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

Table of Contents

• definePropertiesFromOptions
  • Parameters
• setAttribute
  • Parameters
• getAttribute
  • Parameters
• optionJSON
  • Parameters
• mapAttributes
  • Parameters
• mapAttributesInverse
  • Parameters
• Base
  • Parameters
  • Properties
  • key
  • write
    • Parameters
  • readDetails
    • Parameters
  • delete
    • Parameters
  • keyPrefix
  • keyPrefixWith
    • Parameters
  • typeName
  • attributes
  • entries
    • Parameters
  • entriesWith
    • Parameters
  • entry
    • Parameters
• description
• Category
  • Parameters
  • Properties
  • valueKey
    • Parameters
  • writeValue
    • Parameters
  • getValue
    • Parameters
  • deleteValue
    • Parameters
  • values
    • Parameters
  • readStream
    • Parameters
  • meters
    • Parameters
  • notes
    • Parameters
  • entries
    • Parameters
• MASTER
• SCHEMA_VERSION_1
• SCHEMA_VERSION_2
• SCHEMA_VERSION_CURRENT
• CATEGORY_PREFIX
• VALUE_PREFIX
• unit
• fractionalDigits
• Master
  • Properties
  • close
  • categories
    • Parameters
  • backup
    • Parameters
  • restore
    • Parameters
  • initialize
    • Parameters
• Meter
  • Parameters
  • Properties
• Note
  • Parameters
• secondsAsString
  • Parameters

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 {})

setAttribute

Set Object attribute. The name may be a property path like 'a.b.c'.

Parameters

• object Object
• name string
• value any

getAttribute

Deliver attribute value. The name may be a property path like 'a.b.c'.

Parameters

• object Object
• name string

Returns any value associated with the given property name

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 {})
• skip Array<string> keys not to put in the result (optional, default [])

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

Base

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 Iterator<factory>

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
• gte string lowest name (optional, default "\u0000")
• lte string highst name (optional, default "\uFFFF")
• owner Object

Returns AsyncIterator<Base>

entry

Get a single instance.

Parameters

• db levelup
• key string

Returns Base

description

Description of the content.

Returns string

Category

Extends Base

Value Category.

Parameters

• name string category name

• options Object

  • options.description string
  • options.unit string physical unit like kWh or m3
  • options.fractionalDigits number display precission

Properties

• name string category name
• description string
• unit string physical unit
• fractionalDigits number display precission

valueKey

Key for a given value.

Parameters

• time number seconds since epoch

Returns string key

writeValue

Write a time/value pair.

Parameters

• db levelup
• value number
• time number seconds since epoch

getValue

Parameters

• db levelup
• time number seconds since epoch

deleteValue

Parameters

• db levelup
• time number seconds since epoch

values

Get values of the category.

Parameters

• db levelup

• options Object

  • options.gte string time of earliest value
  • options.lte string time of latest value
  • options.reverse boolean order

Returns Iterator<Object>

readStream

Get values of the category as ascii text stream with time and value on each line.

Parameters

• db levelup

• options Object

  • options.gte string time of earliest value
  • options.lte string time of latest value
  • options.reverse boolean order

Returns Readable

meters

Get Meters of the category.

Parameters

• db levelup

• options Object

  • options.gte string from name
  • options.lte string up to name
  • options.reverse boolean order

Returns Iterator<Meter>

notes

Get Notes of the category.

Parameters

• db levelup

• options Object

  • options.gte string time
  • options.lte string up to time
  • options.reverse boolean order

Returns Iterator<Meter>

entries

Get categories.

Parameters

• db levelup
• gte string lowest name
• lte string highst name

Returns AsyncIterator<Category>

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.

categories

List Categories.

Parameters

• gte string
• lte string

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 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

Properties

• name string category name
• description string
• unit string physical unit
• fractionalDigits number display precission

Note

Extends Base

Hints placed on a category at a specific time.

Parameters

• time
• owner
• options

secondsAsString

Format seconds as string left padded with '0'.

Parameters

• seconds number seconds since epoch

Returns string padded seconds