move files to src; add README.txt

1 files changed, 154 insertions, 0 deletions

diff --git a/src/sliceweasel.lib.sh b/src/sliceweasel.lib.sh
new file mode 100755
index 0000000..549e1e8
--- /dev/null
+++ b/src/sliceweasel.lib.sh
@@ -0,0 +1,154 @@
+#!/bin/sh
+die()
+{
+    printf '%s: Error: %s\n' "$0" "$*" >&2
+    exit 1
+}
+
+get_age()
+{
+    local mtime now
+    mtime=$(stat --format=%Y "$1") || return
+    now=$(date +%s) || return
+    echo $(( now - mtime ))
+}
+
+get_filesystem()
+{
+    echo /
+}
+
+get_total_memory()
+{
+    free -b | {
+        read _
+        read _ total _
+        echo $total
+    }
+}
+
+math()
+{
+    printf '%s\n' "$*" | bc -lq
+}
+
+get_total_io()
+{
+    results=$IO_ROOT_DIR/io.test.result
+    zeroes=$IO_ROOT_DIR/io.test
+    if [ -e "$results" ]
+    then
+        age=$(get_age "$results") || return
+        if [ "$age" -gt $((60 * 60 * 24 * 7)) ]
+        then
+            rm "$results"
+        fi
+    fi
+
+    if ! [ -e "$results" ]
+    then
+        MEGS=128
+        then=$(date +%s.%N) || return
+        dd if=/dev/zero of="$zeroes" bs=${MEGS}M count=1 || return
+        now=$(date +%s.%N) || return
+        rm "$zeroes"
+        speed=$(math $now - $then / $((MEGS * 1024 * 1024))) || return
+        echo $speed > "$results"
+    fi
+    read total < "$results" || return
+    echo ${total%.*}
+}
+
+root_write()
+{
+    $AS_ROOT sh -c 'cat > "$1"' sh "$1" || true
+}
+
+join_group()
+{
+    GROUP_DIR="$1"
+    [ -d "$GROUP_DIR" ] || $AS_ROOT mkdir "$GROUP_DIR"
+    echo $$ | root_write "$GROUP_DIR"/cgroup.procs
+}
+
+add_subtree_controller()
+{
+    local group="$1" controller="$2" control_file
+    control_file="$group/cgroup.subtree_control"
+
+    [ "$group" ] && [ "$controller" ] && [ -d "$group" ] && [ -e "$control_file" ] || return
+
+    case "$group" in
+        /sys/fs/cgroup) ;;
+        *) add_subtree_controller "$(realpath "$group/..")" "$2" ;;
+    esac
+
+    if ! grep -qe "\\b${controller}\\b" "$control_file"
+    then
+        echo +"$controller" | root_write "$control_file"
+    fi
+}
+
+set_max()
+{
+    max_file=$group/$2.max
+    if [ ! -e "$max_file" ]
+    then
+        add_subtree_controller "$1"/.. "$2"
+        [ -e "$max_file" ] || return
+    fi
+    printf '%s\n' "$3" | root_write "$max_file"
+}
+
+set_max_ratio()
+{
+    local group="$1" controller="$2" ratio="$3" limit
+    total=$(get_total_$controller)
+    n=${ratio%%/*}
+    d=${ratio#$n/}
+    [ "$d" = "${d%/*}" ] || return
+    limit=$(( total * n / d ))
+    [ "$limit" ] || return
+    [ "$limit" -gt 0 ] || return
+    case "$controller" in
+        io)
+            fsroot=$(get_filesystem "$IO_ROOT_DIR") || return
+            # TODO: Do not use lsblk, because it fails to report the correct
+            # MOUNTPOINT when a bind mount is present.
+            majmin=$(lsblk -o 'MOUNTPOINT,MAJ:MIN' | sed -ne "s?^$fsroot  *??p") || return
+            case "$majmin" in
+                *:*) ;;
+                *) echo "Error: majmin=$majmin" >&2; return 1 ;;
+            esac
+            set_max "$group" "$controller" "$majmin wbps=$limit rbps=$limit"
+        ;;
+        *) set_max "$group" "$controller" "$limit"
+    esac
+}
+
+get_uid()
+{
+    (
+        if [ "$SUDO_USER" ]
+        then
+            IFS=:
+            set -- $(getent passwd "${SUDO_USER}") || return
+            echo $3
+        else
+            id -u
+        fi
+    )
+}
+
+get_firefox_cgroup_procs()
+{
+    uid=$(get_uid)
+    [ "$uid" ] || return
+    echo /sys/fs/cgroup/user.slice/user-$uid.slice/user@$uid.service/app.slice/firefox.service/cgroup.procs
+}
+
+get_current_group()
+{
+    read g < /proc/$$/cgroup
+    echo /sys/fs/cgroup/${g#0::/}
+}