diff options
Diffstat (limited to 'vendor/gopkg.in/mgo.v2/queue.go')
-rw-r--r-- | vendor/gopkg.in/mgo.v2/queue.go | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/vendor/gopkg.in/mgo.v2/queue.go b/vendor/gopkg.in/mgo.v2/queue.go new file mode 100644 index 0000000..e9245de --- /dev/null +++ b/vendor/gopkg.in/mgo.v2/queue.go @@ -0,0 +1,91 @@ +// mgo - MongoDB driver for Go +// +// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net> +// +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are met: +// +// 1. Redistributions of source code must retain the above copyright notice, this +// list of conditions and the following disclaimer. +// 2. Redistributions in binary form must reproduce the above copyright notice, +// this list of conditions and the following disclaimer in the documentation +// and/or other materials provided with the distribution. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND +// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED +// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR +// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES +// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +package mgo + +type queue struct { + elems []interface{} + nelems, popi, pushi int +} + +func (q *queue) Len() int { + return q.nelems +} + +func (q *queue) Push(elem interface{}) { + //debugf("Pushing(pushi=%d popi=%d cap=%d): %#v\n", + // q.pushi, q.popi, len(q.elems), elem) + if q.nelems == len(q.elems) { + q.expand() + } + q.elems[q.pushi] = elem + q.nelems++ + q.pushi = (q.pushi + 1) % len(q.elems) + //debugf(" Pushed(pushi=%d popi=%d cap=%d): %#v\n", + // q.pushi, q.popi, len(q.elems), elem) +} + +func (q *queue) Pop() (elem interface{}) { + //debugf("Popping(pushi=%d popi=%d cap=%d)\n", + // q.pushi, q.popi, len(q.elems)) + if q.nelems == 0 { + return nil + } + elem = q.elems[q.popi] + q.elems[q.popi] = nil // Help GC. + q.nelems-- + q.popi = (q.popi + 1) % len(q.elems) + //debugf(" Popped(pushi=%d popi=%d cap=%d): %#v\n", + // q.pushi, q.popi, len(q.elems), elem) + return elem +} + +func (q *queue) expand() { + curcap := len(q.elems) + var newcap int + if curcap == 0 { + newcap = 8 + } else if curcap < 1024 { + newcap = curcap * 2 + } else { + newcap = curcap + (curcap / 4) + } + elems := make([]interface{}, newcap) + + if q.popi == 0 { + copy(elems, q.elems) + q.pushi = curcap + } else { + newpopi := newcap - (curcap - q.popi) + copy(elems, q.elems[:q.popi]) + copy(elems[newpopi:], q.elems[q.popi:]) + q.popi = newpopi + } + for i := range q.elems { + q.elems[i] = nil // Help GC. + } + q.elems = elems +} |