golang/dep

// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package gps

import (
    "bytes"
    "fmt"
    "log"
    "sort"
    "text/tabwriter"
    "time"
)

type metrics struct {
    stack []string
    times map[string]time.Duration
    last  time.Time
}

func newMetrics() *metrics {
    return &metrics{
        stack: []string{"other"},
        times: map[string]time.Duration{
            "other": 0,
        },
        last: time.Now(),
    }
}

func (m *metrics) push(name string) {
    cn := m.stack[len(m.stack)-1]
    m.times[cn] += time.Since(m.last)

    m.stack = append(m.stack, name)
    m.last = time.Now()
}

func (m *metrics) pop() {
    on := m.stack[len(m.stack)-1]
    m.times[on] += time.Since(m.last)

    m.stack = m.stack[:len(m.stack)-1]
    m.last = time.Now()
}

func (m *metrics) dump(l *log.Logger) {
    s := make(ndpairs, len(m.times))
    k := 0
    for n, d := range m.times {
        s[k] = ndpair{
            n: n,
            d: d,
        }
        k++
    }

    sort.Sort(sort.Reverse(s))

    var tot time.Duration
    var buf bytes.Buffer
    w := tabwriter.NewWriter(&buf, 0, 0, 1, ' ', tabwriter.AlignRight)
    for _, nd := range s {
        tot += nd.d
        fmt.Fprintf(w, "\t%s:\t%v\t\n", nd.n, nd.d)
    }
    fmt.Fprintf(w, "\n\tTOTAL:\t%v\t\n", tot)
    w.Flush()

    l.Println("\nSolver wall times by segment:")
    l.Println((&buf).String())
}

type ndpair struct {
    n string
    d time.Duration
}

type ndpairs []ndpair

func (s ndpairs) Less(i, j int) bool { return s[i].d < s[j].d }
func (s ndpairs) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
func (s ndpairs) Len() int           { return len(s) }