Using simpler download library

There is no need for a fully fledged download library like `grab`.
This commit fix cavaliergopher/grab#43 (comment)

Author: cmaglie

Gopkg.lock

@@ -121,11 +121,6 @@
   name = "github.com/bouk/monkey"
   revision = "5df1f207ff77e025801505ae4d903133a0b4353f"
 
-[[constraint]]
-  name = "github.com/cavaliercoder/grab"
-  branch = "master"
-
-
 [prune]
   go-tests = true
   unused-packages = true

Gopkg.toml

@@ -21,7 +21,7 @@ import (
 	"fmt"
 
 	"github.com/arduino/arduino-cli/arduino/cores"
-	"github.com/cavaliercoder/grab"
+	"go.bug.st/downloader"
 	"go.bug.st/relaxed-semver"
 )
 
@@ -102,7 +102,7 @@ func (pm *PackageManager) FindPlatformReleaseDependencies(item *PlatformReferenc
 
 // DownloadToolRelease downloads a ToolRelease. If the tool is already downloaded a nil Response
 // is returned.
-func (pm *PackageManager) DownloadToolRelease(tool *cores.ToolRelease) (*grab.Response, error) {
+func (pm *PackageManager) DownloadToolRelease(tool *cores.ToolRelease) (*downloader.Downloader, error) {
 	resource := tool.GetCompatibleFlavour()
 	if resource == nil {
 		return nil, fmt.Errorf("tool not available for your OS")
@@ -112,6 +112,6 @@ func (pm *PackageManager) DownloadToolRelease(tool *cores.ToolRelease) (*grab.Re
 
 // DownloadPlatformRelease downloads a PlatformRelease. If the platform is already downloaded a
 // nil Response is returned.
-func (pm *PackageManager) DownloadPlatformRelease(platform *cores.PlatformRelease) (*grab.Response, error) {
+func (pm *PackageManager) DownloadPlatformRelease(platform *cores.PlatformRelease) (*downloader.Downloader, error) {
 	return platform.Resource.Download(pm.DownloadDir)
 }

arduino/cores/packagemanager/download.go

@@ -18,24 +18,17 @@
 package librariesmanager
 
 import (
-	"fmt"
 	"net/url"
 
-	"github.com/cavaliercoder/grab"
+	"go.bug.st/downloader"
 )
 
 // LibraryIndexURL is the URL where to get library index.
 var LibraryIndexURL, _ = url.Parse("https://downloads.arduino.cc/libraries/library_index.json")
 
 // UpdateIndex downloads the libraries index file from Arduino repository.
-func (lm *LibrariesManager) UpdateIndex() (*grab.Response, error) {
-	req, err := grab.NewRequest(lm.IndexFile.String(), LibraryIndexURL.String())
-	req.NoResume = true
-	if err != nil {
-		return nil, fmt.Errorf("creating HTTP request: %s", err)
-	}
-	client := grab.NewClient()
-	return client.Do(req), nil
-
+func (lm *LibrariesManager) UpdateIndex() (*downloader.Downloader, error) {
+	lm.IndexFile.Remove()
 	// TODO: Download from gzipped URL index
+	return downloader.Download(lm.IndexFile.String(), LibraryIndexURL.String())
 }

arduino/libraries/librariesmanager/download.go

@@ -22,7 +22,7 @@ import (
 	"os"
 
 	paths "github.com/arduino/go-paths-helper"
-	"github.com/cavaliercoder/grab"
+	"go.bug.st/downloader"
 )
 
 // ArchivePath returns the path of the Archive of the specified DownloadResource relative
@@ -45,7 +45,7 @@ func (r *DownloadResource) IsCached(downloadDir *paths.Path) (bool, error) {
 }
 
 // Download a DownloadResource.
-func (r *DownloadResource) Download(downloadDir *paths.Path) (*grab.Response, error) {
+func (r *DownloadResource) Download(downloadDir *paths.Path) (*downloader.Downloader, error) {
 	cached, err := r.TestLocalArchiveIntegrity(downloadDir)
 	if err != nil {
 		return nil, fmt.Errorf("testing local archive integrity: %s", err)
@@ -73,10 +73,5 @@ func (r *DownloadResource) Download(downloadDir *paths.Path) (*grab.Response, er
 		return nil, fmt.Errorf("getting archive file info: %s", err)
 	}
 
-	req, err := grab.NewRequest(path.String(), r.URL)
-	if err != nil {
-		return nil, fmt.Errorf("creating HTTP request: %s", err)
-	}
-	client := grab.NewClient()
-	return client.Do(req), nil
+	return downloader.Download(path.String(), r.URL)
 }

arduino/resources/helpers.go

@@ -155,14 +155,14 @@ func InitLibraryManager(pm *packagemanager.PackageManager) *librariesmanager.Lib
 // UpdateLibrariesIndex updates the library_index.json
 func UpdateLibrariesIndex(lm *librariesmanager.LibrariesManager) {
 	logrus.Info("Updating libraries index")
-	resp, err := lm.UpdateIndex()
+	d, err := lm.UpdateIndex()
 	if err != nil {
 		formatter.PrintError(err, "Error downloading librarires index")
 		os.Exit(ErrNetwork)
 	}
-	formatter.DownloadProgressBar(resp, "Updating index: library_index.json")
-	if resp.Err() != nil {
-		formatter.PrintError(resp.Err(), "Error downloading librarires index")
+	formatter.DownloadProgressBar(d, "Updating index: library_index.json")
+	if d.Error() != nil {
+		formatter.PrintError(d.Error(), "Error downloading librarires index")
 		os.Exit(ErrNetwork)
 	}
 }

commands/commands.go

@@ -20,11 +20,12 @@ package core
 import (
 	"os"
 
+	"go.bug.st/downloader"
+
 	"github.com/arduino/arduino-cli/arduino/cores"
 	"github.com/arduino/arduino-cli/arduino/cores/packagemanager"
 	"github.com/arduino/arduino-cli/commands"
 	"github.com/arduino/arduino-cli/common/formatter"
-	"github.com/cavaliercoder/grab"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 )
@@ -88,18 +89,18 @@ func DownloadToolRelease(pm *packagemanager.PackageManager, toolRelease *cores.T
 	download(resp, err, toolRelease.String())
 }
 
-func download(resp *grab.Response, err error, label string) {
+func download(d *downloader.Downloader, err error, label string) {
 	if err != nil {
 		formatter.PrintError(err, "Error downloading "+label)
 		os.Exit(commands.ErrNetwork)
 	}
-	if resp == nil {
+	if d == nil {
 		formatter.Print(label + " already downloaded")
 		return
 	}
-	formatter.DownloadProgressBar(resp, label)
-	if resp.Err() != nil {
-		formatter.PrintError(resp.Err(), "Error downloading "+label)
+	formatter.DownloadProgressBar(d, label)
+	if d.Error() != nil {
+		formatter.PrintError(d.Error(), "Error downloading "+label)
 		os.Exit(commands.ErrNetwork)
 	}
 }

commands/core/download.go

@@ -23,11 +23,12 @@ import (
 	"os"
 	"path"
 
+	"go.bug.st/downloader"
+
 	"github.com/arduino/arduino-cli/commands"
 	"github.com/arduino/arduino-cli/common/formatter"
 	"github.com/arduino/arduino-cli/configs"
 	"github.com/arduino/go-paths-helper"
-	"github.com/cavaliercoder/grab"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 )
@@ -68,16 +69,14 @@ func updateIndex(URL *url.URL) {
 	defer os.Remove(tmpFile.Name())
 	tmpFile.Close()
 
-	req, err := grab.NewRequest(tmpFile.Name(), URL.String())
+	d, err := downloader.Download(tmpFile.Name(), URL.String())
 	if err != nil {
 		formatter.PrintError(err, "Error downloading index "+URL.String())
 		os.Exit(commands.ErrNetwork)
 	}
-	client := grab.NewClient()
-	resp := client.Do(req)
-	formatter.DownloadProgressBar(resp, "Updating index: "+coreIndexPath.Base())
-	if resp.Err() != nil {
-		formatter.PrintError(resp.Err(), "Error downloading index "+URL.String())
+	formatter.DownloadProgressBar(d, "Updating index: "+coreIndexPath.Base())
+	if d.Error() != nil {
+		formatter.PrintError(d.Error(), "Error downloading index "+URL.String())
 		os.Exit(commands.ErrNetwork)
 	}
 

commands/core/update_index.go

@@ -72,14 +72,14 @@ func downloadLibrariesFromReferences(lm *librariesmanager.LibrariesManager, refs
 func downloadLibraries(lm *librariesmanager.LibrariesManager, libReleases []*librariesindex.Release) {
 	logrus.Info("Downloading libraries")
 	for _, libRelease := range libReleases {
-		resp, err := libRelease.Resource.Download(lm.DownloadsDir)
+		d, err := libRelease.Resource.Download(lm.DownloadsDir)
 		if err != nil {
 			formatter.PrintError(err, "Error downloading "+libRelease.String())
 			os.Exit(commands.ErrNetwork)
 		}
-		formatter.DownloadProgressBar(resp, libRelease.String())
-		if resp.Err() != nil {
-			formatter.PrintError(err, "Error downloading "+libRelease.String())
+		formatter.DownloadProgressBar(d, libRelease.String())
+		if d.Error() != nil {
+			formatter.PrintError(d.Error(), "Error downloading "+libRelease.String())
 			os.Exit(commands.ErrNetwork)
 		}
 	}

commands/lib/download.go

@@ -18,10 +18,10 @@
 package formatter
 
 import (
-	"github.com/cavaliercoder/grab"
+	"go.bug.st/downloader"
 )
 
 // DownloadProgressBar prints a progress bar from a running download Request
-func DownloadProgressBar(resp *grab.Response, prefix string) {
-	defaultFormatter.DownloadProgressBar(resp, prefix)
+func DownloadProgressBar(d *downloader.Downloader, prefix string) {
+	defaultFormatter.DownloadProgressBar(d, prefix)
 }