git wrapper to make cabal and hls cache git checkouts more efficiently

git

#!/usr/bin/env bash

# only subvert cabal
PARENT_COMMAND=$(ps -o comm= $PPID)
if [ "$PARENT_COMMAND" != "cabal" ]; then
  exec /usr/bin/git "$@"
fi

echo "$PWD /usr/bin/git $*" >> ~/git-log

case $1 in
  clone)
    srcurl="$3"
    # normalise url by stripping .git suffix (perhaps only appropriate for
    # github?
    srcurl=${srcurl%.git}
    dstdir="$4"
    cachedir="$HOME/.cache/git/${srcurl#*//}"

    if [ ! -d "$cachedir" ]; then
      /usr/bin/git clone --mirror "$srcurl" "$cachedir"
    else
      # Automatic garbage collection
      /usr/bin/git -C "$cachedir" worktree prune
    fi
    # Set up the worktree
    /usr/bin/git -C "$cachedir" worktree add --force --no-checkout "$dstdir"
  ;;
  checkout)
    # do the thing, if it fails try to fetch new refs and try again
    if /usr/bin/git "$@"; then
      echo "all good" >> ~/git-log
    else
      echo "trying git fetch" >> ~/git-log
      /usr/bin/git fetch origin --force --recurse-submodules --tags --prune-tags 'refs/heads/*:refs/heads/*'
      /usr/bin/git "$@"
    fi
  ;;
  fetch)
    # ignore fetches, we do it opportunistically as part of checkout
  ;;
  *)
    /usr/bin/git "$@"
  ;;
esac