Add support for installing precompiled rubies from jdx/ruby

bin/install

@@ -4,6 +4,8 @@ set -euo pipefail
 
 # shellcheck source=/dev/null
 source "$(dirname "$0")/../lib/utils.sh"
+# shellcheck source=/dev/null
+source "$(dirname "$0")/../lib/precompiled.sh"
 
 install_ruby() {
   ensure_ruby_build_setup
@@ -130,5 +132,16 @@ install_default_gems() {
   )
 }
 
-install_ruby "$ASDF_INSTALL_TYPE" "$ASDF_INSTALL_VERSION" "$ASDF_INSTALL_PATH"
+should_compile_from_source() {
+  local val="${ASDF_RUBY_COMPILE_FROM_SOURCE:-}"
+  [[ "$val" == "1" || "$val" == "true" || "$val" == "yes" ]]
+}
+
+if should_compile_from_source || [ "$ASDF_INSTALL_TYPE" != "version" ]; then
+  install_ruby "$ASDF_INSTALL_TYPE" "$ASDF_INSTALL_VERSION" "$ASDF_INSTALL_PATH"
+elif ! install_precompiled "$ASDF_INSTALL_VERSION" "$ASDF_INSTALL_PATH"; then
+  echoerr "Falling back to building Ruby from source..."
+  install_ruby "$ASDF_INSTALL_TYPE" "$ASDF_INSTALL_VERSION" "$ASDF_INSTALL_PATH"
+fi
+
 install_default_gems

lib/precompiled.sh

@@ -0,0 +1,88 @@
+#!/usr/bin/env bash
+
+PRECOMPILED_BASE_URL="${ASDF_RUBY_PRECOMPILED_URL:-https://github.com/jdx/ruby/releases/download}"
+
+precompiled_platform() {
+  local os arch
+  os="$(uname -s)"
+  arch="$(uname -m)"
+
+  case "$os" in
+  Darwin)
+    case "$arch" in
+    arm64) echo "macos" ;;
+    *) return 1 ;;
+    esac
+    ;;
+  Linux)
+    case "$arch" in
+    x86_64) echo "x86_64_linux" ;;
+    aarch64) echo "arm64_linux" ;;
+    *) return 1 ;;
+    esac
+    ;;
+  *) return 1 ;;
+  esac
+}
+
+is_version_precompilable() {
+  local version="$1"
+  # Only standard MRI/CRuby versions (e.g. 4.0.1) are available as precompiled
+  # binaries. Ignore prefixed variants like jruby-*, truffleruby-*, mruby-*, etc
+  [[ "$version" =~ ^[0-9]+\.[0-9]+\.[0-9]+([-.](preview|rc|dev)[0-9]*)?$ ]]
+}
+
+precompiled_url() {
+  local version="$1"
+  local platform="$2"
+  echo "${PRECOMPILED_BASE_URL}/${version}/ruby-${version}.${platform}.tar.gz"
+}
+
+download_precompiled() {
+  local url="$1"
+  local download_path="$2"
+
+  if ! curl -fLsS -o "$download_path" "$url"; then
+    return 1
+  fi
+
+  return 0
+}
+
+install_precompiled() {
+  local version="$1"
+  local install_path="$2"
+
+  local platform
+  if ! platform="$(precompiled_platform)"; then
+    return 1
+  fi
+
+  if ! is_version_precompilable "$version"; then
+    return 1
+  fi
+
+  local url
+  url="$(precompiled_url "$version" "$platform")"
+
+  local tmp_dir
+  tmp_dir="$(mktemp -d)"
+  local tarball="${tmp_dir}/ruby-${version}.tar.gz"
+
+  echo "Looking for precompiled Ruby ${version} for ${platform}..."
+
+  if ! download_precompiled "$url" "$tarball"; then
+    rm -rf "$tmp_dir"
+    return 1
+  fi
+
+  mkdir -p "$install_path"
+  if ! tar -xzf "$tarball" -C "$install_path" --strip-components=1; then
+    rm -rf "$tmp_dir" "$install_path"
+    return 1
+  fi
+
+  rm -rf "$tmp_dir"
+  echo "Installed precompiled Ruby ${version} successfully."
+  return 0
+}