66 lines
1.2 KiB
Markdown
66 lines
1.2 KiB
Markdown
|
# memory-pager
|
||
|
|
|
||
|
|
Access memory using small fixed sized buffers instead of allocating a huge buffer.
|
||
|
|
Useful if you are implementing sparse data structures (such as large bitfield).
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
```
|
||
|
|
npm install memory-pager
|
||
|
|
```
|
||
|
|
|
||
|
|
## Usage
|
||
|
|
|
||
|
|
``` js
|
||
|
|
var pager = require('paged-memory')
|
||
|
|
|
||
|
|
var pages = pager(1024) // use 1kb per page
|
||
|
|
|
||
|
|
var page = pages.get(10) // get page #10
|
||
|
|
|
||
|
|
console.log(page.offset) // 10240
|
||
|
|
console.log(page.buffer) // a blank 1kb buffer
|
||
|
|
```
|
||
|
|
|
||
|
|
## API
|
||
|
|
|
||
|
|
#### `var pages = pager(pageSize)`
|
||
|
|
|
||
|
|
Create a new pager. `pageSize` defaults to `1024`.
|
||
|
|
|
||
|
|
#### `var page = pages.get(pageNumber, [noAllocate])`
|
||
|
|
|
||
|
|
Get a page. The page will be allocated at first access.
|
||
|
|
|
||
|
|
Optionally you can set the `noAllocate` flag which will make the
|
||
|
|
method return undefined if no page has been allocated already
|
||
|
|
|
||
|
|
A page looks like this
|
||
|
|
|
||
|
|
``` js
|
||
|
|
{
|
||
|
|
offset: byteOffset,
|
||
|
|
buffer: bufferWithPageSize
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
#### `pages.set(pageNumber, buffer)`
|
||
|
|
|
||
|
|
Explicitly set the buffer for a page.
|
||
|
|
|
||
|
|
#### `pages.updated(page)`
|
||
|
|
|
||
|
|
Mark a page as updated.
|
||
|
|
|
||
|
|
#### `pages.lastUpdate()`
|
||
|
|
|
||
|
|
Get the last page that was updated.
|
||
|
|
|
||
|
|
#### `var buf = pages.toBuffer()`
|
||
|
|
|
||
|
|
Concat all pages allocated pages into a single buffer
|
||
|
|
|
||
|
|
## License
|
||
|
|
|
||
|
|
MIT
|