Improve performance and output of pyenv virtualenvs (#502)

* With 160 envs, cuts time from ~14s to ~2.5s
* Change the output to be more like `pyenv-versions'
* Shellcheck fixes
* virtualenv: Only show non-envs for completion since env engines don't support piggy-backing envs
* Remove dead/unused code
* Fix IFS handling
`IFS=: <command>' doesn't apply that IFS to expansions in <command>,
it has to be set separately earlier
* Adjust and refactor tests

---------

Co-authored-by: Ivan Pozdeev <vano@mail.mipt.ru>

Author: samdoran

bin/pyenv-virtualenv

@@ -24,7 +24,7 @@ fi
 
 # Provide pyenv completions
 if [ "$1" = "--complete" ]; then
-  exec pyenv-versions --bare
+  exec pyenv-versions --bare --skip-envs
 fi
 
 unset PIP_REQUIRE_VENV

bin/pyenv-virtualenv-prefix

@@ -26,13 +26,17 @@ if [ -z "$PYENV_ROOT" ]; then
   PYENV_ROOT="${HOME}/.pyenv"
 fi
 
+OLDIFS="$IFS"
+IFS=:
 if [ -n "$1" ]; then
-  versions=($@)
-  IFS=: PYENV_VERSION="${versions[*]}"
+  # $@ is not affected by IFS
+  versions=("$@")
+  PYENV_VERSION="${versions[*]}"
   export PYENV_VERSION
 else
-  IFS=: versions=($(pyenv-version-name))
+  versions=($(pyenv-version-name))
 fi
+IFS="$OLDIFS"
 
 append_virtualenv_prefix() {
   if [ -d "${VIRTUALENV_PREFIX_PATH}" ]; then
@@ -49,7 +53,18 @@ for version in "${versions[@]}"; do
     echo "pyenv-virtualenv: version \`${version}' is not a virtualenv" 1>&2
     exit 1
   fi
-  PYENV_PREFIX_PATH="$(pyenv-prefix "${version}")"
+
+  # In the vast majority of cases, there's a direct match and 
+  # not spawning `pyenv-prefix' saves about half the invocation time
+  # with a signle argument which accumulates when called repeatedly
+  # (e.g. from `pyenv-virtualenvs').
+  # `pyenv-prefix' also does not have hooks to worry about.
+  # XXX: refactor the test into a shared module?
+  PYENV_PREFIX_PATH="${PYENV_ROOT}/versions/${version}"
+  if [[ ! -d "$PYENV_PREFIX_PATH" ]]; then
+    PYENV_PREFIX_PATH="$(pyenv-prefix "${version}")"
+  fi
+
   if [ -x "${PYENV_PREFIX_PATH}/bin/python" ]; then
     if [ -f "${PYENV_PREFIX_PATH}/bin/activate" ]; then
       if [ -f "${PYENV_PREFIX_PATH}/bin/conda" ]; then
@@ -94,4 +109,7 @@ for version in "${versions[@]}"; do
   fi
 done
 
-IFS=: echo "${VIRTUALENV_PREFIX_PATHS[*]}"
+OLDIFS="$IFS"
+IFS=:
+echo "${VIRTUALENV_PREFIX_PATHS[*]}"
+IFS="$OLDIFS"

bin/pyenv-virtualenvs

@@ -6,24 +6,9 @@
 # List all virtualenvs found in `$PYENV_ROOT/versions/*' and its `$PYENV_ROOT/versions/envs/*'.
 
 set -e
-[ -n "$PYENV_DEBUG" ] && set -x
-if [ -L "${BASH_SOURCE}" ]; then
-    READLINK=$(type -p greadlink readlink | head -1)
-    if [ -z "$READLINK" ]; then
-        echo "pyenv: cannot find readlink - are you missing GNU coreutils?" >&2
-        exit 1
-    fi
-    resolve_link() {
-        $READLINK -f "$1"
-    }
-    script_path=$(resolve_link ${BASH_SOURCE})
-else
-    script_path=${BASH_SOURCE}
-fi
-
-. ${script_path%/*}/../libexec/pyenv-virtualenv-realpath
+[[ -n $PYENV_DEBUG ]] && set -x
 
-if [ -z "$PYENV_ROOT" ]; then
+if [[ -z $PYENV_ROOT ]]; then
   PYENV_ROOT="${HOME}/.pyenv"
 fi
 
@@ -47,28 +32,26 @@ done
 
 versions_dir="${PYENV_ROOT}/versions"
 
-if [ -d "$versions_dir" ]; then
-  versions_dir="$(realpath "$versions_dir")"
-fi
-
-if [ -n "$bare" ]; then
-  hit_prefix=""
-  miss_prefix=""
-  current_versions=()
-  unset print_origin
-  include_system=""
+if [[ ${BASH_VERSINFO[0]} -gt 3 ]]; then
+  declare -A current_versions
 else
+  current_versions=()
+fi
+if [[ -z $bare ]]; then
   hit_prefix="* "
   miss_prefix="  "
   OLDIFS="$IFS"
-  IFS=: current_versions=($(pyenv-version-name || true))
+  IFS=:
+  if [[ ${BASH_VERSINFO[0]} -gt 3 ]]; then
+    for i in $(pyenv-version-name || true); do
+      current_versions["$i"]="1"
+    done
+  else
+    read -r -a current_versions <<< "$(pyenv-version-name || true)"
+  fi
   IFS="$OLDIFS"
-  print_origin="1"
-  include_system=""
 fi
 
-num_versions=0
-
 exists() {
   local car="$1"
   local cdar
@@ -82,39 +65,67 @@ exists() {
 }
 
 print_version() {
-  if exists "$1" "${current_versions[@]}"; then
-    echo "${hit_prefix}${1}${print_origin+$2}"
+  local version="${1:?}"
+  if [[ -n $bare ]]; then
+    echo "$version"
+    return
+  fi
+  local path="${2:?}"
+  if [[ -L "$path" ]]; then
+    version_repr="$version --> $(readlink "$path")"
+  else
+    version_repr="$version (created from $(pyenv-virtualenv-prefix "$version" 2>/dev/null))"
+  fi
+  if [[ ${BASH_VERSINFO[0]} -gt 3 && ${current_versions["$1"]} ]] || \
+     { [[ ${BASH_VERSINFO[0]} -le 3 ]] && exists "$1" "${current_versions[@]}"; }; then
+    echo "${hit_prefix}${version_repr} (set by $(pyenv-version-origin))"
   else
-    echo "${miss_prefix}${1}${print_origin+$2}"
+    echo "${miss_prefix}${version_repr}"
   fi
-  num_versions=$((num_versions + 1))
 }
 
 shopt -s dotglob
 shopt -s nullglob
-for path in "$versions_dir"/*; do
-  if [ -d "$path" ]; then
-    if [ -n "$skip_aliases" ] && [ -L "$path" ]; then
-      target="$(realpath "$path")"
-      [ "${target%/*/envs/*}" != "$versions_dir" ] || continue
-    fi
-    virtualenv_prefix="$(pyenv-virtualenv-prefix "${path##*/}" 2>/dev/null || true)"
-    if [ -d "${virtualenv_prefix}" ]; then
-      print_version "${path##*/}" " (created from ${virtualenv_prefix})"
-    fi
-    for venv_path in "${path}/envs/"*; do
-      venv="${path##*/}/envs/${venv_path##*/}"
-      virtualenv_prefix="$(pyenv-virtualenv-prefix "${venv}" 2>/dev/null || true)"
-      if [ -d "${virtualenv_prefix}" ]; then
-        print_version "${venv}" " (created from ${virtualenv_prefix})"
+version_dir_entries=("$versions_dir"/*)
+venv_dir_entries=("$versions_dir"/*/envs/*)
+
+if sort --version-sort </dev/null >/dev/null 2>&1; then
+    # system sort supports version sorting
+    OLDIFS="$IFS"
+    IFS='||'
+
+    read -r -a version_dir_entries <<< "$(
+        printf "%s||" "${version_dir_entries[@]}" |
+        sort --version-sort
+    )"
+
+    read -r -a venv_dir_entries <<< "$(
+        printf "%s||" "${venv_dir_entries[@]}" |
+        sort --version-sort
+    )"
+
+    IFS="$OLDIFS"
+fi
+
+for env_path in "${venv_dir_entries[@]}"; do
+  if [[ -d ${env_path} ]]; then
+    print_version "${env_path#"${PYENV_ROOT}"/versions/}" "${env_path}"
+  fi
+done
+
+for env_path in "${version_dir_entries[@]}"; do
+  if [[ -d ${env_path} ]]; then
+    if [[ -L ${env_path} ]]; then
+      if [[ -z $skip_aliases ]]; then
+        print_version "${env_path#"${PYENV_ROOT}"/versions/}" "${env_path}"
       fi
-    done
+    # Mimics the test from pyenv-virtualenv-prefix
+    # XXX: refactor itto a shared module ?
+    elif [[ -f "${env_path}/bin/activate" ]]; then
+      print_version "${env_path#"${PYENV_ROOT}"/versions/}" "${env_path}"
+    fi
   fi
 done
+
 shopt -u dotglob
 shopt -u nullglob
-
-if [ "$num_versions" -eq 0 ] && [ -n "$include_system" ]; then
-  echo "Warning: no Python virtualenv detected on the system" >&2
-  exit 1
-fi

test/conda-prefix.bats

@@ -9,7 +9,6 @@ setup() {
 @test "display conda root" {
   setup_conda "anaconda-2.3.0"
   stub pyenv-version-name "echo anaconda-2.3.0"
-  stub pyenv-prefix "anaconda-2.3.0 : echo \"${PYENV_ROOT}/versions/anaconda-2.3.0\""
 
   PYENV_VERSION="anaconda-2.3.0" run pyenv-virtualenv-prefix
 
@@ -19,14 +18,12 @@ ${PYENV_ROOT}/versions/anaconda-2.3.0
 OUT
 
   unstub pyenv-version-name
-  unstub pyenv-prefix
   teardown_conda "anaconda-2.3.0"
 }
 
 @test "display conda env" {
   setup_conda "anaconda-2.3.0" "foo"
   stub pyenv-version-name "echo anaconda-2.3.0/envs/foo"
-  stub pyenv-prefix "anaconda-2.3.0/envs/foo : echo \"${PYENV_ROOT}/versions/anaconda-2.3.0/envs/foo\""
 
   PYENV_VERSION="anaconda-2.3.0/envs/foo" run pyenv-virtualenv-prefix
 
@@ -36,6 +33,5 @@ ${PYENV_ROOT}/versions/anaconda-2.3.0/envs/foo
 OUT
 
   unstub pyenv-version-name
-  unstub pyenv-prefix
   teardown_conda "anaconda-2.3.0" "foo"
 }