Skeleton for prune command & algorithm in pseudocode

commands/command_prune.go

@@ -0,0 +1,72 @@
+package commands
+
+import (
+	"github.com/github/git-lfs/lfs"
+	"github.com/github/git-lfs/vendor/_nuts/github.com/spf13/cobra"
+)
+
+var (
+	pruneCmd = &cobra.Command{
+		Use:   "prune",
+		Short: "Deletes old LFS files from the local store",
+		Run:   pruneCommand,
+	}
+	pruneDryRunArg      bool
+	pruneVerboseArg     bool
+	pruneVerifyArg      bool
+	pruneDoNotVerifyArg bool
+)
+
+func pruneCommand(cmd *cobra.Command, args []string) {
+
+	// Guts of this must be re-usable from fetch --prune so just parse & dispatch
+	if pruneVerifyArg && pruneDoNotVerifyArg {
+		Exit("Cannot specify both --verify-remote and --no-verify-remote")
+	}
+
+	verify := !pruneDoNotVerifyArg &&
+		(lfs.Config.FetchPruneConfig().PruneVerifyRemoteAlways || pruneVerifyArg)
+
+	prune(verify, pruneDryRunArg, pruneVerboseArg)
+
+}
+
+func prune(verifyRemote, dryRun, verbose bool) {
+	// TODO
+	// Separate goroutines must find:
+	//  1. Local objects
+	//  2. Current checkout, 2 sub-goroutines
+	//     a. LFS files at checkout + index
+	//     b. LFS files at recent commits on HEAD
+	//  3. List of recent refs (unique SHA, not HEAD), pass to 2 sub-goroutines >
+	//     a. LFS files at ref
+	//     b. LFS files at recent commits of ref
+	//  4. Unpushed objects
+	//  5. Other worktree checkouts (1 sub-goroutine per other worktree)
+	//  6. [if --verify-remote] Reachable objects
+
+	// This main routine will collate the outputs of chans, report progress
+	// with spinner of # objects stored, # objects referenced
+
+	// storedObjects:array = 1
+	// retainedObjects:set = 2..5
+	// [if --verify-remote] reachableObjects:set = 6
+
+	// prunableObjects:set = (storedObjects - retainedObjects)
+	// [if --verify-remote] verifyObjects:set = (prunableObjects n reachableObjects)
+	//    (this is so we don't try to verify unreachable objects on remote)
+	// [if --verify-remote] call remote, remove unverified objects from prunableObjects & report
+
+	// Report number & size of objects to delete
+	// [if !dry-run] delete prunableObjects
+	// [if verbose] report oids & individual sizes
+
+}
+
+func init() {
+	pruneCmd.Flags().BoolVarP(&pruneDryRunArg, "dry-run", "d", false, "Don't delete anything, just report")
+	pruneCmd.Flags().BoolVarP(&pruneDryRunArg, "verbose", "v", false, "Print full details of what is/would be deleted")
+	pruneCmd.Flags().BoolVarP(&pruneDryRunArg, "verify-remote", "c", false, "Verify that remote has LFS files before deleting")
+	pruneCmd.Flags().BoolVar(&pruneDryRunArg, "no-verify-remote", false, "Override lfs.pruneverifyremotealways and don't verify")
+	RootCmd.AddCommand(pruneCmd)
+}