Current File : //proc/309157/root/www/specpages-backup/node_modules/sharp/lib/utility.js
'use strict';
const is = require('./is');
const sharp = require('../build/Release/sharp.node');
/**
* Gets or, when options are provided, sets the limits of _libvips'_ operation cache.
* Existing entries in the cache will be trimmed after any change in limits.
* This method always returns cache statistics,
* useful for determining how much working memory is required for a particular task.
*
* @example
* const stats = sharp.cache();
* @example
* sharp.cache( { items: 200 } );
* sharp.cache( { files: 0 } );
* sharp.cache(false);
*
* @param {Object|Boolean} [options=true] - Object with the following attributes, or Boolean where true uses default cache settings and false removes all caching
* @param {Number} [options.memory=50] - is the maximum memory in MB to use for this cache
* @param {Number} [options.files=20] - is the maximum number of files to hold open
* @param {Number} [options.items=100] - is the maximum number of operations to cache
* @returns {Object}
*/
function cache (options) {
if (is.bool(options)) {
if (options) {
// Default cache settings of 50MB, 20 files, 100 items
return sharp.cache(50, 20, 100);
} else {
return sharp.cache(0, 0, 0);
}
} else if (is.object(options)) {
return sharp.cache(options.memory, options.files, options.items);
} else {
return sharp.cache();
}
}
cache(true);
/**
* Gets or, when a concurrency is provided, sets
* the number of threads _libvips'_ should create to process each image.
* The default value is the number of CPU cores.
* A value of `0` will reset to this default.
*
* The maximum number of images that can be processed in parallel
* is limited by libuv's `UV_THREADPOOL_SIZE` environment variable.
*
* This method always returns the current concurrency.
*
* @example
* const threads = sharp.concurrency(); // 4
* sharp.concurrency(2); // 2
* sharp.concurrency(0); // 4
*
* @param {Number} [concurrency]
* @returns {Number} concurrency
*/
function concurrency (concurrency) {
return sharp.concurrency(is.integer(concurrency) ? concurrency : null);
}
/**
* Provides access to internal task counters.
* - queue is the number of tasks this module has queued waiting for _libuv_ to provide a worker thread from its pool.
* - process is the number of resize tasks currently being processed.
*
* @example
* const counters = sharp.counters(); // { queue: 2, process: 4 }
*
* @returns {Object}
*/
function counters () {
return sharp.counters();
}
/**
* Get and set use of SIMD vector unit instructions.
* Requires libvips to have been compiled with liborc support.
*
* Improves the performance of `resize`, `blur` and `sharpen` operations
* by taking advantage of the SIMD vector unit of the CPU, e.g. Intel SSE and ARM NEON.
*
* @example
* const simd = sharp.simd();
* // simd is `true` if the runtime use of liborc is currently enabled
* @example
* const simd = sharp.simd(false);
* // prevent libvips from using liborc at runtime
*
* @param {Boolean} [simd=true]
* @returns {Boolean}
*/
function simd (simd) {
return sharp.simd(is.bool(simd) ? simd : null);
}
simd(true);
/**
* Decorate the Sharp class with utility-related functions.
* @private
*/
module.exports = function (Sharp) {
[
cache,
concurrency,
counters,
simd
].forEach(function (f) {
Sharp[f.name] = f;
});
};
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