cmake-js/ref-struct

Name: ref-struct

Owner: CMake.js

Description: Create ABI-compliant "struct" instances on top of Buffers

Created: 2016-09-15 20:40:43.0

Updated: 2016-09-15 20:40:44.0

Pushed: 2016-08-03 05:34:11.0

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Size: 129

Language: JavaScript

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README

ref-struct

Create ABI-compliant “struct” instances on top of Buffers

This module offers a “struct” implementation on top of Node.js Buffers using the ref “type” interface.

Installation

Install with npm:

m install ref-struct

Examples

Say you wanted to emulate the timeval struct from the stdlib:

ct timeval {
me_t       tv_sec;   /* seconds since Jan. 1, 1970 */
seconds_t  tv_usec;  /* and microseconds */

js
ref = require('ref')
StructType = require('ref-struct')

efine the time types
time_t = ref.types.long
suseconds_t = ref.types.long

efine the "timeval" struct type
timeval = StructType({
_sec: time_t,
_usec: suseconds_t


ow we can create instances of it
tv = new timeval

With node-ffi

This gets very powerful when combined with node-ffi to invoke C functions:

ffi = require('ffi')

tv = new timeval
imeofday(tv.ref(), null)

Progressive API

You can build up a Struct “type” incrementally (useful when interacting with a parser) using the defineProperty() function. But as soon as you create an instance of the struct type, then the struct type is finalized, and no more properties may be added to it.

ref = require('ref')
StructType = require('ref-struct')

MyStruct = StructType()
ruct.defineProperty('width', ref.types.int)
ruct.defineProperty('height', ref.types.int)

i = new MyStruct({ width: 5, height: 10 })

ruct.defineProperty('weight', ref.types.int)
ssertionError: an instance of this Struct type has already been created, cannot add new "fields" anymore
    at Function.defineProperty (/Users/nrajlich/ref-struct/lib/struct.js:180:3)

License

(The MIT License)

Copyright (c) 2012 Nathan Rajlich <nathan@tootallnate.net>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.