faster git checkout options

blobless-sparse-git-clone.sh

#!/bin/bash 

# for large repos or repos with binary blobs in them, this is much faster

FORK=https://github.com/rhdh-bot/openshift-helm-charts.git
GIT_DIR=/tmp/catalog
BRANCH=rhdh-1-rhel-9

# under 2 seconds
# remote: Counting objects: 100% (4/4), done.
# remote: Compressing objects: 100% (4/4), done.
# remote: Total 4 (delta 0), reused 4 (delta 0), pack-reused 0
# Receiving objects: 100% (4/4), 1.97 KiB | 1.97 MiB/s, done.
function sparseclone {
  pushd /tmp >/dev/null
  rm -fr $GIT_DIR
  git clone --filter=blob:none --no-checkout --depth=1 -q "${FORK}" "${GIT_DIR}" && cd "${GIT_DIR}"
  git sparse-checkout init --cone
  git read-tree -mu HEAD
  git checkout -q -b "${BRANCH}" 1>/dev/null 2>&1 || true
  git pull $QUIET origin "${BRANCH}" 1>/dev/null 2>&1 || true
  popd >/dev/null
  # note: must use `git add [files] --sparse` to add files into the index when committing changes
}

# >2m40s 
# remote: Counting objects: 100% (2567/2567), done.
# remote: Compressing objects: 100% (1205/1205), done.
# remote: Total 2567 (delta 824), reused 2273 (delta 727), pack-reused 0
# Receiving objects: 100% (2567/2567), 46.58 MiB | 293.00 KiB/s, done.
# Resolving deltas: 100% (824/824), done.
function shallowclone {
  pushd /tmp >/dev/null
  rm -fr $GIT_DIR
  git clone --depth=1 "${FORK}" "${GIT_DIR}" -b "${BRANCH}" 
  popd >/dev/null
}

# >2m40s
# remote: Counting objects: 100% (306/306), done.
# remote: Compressing objects: 100% (165/165), done.
# remote: Total 12587 (delta 152), reused 294 (delta 141), pack-reused 12281
# Receiving objects: 100% (12587/12587), 54.11 MiB | 342.00 KiB/s, done.
# Resolving deltas: 100% (5773/5773), done.
function normalclone {
  pushd /tmp >/dev/null
  rm -fr $GIT_DIR
  git clone "${FORK}" "${GIT_DIR}" -b "${BRANCH}" 
  popd >/dev/null
}

time sparseclone 
time shallowclone
time normalclone