diff options
Diffstat (limited to 'node_modules/sparse-bitfield/index.js')
-rw-r--r-- | node_modules/sparse-bitfield/index.js | 95 |
1 files changed, 0 insertions, 95 deletions
diff --git a/node_modules/sparse-bitfield/index.js b/node_modules/sparse-bitfield/index.js deleted file mode 100644 index ff458c9..0000000 --- a/node_modules/sparse-bitfield/index.js +++ /dev/null @@ -1,95 +0,0 @@ -var pager = require('memory-pager') - -module.exports = Bitfield - -function Bitfield (opts) { - if (!(this instanceof Bitfield)) return new Bitfield(opts) - if (!opts) opts = {} - if (Buffer.isBuffer(opts)) opts = {buffer: opts} - - this.pageOffset = opts.pageOffset || 0 - this.pageSize = opts.pageSize || 1024 - this.pages = opts.pages || pager(this.pageSize) - - this.byteLength = this.pages.length * this.pageSize - this.length = 8 * this.byteLength - - if (!powerOfTwo(this.pageSize)) throw new Error('The page size should be a power of two') - - this._trackUpdates = !!opts.trackUpdates - this._pageMask = this.pageSize - 1 - - if (opts.buffer) { - for (var i = 0; i < opts.buffer.length; i += this.pageSize) { - this.pages.set(i / this.pageSize, opts.buffer.slice(i, i + this.pageSize)) - } - this.byteLength = opts.buffer.length - this.length = 8 * this.byteLength - } -} - -Bitfield.prototype.get = function (i) { - var o = i & 7 - var j = (i - o) / 8 - - return !!(this.getByte(j) & (128 >> o)) -} - -Bitfield.prototype.getByte = function (i) { - var o = i & this._pageMask - var j = (i - o) / this.pageSize - var page = this.pages.get(j, true) - - return page ? page.buffer[o + this.pageOffset] : 0 -} - -Bitfield.prototype.set = function (i, v) { - var o = i & 7 - var j = (i - o) / 8 - var b = this.getByte(j) - - return this.setByte(j, v ? b | (128 >> o) : b & (255 ^ (128 >> o))) -} - -Bitfield.prototype.toBuffer = function () { - var all = alloc(this.pages.length * this.pageSize) - - for (var i = 0; i < this.pages.length; i++) { - var next = this.pages.get(i, true) - var allOffset = i * this.pageSize - if (next) next.buffer.copy(all, allOffset, this.pageOffset, this.pageOffset + this.pageSize) - } - - return all -} - -Bitfield.prototype.setByte = function (i, b) { - var o = i & this._pageMask - var j = (i - o) / this.pageSize - var page = this.pages.get(j, false) - - o += this.pageOffset - - if (page.buffer[o] === b) return false - page.buffer[o] = b - - if (i >= this.byteLength) { - this.byteLength = i + 1 - this.length = this.byteLength * 8 - } - - if (this._trackUpdates) this.pages.updated(page) - - return true -} - -function alloc (n) { - if (Buffer.alloc) return Buffer.alloc(n) - var b = new Buffer(n) - b.fill(0) - return b -} - -function powerOfTwo (x) { - return !(x & (x - 1)) -} |