Checksum computation only if !ignoreChecksum and size varies.

README.md

@@ -91,6 +91,12 @@ To pull specific files or directories, pass in one or more paths:
 $ drive pull photos/img001.png docs
 ```
 
+Note: To ignore checksum verification during a pull:
+
+```shell
+$ drive pull -ignore-checksum
+```
+
 #### Exporting Docs
 
 By default, the `pull` command will export Google Docs documents as PDF files. To specify other formats, use the `-export` option:
@@ -126,6 +132,13 @@ The `push` command uploads data to Google Drive to mirror data stored locally.
 
 Like `pull`, you can run it without any arguments to push all of the files from the current path, or you can pass in one or more paths to push specific files or directories.
 
+Note: To ignore checksum verification during a push:
+
+```shell
+$ drive push -ignore-checksum
+```
+
+
 To get Google Drive to convert a file to its native Google Docs format
 
 ```shell

cmd/drive/main.go

@@ -197,13 +197,14 @@ func (cmd *listCmd) Run(args []string) {
 }
 
 type pullCmd struct {
-	exportsDir *string
-	export     *string
-	force      *bool
-	hidden     *bool
-	noPrompt   *bool
-	noClobber  *bool
-	recursive  *bool
+	exportsDir     *string
+	export         *string
+	force          *bool
+	hidden         *bool
+	noPrompt       *bool
+	noClobber      *bool
+	recursive      *bool
+	ignoreChecksum *bool
 }
 
 func (cmd *pullCmd) Flags(fs *flag.FlagSet) *flag.FlagSet {
@@ -214,6 +215,7 @@ func (cmd *pullCmd) Flags(fs *flag.FlagSet) *flag.FlagSet {
 	cmd.noPrompt = fs.Bool("no-prompt", false, "shows no prompt before applying the pull action")
 	cmd.hidden = fs.Bool("hidden", false, "allows pulling of hidden paths")
 	cmd.force = fs.Bool("force", false, "forces a pull even if no changes present")
+	cmd.ignoreChecksum = fs.Bool(drive.CLIOptionIgnoreChecksum, false, drive.DescIgnoreChecksum)
 	cmd.exportsDir = fs.String("export-dir", "", "directory to place exports")
 
 	return fs
@@ -235,15 +237,16 @@ func (cmd *pullCmd) Run(args []string) {
 	exports := nonEmptyStrings(strings.Split(*cmd.export, ","))
 
 	exitWithError(drive.New(context, &drive.Options{
-		Exports:    uniqOrderedStr(exports),
-		ExportsDir: strings.Trim(*cmd.exportsDir, " "),
-		Force:      *cmd.force,
-		Hidden:     *cmd.hidden,
-		NoPrompt:   *cmd.noPrompt,
-		NoClobber:  *cmd.noClobber,
-		Path:       path,
-		Recursive:  *cmd.recursive,
-		Sources:    sources,
+		Exports:        uniqOrderedStr(exports),
+		ExportsDir:     strings.Trim(*cmd.exportsDir, " "),
+		Force:          *cmd.force,
+		Hidden:         *cmd.hidden,
+		IgnoreChecksum: *cmd.ignoreChecksum,
+		NoPrompt:       *cmd.noPrompt,
+		NoClobber:      *cmd.noClobber,
+		Path:           path,
+		Recursive:      *cmd.recursive,
+		Sources:        sources,
 	}).Pull())
 }
 
@@ -259,7 +262,8 @@ type pushCmd struct {
 	convert *bool
 	// ocr when set indicates that Optical Character Recognition should be
 	// attempted on .[gif, jpg, pdf, png] uploads
-	ocr *bool
+	ocr            *bool
+	ignoreChecksum *bool
 }
 
 func (cmd *pushCmd) Flags(fs *flag.FlagSet) *flag.FlagSet {
@@ -270,6 +274,7 @@ func (cmd *pushCmd) Flags(fs *flag.FlagSet) *flag.FlagSet {
 	cmd.force = fs.Bool("force", false, "forces a push even if no changes present")
 	cmd.mountedPush = fs.Bool("m", false, "allows pushing of mounted paths")
 	cmd.convert = fs.Bool("convert", false, "toggles conversion of the file to its appropriate Google Doc format")
+	cmd.ignoreChecksum = fs.Bool(drive.CLIOptionIgnoreChecksum, false, drive.DescIgnoreChecksum)
 	cmd.ocr = fs.Bool("ocr", false, "if true, attempt OCR on gif, jpg, pdf and png uploads")
 	return fs
 }
@@ -322,12 +327,13 @@ func (cmd *pushCmd) createPushOptions() *drive.Options {
 	}
 
 	return &drive.Options{
-		Force:     *cmd.force,
-		Hidden:    *cmd.hidden,
-		NoClobber: *cmd.noClobber,
-		NoPrompt:  *cmd.noPrompt,
-		TypeMask:  mask,
-		Recursive: *cmd.recursive,
+		Force:          *cmd.force,
+		Hidden:         *cmd.hidden,
+		NoClobber:      *cmd.noClobber,
+		NoPrompt:       *cmd.noPrompt,
+		TypeMask:       mask,
+		IgnoreChecksum: *cmd.ignoreChecksum,
+		Recursive:      *cmd.recursive,
 	}
 }
 
@@ -404,21 +410,24 @@ func (cmd *aboutCmd) Run(args []string) {
 }
 
 type diffCmd struct {
-	hidden *bool
+	hidden         *bool
+	ignoreChecksum *bool
 }
 
 func (cmd *diffCmd) Flags(fs *flag.FlagSet) *flag.FlagSet {
 	cmd.hidden = fs.Bool("hidden", false, "allows pulling of hidden paths")
+	cmd.ignoreChecksum = fs.Bool(drive.CLIOptionIgnoreChecksum, false, drive.DescIgnoreChecksum)
 	return fs
 }
 
 func (cmd *diffCmd) Run(args []string) {
 	sources, context, path := preprocessArgs(args)
 	exitWithError(drive.New(context, &drive.Options{
-		Recursive: true,
-		Path:      path,
-		Hidden:    *cmd.hidden,
-		Sources:   sources,
+		Recursive:      true,
+		Path:           path,
+		Hidden:         *cmd.hidden,
+		Sources:        sources,
+		IgnoreChecksum: *cmd.ignoreChecksum,
 	}).Diff())
 }
 

src/about.go

@@ -19,7 +19,7 @@ import (
 	drive "github.com/google/google-api-go-client/drive/v2"
 )
 
-const Version = "0.0.6"
+const Version = "0.0.7"
 
 const (
 	Barely = iota

src/changes.go

@@ -121,6 +121,10 @@ func (g *Commands) clearMountPoints() {
 	}
 }
 
+func (g *Commands) differ(a, b *File) bool {
+	return fileDifferences(a, b, g.opts.IgnoreChecksum) == DifferNone
+}
+
 func (g *Commands) resolveChangeListRecv(
 	isPush bool, d, p string, r *File, l *File) (cl []*Change, err error) {
 	var change *Change
@@ -135,7 +139,7 @@ func (g *Commands) resolveChangeListRecv(
 		if !g.opts.Force && hasExportLinks(r) {
 			// The case when we have files that don't provide the download urls
 			// but exportable links, we just need to check that mod times are the same.
-			mask := fileDifferences(r, l)
+			mask := fileDifferences(r, l, g.opts.IgnoreChecksum)
 			if !dirTypeDiffers(mask) && !modTimeDiffers(mask) {
 				return cl, nil
 			}
@@ -145,6 +149,7 @@ func (g *Commands) resolveChangeListRecv(
 
 	change.Force = g.opts.Force
 	change.NoClobber = g.opts.NoClobber
+	change.IgnoreChecksum = g.opts.IgnoreChecksum
 
 	if change.Op() != OpNone {
 		cl = append(cl, change)

src/commands.go

@@ -39,6 +39,9 @@ type Options struct {
 	Force bool
 	// Hidden discovers hidden paths if set
 	Hidden bool
+	// IgnoreChecksum when set avoids the step
+	// of comparing checksums as a final check.
+	IgnoreChecksum bool
 	// Allows listing of content in trash
 	InTrash bool
 	Meta    *map[string][]string

src/diff.go

@@ -96,7 +96,11 @@ func (g *Commands) perDiff(change *Change, diffProgPath, cwd string) (err error)
 			change.Path, l.Size)
 	}
 
-	if sameFileTillChecksum(r, l) {
+	mask := fileDifferences(r, l, g.opts.IgnoreChecksum)
+	if modTimeDiffers(mask) {
+		fmt.Printf("* %-15s %-40s\n* %-15s %-40s\n",
+			"remote:", toUTCString(r.ModTime), "local:", toUTCString(l.ModTime))
+	} else if mask == DifferNone {
 		// No output when "no changes found"
 		return nil
 	}

src/help.go

@@ -41,35 +41,45 @@ const (
 )
 
 const (
-	DescAbout       = "print out information about your Google drive"
-	DescAll         = "print out the entire help section"
-	DescDiff        = "compares local files with their remote equivalent"
-	DescEmptyTrash  = "permanently cleans out your trash"
-	DescFeatures    = "returns information about the features of your drive"
-	DescHelp        = "Get help for a topic"
-	DescInit        = "initializes a directory and authenticates user"
-	DescList        = "lists the contents of remote path"
-	DescQuota       = "prints out information related to your quota space"
-	DescPublish     = "publishes a file and prints its publicly available url"
-	DescPull        = "pulls remote changes from Google Drive"
-	DescPush        = "push local changes to Google Drive"
-	DescShare       = "share files with specific emails giving the specified users specifies roles and permissions"
-	DescTouch       = "updates a remote file's modification time to that currently on the server"
-	DescTrash       = "moves files to trash"
-	DescUnshare     = "revoke a user's access to a file"
-	DescUntrash     = "restores files from trash to their original locations"
-	DescUnpublish   = "revokes public access to a file"
-	DescVersion     = "prints the version"
-	DescAccountType = "\n\t* anyone.\n\t* user.\n\t* domain.\n\t* group"
-	DescRoles       = "\n\t* owner.\n\t* reader.\n\t* writer.\n\t* commenter."
+	DescAbout          = "print out information about your Google drive"
+	DescAll            = "print out the entire help section"
+	DescDiff           = "compares local files with their remote equivalent"
+	DescEmptyTrash     = "permanently cleans out your trash"
+	DescFeatures       = "returns information about the features of your drive"
+	DescHelp           = "Get help for a topic"
+	DescInit           = "initializes a directory and authenticates user"
+	DescList           = "lists the contents of remote path"
+	DescQuota          = "prints out information related to your quota space"
+	DescPublish        = "publishes a file and prints its publicly available url"
+	DescPull           = "pulls remote changes from Google Drive"
+	DescPush           = "push local changes to Google Drive"
+	DescShare          = "share files with specific emails giving the specified users specifies roles and permissions"
+	DescTouch          = "updates a remote file's modification time to that currently on the server"
+	DescTrash          = "moves files to trash"
+	DescUnshare        = "revoke a user's access to a file"
+	DescUntrash        = "restores files from trash to their original locations"
+	DescUnpublish      = "revokes public access to a file"
+	DescVersion        = "prints the version"
+	DescAccountType    = "\n\t* anyone.\n\t* user.\n\t* domain.\n\t* group"
+	DescRoles          = "\n\t* owner.\n\t* reader.\n\t* writer.\n\t* commenter."
+	DescIgnoreChecksum = "avoids computation of checksums as a final check" +
+		"in case for example you are low on bandwidth"
 )
 
+const (
+	CLIOptionIgnoreChecksum = "ignore-checksum"
+)
+
+var skipChecksumNote = fmt.Sprintf(
+	"\nNote: You can skip checksum verification by using `-%s`", CLIOptionIgnoreChecksum)
+
 var docMap = map[string][]string{
 	AboutKey: []string{
 		DescAbout,
 	},
 	DiffKey: []string{
 		DescDiff, "Accepts multiple remote paths for line by line comparison",
+		skipChecksumNote,
 	},
 	EmptyTrashKey: []string{
 		DescEmptyTrash,
@@ -85,12 +95,14 @@ var docMap = map[string][]string{
 	PullKey: []string{
 		DescPull, "Downloads content from the remote drive or modifies",
 		" local content to match that on your Google Drive",
+		skipChecksumNote,
 	},
 	PushKey: []string{
 		DescPush, "Uploads content to your Google Drive from your local path",
 		"Push comes in a couple of flavors",
 		"\t* Ordinary push: `drive push path1 path2 path3`",
 		"\t* Mounted push: `drive push -m path1 [path2 path3] drive_context_path`",
+		skipChecksumNote,
 	},
 	ListKey: []string{
 		DescList,

src/pull.go

@@ -98,7 +98,7 @@ func (g *Commands) localMod(wg *sync.WaitGroup, change *Change, exports []string
 
 	// Simple heuristic to avoid downloading all the
 	// content yet it could just be a modTime difference
-	mask := fileDifferences(change.Src, change.Dest)
+	mask := fileDifferences(change.Src, change.Dest, change.IgnoreChecksum)
 	if checksumDiffers(mask) {
 		// download and replace
 		if err = g.download(change, exports); err != nil {

src/push.go

@@ -197,7 +197,15 @@ func (g *Commands) remoteMod(change *Change) (err error) {
 		return
 	}
 
-	_, err = g.rem.UpsertByComparison(parent.Id, absPath, change.Src, change.Dest, g.opts.TypeMask)
+	args := upsertOpt{
+		parentId:       parent.Id,
+		fsAbsPath:      absPath,
+		src:            change.Src,
+		dest:           change.Dest,
+		mask:           g.opts.TypeMask,
+		ignoreChecksum: g.opts.IgnoreChecksum,
+	}
+	_, err = g.rem.UpsertByComparison(&args)
 	return err
 }