URI: 
       tpl/partials: Make sure a cached partial is invoked only once - hugo - [fork] hugo port for 9front
  HTML git clone git@git.drkhsh.at/hugo.git
   DIR Log
   DIR Files
   DIR Refs
   DIR Submodules
   DIR README
   DIR LICENSE
       ---
   DIR commit 0927cf739fee9646c7fb917965799d9acf080922
   DIR parent 26a5e89faa6dd1d40d6e731ab10e565b5323dfd3
  HTML Author: Bjørn Erik Pedersen <bjorn.erik.pedersen@gmail.com>
       Date:   Wed, 16 Feb 2022 10:26:42 +0100
       
       tpl/partials: Make sure a cached partial is invoked only once
       
       This commit revises the locking strategy for `partialCached`. We have added a benchmark that may be a little artificial, but it should at least show that we're not losing any performance over this:
       
       ```bash
       name              old time/op    new time/op    delta
       IncludeCached-10    12.2ms ± 2%    11.3ms ± 1%   -7.36%  (p=0.029 n=4+4)
       
       name              old alloc/op   new alloc/op   delta
       IncludeCached-10    7.17MB ± 0%    5.09MB ± 0%  -29.00%  (p=0.029 n=4+4)
       
       name              old allocs/op  new allocs/op  delta
       IncludeCached-10      128k ± 1%       70k ± 0%  -45.42%  (p=0.029 n=4+4)
       ```
       
       This commit also revises the template metrics hints logic a little, and add a test for it, which output is currently this:
       
       ```bash
        cumulative       average       maximum      cache  percent  cached  total
              duration      duration      duration  potential   cached   count  count  template
            ----------      --------      --------  ---------  -------  ------  -----  --------
             163.334µs     163.334µs     163.334µs          0        0       0      1  index.html
              23.749µs       5.937µs      19.916µs         25       50       2      4  partials/dynamic1.html
               9.625µs       4.812µs        6.75µs        100       50       1      2  partials/static1.html
               7.625µs       7.625µs       7.625µs        100        0       0      1  partials/static2.html
       ```
       
       Some notes:
       
       * The duration now includes the cached invocations (which should be very short)
       * A cached template gets executed once before it gets cached, so the "percent cached" will never be 100.
       
       Fixes #4086
       Fixes #9506
       
       Diffstat:
         M htesting/hqt/checkers.go            |       7 ++++---
         M tpl/math/math.go                    |      12 ++++++++++++
         M tpl/partials/init.go                |       4 ++--
         M tpl/partials/init_test.go           |       2 +-
         M tpl/partials/integration_test.go    |     131 +++++++++++++++++++++++++++++++
         M tpl/partials/partials.go            |      29 +++++++++++++++++++++--------
       
       6 files changed, 171 insertions(+), 14 deletions(-)
       ---
   DIR diff --git a/htesting/hqt/checkers.go b/htesting/hqt/checkers.go
       @@ -63,7 +63,7 @@ type stringChecker struct {
                argNames
        }
        
       -// Check implements Checker.Check by checking that got and args[0] represents the same normalized text (whitespace etc. trimmed).
       +// Check implements Checker.Check by checking that got and args[0] represents the same normalized text (whitespace etc. removed).
        func (c *stringChecker) Check(got interface{}, args []interface{}, note func(key string, value interface{})) (err error) {
                s1, s2 := cast.ToString(got), cast.ToString(args[0])
        
       @@ -81,11 +81,12 @@ func (c *stringChecker) Check(got interface{}, args []interface{}, note func(key
        }
        
        func normalizeString(s string) string {
       +        s = strings.ReplaceAll(s, "\r\n", "\n")
       +
                lines := strings.Split(strings.TrimSpace(s), "\n")
                for i, line := range lines {
       -                lines[i] = strings.TrimSpace(line)
       +                lines[i] = strings.Join(strings.Fields(strings.TrimSpace(line)), "")
                }
       -
                return strings.Join(lines, "\n")
        }
        
   DIR diff --git a/tpl/math/math.go b/tpl/math/math.go
       @@ -17,6 +17,7 @@ package math
        import (
                "errors"
                "math"
       +        "sync/atomic"
        
                _math "github.com/gohugoio/hugo/common/math"
        
       @@ -162,3 +163,14 @@ func (ns *Namespace) Sqrt(a interface{}) (float64, error) {
        func (ns *Namespace) Sub(a, b interface{}) (interface{}, error) {
                return _math.DoArithmetic(a, b, '-')
        }
       +
       +var counter uint64
       +
       +// Counter increments and returns a global counter.
       +// This was originally added to be used in tests where now.UnixNano did not
       +// have the needed precision (especially on Windows).
       +// Note that given the parallel nature of Hugo, you cannot use this to get sequences of numbers,
       +// and the counter will reset on new builds.
       +func (ns *Namespace) Counter() uint64 {
       +        return atomic.AddUint64(&counter, uint64(1))
       +}
   DIR diff --git a/tpl/partials/init.go b/tpl/partials/init.go
       @@ -18,14 +18,14 @@ import (
                "github.com/gohugoio/hugo/tpl/internal"
        )
        
       -const name = "partials"
       +const namespaceName = "partials"
        
        func init() {
                f := func(d *deps.Deps) *internal.TemplateFuncsNamespace {
                        ctx := New(d)
        
                        ns := &internal.TemplateFuncsNamespace{
       -                        Name:    name,
       +                        Name:    namespaceName,
                                Context: func(args ...interface{}) (interface{}, error) { return ctx, nil },
                        }
        
   DIR diff --git a/tpl/partials/init_test.go b/tpl/partials/init_test.go
       @@ -33,7 +33,7 @@ func TestInit(t *testing.T) {
                                BuildStartListeners: &deps.Listeners{},
                                Log:                 loggers.NewErrorLogger(),
                        })
       -                if ns.Name == name {
       +                if ns.Name == namespaceName {
                                found = true
                                break
                        }
   DIR diff --git a/tpl/partials/integration_test.go b/tpl/partials/integration_test.go
       @@ -14,8 +14,14 @@
        package partials_test
        
        import (
       +        "bytes"
       +        "fmt"
       +        "regexp"
       +        "sort"
       +        "strings"
                "testing"
        
       +        "github.com/gohugoio/hugo/htesting/hqt"
                "github.com/gohugoio/hugo/hugolib"
        )
        
       @@ -68,3 +74,128 @@ partialCached: foo
        partialCached: foo
        `)
        }
       +
       +func TestIncludeCacheHints(t *testing.T) {
       +        t.Parallel()
       +
       +        files := `
       +-- config.toml --
       +baseURL = 'http://example.com/'
       +templateMetrics=true
       +templateMetricsHints=true
       +disableKinds = ["page", "section", "taxonomy", "term", "sitemap"]
       +[outputs]
       +home = ["HTML"]
       +-- layouts/index.html --
       +{{ partials.IncludeCached "static1.html" . }}
       +{{ partials.IncludeCached "static1.html" . }}
       +{{ partials.Include "static2.html" . }}
       +
       +D1I: {{ partials.Include "dynamic1.html" . }}
       +D1C: {{ partials.IncludeCached "dynamic1.html" . }}
       +D1C: {{ partials.IncludeCached "dynamic1.html" . }}
       +D1C: {{ partials.IncludeCached "dynamic1.html" . }}
       +H1I: {{ partials.Include "halfdynamic1.html" . }}
       +H1C: {{ partials.IncludeCached "halfdynamic1.html" . }}
       +H1C: {{ partials.IncludeCached "halfdynamic1.html" . }}
       +
       +-- layouts/partials/static1.html --
       +P1
       +-- layouts/partials/static2.html --
       +P2
       +-- layouts/partials/dynamic1.html --
       +{{ math.Counter }}
       +-- layouts/partials/halfdynamic1.html --
       +D1
       +{{ math.Counter }}
       +
       +
       +  `
       +
       +        b := hugolib.NewIntegrationTestBuilder(
       +                hugolib.IntegrationTestConfig{
       +                        T:           t,
       +                        TxtarString: files,
       +                },
       +        ).Build()
       +
       +        // fmt.Println(b.FileContent("public/index.html"))
       +
       +        var buf bytes.Buffer
       +        b.H.Metrics.WriteMetrics(&buf)
       +
       +        got := buf.String()
       +
       +        // Get rid of all the durations, they are never the same.
       +        durationRe := regexp.MustCompile(`\b[\.\d]*(ms|µs|s)\b`)
       +
       +        normalize := func(s string) string {
       +                s = durationRe.ReplaceAllString(s, "")
       +                linesIn := strings.Split(s, "\n")[3:]
       +                var lines []string
       +                for _, l := range linesIn {
       +                        l = strings.TrimSpace(l)
       +                        if l == "" {
       +                                continue
       +                        }
       +                        lines = append(lines, l)
       +                }
       +
       +                sort.Strings(lines)
       +
       +                return strings.Join(lines, "\n")
       +        }
       +
       +        got = normalize(got)
       +
       +        expect := `
       +        0        0       0      1  index.html
       +        100        0       0      1  partials/static2.html
       +        100       50       1      2  partials/static1.html
       +        25       50       2      4  partials/dynamic1.html
       +        66       33       1      3  partials/halfdynamic1.html
       +        `
       +
       +        b.Assert(got, hqt.IsSameString, expect)
       +}
       +
       +//  gobench --package ./tpl/partials
       +func BenchmarkIncludeCached(b *testing.B) {
       +        files := `
       +-- config.toml --
       +baseURL = 'http://example.com/'
       +-- layouts/index.html --
       +-- layouts/_default/single.html --
       +{{ partialCached "heavy.html" "foo" }}
       +-- layouts/partials/heavy.html --
       +{{ $result := slice }}
       +{{ range site.RegularPages }}
       +{{ $result = $result | append (dict "title" .Title "link" .RelPermalink "readingTime" .ReadingTime) }}
       +{{ end }}
       +{{ range $result }}
       +* {{ .title }} {{ .link }} {{ .readingTime }}
       +{{ end }}
       +
       +
       +`
       +
       +        for i := 1; i < 100; i++ {
       +                files += fmt.Sprintf("\n-- content/p%d.md --\n---\ntitle: page\n---\n"+strings.Repeat("FOO ", i), i)
       +        }
       +
       +        cfg := hugolib.IntegrationTestConfig{
       +                T:           b,
       +                TxtarString: files,
       +        }
       +        builders := make([]*hugolib.IntegrationTestBuilder, b.N)
       +
       +        for i, _ := range builders {
       +                builders[i] = hugolib.NewIntegrationTestBuilder(cfg)
       +        }
       +
       +        b.ResetTimer()
       +
       +        for i := 0; i < b.N; i++ {
       +                builders[i].Build()
       +        }
       +}
   DIR diff --git a/tpl/partials/partials.go b/tpl/partials/partials.go
       @@ -24,6 +24,7 @@ import (
                "reflect"
                "strings"
                "sync"
       +        "time"
        
                texttemplate "github.com/gohugoio/hugo/tpl/internal/go_templates/texttemplate"
        
       @@ -44,6 +45,13 @@ type partialCacheKey struct {
                variant interface{}
        }
        
       +func (k partialCacheKey) templateName() string {
       +        if !strings.HasPrefix(k.name, "partials/") {
       +                return "partials/" + k.name
       +        }
       +        return k.name
       +}
       +
        // partialCache represents a cache of partials protected by a mutex.
        type partialCache struct {
                sync.RWMutex
       @@ -211,6 +219,7 @@ func createKey(name string, variants ...interface{}) (partialCacheKey, error) {
        var errUnHashable = errors.New("unhashable")
        
        func (ns *Namespace) getOrCreate(key partialCacheKey, context interface{}) (result interface{}, err error) {
       +        start := time.Now()
                defer func() {
                        if r := recover(); r != nil {
                                err = r.(error)
       @@ -226,9 +235,20 @@ func (ns *Namespace) getOrCreate(key partialCacheKey, context interface{}) (resu
                ns.cachedPartials.RUnlock()
        
                if ok {
       +                if ns.deps.Metrics != nil {
       +                        ns.deps.Metrics.TrackValue(key.templateName(), p, true)
       +                        // The templates that gets executed is measued in Execute.
       +                        // We need to track the time spent in the cache to
       +                        // get the totals correct.
       +                        ns.deps.Metrics.MeasureSince(key.templateName(), start)
       +
       +                }
                        return p, nil
                }
        
       +        ns.cachedPartials.Lock()
       +        defer ns.cachedPartials.Unlock()
       +
                var name string
                name, p, err = ns.include(key.name, context)
                if err != nil {
       @@ -236,14 +256,7 @@ func (ns *Namespace) getOrCreate(key partialCacheKey, context interface{}) (resu
                }
        
                if ns.deps.Metrics != nil {
       -                ns.deps.Metrics.TrackValue(name, p, true)
       -        }
       -
       -        ns.cachedPartials.Lock()
       -        defer ns.cachedPartials.Unlock()
       -        // Double-check.
       -        if p2, ok := ns.cachedPartials.p[key]; ok {
       -                return p2, nil
       +                ns.deps.Metrics.TrackValue(name, p, false)
                }
                ns.cachedPartials.p[key] = p