;;======================================================================
;; 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.
;;======================================================================
(declare (unit env))
(use sql-de-lite) ;; srfi-1 posix regex regex-case srfi-69 nanomsg srfi-18 call-with-environment-variables)
(define (env:open-db fname)
(let* ((db-exists (file-exists? fname))
(db (open-database fname)))
(if (not db-exists)
(begin
(exec (sql db "CREATE TABLE envvars (
id INTEGER PRIMARY KEY,
context TEXT NOT NULL,
var TEXT NOT NULL,
val TEXT NOT NULL,
CONSTRAINT envvars_constraint UNIQUE (context,var))"))))
(set-busy-handler! db (busy-timeout 10000))
db))
;; save vars in given context, this is NOT incremental by default
;;
(define (env:save-env-vars db context #!key (incremental #f)(vardat #f))
(with-transaction
db
(lambda ()
;; first clear out any vars for this context
(if (not incremental)(exec (sql db "DELETE FROM envvars WHERE context=?") context))
(for-each
(lambda (varval)
(let ((var (car varval))
(val (cdr varval)))
(if incremental (exec (sql db "DELETE FROM envvars WHERE context=? AND var=?") context var))
(exec (sql db "INSERT INTO envvars (context,var,val) VALUES (?,?,?)") context var val)))
(if vardat
(hash-table->alist vardat)
(get-environment-variables))))))
;; merge contexts in the order given
;; - each context is applied in the given order
;; - variables in the paths list are split on the separator and the components
;; merged using simple delta addition
;; returns a hash of the merged vars
;;
(define (env:merge-contexts db basecontext contexts paths)
(let ((result (make-hash-table)))
(for-each
(lambda (context)
(query
(for-each-row
(lambda (row)
(let ((var (car row))
(val (cadr row)))
(hash-table-set! result var
(if (and (hash-table-ref/default results var #f)
(assoc var paths)) ;; this var is a path and there is a previous path
(let ((sep (cadr (assoc var paths))))
(env:merge-path-envvar sep (hash-table-ref results var) valb))
valb)))))
(sql db "SELECT var,val FROM envvars WHERE context=?")
context))
contexts)
result))
;; get list of removed variables between two contexts
;;
(define (env:get-removed db contexta contextb)
(let ((result (make-hash-table)))
(query
(for-each-row
(lambda (row)
(let ((var (car row))
(val (cadr row)))
(hash-table-set! result var val))))
(sql db "SELECT var,val FROM envvars WHERE context=? AND var NOT IN (SELECT var FROM envvars WHERE context=?)")
contexta contextb)
result))
;; get list of variables added to contextb from contexta
;;
(define (env:get-added db contexta contextb)
(let ((result (make-hash-table)))
(query
(for-each-row
(lambda (row)
(let ((var (car row))
(val (cadr row)))
(hash-table-set! result var val))))
(sql db "SELECT var,val FROM envvars WHERE context=? AND var NOT IN (SELECT var FROM envvars WHERE context=?)")
contextb contexta)
result))
;; get list of variables in both contexta and contexb that have been changed
;;
(define (env:get-changed db contexta contextb)
(let ((result (make-hash-table)))
(query
(for-each-row
(lambda (row)
(let ((var (car row))
(val (cadr row)))
(hash-table-set! result var val))))
(sql db "SELECT var,val FROM envvars AS a WHERE context=? AND val != (SELECT val FROM envvars WHERE var=a.var AND context=?)")
contexta contextb)
result))
;;
(define (env:blind-merge l1 l2)
(if (null? l1) l2
(if (null? l2) l1
(cons (car l1) (cons (car l2) (env:blind-merge (cdr l1) (cdr l2)))))))
;; given a before and an after envvar calculate a new merged path
;;
(define (env:merge-path-envvar separator patha pathb)
(let* ((patha-parts (string-split patha separator))
(pathb-parts (string-split pathb separator))
(common-parts (lset-intersection equal? patha-parts pathb-parts))
(final (delete-duplicates ;; env:blind-merge
(append pathb-parts common-parts patha-parts))))
;; (print "BEFORE: " (string-intersperse patha-parts "\n "))
;; (print "AFTER: " (string-intersperse pathb-parts "\n "))
;; (print "COMMON: " (string-intersperse common-parts "\n "))
(string-intersperse final separator)))
(define (env:process-path-envvar varname separator patha pathb)
(let ((newpath (env:merge-path-envvar separator patha pathb)))
(setenv varname newpath)))
(define (env:have-context db context)
(> (query fetch-value (sql db "SELECT count(id) FROM envvars WHERE context=?") context)
0))
;; this is so the calling block does not need to import sql-de-lite
(define (env:close-database db)
(close-database db))
(define (env:lazy-hash-table->alist indat)
(if (hash-table? indat)
(let ((dat (hash-table->alist indat)))
(if (null? dat)
#f
dat))
#f))
(define (env:print added removed changed)
(let ((a (env:lazy-hash-table->alist added))
(r (env:lazy-hash-table->alist removed))
(c (env:lazy-hash-table->alist changed)))
(case (if (args:get-arg "-dumpmode")
(string->symbol (args:get-arg "-dumpmode"))
'bash)
((bash)
(if a
(begin
(print "# Added vars")
(map (lambda (dat)(print "export " (car dat) "=" (cdr dat)))
(hash-table->alist added))))
(if r
(begin
(print "# Removed vars")
(map (lambda (dat)(print "unset " (car dat)))
(hash-table->alist removed))))
(if c
(begin
(print "# Changed vars")
(map (lambda (dat)(print "export " (car dat) "=" (cdr dat)))
(hash-table->alist changed)))))
((csh)
(if a
(begin
(print "# Added vars")
(map (lambda (dat)(print "setenv " (car dat) " " (cdr dat)))
(hash-table->alist added))))
(if r
(begin
(print "# Removed vars")
(map (lambda (dat)(print "unsetenv " (car dat)))
(hash-table->alist removed))))
(if c
(begin
(print "# Changed vars")
(map (lambda (dat)(print "setenv " (car dat) " " (cdr dat)))
(hash-table->alist changed)))))
((config ini)
(if a
(begin
(print "# Added vars")
(map (lambda (dat)(print (car dat) " " (cdr dat)))
(hash-table->alist added))))
(if r
(begin
(print "# Removed vars")
(map (lambda (dat)(print "#{scheme (unsetenv \"" (car dat) "\")}"))
(hash-table->alist removed))))
(if c
(begin
(print "# Changed vars")
(map (lambda (dat)(print (car dat) " " (cdr dat)))
(hash-table->alist changed)))))
(else
(debug:print 0 "ERROR: No dumpmode specified, use -dumpmode [bash|csh|config]")))))