@konsumation/db NPM

konsum-db

timeseries database on leveldb

example

import levelup from "levelup";
import leveldown from "leveldown";

import { Master, Category } from "konsum-db";

async function example() {
 // open database
 const db = await levelup(leveldown("example.db"));
 const master = await Master.initialize(db);

 // create category named EV
 const ev = new Category("EV", master, { unit: "kWh" });
 await ev.write(master.db);
 
 // write entry
 await ev.writeValue(db, Date.now(), 77.34);
}

example();

API

definePropertiesFromOptions

See: Object.definedProperties()
See: Object.getOwnPropertyDescriptor()

Create properties from options and default options. Already present properties (direct) are skipped. The attribute list from the class will be applied to the options and merged with the given set of properties.

class aClass {
  static get attributes() {
    return { with_default: { default: 77 }};
  }
}

definePropertiesFromOptions(new aClass());
// equivalent to
Object.definedProperties(new aClass(),{ with_default: { value: 77 }})

Parameters

object Object target object
options Object as passed to object constructor (optional, default {})
properties Object object properties (optional, default {})
attributes Object? attribute meta info (optional, default object.constructor.attributes)

defaultValues

Get default values.

Parameters

attributes Object
object Object

Returns Object filled with default values

optionJSON

Create json based on present options. In other words only produce key value pairs if value is defined.

Parameters

object Object
initial Object (optional, default {})
attributes Object to operator on (optional, default object.constructor.attributes)

Returns Object initial + defined values

mapAttributes

Rename attributes. Filters out null, undefined and empty strings.

mapAttributes({a:1},{a:"a'"}) // {"a'": 1}

Parameters

object Object
mapping Object

Returns Object keys renamed after mapping

mapAttributesInverse

Same as mapAttributes but with the inverse mapping. Filters out null, undefined and empty strings

Parameters

object Object
mapping Object?

Returns Object keys renamed after mapping

description

Description of the content.

Base

Parameters

name string meter name
owner
options Object
- options.description string
- options.unit string physical unit like kWh or m3

Properties

name string category name
description string
unit string physical unit

key

Returns string

write

See: {key}

Writes object into database. Leaves all other entries alone.

Parameters

db levelup

readDetails

Get detail objects.

Parameters

factory Class
db levelup
options Object
- options.gte string from name
- options.lte string up to name
- options.reverse boolean order

Returns AsyncIterator\

delete

Delete record from database.

Parameters

db levelup

keyPrefix

Prefix of the key

Returns string

keyPrefixWith

Parameters

object Base

Returns String prefix for a given (master) object

typeName

Name of the type in text dump

Returns string

attributes

Additional attributes to be persisted

entries

Get instances without owner.

Parameters

db levelup
prefix string
gte string lowest name (optional, default "\u0000")
lte string highst name (optional, default "\uFFFF")

Returns AsyncIterator<Base>

entriesWith

Get instances with owner.

Parameters

db levelup
object Object
gte string lowest name (optional, default "\u0000")
lte string highst name (optional, default "\uFFFF")

Returns AsyncIterator<Base>

entry

Get a single instance.

Parameters

db levelup
key string

Returns Promise<Base>

MASTER

Prefix of the master record

Type: string

SCHEMA_VERSION_1

Outdated schema version

Type: string

SCHEMA_VERSION_2

Schema with type + name

Type: string

SCHEMA_VERSION_CURRENT

Schema version for newly created databases

CATEGORY_PREFIX

Prefix of the categories. Will be followed by the category name

Type: string

VALUE_PREFIX

Prefix of the values. Will be followed by the category name

Type: string

unit

Physical unit.

Returns string

fractionalDigits

Precission

Returns number

Master

Extends Base

Master record. Holds schema version.

Properties

schemaVersion string

close

Close the underlaying database.

backup

Copy all data into out stream as long time text data.

Parameters

out Writeable

restore

Restore database from input stream.

Parameters

input Readable data from backup

initialize

Initialize database. checks/writes master record.

Parameters

db levelup

Returns Promise<Master>

Meter

Extends Base

Meter

Parameters

name string meter name
category Category
options Object
- options.description string
- options.unit string physical unit like kWh or m3
- options.fractionalDigits number display precission