Add snapshot and move send-delta, plus cleanup

btrfs/btrfs-subvolume-delta

@@ -1,47 +0,0 @@
-#!/bin/sh
-set -e
-
-SRC="$1"
-RECV="$2"
-DSTDIR="$SRC/${3:-.snap}"
-CDATE="$(date '+%s')"
-PREV="prev"
-CUR="cur"
-TMP="tmp"
-
-msg() {
-	echo "$1" >&2
-}
-
-delta() {
-	[ -d "$(realpath "$DSTDIR/$CUR")" ] || return 1
-	msg "Attempting to send delta"
-	btrfs -v send --compressed-data -p "$DSTDIR/$CUR" "$DSTDIR/$TMP" | btrfs -v receive "$RECV"
-}
-
-full() {
-	msg "Attempting to send full"
-	btrfs -v send --compressed-data "$DSTDIR/$TMP" | btrfs -v receive "$RECV"
-}
-
-symdel() {
-	if [ -L "$1" ]; then
-		btrfs subvolume delete "$1" >&2 || true
-		rm -v "$1" >&2
-	fi
-}
-
-mkdir -vp "$DSTDIR" >&2
-
-symdel "$DSTDIR/$TMP"
-symdel "$DSTDIR/$PREV"
-
-ln -sv "$CDATE" "$DSTDIR"/"$TMP" >&2
-btrfs subvolume snapshot -r "$SRC" "$DSTDIR/$CDATE" >&2
-
-delta || full
-
-# Mark snapshot transmission as complete
-[ -L "$DSTDIR/$CUR" ] && \
-	mv -v "$DSTDIR/$CUR" "$DSTDIR/$PREV" >&2
-mv -v "$DSTDIR/$TMP" "$DSTDIR/$CUR" >&2

btrfs/snapshot

@@ -4,15 +4,13 @@
 # CC0 ~caskd
 
 : ${SRC:?'Source not defined'}
-: ${DEST:?'Destination not defined'}
+: ${SNAPDIR:?'Snapdir not defined'}
-: ${NAME:?'Name not defined'}
+: ${SELECTOR:='+%H'}
-: ${SN:?'Selection name not defined'}
+NAME="$(date "$SELECTOR")"
-: ${RT:?'Retention time not defined'}
 
-s="$SRC"
+SNAPSRC="$SRC"
-d="$DEST/$SN/$NAME"
+SNAPDEST="$SRC/$SNAPDIR/$NAME"
 
-mkdir -p "${d%/*}"
+mkdir -p "${SNAPDEST%/*}"
-find "$DEST" -mindepth 1 -maxdepth 1 -type d -ctime +"$RT" -exec echo "{}/$NAME" ';' | xargs btrfs subvolume del
+btrfs subvolume delete "$SNAPDEST"
-btrfs subvolume delete "$d"
+btrfs subvolume snapshot -r "$SNAPSRC" "$SNAPDEST"
-btrfs subvolume snapshot -r "$s" "$d"

btrfs/subvolume-delta

@@ -0,0 +1,53 @@
+#!/bin/sh
+#
+# BTRFS delta snapshots with incomplete send handling
+# CC0 ~caskd
+
+: ${SRC:?'Source not defined'}
+: ${SNAPDIR:?'Snapdir not defined'}
+: ${DEST:?'Destination not defined'}
+
+CDATE="$(date '+%s')"
+SNAPSRC="$SRC"
+SNAPPATH="$SNAPSRC/$SNAPDIR"
+PREV="$SRC/prev"
+CUR="$SRC/cur"
+TMP="$SRC/tmp"
+SNAPDEST="$SNAPPATH/$CDATE"
+
+msg() {
+	echo "$1" >&2
+}
+
+delta() {
+	[ -d "$(realpath "$CUR")" ] || return 1
+	msg "Attempting to send delta"
+	btrfs -v send --compressed-data -p "$CUR" "$TMP" | btrfs -v receive "$DEST"
+}
+
+full() {
+	msg "Attempting to send full"
+	btrfs -v send --compressed-data "$TMP" | btrfs -v receive "$DEST"
+}
+
+symdel() {
+	if [ -L "$1" ]; then
+		btrfs subvolume delete "$1" >&2 || true
+		rm -v "$1" >&2
+	fi
+}
+
+mkdir -vp "$SNAPPATH" >&2
+
+symdel "$TMP"
+symdel "$PREV"
+
+ln -sv "$CDATE" "$TMP" >&2
+btrfs subvolume snapshot -r "$SNAPSRC" "$SNAPDEST" >&2
+
+delta || full
+
+# Mark snapshot transmission as complete
+[ -L "$CUR" ] && \
+	mv -v "$CUR" "$PREV" >&2
+mv -v "$TMP" "$CUR" >&2