[emscripten] build with emscripten

.gitignore

@@ -7,3 +7,9 @@ __pycache__/
 /experiments/issue*/data/
 /misc/.tox/
 /misc/autodoc/downward-xmlrpc.secret
+*.cc.o
+/src/bin
+/src/CMakeFiles
+/src/Makefile
+/src/search/Makefile
+/src/search/CMakeFiles

src/CMakeLists.txt

@@ -40,7 +40,13 @@ include(FastDownwardMacros)
 
 fast_downward_default_to_release_build()
 project(fast-downward)
-fast_downward_report_bitwidth()
+if (EMSCRIPTEN)
+	MESSAGE("Configuring emscripten build.")
+else()
+	MESSAGE("Configuring native build.")
+	fast_downward_report_bitwidth()
+endif()
+
 # Due to a bug in cmake, configuration types are only set up correctly on the second cmake run.
 # This means that cmake has to be called twice for multi-config generators like Visual Studio.
 fast_downward_set_configuration_types()

src/cmake_modules/FastDownwardMacros.cmake

@@ -66,7 +66,9 @@ macro(fast_downward_set_compiler_flags)
 endmacro()
 
 macro(fast_downward_set_linker_flags)
-    if(UNIX)
+    if (EMSCRIPTEN)
+        set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -s ALLOW_MEMORY_GROWTH=1 --bind -s INVOKE_RUN=0 -s EXTRA_EXPORTED_RUNTIME_METHODS=['callMain']")
+    elseif(UNIX)
         set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -g")
     endif()
 endmacro()

src/javascript/search/README.md

@@ -0,0 +1,33 @@
+# Planning in the browser
+- Tested with emscripten version 2.0.8
+
+## Building the JS+WASM files:
+
+- make sure the emscripten sdk is installed and executables (mainly em++ and emcmake) are on the PATH. 
+
+- cmake needs to be installed 
+
+- you can use the `./configure_cmake.sh` file to configure cmake for an emscripten or native build using `./configure_cmake.sh emscripten` or `./configure_cmake.sh native` respectively.
+
+- use above mentioned to switch to emscripten build type, this executes `cmake` with custom parameters: `CMAKE_CXX_COMPILER=em++` and `EMSCRIPTEN=1`.
+
+- build the WebAssembly and Javascript files using `make` in the `/src` directory, output files can be found in `src/bin`.
+
+- as the `CMAKE_CXX_COMPILER` stays to be `em++`, you need to change it back in case you want to build the native version. The configuration script assums `g++` to be your default native compiler.
+
+## Using the JS+WASM files:
+
+- instead of using STDIN to pass the translated `output.sas` file to the program, we added the option to use the `--input` argument, which takes a file handle and treats it as input stream
+
+- thus, before calling the search, but after the Module was loaded, we need to save the translated output file on the browsers virtual filesystem
+
+- There are multiple ways to do this, an example however can be found under `usage_example.js` loaded at the end of `index.html`. The example assumes `output.sas`, `downward.js` as well as `downward.wasm` files in the working directory
+
+- the `runFastDownward()` function executes the example. Make sure to have added the necessary files in beforehand.
+
+## Debug
+
+- you can use the included function `Module.getExceptionMessage(pointer)` to get a more detailed exception message in case you need it for debugging:
+in the `downward.js` file, you need to replace the original exception logging by the result of `Module.getExceptionMessage(pointer)`. I.e. replace `err('exception thrown: ' + toLog);` by 
+`err('exception thrown: ' + Module.getExceptionMessage(toLog));`
+`

src/javascript/search/configure_cmake.sh

@@ -0,0 +1,31 @@
+#!/bin/sh
+cd "$(dirname "$0")/../../"
+if [ $# -eq 0 ]; then
+    echo "No arguments provided"
+    echo "Run either with "
+    echo "./configure_cmake.sh emscripten"
+    echo "or "
+    echo "./configure_cmake.sh native"
+    exit 1
+fi
+
+if [ "$1" = "emscripten" ];
+then 
+	echo 'setting cmake settings for building with emscripten' 
+    # in case of switch we need to execute twice, as cmake notices changed variables and executes itself again but fails as EMSCRIPTEN variable is not passed
+	emcmake cmake -DEMSCRIPTEN=True -DCMAKE_CXX_COMPILER=$(which em++) .
+    emcmake cmake -DEMSCRIPTEN=True -DCMAKE_CXX_COMPILER=$(which em++) .
+elif [ "$1" = "native" ];
+then
+	echo "setting cmake settings for native build"
+    # in case of switch we need to execute twice, as cmake notices changed variables and executes itself again but fails as EMSCRIPTEN variable is not passed
+	cmake -DEMSCRIPTEN=False -DCMAKE_CXX_COMPILER=$(which g++) .
+    cmake -DEMSCRIPTEN=False -DCMAKE_CXX_COMPILER=$(which g++) .
+else 
+    echo "argument not recognized"
+    echo "Run either with "
+    echo "./configure_cmake.sh emscripten"
+    echo "or "
+    echo "./configure_cmake.sh native"
+    exit 1
+fi

src/javascript/search/index.html

@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+
+    <title>Planning in the browser</title>
+</head>
+<body>
+<h1>Planning in the browser</h1>
+</body>
+
+<script type="text/javascript" src='usage_example.js'></script>
+</html>

src/javascript/search/usage_example.js

@@ -0,0 +1,39 @@
+FILE_WASM='downward.wasm'
+FILE_JAVASCRIPT='downward.js'
+PATH_TO_INPUT='output.sas'
+
+// Load the javascript file containing the Downward module
+downwardscript = document.createElement('script');
+downwardscript.src = FILE_JAVASCRIPT;
+downwardscript.onload = function() {
+    // Fetch input data via XHR and save it on the browsers virtual filesystem once it is loaded
+    console.log("Fetching data from " + PATH_TO_INPUT);
+    var inputURL = PATH_TO_INPUT;
+    var inputXHR = new XMLHttpRequest();
+    inputXHR.open('GET', inputURL, true);
+    inputXHR.responseType = 'text';
+    inputXHR.onload = function() {
+        if (inputXHR.status === 200 || inputXHR.status === 0) {
+            let data = new TextEncoder().encode(inputXHR.response);
+            let stream = FS.open('output.sas', 'w+');
+            FS.write(stream, data, 0, data.length, 0);
+            FS.close(stream);
+            console.log('wrote to' + PATH_TO_INPUT);
+        }
+    }
+    inputXHR.send();
+}
+document.body.appendChild(downwardscript);
+
+// function to start the actual program
+function runFastDownward() {
+// define parameters and split them to a list
+    let parameter_string = "--search astar(lmcut()) --input output.sas"
+	let parameter_list = parameter_string.split(" ")
+
+    Module.callMain(parameter_list);
+
+// results are saved on the virtual filesystem in the browser
+    let result = new TextDecoder().decode(FS.readFile('sas_plan'));
+    console.log(result);
+}

src/javascript/translator/README.md

@@ -0,0 +1,19 @@
+# Translator in the browser 
+We offer to build the translator as python wheel.
+This is done by executing the `setup.py` script.
+**Pyodide** can then be used to load the python wheel in the browser.
+
+## How to execute the translator using pyodide
+The following steps are exemplarily presented in `usage_example.html` and `usage_example.js`
+- you need to serve the JS file through a server; python can be used for that: `python -m http.server`
+- in your javascript file, load the current pyodide version
+- load pyodide's *micropip* package
+- load the *.pddl* files into two javascript strings
+- use micropip to install the translator-wheel created by `setup.py` into the python environment
+- store the pddl strings to the browser's virtual filesystem using python
+- import and execute the translator in python:
+	```Python
+from translator.translate import run
+run(["domain.pddl", "problem.pddl", "--sas-file", "output.sas"])
+	```
+- load the result from the python environment to the javascript environment for further use

src/javascript/translator/exampleFiles/domain.pddl

@@ -0,0 +1,34 @@
+(define (domain gripper-strips)
+   (:predicates (room ?r)
+		(ball ?b)
+		(gripper ?g)
+		(at-robby ?r)
+		(at ?b ?r)
+		(free ?g)
+		(carry ?o ?g))
+
+   (:action move
+       :parameters  (?from ?to)
+       :precondition (and  (room ?from) (room ?to) (at-robby ?from))
+       :effect (and  (at-robby ?to)
+		     (not (at-robby ?from))))
+
+
+
+   (:action pick
+       :parameters (?obj ?room ?gripper)
+       :precondition  (and  (ball ?obj) (room ?room) (gripper ?gripper)
+			    (at ?obj ?room) (at-robby ?room) (free ?gripper))
+       :effect (and (carry ?obj ?gripper)
+		    (not (at ?obj ?room)) 
+		    (not (free ?gripper))))
+
+
+   (:action drop
+       :parameters  (?obj  ?room ?gripper)
+       :precondition  (and  (ball ?obj) (room ?room) (gripper ?gripper)
+			    (carry ?obj ?gripper) (at-robby ?room))
+       :effect (and (at ?obj ?room)
+		    (free ?gripper)
+		    (not (carry ?obj ?gripper)))))
+

src/javascript/translator/exampleFiles/problem.pddl

@@ -0,0 +1,22 @@
+(define (problem strips-gripper-x-1)
+   (:domain gripper-strips)
+   (:objects rooma roomb ball4 ball3 ball2 ball1 left right)
+   (:init (room rooma)
+          (room roomb)
+          (ball ball4)
+          (ball ball3)
+          (ball ball2)
+          (ball ball1)
+          (at-robby rooma)
+          (free left)
+          (free right)
+          (at ball4 rooma)
+          (at ball3 rooma)
+          (at ball2 rooma)
+          (at ball1 rooma)
+          (gripper left)
+          (gripper right))
+   (:goal (and (at ball4 roomb)
+               (at ball3 roomb)
+               (at ball2 roomb)
+               (at ball1 roomb))))

src/javascript/translator/setup.py

@@ -0,0 +1,35 @@
+#! /usr/bin/python3
+import os
+import sys
+
+sys.argv.append("bdist_wheel")
+
+home = os.getcwd()
+
+# go to translator root folder
+os.chdir("../../translate")
+
+# setup for bdist_wheel
+from setuptools import setup, find_packages
+setup(
+    name = 'translator',
+    version='1.0',
+    # Use one of the below approach to define package and/or module names:
+
+    #if there are only handful of modules placed in root directory, and no packages/directories exist then can use below syntax
+#     packages=[''], #have to import modules directly in code after installing this wheel, like import mod2 (respective file name in this case is mod2.py) - no direct use of distribution name while importing
+
+    #can list down each package names - no need to keep __init__.py under packages / directories
+    packages=['translator', 'translator/pddl', 'translator/pddl_parser'], #importing is like: from package1 import mod2, or import package1.mod2 as m2
+
+    # this approach automatically finds out all directories (packages) - those must contain a file named __init__.py (can be empty)
+    # packages=find_packages(), #include/exclude arguments take * as wildcard, . for any sub-package names
+)
+
+# move files to home directory and remove unnecessary files
+import shutil
+shutil.rmtree('build/')
+shutil.rmtree('translator.egg-info/')
+for file in os.listdir('dist'):
+    shutil.move('dist/' + file, os.path.join(home, file))
+shutil.rmtree('dist/')

src/javascript/translator/usage_example.html

@@ -0,0 +1,43 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Translator</title>
+    <script src="https://cdn.jsdelivr.net/pyodide/v0.18.1/full/pyodide.js" type="text/javascript"></script>
+    <script src="usage_example.js" type="text/javascript" defer></script>
+</head>
+<body>
+<h1>Translator in the browser</h1>
+Usage example
+<br>
+<hr>
+
+<style>
+    .contentHolder {
+        display: flex;
+    }
+    .contentHolder > div {
+        padding: 0vh 1vw;
+    }
+    .result {
+        padding: 0vh 1vw;   
+    }
+</style>
+<div class=contentHolder>
+    <div class="domain">
+        <h5>Domain:</h5>
+        <code>...</code>
+    </div>
+    <div class="problem">
+        <h5>Problem:</h5>
+        <code>...</code>
+    </div>
+</div>
+<hr>
+
+<div class=result>
+    <code></code>
+</div>
+</body>
+</html>
+