Range-index NPM

range

levelup based range index

install

npm install [--save/--save-dev] range-index

examples

data set

ID	NAME	AGE	SEX
`1`	Divina Ventimiglia	7	F
`2`	Nakisha Robuck	54	F
`3`	Amira Markus	18	F
`4`	Mohamed Kincannon	60	M
`5`	Juana Ardon	23	F
`6`	Hyon Davie	60	F
`7`	Estell Cromer	18	F
`8`	Jacob Neeley	13	M
`9`	Carlene Weatherman	42	F
`10`	Carie Markland	7	F

`age`/`id` range index

AGE	ID
7	`1`, `10`
13	`8`
18	`3`, `7`
23	`5`
42	`9`
54	`2`
60	`4`, `6`

as seen in Database Indexes for The Inquisitive Mind

data set

DOCUMENT	COUNTRIES
`A`	Australia, Canada, Portugal
`B`	Canada, Portugal, Togo
`C`	Algeria, Canada, Portugal, Togo
`D`	Algeria, Canada, Togo
`E`	Canada, Togo
`F`	Togo

`country`/`document` range index

COUNTRY	DOCUMENTS
Algeria	`C`, `D`
Australia	`A`
Canada	`A`, `B`, `C`, `D`, `E`
Portugal	`A`, `B`, `C`
Togo	`B`, `C`, `D`, `E`, `F`

api

var range = require('range-index');

`index` range(string: `location`)

var age = range('path/to/location');

`void` index.put(`string`/`number`: value, `*`: key, `function`: callback)

age.put(18, 7, function (e) {
  if(e) throw e;
  console.log('index saved successfully');
});

countries.put('Portugal', 'A', function (e) {
  if(e) throw e;
  console.log('index saved successfully');
});

`stream` index.get(`string`/`number`: index)

var user = age.get(18);

user.on('data', function (data) {
  assert(data.value == [3, 7]);
  assert(data.key == 18);
});

user.on('error', function (e) {
  throw e;
});

user.on('close', function () {
  console.log('Stream closed')
});

user.on('end', function () {
  console.log('Stream closed')
});

var country = countries.get('Portugal');

user.on('data', function (data) {
  assert(data.value == ['A', 'B', 'C']);
  assert(data.key == 'Portugal');
});

user.on('error', function (e) {
  throw e;
});

user.on('close', function () {
  console.log('Stream closed')
});

user.on('end', function () {
  console.log('Stream closed')
});

index.all()

var users = age.all();

users.on('data', function (data) {
  console.log('Age: ', data.key, 'ID\'s: ', data.value)
});

user.on('error', function (e) {
  throw e;
});

user.on('close', function () {
  console.log('Stream closed')
});

user.on('end', function () {
  console.log('Stream closed')
});

index.from(start)

var users = age.from(54);

users.on('data', function (data) {
  console.log('Age: ', data.key, 'ID\'s: ', data.value)
});

user.on('error', function (e) {
  throw e;
});

user.on('close', function () {
  console.log('Stream closed')
});

user.on('end', function () {
  console.log('Stream closed')
});

returned indexes:

AGE	ID
54	`2`
60	`4`, `6`

var from_countries = countries.from('P');

from_countries.on('data', function (data) {
  console.log('Age: ', data.key, 'ID\'s: ', data.value)
});

from_countries.on('error', function (e) {
  throw e;
});

from_countries.on('close', function () {
  console.log('Stream closed')
});

from_countries.on('end', function () {
  console.log('Stream closed')
});

returned indexes:

COUNTRY	DOCUMENTS
Portugal	`A`, `B`, `C`
Togo	`B`, `C`, `D`, `E`, `F`

index.between(start, end)

var users = age.between(13, 23);

users.on('data', function (data) {
  console.log('Age: ', data.key, 'ID\'s: ', data.value)
});

user.on('error', function (e) {
  throw e;
});

user.on('close', function () {
  console.log('Stream closed')
});

user.on('end', function () {
  console.log('Stream closed')
});

returned indexes:

AGE	ID
13	`8`
18	`3`, `7`
23	`5`

var between_countries = countries.between('A', 'C');

from_countries.on('data', function (data) {
  console.log('Age: ', data.key, 'ID\'s: ', data.value)
});

from_countries.on('error', function (e) {
  throw e;
});

from_countries.on('close', function () {
  console.log('Stream closed')
});

from_countries.on('end', function () {
  console.log('Stream closed')
});

returned indexes:

COUNTRY	DOCUMENTS
Algeria	`C`, `D`
Australia	`A`

index.until(end)

var users = age.until(18);

users.on('data', function (data) {
  console.log('Age: ', data.key, 'ID\'s: ', data.value)
});

user.on('error', function (e) {
  throw e;
});

user.on('close', function () {
  console.log('Stream closed')
});

user.on('end', function () {
  console.log('Stream closed')
});

returned indexes:

AGE	ID
7	`1`, `10`
13	`8`
18	`3`, `7`

var from_countries = countries.until('P');

from_countries.on('data', function (data) {
  console.log('Age: ', data.key, 'ID\'s: ', data.value)
});

from_countries.on('error', function (e) {
  throw e;
});

from_countries.on('close', function () {
  console.log('Stream closed')
});

from_countries.on('end', function () {
  console.log('Stream closed')
});

returned indexes: