49 lines
1.2 KiB
JavaScript
49 lines
1.2 KiB
JavaScript
"use strict";
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module.exports = pool;
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/**
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* An allocator as used by {@link util.pool}.
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* @typedef PoolAllocator
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* @type {function}
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* @param {number} size Buffer size
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* @returns {Uint8Array} Buffer
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*/
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/**
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* A slicer as used by {@link util.pool}.
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* @typedef PoolSlicer
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* @type {function}
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* @param {number} start Start offset
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* @param {number} end End offset
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* @returns {Uint8Array} Buffer slice
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* @this {Uint8Array}
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*/
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/**
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* A general purpose buffer pool.
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* @memberof util
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* @function
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* @param {PoolAllocator} alloc Allocator
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* @param {PoolSlicer} slice Slicer
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* @param {number} [size=8192] Slab size
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* @returns {PoolAllocator} Pooled allocator
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*/
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function pool(alloc, slice, size) {
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var SIZE = size || 8192;
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var MAX = SIZE >>> 1;
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var slab = null;
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var offset = SIZE;
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return function pool_alloc(size) {
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if (size < 1 || size > MAX)
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return alloc(size);
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if (offset + size > SIZE) {
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slab = alloc(SIZE);
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offset = 0;
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}
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var buf = slice.call(slab, offset, offset += size);
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if (offset & 7) // align to 32 bit
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offset = (offset | 7) + 1;
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return buf;
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};
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}
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