From aedbcffc80c58348f09070893746522d8283d117 Mon Sep 17 00:00:00 2001
From: jguer <me@jguer.space>
Date: Fri, 13 Aug 2021 23:37:12 +0200
Subject: [PATCH] feat(sources): concurrent makepkg downloading

---
 aur_source.go | 121 ++++++++++++++++++++++++++++++++++++++++++++++++++
 install.go    |  24 +---------
 2 files changed, 123 insertions(+), 22 deletions(-)
 create mode 100644 aur_source.go

diff --git a/aur_source.go b/aur_source.go
new file mode 100644
index 00000000..aa6d0028
--- /dev/null
+++ b/aur_source.go
@@ -0,0 +1,121 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"path/filepath"
+	"runtime"
+	"sync"
+
+	"github.com/leonelquinteros/gotext"
+
+	"github.com/Jguer/yay/v10/pkg/dep"
+	"github.com/Jguer/yay/v10/pkg/multierror"
+	"github.com/Jguer/yay/v10/pkg/settings/exe"
+	"github.com/Jguer/yay/v10/pkg/stringset"
+	"github.com/Jguer/yay/v10/pkg/text"
+)
+
+type ErrDownloadSource struct {
+	inner   error
+	pkgName string
+	errOut  string
+}
+
+func (e ErrDownloadSource) Error() string {
+	return fmt.Sprintln(gotext.Get("error downloading sources: %s", text.Cyan(e.pkgName)),
+		"\n\t context:", e.inner.Error(), "\n\t", e.errOut)
+}
+
+func (e *ErrDownloadSource) Unwrap() error {
+	return e.inner
+}
+
+func downloadPKGBUILDSource(ctx context.Context, cmdBuilder exe.ICmdBuilder,
+	base string, incompatible stringset.StringSet) (err error) {
+	dir := filepath.Join(config.BuildDir, base)
+	args := []string{"--verifysource", "-Ccf"}
+
+	if incompatible.Get(base) {
+		args = append(args, "--ignorearch")
+	}
+
+	err = cmdBuilder.Show(
+		cmdBuilder.BuildMakepkgCmd(ctx, dir, args...))
+	if err != nil {
+		return ErrDownloadSource{inner: err, pkgName: base, errOut: ""}
+	}
+
+	return nil
+}
+
+func downloadPKGBUILDSourceWorker(ctx context.Context, wg *sync.WaitGroup,
+	cBase <-chan string, valOut chan<- string, errOut chan<- error,
+	cmdBuilder exe.ICmdBuilder, incompatible stringset.StringSet) {
+	for base := range cBase {
+		err := downloadPKGBUILDSource(ctx, cmdBuilder, base, incompatible)
+		if err != nil {
+			errOut <- ErrDownloadSource{inner: err, pkgName: base, errOut: ""}
+		} else {
+			valOut <- base
+		}
+	}
+
+	wg.Done()
+}
+
+func downloadPKGBUILDSourceFanout(ctx context.Context, cmdBuilder exe.ICmdBuilder,
+	bases []dep.Base, incompatible stringset.StringSet) error {
+	if len(bases) == 1 {
+		return downloadPKGBUILDSource(ctx, cmdBuilder, bases[0].Pkgbase(), incompatible)
+	}
+
+	var (
+		numOfWorkers    = runtime.NumCPU()
+		wg              = &sync.WaitGroup{}
+		c               = make(chan string)
+		fanInChanValues = make(chan string)
+		fanInChanErrors = make(chan error)
+	)
+
+	go func() {
+		for _, base := range bases {
+			c <- base.Pkgbase()
+		}
+
+		close(c)
+	}()
+
+	// Launch Workers
+	wg.Add(numOfWorkers)
+
+	for s := 0; s < numOfWorkers; s++ {
+		go downloadPKGBUILDSourceWorker(ctx, wg, c,
+			fanInChanValues, fanInChanErrors, cmdBuilder, incompatible)
+	}
+
+	go func() {
+		wg.Wait()
+		close(fanInChanValues)
+		close(fanInChanErrors)
+	}()
+
+	returnErr := multierror.MultiError{}
+
+receiver:
+	for {
+		select {
+		case _, ok := <-fanInChanValues:
+			if !ok {
+				break receiver
+			}
+		case err, ok := <-fanInChanErrors:
+			if !ok {
+				break receiver
+			}
+			returnErr.Add(err)
+		}
+	}
+
+	return returnErr.Return()
+}
diff --git a/install.go b/install.go
index d631f5af..5230689a 100644
--- a/install.go
+++ b/install.go
@@ -396,9 +396,9 @@ func install(ctx context.Context, cmdArgs *parser.Arguments, dbExecutor db.Execu
 			config.AURURL, config.Runtime.CompletionPath, config.CompletionInterval, false)
 	}()
 
-	err = downloadPkgbuildsSources(ctx, do.Aur, incompatible)
+	err = downloadPKGBUILDSourceFanout(ctx, config.Runtime.CmdBuilder, do.Aur, incompatible)
 	if err != nil {
-		return err
+		text.Errorln(err)
 	}
 
 	err = buildInstallPkgbuilds(ctx, cmdArgs, dbExecutor, dp, do, srcinfos, incompatible, conflicts, noDeps, noCheck)
@@ -876,26 +876,6 @@ func mergePkgbuilds(ctx context.Context, bases []dep.Base) error {
 	return nil
 }
 
-func downloadPkgbuildsSources(ctx context.Context, bases []dep.Base, incompatible stringset.StringSet) (err error) {
-	for _, base := range bases {
-		pkg := base.Pkgbase()
-		dir := filepath.Join(config.BuildDir, pkg)
-		args := []string{"--verifysource", "-Ccf"}
-
-		if incompatible.Get(pkg) {
-			args = append(args, "--ignorearch")
-		}
-
-		err = config.Runtime.CmdBuilder.Show(
-			config.Runtime.CmdBuilder.BuildMakepkgCmd(ctx, dir, args...))
-		if err != nil {
-			return errors.New(gotext.Get("error downloading sources: %s", text.Cyan(base.String())))
-		}
-	}
-
-	return
-}
-
 func buildInstallPkgbuilds(
 	ctx context.Context,
 	cmdArgs *parser.Arguments,