def emscript(in_wasm, out_wasm, outfile_js, memfile, DEBUG):
# Overview:
# * Run wasm-emscripten-finalize to extract metadata and modify the binary
# to use emscripten's wasm<->JS ABI
# * Use the metadata to generate the JS glue that goes with the wasm
if settings.SINGLE_FILE:
# placeholder strings for JS glue, to be replaced with subresource locations in do_binaryen
settings.WASM_BINARY_FILE = '<<< WASM_BINARY_FILE >>>'
else:
# set file locations, so that JS glue can find what it needs
settings.WASM_BINARY_FILE = js_manipulation.escape_for_js_string(
os.path.basename(out_wasm))
metadata = finalize_wasm(in_wasm, out_wasm, memfile, DEBUG)
update_settings_glue(metadata, DEBUG)
if settings.SIDE_MODULE:
if metadata['asmConsts']:
exit_with_error('EM_ASM is not supported in side modules')
if metadata['emJsFuncs']:
exit_with_error('EM_JS is not supported in side modules')
logger.debug('emscript: skipping remaining js glue generation')
return
if DEBUG:
logger.debug('emscript: js compiler glue')
t = time.time()
# memory and global initializers
if settings.RELOCATABLE:
dylink_sec = webassembly.parse_dylink_section(in_wasm)
static_bump = align_memory(dylink_sec.mem_size)
set_memory(static_bump)
logger.debug('stack_base: %d, stack_max: %d, heap_base: %d',
settings.STACK_BASE, settings.STACK_MAX,
settings.HEAP_BASE)
# When building relocatable output (e.g. MAIN_MODULE) the reported table
# size does not include the reserved slot at zero for the null pointer.
# So we need to offset the elements by 1.
if settings.INITIAL_TABLE == -1:
settings.INITIAL_TABLE = dylink_sec.table_size + 1
glue, forwarded_data = compile_settings()
if DEBUG:
logger.debug(' emscript: glue took %s seconds' % (time.time() - t))
t = time.time()
forwarded_json = json.loads(forwarded_data)
pre, post = glue.split('// EMSCRIPTEN_END_FUNCS')
exports = metadata['exports']
if settings.ASYNCIFY:
exports += [
'asyncify_start_unwind', 'asyncify_stop_unwind',
'asyncify_start_rewind', 'asyncify_stop_rewind'
]
report_missing_symbols(forwarded_json['libraryFunctions'])
if not outfile_js:
logger.debug('emscript: skipping remaining js glue generation')
return
if settings.MINIMAL_RUNTIME:
# In MINIMAL_RUNTIME, atinit exists in the postamble part
post = apply_static_code_hooks(forwarded_json, post)
else:
# In regular runtime, atinits etc. exist in the preamble part
pre = apply_static_code_hooks(forwarded_json, pre)
asm_consts = create_asm_consts(metadata)
em_js_funcs = create_em_js(metadata)
asm_const_pairs = ['%s: %s' % (key, value) for key, value in asm_consts]
asm_const_map = 'var ASM_CONSTS = {\n ' + ', \n '.join(
asm_const_pairs) + '\n};\n'
pre = pre.replace('// === Body ===',
('// === Body ===\n\n' + asm_const_map +
'\n'.join(em_js_funcs) + '\n'))
with open(outfile_js, 'w') as out:
out.write(normalize_line_endings(pre))
pre = None
invoke_funcs = metadata['invokeFuncs']
sending = create_sending(invoke_funcs, metadata)
receiving = create_receiving(exports)
if settings.MINIMAL_RUNTIME:
if settings.DECLARE_ASM_MODULE_EXPORTS:
post = compute_minimal_runtime_initializer_and_exports(
post, exports, receiving)
receiving = ''
module = create_module(sending, receiving, invoke_funcs, metadata)
write_output_file(out, module)
out.write(normalize_line_endings(post))
module = None
def generate_js(data_target, data_files, metadata):
# emcc will add this to the output itself, so it is only needed for
# standalone calls
if options.from_emcc:
ret = ''
else:
ret = '''
var Module = typeof %(EXPORT_NAME)s !== 'undefined' ? %(EXPORT_NAME)s : {};\n''' % {
"EXPORT_NAME": options.export_name
}
ret += '''
if (!Module.expectedDataFileDownloads) {
Module.expectedDataFileDownloads = 0;
}
Module.expectedDataFileDownloads++;
(function() {
// When running as a pthread, FS operations are proxied to the main thread, so we don't need to
// fetch the .data bundle on the worker
if (Module['ENVIRONMENT_IS_PTHREAD']) return;
var loadPackage = function(metadata) {\n'''
code = '''
function assert(check, msg) {
if (!check) throw msg + new Error().stack;
}\n'''
# Set up folders
partial_dirs = []
for file_ in data_files:
dirname = os.path.dirname(file_.dstpath)
dirname = dirname.lstrip(
'/') # absolute paths start with '/', remove that
if dirname != '':
parts = dirname.split('/')
for i in range(len(parts)):
partial = '/'.join(parts[:i + 1])
if partial not in partial_dirs:
code += (
'''Module['FS_createPath'](%s, %s, true, true);\n''' %
(json.dumps('/' + '/'.join(parts[:i])),
json.dumps(parts[i])))
partial_dirs.append(partial)
if options.has_preloaded:
# Bundle all datafiles into one archive. Avoids doing lots of simultaneous
# XHRs which has overhead.
start = 0
with open(data_target, 'wb') as data:
for file_ in data_files:
file_.data_start = start
with open(file_.srcpath, 'rb') as f:
curr = f.read()
file_.data_end = start + len(curr)
if AV_WORKAROUND:
curr += '\x00'
start += len(curr)
data.write(curr)
if start > 256 * 1024 * 1024:
err('warning: file packager is creating an asset bundle of %d MB. '
'this is very large, and browsers might have trouble loading it. '
'see https://hacks.mozilla.org/2015/02/synchronous-execution-and-filesystem-access-in-emscripten/'
% (start / (1024 * 1024)))
create_preloaded = '''
Module['FS_createPreloadedFile'](this.name, null, byteArray, true, true, function() {
Module['removeRunDependency']('fp ' + that.name);
}, function() {
if (that.audio) {
Module['removeRunDependency']('fp ' + that.name); // workaround for chromium bug 124926 (still no audio with this, but at least we don't hang)
} else {
err('Preloading file ' + that.name + ' failed');
}
}, false, true); // canOwn this data in the filesystem, it is a slide into the heap that will never change\n'''
create_data = '''// canOwn this data in the filesystem, it is a slide into the heap that will never change
Module['FS_createDataFile'](this.name, null, byteArray, true, true, true);
Module['removeRunDependency']('fp ' + that.name);'''
if not options.lz4:
# Data requests - for getting a block of data out of the big archive - have
# a similar API to XHRs
code += '''
/** @constructor */
function DataRequest(start, end, audio) {
this.start = start;
this.end = end;
this.audio = audio;
}
DataRequest.prototype = {
requests: {},
open: function(mode, name) {
this.name = name;
this.requests[name] = this;
Module['addRunDependency']('fp ' + this.name);
},
send: function() {},
onload: function() {
var byteArray = this.byteArray.subarray(this.start, this.end);
this.finish(byteArray);
},
finish: function(byteArray) {
var that = this;
%s
this.requests[this.name] = null;
}
};
var files = metadata['files'];
for (var i = 0; i < files.length; ++i) {
new DataRequest(files[i]['start'], files[i]['end'], files[i]['audio'] || 0).open('GET', files[i]['filename']);
}\n''' % (create_preloaded
if options.use_preload_plugins else create_data)
if options.has_embedded and not options.obj_output:
err('--obj-output is recommended when using --embed. This outputs an object file for linking directly into your application is more effecient than JS encoding'
)
for counter, file_ in enumerate(data_files):
filename = file_.dstpath
dirname = os.path.dirname(filename)
basename = os.path.basename(filename)
if file_.mode == 'embed':
if not options.obj_output:
# Embed (only needed when not generating object file output)
data = base64_encode(utils.read_binary(file_.srcpath))
code += " var fileData%d = '%s';\n" % (counter, data)
# canOwn this data in the filesystem (i.e. there is no need to create a copy in the FS layer).
code += (
" Module['FS_createDataFile']('%s', '%s', decodeBase64(fileData%d), true, true, true);\n"
% (dirname, basename, counter))
elif file_.mode == 'preload':
# Preload
metadata_el = {
'filename': file_.dstpath,
'start': file_.data_start,
'end': file_.data_end,
}
if filename[-4:] in AUDIO_SUFFIXES:
metadata_el['audio'] = 1
metadata['files'].append(metadata_el)
else:
assert 0
if options.has_preloaded:
if not options.lz4:
# Get the big archive and split it up
use_data = '''// Reuse the bytearray from the XHR as the source for file reads.
DataRequest.prototype.byteArray = byteArray;
var files = metadata['files'];
for (var i = 0; i < files.length; ++i) {
DataRequest.prototype.requests[files[i].filename].onload();
}'''
use_data += (
" Module['removeRunDependency']('datafile_%s');\n" %
js_manipulation.escape_for_js_string(data_target))
else:
# LZ4FS usage
temp = data_target + '.orig'
shutil.move(data_target, temp)
meta = shared.run_js_tool(
utils.path_from_root('tools/lz4-compress.js'), [
utils.path_from_root('third_party/mini-lz4.js'), temp,
data_target
],
stdout=PIPE)
os.unlink(temp)
use_data = '''var compressedData = %s;
compressedData['data'] = byteArray;
assert(typeof Module['LZ4'] === 'object', 'LZ4 not present - was your app build with -sLZ4?');
Module['LZ4'].loadPackage({ 'metadata': metadata, 'compressedData': compressedData }, %s);
Module['removeRunDependency']('datafile_%s');''' % (
meta, "true" if options.use_preload_plugins else "false",
js_manipulation.escape_for_js_string(data_target))
package_name = data_target
remote_package_size = os.path.getsize(package_name)
remote_package_name = os.path.basename(package_name)
ret += '''
var PACKAGE_PATH = '';
if (typeof window === 'object') {
PACKAGE_PATH = window['encodeURIComponent'](window.location.pathname.toString().substring(0, window.location.pathname.toString().lastIndexOf('/')) + '/');
} else if (typeof process === 'undefined' && typeof location !== 'undefined') {
// web worker
PACKAGE_PATH = encodeURIComponent(location.pathname.toString().substring(0, location.pathname.toString().lastIndexOf('/')) + '/');
}
var PACKAGE_NAME = '%s';
var REMOTE_PACKAGE_BASE = '%s';
if (typeof Module['locateFilePackage'] === 'function' && !Module['locateFile']) {
Module['locateFile'] = Module['locateFilePackage'];
err('warning: you defined Module.locateFilePackage, that has been renamed to Module.locateFile (using your locateFilePackage for now)');
}
var REMOTE_PACKAGE_NAME = Module['locateFile'] ? Module['locateFile'](REMOTE_PACKAGE_BASE, '') : REMOTE_PACKAGE_BASE;\n''' % (
js_manipulation.escape_for_js_string(data_target),
js_manipulation.escape_for_js_string(remote_package_name))
metadata['remote_package_size'] = remote_package_size
ret += '''var REMOTE_PACKAGE_SIZE = metadata['remote_package_size'];\n'''
if options.use_preload_cache:
# Set the id to a hash of the preloaded data, so that caches survive over multiple builds
# if the data has not changed.
data = utils.read_binary(data_target)
package_uuid = 'sha256-' + hashlib.sha256(data).hexdigest()
metadata['package_uuid'] = str(package_uuid)
code += r'''
var PACKAGE_UUID = metadata['package_uuid'];
var indexedDB;
if (typeof window === 'object') {
indexedDB = window.indexedDB || window.mozIndexedDB || window.webkitIndexedDB || window.msIndexedDB;
} else if (typeof location !== 'undefined') {
// worker
indexedDB = self.indexedDB;
} else {
throw 'using IndexedDB to cache data can only be done on a web page or in a web worker';
}
var IDB_RO = "readonly";
var IDB_RW = "readwrite";
var DB_NAME = "''' + options.indexeddb_name + '''";
var DB_VERSION = 1;
var METADATA_STORE_NAME = 'METADATA';
var PACKAGE_STORE_NAME = 'PACKAGES';
function openDatabase(callback, errback) {
try {
var openRequest = indexedDB.open(DB_NAME, DB_VERSION);
} catch (e) {
return errback(e);
}
openRequest.onupgradeneeded = function(event) {
var db = /** @type {IDBDatabase} */ (event.target.result);
if (db.objectStoreNames.contains(PACKAGE_STORE_NAME)) {
db.deleteObjectStore(PACKAGE_STORE_NAME);
}
var packages = db.createObjectStore(PACKAGE_STORE_NAME);
if (db.objectStoreNames.contains(METADATA_STORE_NAME)) {
db.deleteObjectStore(METADATA_STORE_NAME);
}
var metadata = db.createObjectStore(METADATA_STORE_NAME);
};
openRequest.onsuccess = function(event) {
var db = /** @type {IDBDatabase} */ (event.target.result);
callback(db);
};
openRequest.onerror = function(error) {
errback(error);
};
};
// This is needed as chromium has a limit on per-entry files in IndexedDB
// https://cs.chromium.org/chromium/src/content/renderer/indexed_db/webidbdatabase_impl.cc?type=cs&sq=package:chromium&g=0&l=177
// https://cs.chromium.org/chromium/src/out/Debug/gen/third_party/blink/public/mojom/indexeddb/indexeddb.mojom.h?type=cs&sq=package:chromium&g=0&l=60
// We set the chunk size to 64MB to stay well-below the limit
var CHUNK_SIZE = 64 * 1024 * 1024;
function cacheRemotePackage(
db,
packageName,
packageData,
packageMeta,
callback,
errback
) {
var transactionPackages = db.transaction([PACKAGE_STORE_NAME], IDB_RW);
var packages = transactionPackages.objectStore(PACKAGE_STORE_NAME);
var chunkSliceStart = 0;
var nextChunkSliceStart = 0;
var chunkCount = Math.ceil(packageData.byteLength / CHUNK_SIZE);
var finishedChunks = 0;
for (var chunkId = 0; chunkId < chunkCount; chunkId++) {
nextChunkSliceStart += CHUNK_SIZE;
var putPackageRequest = packages.put(
packageData.slice(chunkSliceStart, nextChunkSliceStart),
'package/' + packageName + '/' + chunkId
);
chunkSliceStart = nextChunkSliceStart;
putPackageRequest.onsuccess = function(event) {
finishedChunks++;
if (finishedChunks == chunkCount) {
var transaction_metadata = db.transaction(
[METADATA_STORE_NAME],
IDB_RW
);
var metadata = transaction_metadata.objectStore(METADATA_STORE_NAME);
var putMetadataRequest = metadata.put(
{
'uuid': packageMeta.uuid,
'chunkCount': chunkCount
},
'metadata/' + packageName
);
putMetadataRequest.onsuccess = function(event) {
callback(packageData);
};
putMetadataRequest.onerror = function(error) {
errback(error);
};
}
};
putPackageRequest.onerror = function(error) {
errback(error);
};
}
}
/* Check if there's a cached package, and if so whether it's the latest available */
function checkCachedPackage(db, packageName, callback, errback) {
var transaction = db.transaction([METADATA_STORE_NAME], IDB_RO);
var metadata = transaction.objectStore(METADATA_STORE_NAME);
var getRequest = metadata.get('metadata/' + packageName);
getRequest.onsuccess = function(event) {
var result = event.target.result;
if (!result) {
return callback(false, null);
} else {
return callback(PACKAGE_UUID === result['uuid'], result);
}
};
getRequest.onerror = function(error) {
errback(error);
};
}
function fetchCachedPackage(db, packageName, metadata, callback, errback) {
var transaction = db.transaction([PACKAGE_STORE_NAME], IDB_RO);
var packages = transaction.objectStore(PACKAGE_STORE_NAME);
var chunksDone = 0;
var totalSize = 0;
var chunkCount = metadata['chunkCount'];
var chunks = new Array(chunkCount);
for (var chunkId = 0; chunkId < chunkCount; chunkId++) {
var getRequest = packages.get('package/' + packageName + '/' + chunkId);
getRequest.onsuccess = function(event) {
// If there's only 1 chunk, there's nothing to concatenate it with so we can just return it now
if (chunkCount == 1) {
callback(event.target.result);
} else {
chunksDone++;
totalSize += event.target.result.byteLength;
chunks.push(event.target.result);
if (chunksDone == chunkCount) {
if (chunksDone == 1) {
callback(event.target.result);
} else {
var tempTyped = new Uint8Array(totalSize);
var byteOffset = 0;
for (var chunkId in chunks) {
var buffer = chunks[chunkId];
tempTyped.set(new Uint8Array(buffer), byteOffset);
byteOffset += buffer.byteLength;
buffer = undefined;
}
chunks = undefined;
callback(tempTyped.buffer);
tempTyped = undefined;
}
}
}
};
getRequest.onerror = function(error) {
errback(error);
};
}
}\n'''
# add Node.js support code, if necessary
node_support_code = ''
if options.support_node:
node_support_code = '''
if (typeof process === 'object' && typeof process.versions === 'object' && typeof process.versions.node === 'string') {
require('fs').readFile(packageName, function(err, contents) {
if (err) {
errback(err);
} else {
callback(contents.buffer);
}
});
return;
}'''.strip()
ret += '''
function fetchRemotePackage(packageName, packageSize, callback, errback) {
%(node_support_code)s
var xhr = new XMLHttpRequest();
xhr.open('GET', packageName, true);
xhr.responseType = 'arraybuffer';
xhr.onprogress = function(event) {
var url = packageName;
var size = packageSize;
if (event.total) size = event.total;
if (event.loaded) {
if (!xhr.addedTotal) {
xhr.addedTotal = true;
if (!Module.dataFileDownloads) Module.dataFileDownloads = {};
Module.dataFileDownloads[url] = {
loaded: event.loaded,
total: size
};
} else {
Module.dataFileDownloads[url].loaded = event.loaded;
}
var total = 0;
var loaded = 0;
var num = 0;
for (var download in Module.dataFileDownloads) {
var data = Module.dataFileDownloads[download];
total += data.total;
loaded += data.loaded;
num++;
}
total = Math.ceil(total * Module.expectedDataFileDownloads/num);
if (Module['setStatus']) Module['setStatus']('Downloading data... (' + loaded + '/' + total + ')');
} else if (!Module.dataFileDownloads) {
if (Module['setStatus']) Module['setStatus']('Downloading data...');
}
};
xhr.onerror = function(event) {
throw new Error("NetworkError for: " + packageName);
}
xhr.onload = function(event) {
if (xhr.status == 200 || xhr.status == 304 || xhr.status == 206 || (xhr.status == 0 && xhr.response)) { // file URLs can return 0
var packageData = xhr.response;
callback(packageData);
} else {
throw new Error(xhr.statusText + " : " + xhr.responseURL);
}
};
xhr.send(null);
};
function handleError(error) {
console.error('package error:', error);
};\n''' % {
'node_support_code': node_support_code
}
code += '''
function processPackageData(arrayBuffer) {
assert(arrayBuffer, 'Loading data file failed.');
assert(arrayBuffer instanceof ArrayBuffer, 'bad input to processPackageData');
var byteArray = new Uint8Array(arrayBuffer);
var curr;
%s
};
Module['addRunDependency']('datafile_%s');\n''' % (
use_data, js_manipulation.escape_for_js_string(data_target))
# use basename because from the browser's point of view,
# we need to find the datafile in the same dir as the html file
code += '''
if (!Module.preloadResults) Module.preloadResults = {};\n'''
if options.use_preload_cache:
code += '''
function preloadFallback(error) {
console.error(error);
console.error('falling back to default preload behavior');
fetchRemotePackage(REMOTE_PACKAGE_NAME, REMOTE_PACKAGE_SIZE, processPackageData, handleError);
};
openDatabase(
function(db) {
checkCachedPackage(db, PACKAGE_PATH + PACKAGE_NAME,
function(useCached, metadata) {
Module.preloadResults[PACKAGE_NAME] = {fromCache: useCached};
if (useCached) {
fetchCachedPackage(db, PACKAGE_PATH + PACKAGE_NAME, metadata, processPackageData, preloadFallback);
} else {
fetchRemotePackage(REMOTE_PACKAGE_NAME, REMOTE_PACKAGE_SIZE,
function(packageData) {
cacheRemotePackage(db, PACKAGE_PATH + PACKAGE_NAME, packageData, {uuid:PACKAGE_UUID}, processPackageData,
function(error) {
console.error(error);
processPackageData(packageData);
});
}
, preloadFallback);
}
}
, preloadFallback);
}
, preloadFallback);
if (Module['setStatus']) Module['setStatus']('Downloading...');\n'''
else:
# Not using preload cache, so we might as well start the xhr ASAP,
# potentially before JS parsing of the main codebase if it's after us.
# Only tricky bit is the fetch is async, but also when runWithFS is called
# is async, so we handle both orderings.
ret += '''
var fetchedCallback = null;
var fetched = Module['getPreloadedPackage'] ? Module['getPreloadedPackage'](REMOTE_PACKAGE_NAME, REMOTE_PACKAGE_SIZE) : null;
if (!fetched) fetchRemotePackage(REMOTE_PACKAGE_NAME, REMOTE_PACKAGE_SIZE, function(data) {
if (fetchedCallback) {
fetchedCallback(data);
fetchedCallback = null;
} else {
fetched = data;
}
}, handleError);\n'''
code += '''
Module.preloadResults[PACKAGE_NAME] = {fromCache: false};
if (fetched) {
processPackageData(fetched);
fetched = null;
} else {
fetchedCallback = processPackageData;
}\n'''
ret += '''
function runWithFS() {\n'''
ret += code
ret += '''
}
if (Module['calledRun']) {
runWithFS();
} else {
if (!Module['preRun']) Module['preRun'] = [];
Module["preRun"].push(runWithFS); // FS is not initialized yet, wait for it
}\n'''
if options.separate_metadata:
_metadata_template = '''
Module['removeRunDependency']('%(metadata_file)s');
}
function runMetaWithFS() {
Module['addRunDependency']('%(metadata_file)s');
var REMOTE_METADATA_NAME = Module['locateFile'] ? Module['locateFile']('%(metadata_file)s', '') : '%(metadata_file)s';
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
if (xhr.readyState === 4 && xhr.status === 200) {
loadPackage(JSON.parse(xhr.responseText));
}
}
xhr.open('GET', REMOTE_METADATA_NAME, true);
xhr.overrideMimeType('application/json');
xhr.send(null);
}
if (Module['calledRun']) {
runMetaWithFS();
} else {
if (!Module['preRun']) Module['preRun'] = [];
Module["preRun"].push(runMetaWithFS);
}\n''' % {
'metadata_file': os.path.basename(options.jsoutput + '.metadata')
}
else:
_metadata_template = '''
}
loadPackage(%s);\n''' % json.dumps(metadata)
ret += '''%s
})();\n''' % _metadata_template
return ret
def emscript(in_wasm, out_wasm, outfile_js, memfile):
# Overview:
# * Run wasm-emscripten-finalize to extract metadata and modify the binary
# to use emscripten's wasm<->JS ABI
# * Use the metadata to generate the JS glue that goes with the wasm
if settings.SINGLE_FILE:
# placeholder strings for JS glue, to be replaced with subresource locations in do_binaryen
settings.WASM_BINARY_FILE = '<<< WASM_BINARY_FILE >>>'
else:
# set file locations, so that JS glue can find what it needs
settings.WASM_BINARY_FILE = js_manipulation.escape_for_js_string(
os.path.basename(out_wasm))
metadata = finalize_wasm(in_wasm, out_wasm, memfile)
update_settings_glue(out_wasm, metadata)
if not settings.WASM_BIGINT and metadata['emJsFuncs']:
module = webassembly.Module(in_wasm)
types = module.get_types()
import_map = {}
for imp in module.get_imports():
import_map[imp.field] = imp
for em_js_func, raw in metadata.get('emJsFuncs', {}).items():
c_sig = raw.split('<::>')[0].strip('()')
if not c_sig or c_sig == 'void':
c_sig = []
else:
c_sig = c_sig.split(',')
if em_js_func in import_map:
imp = import_map[em_js_func]
assert (imp.kind == webassembly.ExternType.FUNC)
signature = types[imp.type]
if len(signature.params) != len(c_sig):
diagnostics.warning(
'em-js-i64',
'using 64-bit arguments in EM_JS function without WASM_BIGINT is not yet fully supported: `%s` (%s, %s)',
em_js_func, c_sig, signature.params)
if settings.SIDE_MODULE:
if metadata['asmConsts']:
exit_with_error('EM_ASM is not supported in side modules')
if metadata['emJsFuncs']:
exit_with_error('EM_JS is not supported in side modules')
logger.debug('emscript: skipping remaining js glue generation')
return
if DEBUG:
logger.debug('emscript: js compiler glue')
t = time.time()
# memory and global initializers
if settings.RELOCATABLE:
dylink_sec = webassembly.parse_dylink_section(in_wasm)
static_bump = align_memory(dylink_sec.mem_size)
set_memory(static_bump)
logger.debug('stack_base: %d, stack_max: %d, heap_base: %d',
settings.STACK_BASE, settings.STACK_MAX,
settings.HEAP_BASE)
# When building relocatable output (e.g. MAIN_MODULE) the reported table
# size does not include the reserved slot at zero for the null pointer.
# So we need to offset the elements by 1.
if settings.INITIAL_TABLE == -1:
settings.INITIAL_TABLE = dylink_sec.table_size + 1
if settings.ASYNCIFY:
metadata['globalImports'] += [
'__asyncify_state', '__asyncify_data'
]
invoke_funcs = metadata['invokeFuncs']
if invoke_funcs:
settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$getWasmTableEntry']
glue, forwarded_data = compile_settings()
if DEBUG:
logger.debug(' emscript: glue took %s seconds' % (time.time() - t))
t = time.time()
forwarded_json = json.loads(forwarded_data)
if forwarded_json['warnings']:
diagnostics.warning('js-compiler',
'warnings in JS library compilation')
pre, post = glue.split('// EMSCRIPTEN_END_FUNCS')
if settings.ASSERTIONS:
pre += "function checkIncomingModuleAPI() {\n"
for sym in settings.ALL_INCOMING_MODULE_JS_API:
if sym not in settings.INCOMING_MODULE_JS_API:
pre += f" ignoredModuleProp('{sym}');\n"
pre += "}\n"
exports = metadata['exports']
if settings.ASYNCIFY:
exports += [
'asyncify_start_unwind', 'asyncify_stop_unwind',
'asyncify_start_rewind', 'asyncify_stop_rewind'
]
report_missing_symbols(forwarded_json['librarySymbols'])
if not outfile_js:
logger.debug('emscript: skipping remaining js glue generation')
return
if settings.MINIMAL_RUNTIME:
# In MINIMAL_RUNTIME, atinit exists in the postamble part
post = apply_static_code_hooks(forwarded_json, post)
else:
# In regular runtime, atinits etc. exist in the preamble part
pre = apply_static_code_hooks(forwarded_json, pre)
asm_consts = create_asm_consts(metadata)
em_js_funcs = create_em_js(metadata)
asm_const_pairs = ['%s: %s' % (key, value) for key, value in asm_consts]
asm_const_map = 'var ASM_CONSTS = {\n ' + ', \n '.join(
asm_const_pairs) + '\n};\n'
pre = pre.replace('// === Body ===',
('// === Body ===\n\n' + asm_const_map +
'\n'.join(em_js_funcs) + '\n'))
with open(outfile_js, 'w', encoding='utf-8') as out:
out.write(normalize_line_endings(pre))
pre = None
sending = create_sending(invoke_funcs, metadata)
receiving = create_receiving(exports)
if settings.MINIMAL_RUNTIME:
if settings.DECLARE_ASM_MODULE_EXPORTS:
post = compute_minimal_runtime_initializer_and_exports(
post, exports, receiving)
receiving = ''
module = create_module(sending, receiving, invoke_funcs, metadata)
write_output_file(out, module)
out.write(normalize_line_endings(post))
module = None
def main():
data_files = []
export_name = 'Module'
leading = ''
has_preloaded = False
plugins = []
jsoutput = None
from_emcc = False
force = True
# If set to True, IndexedDB (IDBFS in library_idbfs.js) is used to locally
# cache VFS XHR so that subsequent page loads can read the data from the
# offline cache instead.
use_preload_cache = False
indexeddb_name = 'EM_PRELOAD_CACHE'
# If set to True, the package metadata is stored separately from js-output
# file which makes js-output file immutable to the package content changes.
# If set to False, the package metadata is stored inside the js-output file
# which makes js-output file to mutate on each invocation of this packager tool.
separate_metadata = False
lz4 = False
use_preload_plugins = False
support_node = True
for arg in sys.argv[2:]:
if arg == '--preload':
has_preloaded = True
leading = 'preload'
elif arg == '--embed':
leading = 'embed'
elif arg == '--exclude':
leading = 'exclude'
elif arg == '--no-force':
force = False
leading = ''
elif arg == '--use-preload-cache':
use_preload_cache = True
leading = ''
elif arg.startswith('--indexedDB-name'):
indexeddb_name = arg.split('=', 1)[1] if '=' in arg else None
leading = ''
elif arg == '--no-heap-copy':
print(
'ignoring legacy flag --no-heap-copy (that is the only mode supported now)'
)
leading = ''
elif arg == '--separate-metadata':
separate_metadata = True
leading = ''
elif arg == '--lz4':
lz4 = True
leading = ''
elif arg == '--use-preload-plugins':
use_preload_plugins = True
leading = ''
elif arg == '--no-node':
support_node = False
leading = ''
elif arg.startswith('--js-output'):
jsoutput = arg.split('=', 1)[1] if '=' in arg else None
leading = ''
elif arg.startswith('--export-name'):
if '=' in arg:
export_name = arg.split('=', 1)[1]
leading = ''
elif arg.startswith('--from-emcc'):
from_emcc = True
leading = ''
elif arg.startswith('--plugin'):
with open(arg.split('=', 1)[1]) as f:
plugin = f.read()
eval(plugin) # should append itself to plugins
leading = ''
elif leading == 'preload' or leading == 'embed':
mode = leading
# position of @ if we're doing 'src@dst'. '__' is used to keep the index
# same with the original if they escaped with '@@'.
at_position = arg.replace('@@', '__').find('@')
# '@@' in input string means there is an actual @ character, a single '@'
# means the 'src@dst' notation.
uses_at_notation = (at_position != -1)
if uses_at_notation:
srcpath = arg[0:at_position].replace('@@',
'@') # split around the @
dstpath = arg[at_position + 1:].replace('@@', '@')
else:
# Use source path as destination path.
srcpath = dstpath = arg.replace('@@', '@')
if os.path.isfile(srcpath) or os.path.isdir(srcpath):
data_files.append({
'srcpath': srcpath,
'dstpath': dstpath,
'mode': mode,
'explicit_dst_path': uses_at_notation
})
else:
print('error: ' + arg + ' does not exist', file=sys.stderr)
return 1
elif leading == 'exclude':
excluded_patterns.append(arg)
else:
print('Unknown parameter:', arg, file=sys.stderr)
return 1
if (not force) and not data_files:
has_preloaded = False
if not has_preloaded or jsoutput is None:
assert not separate_metadata, (
'cannot separate-metadata without both --preloaded files '
'and a specified --js-output')
if not from_emcc:
print(
'Remember to build the main file with -s FORCE_FILESYSTEM=1 '
'so that it includes support for loading this file package',
file=sys.stderr)
if jsoutput and os.path.abspath(jsoutput) == os.path.abspath(data_target):
print('error: TARGET should not be the same value of --js-output',
file=sys.stderr)
return 1
ret = ''
# emcc will add this to the output itself, so it is only needed for
# standalone calls
if not from_emcc:
ret = '''
var Module = typeof %(EXPORT_NAME)s !== 'undefined' ? %(EXPORT_NAME)s : {};
''' % {
"EXPORT_NAME": export_name
}
ret += '''
if (!Module.expectedDataFileDownloads) {
Module.expectedDataFileDownloads = 0;
}
Module.expectedDataFileDownloads++;
(function() {
// When running as a pthread, FS operations are proxied to the main thread, so we don't need to
// fetch the .data bundle on the worker
if (Module['ENVIRONMENT_IS_PTHREAD']) return;
var loadPackage = function(metadata) {
'''
code = '''
function assert(check, msg) {
if (!check) throw msg + new Error().stack;
}
'''
for file_ in data_files:
if not should_ignore(file_['srcpath']):
if os.path.isdir(file_['srcpath']):
add(file_['mode'], file_['srcpath'], file_['dstpath'])
else:
new_data_files.append(file_)
data_files = [
file_ for file_ in new_data_files
if not os.path.isdir(file_['srcpath'])
]
if len(data_files) == 0:
print('Nothing to do!', file=sys.stderr)
sys.exit(1)
# Absolutize paths, and check that they make sense
# os.getcwd() always returns the hard path with any symbolic links resolved,
# even if we cd'd into a symbolic link.
curr_abspath = os.path.abspath(os.getcwd())
for file_ in data_files:
if not file_['explicit_dst_path']:
# This file was not defined with src@dst, so we inferred the destination
# from the source. In that case, we require that the destination not be
# under the current location
path = file_['dstpath']
# Use os.path.realpath to resolve any symbolic links to hard paths,
# to match the structure in curr_abspath.
abspath = os.path.realpath(os.path.abspath(path))
if DEBUG:
print(path, abspath, curr_abspath, file=sys.stderr)
if not abspath.startswith(curr_abspath):
print(
'Error: Embedding "%s" which is below the current directory '
'"%s". This is invalid since the current directory becomes the '
'root that the generated code will see' %
(path, curr_abspath),
file=sys.stderr)
sys.exit(1)
file_['dstpath'] = abspath[len(curr_abspath) + 1:]
if os.path.isabs(path):
print(
'Warning: Embedding an absolute file/directory name "%s" to the '
'virtual filesystem. The file will be made available in the '
'relative path "%s". You can use the explicit syntax '
'--preload-file srcpath@dstpath to explicitly specify the target '
'location the absolute source path should be directed to.'
% (path, file_['dstpath']),
file=sys.stderr)
for file_ in data_files:
# name in the filesystem, native and emulated
file_['dstpath'] = file_['dstpath'].replace(os.path.sep, '/')
# If user has submitted a directory name as the destination but omitted
# the destination filename, use the filename from source file
if file_['dstpath'].endswith('/'):
file_['dstpath'] = file_['dstpath'] + os.path.basename(
file_['srcpath'])
# make destination path always relative to the root
file_['dstpath'] = posixpath.normpath(
os.path.join('/', file_['dstpath']))
if DEBUG:
print('Packaging file "%s" to VFS in path "%s".' %
(file_['srcpath'], file_['dstpath']),
file=sys.stderr)
# Remove duplicates (can occur naively, for example preload dir/, preload dir/subdir/)
seen = {}
def was_seen(name):
if seen.get(name):
return True
seen[name] = 1
return False
data_files = [
file_ for file_ in data_files if not was_seen(file_['dstpath'])
]
if AV_WORKAROUND:
random.shuffle(data_files)
# Apply plugins
for file_ in data_files:
for plugin in plugins:
plugin(file_)
metadata = {'files': []}
# Set up folders
partial_dirs = []
for file_ in data_files:
dirname = os.path.dirname(file_['dstpath'])
dirname = dirname.lstrip(
'/') # absolute paths start with '/', remove that
if dirname != '':
parts = dirname.split('/')
for i in range(len(parts)):
partial = '/'.join(parts[:i + 1])
if partial not in partial_dirs:
code += (
'''Module['FS_createPath'](%s, %s, true, true);\n''' %
(json.dumps('/' + '/'.join(parts[:i])),
json.dumps(parts[i])))
partial_dirs.append(partial)
if has_preloaded:
# Bundle all datafiles into one archive. Avoids doing lots of simultaneous
# XHRs which has overhead.
start = 0
with open(data_target, 'wb') as data:
for file_ in data_files:
file_['data_start'] = start
with open(file_['srcpath'], 'rb') as f:
curr = f.read()
file_['data_end'] = start + len(curr)
if AV_WORKAROUND:
curr += '\x00'
start += len(curr)
data.write(curr)
# TODO: sha256sum on data_target
if start > 256 * 1024 * 1024:
print(
'warning: file packager is creating an asset bundle of %d MB. '
'this is very large, and browsers might have trouble loading it. '
'see https://hacks.mozilla.org/2015/02/synchronous-execution-and-filesystem-access-in-emscripten/'
% (start / (1024 * 1024)),
file=sys.stderr)
create_preloaded = '''
Module['FS_createPreloadedFile'](this.name, null, byteArray, true, true, function() {
Module['removeRunDependency']('fp ' + that.name);
}, function() {
if (that.audio) {
Module['removeRunDependency']('fp ' + that.name); // workaround for chromium bug 124926 (still no audio with this, but at least we don't hang)
} else {
err('Preloading file ' + that.name + ' failed');
}
}, false, true); // canOwn this data in the filesystem, it is a slide into the heap that will never change
'''
create_data = '''
Module['FS_createDataFile'](this.name, null, byteArray, true, true, true); // canOwn this data in the filesystem, it is a slide into the heap that will never change
Module['removeRunDependency']('fp ' + that.name);
'''
if not lz4:
# Data requests - for getting a block of data out of the big archive - have
# a similar API to XHRs
code += '''
/** @constructor */
function DataRequest(start, end, audio) {
this.start = start;
this.end = end;
this.audio = audio;
}
DataRequest.prototype = {
requests: {},
open: function(mode, name) {
this.name = name;
this.requests[name] = this;
Module['addRunDependency']('fp ' + this.name);
},
send: function() {},
onload: function() {
var byteArray = this.byteArray.subarray(this.start, this.end);
this.finish(byteArray);
},
finish: function(byteArray) {
var that = this;
%s
this.requests[this.name] = null;
}
};
%s
''' % (create_preloaded if use_preload_plugins else create_data, '''
var files = metadata['files'];
for (var i = 0; i < files.length; ++i) {
new DataRequest(files[i]['start'], files[i]['end'], files[i]['audio'] || 0).open('GET', files[i]['filename']);
}
''')
counter = 0
for file_ in data_files:
filename = file_['dstpath']
dirname = os.path.dirname(filename)
basename = os.path.basename(filename)
if file_['mode'] == 'embed':
# Embed
data = base64_encode(utils.read_binary(file_['srcpath']))
code += '''var fileData%d = '%s';\n''' % (counter, data)
code += (
'''Module['FS_createDataFile']('%s', '%s', decodeBase64(fileData%d), true, true, false);\n'''
% (dirname, basename, counter))
counter += 1
elif file_['mode'] == 'preload':
# Preload
counter += 1
metadata_el = {
'filename': file_['dstpath'],
'start': file_['data_start'],
'end': file_['data_end'],
}
if filename[-4:] in AUDIO_SUFFIXES:
metadata_el['audio'] = 1
metadata['files'].append(metadata_el)
else:
assert 0
if has_preloaded:
if not lz4:
# Get the big archive and split it up
use_data = '''
// Reuse the bytearray from the XHR as the source for file reads.
DataRequest.prototype.byteArray = byteArray;
'''
use_data += '''
var files = metadata['files'];
for (var i = 0; i < files.length; ++i) {
DataRequest.prototype.requests[files[i].filename].onload();
}
'''
use_data += (
" Module['removeRunDependency']('datafile_%s');\n" %
js_manipulation.escape_for_js_string(data_target))
else:
# LZ4FS usage
temp = data_target + '.orig'
shutil.move(data_target, temp)
meta = shared.run_js_tool(
utils.path_from_root('tools/lz4-compress.js'), [
utils.path_from_root('third_party/mini-lz4.js'), temp,
data_target
],
stdout=PIPE)
os.unlink(temp)
use_data = '''
var compressedData = %s;
compressedData['data'] = byteArray;
assert(typeof Module['LZ4'] === 'object', 'LZ4 not present - was your app build with -s LZ4=1 ?');
Module['LZ4'].loadPackage({ 'metadata': metadata, 'compressedData': compressedData }, %s);
Module['removeRunDependency']('datafile_%s');
''' % (meta, "true" if use_preload_plugins else "false",
js_manipulation.escape_for_js_string(data_target))
package_uuid = uuid.uuid4()
package_name = data_target
remote_package_size = os.path.getsize(package_name)
remote_package_name = os.path.basename(package_name)
ret += r'''
var PACKAGE_PATH = '';
if (typeof window === 'object') {
PACKAGE_PATH = window['encodeURIComponent'](window.location.pathname.toString().substring(0, window.location.pathname.toString().lastIndexOf('/')) + '/');
} else if (typeof process === 'undefined' && typeof location !== 'undefined') {
// web worker
PACKAGE_PATH = encodeURIComponent(location.pathname.toString().substring(0, location.pathname.toString().lastIndexOf('/')) + '/');
}
var PACKAGE_NAME = '%s';
var REMOTE_PACKAGE_BASE = '%s';
if (typeof Module['locateFilePackage'] === 'function' && !Module['locateFile']) {
Module['locateFile'] = Module['locateFilePackage'];
err('warning: you defined Module.locateFilePackage, that has been renamed to Module.locateFile (using your locateFilePackage for now)');
}
var REMOTE_PACKAGE_NAME = Module['locateFile'] ? Module['locateFile'](REMOTE_PACKAGE_BASE, '') : REMOTE_PACKAGE_BASE;
''' % (js_manipulation.escape_for_js_string(data_target),
js_manipulation.escape_for_js_string(remote_package_name))
metadata['remote_package_size'] = remote_package_size
metadata['package_uuid'] = str(package_uuid)
ret += '''
var REMOTE_PACKAGE_SIZE = metadata['remote_package_size'];
var PACKAGE_UUID = metadata['package_uuid'];
'''
if use_preload_cache:
code += r'''
var indexedDB;
if (typeof window === 'object') {
indexedDB = window.indexedDB || window.mozIndexedDB || window.webkitIndexedDB || window.msIndexedDB;
} else if (typeof location !== 'undefined') {
// worker
indexedDB = self.indexedDB;
} else {
throw 'using IndexedDB to cache data can only be done on a web page or in a web worker';
}
var IDB_RO = "readonly";
var IDB_RW = "readwrite";
var DB_NAME = "''' + indexeddb_name + '''";
var DB_VERSION = 1;
var METADATA_STORE_NAME = 'METADATA';
var PACKAGE_STORE_NAME = 'PACKAGES';
function openDatabase(callback, errback) {
try {
var openRequest = indexedDB.open(DB_NAME, DB_VERSION);
} catch (e) {
return errback(e);
}
openRequest.onupgradeneeded = function(event) {
var db = event.target.result;
if(db.objectStoreNames.contains(PACKAGE_STORE_NAME)) {
db.deleteObjectStore(PACKAGE_STORE_NAME);
}
var packages = db.createObjectStore(PACKAGE_STORE_NAME);
if(db.objectStoreNames.contains(METADATA_STORE_NAME)) {
db.deleteObjectStore(METADATA_STORE_NAME);
}
var metadata = db.createObjectStore(METADATA_STORE_NAME);
};
openRequest.onsuccess = function(event) {
var db = event.target.result;
callback(db);
};
openRequest.onerror = function(error) {
errback(error);
};
};
// This is needed as chromium has a limit on per-entry files in IndexedDB
// https://cs.chromium.org/chromium/src/content/renderer/indexed_db/webidbdatabase_impl.cc?type=cs&sq=package:chromium&g=0&l=177
// https://cs.chromium.org/chromium/src/out/Debug/gen/third_party/blink/public/mojom/indexeddb/indexeddb.mojom.h?type=cs&sq=package:chromium&g=0&l=60
// We set the chunk size to 64MB to stay well-below the limit
var CHUNK_SIZE = 64 * 1024 * 1024;
function cacheRemotePackage(
db,
packageName,
packageData,
packageMeta,
callback,
errback
) {
var transactionPackages = db.transaction([PACKAGE_STORE_NAME], IDB_RW);
var packages = transactionPackages.objectStore(PACKAGE_STORE_NAME);
var chunkSliceStart = 0;
var nextChunkSliceStart = 0;
var chunkCount = Math.ceil(packageData.byteLength / CHUNK_SIZE);
var finishedChunks = 0;
for (var chunkId = 0; chunkId < chunkCount; chunkId++) {
nextChunkSliceStart += CHUNK_SIZE;
var putPackageRequest = packages.put(
packageData.slice(chunkSliceStart, nextChunkSliceStart),
'package/' + packageName + '/' + chunkId
);
chunkSliceStart = nextChunkSliceStart;
putPackageRequest.onsuccess = function(event) {
finishedChunks++;
if (finishedChunks == chunkCount) {
var transaction_metadata = db.transaction(
[METADATA_STORE_NAME],
IDB_RW
);
var metadata = transaction_metadata.objectStore(METADATA_STORE_NAME);
var putMetadataRequest = metadata.put(
{
'uuid': packageMeta.uuid,
'chunkCount': chunkCount
},
'metadata/' + packageName
);
putMetadataRequest.onsuccess = function(event) {
callback(packageData);
};
putMetadataRequest.onerror = function(error) {
errback(error);
};
}
};
putPackageRequest.onerror = function(error) {
errback(error);
};
}
}
/* Check if there's a cached package, and if so whether it's the latest available */
function checkCachedPackage(db, packageName, callback, errback) {
var transaction = db.transaction([METADATA_STORE_NAME], IDB_RO);
var metadata = transaction.objectStore(METADATA_STORE_NAME);
var getRequest = metadata.get('metadata/' + packageName);
getRequest.onsuccess = function(event) {
var result = event.target.result;
if (!result) {
return callback(false, null);
} else {
return callback(PACKAGE_UUID === result['uuid'], result);
}
};
getRequest.onerror = function(error) {
errback(error);
};
}
function fetchCachedPackage(db, packageName, metadata, callback, errback) {
var transaction = db.transaction([PACKAGE_STORE_NAME], IDB_RO);
var packages = transaction.objectStore(PACKAGE_STORE_NAME);
var chunksDone = 0;
var totalSize = 0;
var chunkCount = metadata['chunkCount'];
var chunks = new Array(chunkCount);
for (var chunkId = 0; chunkId < chunkCount; chunkId++) {
var getRequest = packages.get('package/' + packageName + '/' + chunkId);
getRequest.onsuccess = function(event) {
// If there's only 1 chunk, there's nothing to concatenate it with so we can just return it now
if (chunkCount == 1) {
callback(event.target.result);
} else {
chunksDone++;
totalSize += event.target.result.byteLength;
chunks.push(event.target.result);
if (chunksDone == chunkCount) {
if (chunksDone == 1) {
callback(event.target.result);
} else {
var tempTyped = new Uint8Array(totalSize);
var byteOffset = 0;
for (var chunkId in chunks) {
var buffer = chunks[chunkId];
tempTyped.set(new Uint8Array(buffer), byteOffset);
byteOffset += buffer.byteLength;
buffer = undefined;
}
chunks = undefined;
callback(tempTyped.buffer);
tempTyped = undefined;
}
}
}
};
getRequest.onerror = function(error) {
errback(error);
};
}
}
'''
# add Node.js support code, if necessary
node_support_code = ''
if support_node:
node_support_code = r'''
if (typeof process === 'object' && typeof process.versions === 'object' && typeof process.versions.node === 'string') {
require('fs').readFile(packageName, function(err, contents) {
if (err) {
errback(err);
} else {
callback(contents.buffer);
}
});
return;
}
'''
ret += r'''
function fetchRemotePackage(packageName, packageSize, callback, errback) {
%(node_support_code)s
var xhr = new XMLHttpRequest();
xhr.open('GET', packageName, true);
xhr.responseType = 'arraybuffer';
xhr.onprogress = function(event) {
var url = packageName;
var size = packageSize;
if (event.total) size = event.total;
if (event.loaded) {
if (!xhr.addedTotal) {
xhr.addedTotal = true;
if (!Module.dataFileDownloads) Module.dataFileDownloads = {};
Module.dataFileDownloads[url] = {
loaded: event.loaded,
total: size
};
} else {
Module.dataFileDownloads[url].loaded = event.loaded;
}
var total = 0;
var loaded = 0;
var num = 0;
for (var download in Module.dataFileDownloads) {
var data = Module.dataFileDownloads[download];
total += data.total;
loaded += data.loaded;
num++;
}
total = Math.ceil(total * Module.expectedDataFileDownloads/num);
if (Module['setStatus']) Module['setStatus']('Downloading data... (' + loaded + '/' + total + ')');
} else if (!Module.dataFileDownloads) {
if (Module['setStatus']) Module['setStatus']('Downloading data...');
}
};
xhr.onerror = function(event) {
throw new Error("NetworkError for: " + packageName);
}
xhr.onload = function(event) {
if (xhr.status == 200 || xhr.status == 304 || xhr.status == 206 || (xhr.status == 0 && xhr.response)) { // file URLs can return 0
var packageData = xhr.response;
callback(packageData);
} else {
throw new Error(xhr.statusText + " : " + xhr.responseURL);
}
};
xhr.send(null);
};
function handleError(error) {
console.error('package error:', error);
};
''' % {
'node_support_code': node_support_code
}
code += r'''
function processPackageData(arrayBuffer) {
assert(arrayBuffer, 'Loading data file failed.');
assert(arrayBuffer instanceof ArrayBuffer, 'bad input to processPackageData');
var byteArray = new Uint8Array(arrayBuffer);
var curr;
%s
};
Module['addRunDependency']('datafile_%s');
''' % (use_data, js_manipulation.escape_for_js_string(data_target))
# use basename because from the browser's point of view,
# we need to find the datafile in the same dir as the html file
code += r'''
if (!Module.preloadResults) Module.preloadResults = {};
'''
if use_preload_cache:
code += r'''
function preloadFallback(error) {
console.error(error);
console.error('falling back to default preload behavior');
fetchRemotePackage(REMOTE_PACKAGE_NAME, REMOTE_PACKAGE_SIZE, processPackageData, handleError);
};
openDatabase(
function(db) {
checkCachedPackage(db, PACKAGE_PATH + PACKAGE_NAME,
function(useCached, metadata) {
Module.preloadResults[PACKAGE_NAME] = {fromCache: useCached};
if (useCached) {
fetchCachedPackage(db, PACKAGE_PATH + PACKAGE_NAME, metadata, processPackageData, preloadFallback);
} else {
fetchRemotePackage(REMOTE_PACKAGE_NAME, REMOTE_PACKAGE_SIZE,
function(packageData) {
cacheRemotePackage(db, PACKAGE_PATH + PACKAGE_NAME, packageData, {uuid:PACKAGE_UUID}, processPackageData,
function(error) {
console.error(error);
processPackageData(packageData);
});
}
, preloadFallback);
}
}
, preloadFallback);
}
, preloadFallback);
if (Module['setStatus']) Module['setStatus']('Downloading...');
'''
else:
# Not using preload cache, so we might as well start the xhr ASAP,
# potentially before JS parsing of the main codebase if it's after us.
# Only tricky bit is the fetch is async, but also when runWithFS is called
# is async, so we handle both orderings.
ret += r'''
var fetchedCallback = null;
var fetched = Module['getPreloadedPackage'] ? Module['getPreloadedPackage'](REMOTE_PACKAGE_NAME, REMOTE_PACKAGE_SIZE) : null;
if (!fetched) fetchRemotePackage(REMOTE_PACKAGE_NAME, REMOTE_PACKAGE_SIZE, function(data) {
if (fetchedCallback) {
fetchedCallback(data);
fetchedCallback = null;
} else {
fetched = data;
}
}, handleError);
'''
code += r'''
Module.preloadResults[PACKAGE_NAME] = {fromCache: false};
if (fetched) {
processPackageData(fetched);
fetched = null;
} else {
fetchedCallback = processPackageData;
}
'''
ret += '''
function runWithFS() {
'''
ret += code
ret += '''
}
if (Module['calledRun']) {
runWithFS();
} else {
if (!Module['preRun']) Module['preRun'] = [];
Module["preRun"].push(runWithFS); // FS is not initialized yet, wait for it
}
'''
if separate_metadata:
_metadata_template = '''
Module['removeRunDependency']('%(metadata_file)s');
}
function runMetaWithFS() {
Module['addRunDependency']('%(metadata_file)s');
var REMOTE_METADATA_NAME = Module['locateFile'] ? Module['locateFile']('%(metadata_file)s', '') : '%(metadata_file)s';
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
if (xhr.readyState === 4 && xhr.status === 200) {
loadPackage(JSON.parse(xhr.responseText));
}
}
xhr.open('GET', REMOTE_METADATA_NAME, true);
xhr.overrideMimeType('application/json');
xhr.send(null);
}
if (Module['calledRun']) {
runMetaWithFS();
} else {
if (!Module['preRun']) Module['preRun'] = [];
Module["preRun"].push(runMetaWithFS);
}
''' % {
'metadata_file': os.path.basename(jsoutput + '.metadata')
}
else:
_metadata_template = '''
}
loadPackage(%s);
''' % json.dumps(metadata)
ret += '''%s
})();
''' % _metadata_template
if force or len(data_files):
if jsoutput is None:
print(ret)
else:
# Overwrite the old jsoutput file (if exists) only when its content
# differs from the current generated one, otherwise leave the file
# untouched preserving its old timestamp
if os.path.isfile(jsoutput):
with open(jsoutput) as f:
old = f.read()
if old != ret:
with open(jsoutput, 'w') as f:
f.write(ret)
else:
with open(jsoutput, 'w') as f:
f.write(ret)
if separate_metadata:
with open(jsoutput + '.metadata', 'w') as f:
json.dump(metadata, f, separators=(',', ':'))
return 0