# [LMDB](http://www.lmdb.tech/doc/index.html) bindings for lua
license: MIT

## errors
operations that can fail will return `nil, error, errno` on failure.

## functions
### `lmdb.open(path, opt)`
create a new environment handle and open the database at the `path`. returns the environment handle (`env`) on success.

`opt` is an optional table of options:

* `maxdbs`: number: the maximum number of databases in the environment. must be set if multiple databases will be used.
* `rdonly`: boolean: open the environment in read-only mode.
* `nosubdir`: boolean: the `path` is used for the database file itself and not its containing directory.
* `nosync`: boolean: don't flush buffers to disk when committing.
* `nolock`: boolean: turn off locking. the application must manage all concurrency.

### `lmdb.version()`
returns the LMDB version as `major, minor, patch`.

### `env:txn_begin(write_enabled)`
create a new transaction in the environment. if `write_enabled` is true, then the transaction may make modifications to the database. returns the transaction handle (`txn`) on success.

### `env:copy(path)`
copy the environment to the specified `path`. return `true` on success.

### `env:sync(force)`
flush buffers to disk. if `force` is `true`, a synchronous flush is performed even if `nosync` is set. return `true` on success.

### `env:close()`
close the environment.

### `txn:open(name, create)`
open a database in the environment. if multiple databases are to be used in the environment, `name` is the name of the database to open. otherwise, it should not be supplied. if `create` is true, the database is created if it does not exist. returns a database handle on success.

the database handle behaves as a table that may be indexed with string keys and contains string values, read from the database. any changes made will be saved to the database when the transaction is committed.

### `txn:drop(name)`
delete the database `name` from the environment. (or clear the database, if `name` is not supplied)

### `txn:abort()`
abandon all operations performed in the transaction.

### `txn:commit()`
commit all operations of the transaction into the database.

### `txn:txn_begin()`
create a nested transaction in the parent transaction.