emscripten/tools/split.py

97 строки
4.6 KiB
Python

import sys
import os
def split_javascript_file(input_filename, output_filename_prefix, max_part_size_in_bytes):
try:
# Contains the entire Emscripten generated Javascript code
input_file = open(input_filename,'r')
# Javascript main file. On execution, this file needs to be loaded at last (!)
output_main_filename = output_filename_prefix + ".js"
output_main_file = open(output_main_filename,'w')
# File with HTML script tags to load the Javascript files in HTML later on
output_html_include_file = open(output_filename_prefix + ".include.html",'w')
# Variable will contain the source of a Javascript function if we find one during parsing
js_function = None
# Dictionary with lower case source file as key and a tupel of case sensitive source file name (first encountered case wins)
# and an array of functions associated to that source file as value
function_buckets = {};
output_part_file = None
# Iterate over Javascript source; write main file; parse function declarations.
for line in input_file:
if line == "//FUNCTION_BEGIN_MARKER\n":
js_function = "//Func\n"
elif line.startswith("//FUNCTION_END_MARKER_OF_SOURCE_FILE_"):
# At the end of the function marker we get the source file that is associated to that function.
associated_source_file_base = line[len("//FUNCTION_END_MARKER_OF_SOURCE_FILE_"):len(line)-1]
if associated_source_file_base == "NO_SOURCE":
# Functions without associated source file are stored in a file in the base directory
associated_source_file_base = output_filename_prefix + "_functions";
else:
# Functions with a known associated source file are stored in a file in the directory `output_filename_prefix`
associated_source_file_base = output_filename_prefix + os.path.realpath(associated_source_file_base)
associated_source_file_base_lower = associated_source_file_base.lower()
# Add the function to its respective file
if associated_source_file_base_lower not in function_buckets:
function_buckets[associated_source_file_base_lower] = [associated_source_file_base, []]
function_buckets[associated_source_file_base_lower][1] += [js_function]
# Clear the function read cache
js_function = None
else:
if js_function is None:
output_main_file.write(line)
else:
js_function += line
# Iterate over all function buckets and write their functions to the associated files
# An associated file is split into chunks of `max_part_size_in_bytes`
for associated_source_file_base in function_buckets:
# At first we try to name the Javascript source file to match the assoicated source file + `.js`
js_source_file = function_buckets[associated_source_file_base][0] + ".js"
# Check if the directory of the Javascript source file exists
js_source_dir = os.path.dirname(js_source_file)
if len(js_source_dir) > 0 and not os.path.exists(js_source_dir):
os.makedirs(js_source_dir)
output_part_file_counter = 0
output_part_file = None
for js_function in function_buckets[associated_source_file_base][1]:
if output_part_file is None:
output_html_include_file.write("<script type=\"text/javascript\" src=\"" + js_source_file + "\"></script>")
output_part_file = open(js_source_file,'w')
output_part_file.write(js_function)
if output_part_file is not None and output_part_file.tell() > max_part_size_in_bytes:
output_part_file.close()
output_part_file = None
output_part_file_counter += 1
js_source_file = function_buckets[associated_source_file_base][0] + ".part" + str(output_part_file_counter) + ".js"
if output_part_file is not None:
output_part_file.close()
output_part_file = None
# Write the main Javascript file at last to the HTML includes because this file contains the code to start
# the execution of the generated Emscripten application and requires all the extracted functions.
output_html_include_file.write("<script type=\"text/javascript\" src=\"" + output_main_filename + "\"></script>")
except Exception, e:
print >> sys.stderr, 'error: Splitting of Emscripten generated Javascript failed: %s' % str(e)
finally:
if input_file is not None: input_file.close()
if output_main_file is not None: output_main_file.close()
if output_part_file is not None: output_part_file.close()
if output_html_include_file is not None: output_html_include_file.close()