;;======================================================================
;; Simple persistant strings lookup table. Keep out of the main db
;; so writes/reads don't slow down central access.
;;======================================================================
(require-extension (srfi 18) extras)
(use sqlite3 srfi-1 posix regex regex-case srfi-69 csv-xml s11n md5 message-digest base64)
(import (prefix sqlite3 sqlite3:))
(import (prefix base64 base64:))
(declare (unit sdb))
;;
(define (sdb:open fname)
(let* ((dbpath (pathname-directory fname))
(dbexists (let ((fe (file-exists? fname)))
(if fe
fe
(begin
(create-directory dbpath #t)
#f))))
(sdb (sqlite3:open-database fname))
(handler (make-busy-timeout 136000)))
(sqlite3:set-busy-handler! sdb handler)
(if (not dbexists)
(sdb:initialize sdb))
(sqlite3:execute sdb "PRAGMA synchronous = 1;")
sdb))
(define (sdb:initialize sdb)
(sqlite3:execute sdb "CREATE TABLE IF NOT EXISTS strs
(id INTEGER PRIMARY KEY,
str TEXT,
CONSTRAINT str UNIQUE (str));")
(sqlite3:execute sdb "CREATE INDEX IF NOT EXISTS strindx ON strs (str);"))
;; (define sumup (let ((a 0))(lambda (x)(set! a (+ x a)) a)))
(define (sdb:register-string sdb str)
(sqlite3:execute sdb "INSERT OR IGNORE INTO strs (str) VALUES (?);" str))
(define (sdb:string->id sdb str-cache str)
(let ((id (hash-table-ref/default str-cache str #f)))
(if (not id)
(sqlite3:for-each-row
(lambda (sid)
(set! id sid)
(hash-table-set! str-cache str id))
sdb
"SELECT id FROM strs WHERE str=?;" str))
id))
(define (sdb:id->string sdb id-cache id)
(let ((str (hash-table-ref/default id-cache id #f)))
(if (not str)
(sqlite3:for-each-row
(lambda (istr)
(set! str istr)
(hash-table-set! id-cache id str))
sdb
"SELECT str FROM strs WHERE id=?;" id))
str))
;; Numbers get passed though in both directions
;;
(define (make-sdb:qry fname)
(let ((sdb #f)
(scache (make-hash-table))
(icache (make-hash-table)))
(lambda (cmd var)
(case cmd
((setup) (set! sdb (if (not sdb)
(sdb:open (if var var fname)))))
((setdb) (set! sdb var))
((getdb) sdb)
((finalize) (if sdb
(begin
(sqlite3:finalize! sdb)
(set! sdb #f))))
((getid) (let ((id (if (or (number? var)
(string->number var))
var
(sdb:string->id sdb scache var))))
(if id
id
(begin
(sdb:register-string sdb var)
(sdb:string->id sdb scache var)))))
((getstr) (if (or (number? var)
(string->number var))
(sdb:id->string sdb icache var)
var))
((passid) var)
((passstr) var)
(else #f)))))