dotfiles/zsh/zplg.zsh
2019-10-27 10:22:03 +02:00

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#!/usr/bin/env zsh
# This... is my DIY plugin manager for Zsh. "Why did I reinvent the wheel yet
# again and created my own plugin manager?" you might ask. Well, some of them
# are too slow (antigen, zplug), some are too complicated (antigen-hs, zplugin)
# and some are too simple (zgen, antibody). So, I decided to go into into my
# cave for a couple of weeks and now, I proudly present to you MY ZSH PLUGIN
# MANAGER (ZPLG for short). It is very fast even without caching (that's why it
# isn't implemented), has the most essential features and is not bloated. The
# code is rather complex at the first glance because of two reasons:
#
# 1. The syntax of the shell language, to put it simply, utter trash designed
# 40 (!!!) years ago.
# 2. The shell language, especially when it comes to Zsh, is rather slow, so I
# had to use as less abstractions as possible.
#
# But, read my comments and they'll guide you through this jungle of shell
# script mess.
# Also:
#
# 1. This script is compatitable with SH_WORD_SPLIT (if you for whatever reason
# want to enable this), so I use "@" everywhere. This expansion modifier
# means "put all elements of the array in separate quotes".
# 2. I often use the following snippet to exit functions on errors:
# eval "$some_user_command_that_might_fail" || return "$?"
# I do this instead of `setopt local_options err_exit` because some plugins
# may not be compatitable with ERREXIT.
_ZPLG_SCRIPT_PATH="${(%):-%N}"
# $ZPLG_HOME is a directory where all your plugins are downloaded, it also
# might contain in the future some kind of state/lock/database files. It is
# recommended to change it before `source`-ing this script because you may end
# up with a broken plugin directory.
if [[ -z "$ZPLG_HOME" ]]; then
ZPLG_HOME="${XDG_DATA_HOME:-$HOME/.local/share}/zplg"
fi
# Default plugin source, see the `plugin` function for description.
if [[ -z "$ZPLG_DEFAULT_SOURCE" ]]; then
ZPLG_DEFAULT_SOURCE="github"
fi
# Directory in which plugins are stored. It is separate from $ZPLG_HOME for
# compatitability with future versions.
_ZPLG_PLUGINS_DIR="$ZPLG_HOME/plugins"
# basic logging {{{
_zplg_log() {
print >&2 "${fg_bold[blue]}[zplg]${reset_color} $@"
}
_zplg_debug() {
if [[ -n "$ZPLG_DEBUG" ]]; then
_zplg_log "${fg[green]}debug:${reset_color} $@"
fi
}
_zplg_error() {
# try to find the place outside of the script that caused this error
local external_caller
local i; for (( i=1; i<=${#funcfiletrace}; i++ )); do
# $funcfiletrace contains file paths and line numbers
if [[ "${funcfiletrace[$i]}" != "$_ZPLG_SCRIPT_PATH"* ]]; then
# $functrace contains "ugly" call sites, the line numbers are
# relative to the beginning of a function/file here. I use it here
# only for consistency with the shell, TODO might change this in the
# future.
_zplg_log "${fg[red]}error:${reset_color} ${functrace[$i]}: $@"
return 1
fi
done
# if for whatever reason we couldn't find the caller, simply print the
# error without it
_zplg_log "${fg[red]}error:${reset_color} $@"
return 1
}
# }}}
# These variables contain essential information about the currently loaded
# plugins. When I say "essential" I mean "required for upgrading,
# reinstallating and uninstalling plugins", so options for configuring loading
# behavior are not stored here.
#
# $ZPLG_LOADED_PLUGINS is an array of plugin IDs, other variables are
# associative arrays that have IDs as their keys. It is implemented this way
# because you can't put associative arrays (or any other alternative to
# "objects") into another associative array.
typeset -a ZPLG_LOADED_PLUGINS
typeset -A ZPLG_LOADED_PLUGIN_URLS ZPLG_LOADED_PLUGIN_SOURCES ZPLG_LOADED_PLUGIN_BUILD_CMDS
# Takes name of a variable with an array (array is passed by variable name
# because this reduces boilerplate) and runs every command in it, exits
# immediately with an error code if any command fails. This snippet was
# extracted in a function because it's often used to run plugin loading hooks
# (before_load/after_load) or build commands.
_zplg_run_commands() {
local var_name="$1"
# (P) modifier lets you access the variable dynamically by its name stored in
# another variable
local cmd; for cmd in "${(@P)var_name}"; do
eval "$cmd" || return "$?"
done
}
# Expands a glob pattern with the NULL_GLOB flag from the first argument and
# puts all matched filenames into a variable from the second argument because
# shell functions can't return arrays. This function is needed to simplify
# handling of user-provided glob expressions because I can use LOCAL_OPTIONS
# inside a function which reverts NULL_GLOB to its previous value as soon as
# the function returns.
_zplg_expand_pattern() {
setopt local_options null_glob
local pattern="$1" out_var_name="$2"
# ${~var_name} turns on globbing for this expansion, note lack of quotes: as
# it turns out glob expansions are automatically quoted by design, and when
# you explicitly write `"${~pattern}"` it is basically the same as
# `"$pattern"`
eval "$out_var_name=(\${~pattern})"
}
# Wrapper around `source` for simpler profiling and debugging. You can override
# this function to change plugin loading strategy
_zplg_load() {
local script_path="$1"
source "$script_path"
}
# plugin sources {{{
# See documentation of the `plugin` function for description.
_zplg_source_url_download() {
local plugin_url="$1" plugin_dir="$2"
wget --timestamping --directory-prefix "$plugin_dir" -- "$plugin_url"
}
_zplg_source_url_upgrade() {
_zplg_source_url_download "$@"
}
_zplg_source_git_download() {
local plugin_url="$1" plugin_dir="$2"
git clone --recurse-submodules -- "$plugin_url" "$plugin_dir"
}
_zplg_source_git_upgrade() {
local plugin_url="$1" plugin_dir="$2"
( cd "$plugin_dir" && git pull && git submodule update --init --recursive )
}
# small helper for the git source
plugin-git-checkout-latest-version() {
local latest_tag
git tag --list --sort -version:refname | read -r latest_tag
if (( ${#tags} == 0 )); then
_zplg_error "$0: no tags in the Git repository"
return 1
fi
# git checkout
}
_zplg_source_github_download() {
local plugin_url="$1" plugin_dir="$2"
_zplg_source_git_download "https://github.com/$plugin_url.git" "$plugin_dir"
}
_zplg_source_github_upgrade() {
local plugin_url="$1" plugin_dir="$2"
_zplg_source_git_upgrade "https://github.com/$plugin_url.git" "$plugin_dir"
}
# }}}
# The main part of my plugin manager. This function does two things: it
# downloads a plugin if necessary and loads it into the shell. Usage is very
# simple:
#
# plugin <id> <url> option_a=value_a option_b=value_b ...
#
# <id>
# identifier of the plugin, alphanumeric, may contain underscores,
# hyphens and periods, mustn't start with a period.
#
# <url>
# I guess this is self-descreptive.
#
# Some options can be repeated (marked with a plus). Available options:
#
# from
# Sets plugin source. Sources are where the plugin will be downloaded from.
# Currently supported sources are:
# * git - clones a repository
# * github - clones a repository from GitHub
# * url - simply downloads a file
# Custom sources can easily be defined. Just create two functions:
# `_zplg_source_${name}_download` and `_zplg_source_${name}_upgrade`. Both
# functions take two arguments: plugin URL and plugin directory. Download
# function must, well, download a plugin from the given URL into the given
# directory, ugrade one, obviously, upgrades plugin inside of the given
# directory. Please note that neither of these functions is executed INSIDE
# of the plugin directory (i.e. current working directory is not changed).
#
# build (+)
# Command which builds/compiles the plugin, executed INSIDE of $plugin_dir
# (i.e. cd $plugin_dir) once after downloading. Plugin directory can be
# accessed through the $plugin_dir variable.
#
# before_load (+) and after_load (+)
# Execute commands before and after loading of the plugin, useful when you
# need to read plugin directory which is available through the $plugin_dir
# variable.
#
# load (+) and ignore (+)
# Globs which tell what files should be sourced (load) or ignored (ignore).
# If glob expands to nothing (NULL_GLOB), nothing is loaded.
#
# Neat trick when using options: if you want to assign values using an array,
# write it like this: option=${^array}. That way `option=` is prepended to
# each element of `array`.
#
# For examples see my dotfiles: https://github.com/dmitmel/dotfiles/blob/master/zsh/plugins.zsh
# You may ask me why did I choose to merge loading and downloading behavior
# into one function. Well, first of all plugin manager itself becomes much
# simpler. Second: it allows you to load plugins from any part of zshrc (which
# is useful for me because my dotfiles are used by my friends, and they too
# want customization) and even in an active shell.
#
# Oh, and I had to optimize this function, so it is very long because I merged
# everything into one code block. I hope (this is also a message for my future
# self) that you'll be able to read this code, I tried to comment everything.
plugin() {
# parse basic arguments {{{
if (( $# < 2 )); then
_zplg_error "usage: $0 <id> <url> [option...]"
return 1
fi
local plugin_id="$1"
local plugin_url="$2"
if [[ ! "$plugin_id" =~ '^[a-zA-Z0-9_\-][a-zA-Z0-9._\-]*$' ]]; then
_zplg_error "invalid plugin ID"
return 1
fi
if [[ -z "$plugin_url" ]]; then
_zplg_error "invalid plugin URL"
return 1
fi
# Don't even try to continue if the plugin has already been loaded. This is
# not or problem. Plugin manager loads plugins and shouldn't bother
# unloading them.
if _zplg_is_plugin_loaded "$plugin_id"; then
_zplg_error "plugin $plugin_id has already been loaded"
return 1
fi
# }}}
# parse options {{{
local plugin_from="$ZPLG_DEFAULT_SOURCE"
local -a plugin_build plugin_before_load plugin_after_load plugin_load plugin_ignore
local option key value; shift 2; for option in "$@"; do
# globs are faster than regular expressions
if [[ "$option" != *?=?* ]]; then
_zplg_error "options must have the following format: <key>=<value>"
return 1
fi
# split 'option' at the first occurence of '='
key="${option%%=*}" value="${option#*=}"
case "$key" in
from)
eval "plugin_$key=\"\$value\"" ;;
build|before_load|after_load|load|ignore)
eval "plugin_$key+=(\"\$value\")" ;;
*)
_zplg_error "unknown option: $key"
return 1 ;;
esac
done; unset option key value
# }}}
if (( ${#plugin_load} == 0 )); then
# default loading patterns:
# - *.plugin.zsh for most plugins and Oh-My-Zsh ones
# - *.zsh-theme for most themes and Oh-My-Zsh ones
# - init.zsh for Prezto plugins
# ([1]) means "expand only to the first match"
plugin_load=("(*.plugin.zsh|*.zsh-theme|init.zsh)([1])")
fi
# download plugin {{{
local plugin_dir="$_ZPLG_PLUGINS_DIR/$plugin_id"
# simple check whether the plugin directory exists is enough for me
if [[ ! -d "$plugin_dir" ]]; then
_zplg_log "downloading $plugin_id"
_zplg_source_"$plugin_from"_download "$plugin_url" "$plugin_dir" || return "$?"
if (( ${#plugin_build} > 0 )); then
_zplg_log "building $plugin_id"
( cd "$plugin_dir" && _zplg_run_commands plugin_build ) || return "$?"
fi
fi
# }}}
# load plugin {{{
{
_zplg_run_commands plugin_before_load || return "$?"
local load_pattern ignore_pattern script_path; local -a script_paths
for load_pattern in "${plugin_load[@]}"; do
_zplg_expand_pattern "$plugin_dir/$load_pattern" script_paths
for script_path in "${script_paths[@]}"; do
for ignore_pattern in "${plugin_ignore[@]}"; do
if [[ "$script_path" == "$plugin_dir/"${~ignore_pattern} ]]; then
# continue outer loop
continue 2
fi
done
_zplg_debug "sourcing $script_path"
if [[ -z "$ZPLG_SKIP_LOADING" ]]; then
_zplg_load "$script_path" || return "$?"
fi
done
done; unset load_pattern ignore_pattern script_path
_zplg_run_commands plugin_after_load || return "$?"
# plugin has finally been loaded, we can add it to $ZPLG_LOADED_PLUGINS
ZPLG_LOADED_PLUGINS+=("$plugin_id")
ZPLG_LOADED_PLUGIN_URLS[$plugin_id]="$plugin_url"
ZPLG_LOADED_PLUGIN_SOURCES[$plugin_id]="$plugin_from"
# HORRIBLE HACK: because you can't store arrays as values in associative
# arrays, I simply quote every element with the (@q) modifier, then join
# quoted ones into a string and put this "encoded" string into the
# associative array. Terrible idea? Maybe. Does it work? YES!!!
if (( ${#plugin_build} > 0 )); then
# extra ${...} is needed to turn array into a string by joining it with
# spaces
ZPLG_LOADED_PLUGIN_BUILD_CMDS[$plugin_id]="${${(@q)plugin_build}}"
fi
} always {
if [[ "$?" != 0 ]]; then
_zplg_error "an error occured while loading $plugin_id"
fi
}
# }}}
}
# helper functions for plugin configuration {{{
# Simplifies modification of path variables (path/fpath/manpath etc) in
# after_load and before_load hooks.
plugin-cfg-path() {
if (( $# < 2 )); then
_zplg_error "usage: $0 <var_name> prepend|append <value...>"
return 1
fi
if [[ -z "$plugin_dir" ]]; then
_zplg_error "this function is intended to be used in after_load or before_load hooks"
return 1
fi
local var_name="$1" operator="$2"; shift 2; local values=("$@")
if [[ "$var_name" != *path || "${(Pt)var_name}" != array* ]]; then
_zplg_error "unknown path variable $var_name"
return 1
fi
case "$operator" in
prepend) eval "$var_name=(\"\$plugin_dir/\"\${^values} \${$var_name[@]})" ;;
append) eval "$var_name=(\${$var_name[@]} \"\$plugin_dir/\"\${^values})" ;;
*) _zplg_error "unknown $0 operator $operator"
esac
}
# }}}
# Exits with success code 0 if the plugin is loaded, otherwise exits with error
# code 1. To be used in `if` statements.
_zplg_is_plugin_loaded() {
local plugin_id="$1"
# (ie) are subscript flags:
# - i returns index of the value (reverse subscripting) in the square
# brackets (subscript)
# - e disables patterns matching, so plain string matching is used instead
# unlike normal programming languages, if the value is not found an index
# greater than the length of the array is returned
(( ${ZPLG_LOADED_PLUGINS[(ie)$plugin_id]} <= ${#ZPLG_LOADED_PLUGINS} ))
}
# Useful commands for managing plugins {{{
# I chose to make each of these commands as a separate function because:
# 1. automatic completion
# 2. automatic correction
# 3. hyphen is a single keystroke, just like space, so `zplg-list` is not
# hard to type fast.
# Prints IDs of all loaded plugins.
zplg-list() {
# (F) modifier joins an array with newlines
print "${(F)ZPLG_LOADED_PLUGINS}"
}
# Upgrades all plugins if no arguments are given, otherwise upgrades plugins by
# their IDs.
zplg-upgrade() {
local plugin_ids_var
if (( $# > 0 )); then
plugin_ids_var="@"
else
plugin_ids_var="ZPLG_LOADED_PLUGINS"
fi
local plugin_id plugin_url plugin_from plugin_dir; local -a plugin_build
# for description of the (P) modifier see `_zplg_run_commands`
for plugin_id in "${(@P)plugin_ids_var}"; do
if ! _zplg_is_plugin_loaded "$plugin_id"; then
_zplg_error "unknown plugin $plugin_id"
return 1
fi
plugin_url="${ZPLG_LOADED_PLUGIN_URLS[$plugin_id]}"
plugin_from="${ZPLG_LOADED_PLUGIN_SOURCES[$plugin_id]}"
plugin_dir="$_ZPLG_PLUGINS_DIR/$plugin_id"
_zplg_log "upgrading $plugin_id"
_zplg_source_"$plugin_from"_upgrade "$plugin_url" "$plugin_dir" || return "$?"
if (( ${+ZPLG_LOADED_PLUGIN_BUILD_CMDS[$plugin_id]} )); then
# TERRIBLE HACK continued: this monstrosity is used to "decode" build
# commands. See ending of the `plugin` function for "encoding" procedure.
# First, I get encoded string. Then with the (z) modifier I split it into
# array taking into account quoting. Then with the (Q) modifier I unquote
# every value.
plugin_build=("${(@Q)${(z)${ZPLG_LOADED_PLUGIN_BUILD_CMDS[$plugin_id]}}}")
_zplg_log "building $plugin_id"
( cd "$plugin_dir" && _zplg_run_commands plugin_build ) || return "$?"
fi
done
}
# Reinstall plugins by IDs.
zplg-reinstall() {
if (( $# == 0 )); then
_zplg_error "usage: $0 <plugin...>"
return 1
fi
local plugin_id plugin_url plugin_from plugin_dir; local -a plugin_build
for plugin_id in "$@"; do
if ! _zplg_is_plugin_loaded "$plugin_id"; then
_zplg_error "unknown plugin $plugin_id"
return 1
fi
plugin_url="${ZPLG_LOADED_PLUGIN_URLS[$plugin_id]}"
plugin_from="${ZPLG_LOADED_PLUGIN_SOURCES[$plugin_id]}"
plugin_dir="$_ZPLG_PLUGINS_DIR/$plugin_id"
_zplg_log "removing $plugin_id"
rm -rf "$plugin_dir"
_zplg_log "downloading $plugin_id"
_zplg_source_"$plugin_from"_download "$plugin_url" "$plugin_dir" || return "$?"
if (( ${+ZPLG_LOADED_PLUGIN_BUILD_CMDS[$plugin_id]} )); then
# for description of this terrible hack see the ending of the
# `zplg-upgrade` function
plugin_build=("${(@Q)${(z)${ZPLG_LOADED_PLUGIN_BUILD_CMDS[$plugin_id]}}}")
_zplg_log "building $plugin_id"
( cd "$plugin_dir" && _zplg_run_commands plugin_build ) || return "$?"
fi
done
}
# Clears directories of plugins by their IDs.
zplg-purge() {
if (( $# == 0 )); then
_zplg_error "usage: $0 <plugin...>"
return 1
fi
for plugin_id in "$@"; do
if ! _zplg_is_plugin_loaded "$plugin_id"; then
_zplg_error "unknown plugin $plugin_id"
return 1
fi
local plugin_dir="$_ZPLG_PLUGINS_DIR/$plugin_id"
_zplg_log "removing $plugin_id"
rm -rf "$plugin_dir"
done
}
# }}}