https://github.com/koopjs/koop-cache-memory
Deprecated
https://github.com/koopjs/koop-cache-memory
deprecated
Last synced: 12 days ago
JSON representation
Deprecated
- Host: GitHub
- URL: https://github.com/koopjs/koop-cache-memory
- Owner: koopjs
- License: other
- Created: 2017-02-12T17:19:42.000Z (about 8 years ago)
- Default Branch: master
- Last Pushed: 2023-07-11T19:11:40.000Z (almost 2 years ago)
- Last Synced: 2024-04-09T14:59:02.930Z (about 1 year ago)
- Topics: deprecated
- Language: JavaScript
- Homepage:
- Size: 114 KB
- Stars: 0
- Watchers: 10
- Forks: 4
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
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README
# Koop Memory Cache
## DEPRECATED - now migrated to a package in the [Koop monorepo](https://github.com/koopjs/koop/).
[](http://unmaintained.tech/)
[](https://travis-ci.org/koopjs/koop-cache-memory) [](https://greenkeeper.io/)
## Usage
This is the default cache for [Koop](https://github.com/koopjs/koop) so you won't need to instantiate it yourself. If you really wanted to, it would look like this:
```js
const Koop = require('koop')
const koop = new Koop()
const cache = require('@koopjs/cache-memory')
koop.register(cache)
```
## Cache API
The cache is a JavaScript object that lives in-memory. It is used to store geojson features.
### `insert`
Insert geojson into the cache
Note: A metadata entry will be created automatically. It can be populated from an object on the inserted geojson.
```js
const geojson = {
type: 'FeatureCollection',
features: [],
metadata: { // Metadata is an arbitrary object that will be stored in the catalog under the same key as the geojson
name: 'Example GeoJSON',
description: 'This is geojson that will be stored in the cache'
}
}
const options = {
ttl: 1000 // The TTL option is measured in seconds, it will be used to set the `expires` field in the catalog entry
}
cache.insert('key', geojson, options, err => {
// This function will call back with an error if there is already data in the cache using the same key
})
```
### `append`
Add features to an existing geojson feature collection in the cache
Note:
```js
const geojson = {
type: 'FeatureCollection',
features: []
}
cache.append('key', geojson, err => {
// This function will call back with an error if the cache key does not exist
})
```
### `update`
Update a cached feature collection with new features.
This will completely replace the features that are in the cache, but the metadata doc will remain in the catalog.
```js
const geojson = {
type: 'FeatureCollection',
features: []
}
const options = {
ttl: 1000
}
cache.update('key', geojson, options, err => {
// This function will call back with an error if the cache key does not exist
})
```
### `upsert`
Update a cached feature collection with new features or insert if the features are not there.
```js
const geojson = {
type: 'FeatureCollection',
features: []
}
const options = {
ttl: 1000
}
cache.upsert('key', geojson, options, err => {
// This function will call back with an error if the cache key does not exist
})
```
### `retrieve`
Retrieve a cached feature collection
```js
const options = {} // For now there are no options on retrieve. This is meant for compatibility with the general cache API
cache.retrieve('key', options, (err, geojson) => {
/* This function will call back with an error if there is no geojson in the cache
The geojson returned will contain the metadata document from the catalog
{
type: 'FeatureCollection',
features: [],
metadata: {}
}
*/
})
```
### `delete`
Remove a feature collection from the cache
```js
cache.delete('key', err => {
// This function will call back with an error if there was nothing to delete
})
```
### `createStream`
Create a stream of features from the cache
```js
cache.createStream('key', options)
.pipe(/* do something with the stream of geojson features emitted one at a time */)
```
## Catalog API
The catalog stores metadata about items that are in the cache.
### `catalog.insert`
Add an arbitrary metadata document to the cache.
Note: This is called automatically by `insert`
```js
const metadata = {
name: 'Standalone metadata',
status: 'Processing',
description: 'Metadata that is not attached to any other data in the cache'
}
cache.catalog.insert('key', metadata, err => {
// this function will call back with an error if there is already a metadata document using the same key
})
```
### `catalog.update`
Update a metadata entry
```js
const original = {
name: 'Doc',
status: 'Processing'
}
cache.catalog.insert('key', original)
const update = {
status: 'Cached'
}
cache.catalog.update('key', update, err => {
// this function will call back with an error if there is no metadata in the catalog using that key
})
cache.catalog.retrieve('key', (err, metadata) => {
/*
Updates are merged into the existing metadata document
Return value will be:
{
name: 'Doc',
status: 'Cached'
}
*/
})
```
### `catalog.retrieve`
Retrieve a metadata entry from the catalog
```js
cache.catalog.retrieve('key', (err, metadata) => {
// This function will call back with an error if there is no metadata stored under the given key
// Or else it will call back with the stored metadata doc
})
```
### `catalog.delete`
Remove a catalog entry from the catalog
Note: This cannot be called if data is in the cache under the same key
```js
cache.catalog.delete('key', err => {
// This function will call back with an error if there is nothing to delete or if there is still data in the cache using the same key
})
```