Merge remote-tracking branch 'lloeki/tarball_cache_support'

bin/rbenv-install

@@ -74,5 +74,9 @@ if [ -n "${RBENV_BUILD_ROOT}" ]; then
   KEEP="-k"
 fi
 
+if [ -z "${CACHE_PATH}" ] && [ -d "${RBENV_ROOT}/cache" ]; then
+  export CACHE_PATH="${RBENV_ROOT}/cache"
+fi
+
 ruby-build $KEEP $VERBOSE "$DEFINITION" "$PREFIX"
 rbenv rehash

bin/ruby-build

@@ -143,8 +143,11 @@ fetch_tarball() {
   local package_url="$2"
 
   echo "Downloading ${package_url}..." >&2
-  { fetch_url "$package_url" > "${package_name}.tar.gz"
-    tar xzvf "${package_name}.tar.gz"
+  { if [ ! -e "${CACHE_PATH}${package_name}.tar.gz" ]; then
+      fetch_url "$package_url" > "${package_name}.tar.gz"
+      [ -n "${CACHE_PATH}" ] && mv "${package_name}.tar.gz" "${CACHE_PATH}${package_name}.tar.gz"
+    fi
+    tar xzvf "${CACHE_PATH}${package_name}.tar.gz"
   } >&4 2>&1
 }
 
@@ -462,6 +465,10 @@ else
   TMP="${TMPDIR%/}"
 fi
 
+if [ -n "$CACHE_PATH" ]; then
+  CACHE_PATH="${CACHE_PATH%/}/"
+fi
+
 SEED="$(date "+%Y%m%d%H%M%S").$$"
 LOG_PATH="${TMP}/ruby-build.${SEED}.log"
 RUBY_BIN="${PREFIX_PATH}/bin/ruby"