fis collect resource algorithm you can enter to http://pythontutor.com/visualize.html

fis.py

#!/usr/bin/env python
'''
fis collect resource algorithm
'''
 
#
# static resoruce
#
collection = {}
 
#
# async js
#
async = {
    'res': {},
    'pkg': {}
}
 
#
# loaded
#
loaded = {}
 
 
#
# async deleted
#
asyncDeleted = {}
 
 
resMap = {
    "res": {
        "async_0.js": {
            'type': 'js',
            'uri': '/static/widget/async_0.js',
            'deps': ['d.js']
        },
        "a0.js": {
            'type': 'js',
            'uri': '/static/widget/a0.js',
        },
        "a.js": {
            'uri': '/static/widget/a.js',
            'type': 'js',
            'pkg': 'p0',
            'deps': ['a0.js']
        },
        "b.js": {
            'uri': '/static/widget/b.js',
            'type': 'js',
            'pkg': 'p0'
        },
        "c.js": {
            'uri': '/static/widget/c.js',
            'type': 'js',
            'extras': {
                'async': ['async_0.js']
            }
        },
        "d.js": {
            'uri': '/static/widget/d.js',
            'type': 'js'
        },
    },
    "pkg": {
        "p0": {
            'uri': '/static/pkg/p0.js',
            'has': ['a.js', 'b.js'],
            'type': 'js'
        }
    }
}
 
 
def delAsync(resId):
    if resId in asyncDeleted:
        return True
    else:
        asyncDeleted[resId] = True
        res = async['res'][resId]
        
        # first deps
        if 'deps' in res:
            for depId in res['deps']:
                delAsync(depId)
                
        # second self
        if 'pkg' in res:
            if res['pkg'] in async['pkg']:
                pkg = async['pkg'][res['pkg']]
                
                del async['pkg'][res['pkg']]
    
                collection[res['type']].append(pkg['uri'])
                for hasId in pkg['has']:
                    loaded[hasId] = pkg['uri']
                    delAsync(hasId)
            else:
                del async['res'][resId]
    
        else:
            collection[res['type']].append(res['uri'])
            loaded[resId] = res['uri']
            del async['res'][resId]
 
 
 
#
# load deps
#
def loadDeps(res, isAsync):
    if 'deps' in res:
        for depId in res['deps']:
            load(depId, isAsync)
    if 'extras' in res:
        if 'async' in res['extras']:
            arrAsync = res['extras']['async']
            for asyncId in arrAsync:
                # change isAsync status == True
                load(asyncId, True)
    return
 
 
def load(resId, isAsync):
    if resId in loaded:
        if resId in async['res']:
            delAsync(resId)
        # if loaded, return it
        return loaded[resId]
    arrRes = resMap['res']
    if resId in arrRes:
        uri = ''
        res = arrRes[resId]
        arrHasPkg = {}
        pkg = {}
        if 'pkg' in res:
            arrPkg = resMap['pkg']
            pkg = arrPkg[res['pkg']]
            uri = pkg['uri']
 
            # first set loaded
            for hasId in pkg['has']:
                loaded[hasId] = uri
 
            for hasId in pkg['has']:
                # collect pkg
                arrHasPkg[hasId] = arrRes[hasId]
                loadDeps(arrRes[hasId], isAsync)
        else:
            uri = res['uri']
            loaded[resId] = uri
            loadDeps(res, isAsync)
        if isAsync and res['type'] == 'js':
            if len(pkg) > 0:
                async['pkg'][res['pkg']] = pkg;
                async['res'].update(arrHasPkg)
            else:
                async['res'][resId] = res
        else:
            if res['type'] not in collection:
                collection[res['type']] = []
            collection[res['type']].append(uri)
        return uri
    return False
 
load('a.js', False)
load('b.js', False)
load('c.js', False)
load('async_0.js', False)