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lmdb
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Usage
(require-extension lmdb)
Documentation
The lmdb library provides bindings for the Lightning Memory-Mapped Database Manager (LMDB) database management library.
Library procedures
- (lmdb-open dbname [key: enckey] [mapsize: size])procedure
Opens or creates LMDB database with optional encryption key and map size, and returns database environment handle.
- lmdb-close dbprocedure
Closes database handle.
- (lmdb-begin db [dbname: dbname])procedure
Begins LMDB transaction with optional database name. This is required for all operations.
- lmdb-end dbprocedure
Commits and ends transaction.
- lmdb-delete-database dbnameprocedure
Deletes LMDB database.
- lmdb-ref db keyprocedure
Looks up key in database.
- lmdb-set! db key valueprocedure
Sets a key-value pair in the database.
- lmdb-count dbprocedure
Returns number of key-value pairs in database.
- lmdb-keys dbprocedure
Returns a list of database keys.
- lmdb-values dbprocedure
Returns a list of database values.
- lmdb-fold f init dbprocedure
Folds over the keys and values in the database.
- lmdb-for-each f dbprocedure
Iterates over the keys and values in the database.
- hash-table->lmdb t dbfile #!optional enckeyprocedure
Saves SRFI-69 hash table to database.
- lmdb->table dbfile #!optional enckeyprocedure
Loads database into SRFI-69 hash table.
Examples
;; lmdb encrypted key-value creation and lookup (let* ((fname (make-pathname "." "mydb.mdb")) (keys (list "k1" 'k2 '(k3))) (values (list 'one 2 "three")) (cryptokey (string->blob "1234")) (mm (lmdb-open fname key: cryptokey))) (lmdb-begin mm) (let loop ((ks keys) (vs values)) (if (> (length ks) 0) (begin (lmdb-set! mm (string->blob (->string (car ks))) (string->blob (->string (car vs)))) (loop (cdr ks) (cdr vs))))) (lmdb-end mm) (lmdb-begin mm) (let ((res (let loop ((ks keys) (vs values)) (if (= (length ks) 0) #t (let ((v (lmdb-ref mm (string->blob (->string (car ks)))))) (if (not (equal? (string->blob (->string (car vs))) v)) #f (loop (cdr ks) (cdr vs))))))) ) (lmdb-end mm) (lmdb-close mm) res) )
About this egg
Author
Based on the lmdb library from LambdaNative - a cross-platform Scheme framework. Copyright (c) 2009-2015, University of British Columbia All rights reserved.
Packaged for Chicken by Ivan Raikov and Caolan McMahon.
Version history
- 2.3
- Using (exn lmdb ...) style composite conditions to signal lmdb exceptions [thanks to Caolan McMahon].
- 2.0
- Added lmdb-begin/end procedures for explicit transaction control.
- 1.0
- Initial release
License
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. Neither the name of the author nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.