#!/usr/bin/env bash
set -euo pipefail

# Build Google TCMalloc (gperftools) locally for LD_PRELOAD benchmarking.
#
# Output:
# - deps/gperftools/install/lib/libtcmalloc.so (or libtcmalloc_minimal.so)
#
# Usage:
#   scripts/setup_tcmalloc_gperftools.sh
#
# Notes:
# - This script does not change any build defaults in this repo.
# - If your system already has libtcmalloc, you can skip building and just set
#   TCMALLOC_SO to that path when running allocator comparisons.

root_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
deps_dir="${root_dir}/deps"
src_dir="${deps_dir}/gperftools-src"
install_dir="${deps_dir}/gperftools/install"

mkdir -p "${deps_dir}"

if command -v ldconfig >/dev/null 2>&1; then
  if ldconfig -p 2>/dev/null | rg -q "libtcmalloc(_minimal)?\\.so"; then
    echo "[tcmalloc] Found system tcmalloc via ldconfig:"
    ldconfig -p | rg "libtcmalloc(_minimal)?\\.so" | head
    echo "[tcmalloc] You can set TCMALLOC_SO to one of the above paths and skip local build."
  fi
fi

if [[ ! -d "${src_dir}/.git" ]]; then
  echo "[tcmalloc] Cloning gperftools into ${src_dir}"
  git clone --depth=1 https://github.com/gperftools/gperftools "${src_dir}"
fi

echo "[tcmalloc] Building gperftools (this may require autoconf/automake/libtool)"
cd "${src_dir}"

./autogen.sh
./configure --prefix="${install_dir}" --disable-static
make -j"$(nproc)"
make install

echo "[tcmalloc] Build complete."
echo "[tcmalloc] Install dir: ${install_dir}"
ls -la "${install_dir}/lib" | rg "libtcmalloc" || true

echo ""
echo "Next:"
echo "  export TCMALLOC_SO=\"${install_dir}/lib/libtcmalloc.so\""
echo "  # or: ${install_dir}/lib/libtcmalloc_minimal.so"
echo "  scripts/bench_allocators_compare.sh --scenario mixed --iterations 50"