cache.py

   1 from __future__ import with_statement
   2 import hashlib, os
   3 from limoutil import *
   4 from settings import Settings
   5
   6 class _AggreggateFileSet:
   7         """ Provides a base class for aggreggating text files.
   8
   9                 First generate some test content.
  10
  11                 >>> import os
  12                 >>> if os.path.isfile(Settings.tempDir+"/test.js"): os.remove(Settings.tempDir+"/test.js")
  13                 >>> o = open(Settings.tempDir+"/test.js").write("function func1() {                                                                      \nalert('with lots of space');}")
  14                 >>> o.close()
  15                 >>> if os.path.isfile(Settings.tempDir+"/test2.js"): os.remove(Settings.tempDir+"/test2.js")
  16                 >>> o = open(Settings.tempDir+"/test2.js").write("function func2() { alert('this is function 2');}")
  17                 >>> o.close()
  18
  19                 Then use defaultFile() to load the test content into the file set.
  20
  21                 >>> Cache.JS.defaultFile(Settings.tempDir+"/test.js")
  22                 >>> Cache.JS.defaultFile(Settings.tempDir+"/test2.js")
  23                 >>> hash = hashlib.sha1(''.join([Settings.tempDir+"/test.js",Settings.tempDir+"/test2.js"])).hexdigest()
  24                 >>> assert(Cache.JS.getOutputFile().startswith('cache/'+hash))
  25                 >>> Cache.JS.saveContent()
  26                 >>> assert(os.path.isfile(Cache.JS.getOutputFile())
  27                 >>> Cache.JS.getText()
  28                 'function func1(){alert('with lots of space');}function func2(){alert('this is function 2');}'
  29         """
  30
  31         def __init__(self):
  32                 self._order = []
  33                 self._data = {}
  34                 self._mtimes = {}
  35
  36         def defaultFile(self, file):
  37                 if file is None or not os.path.isfile(file):
  38                         if Settings.abortOnMissingFile:
  39                                 raise HTTPStatusError(404, "Required asset is missing: %s" % file)
  40                         if Settings.warnOnMissingFile:
  41                                 log("WARNING: File Cache could not load requested file: %s" % file)
  42                 if self._data.get(file, False): # dont add the same file twice
  43                         if os.path.getmtime(file) > self._mtimes.get(file, 0): # unless its been modified
  44                                 log("Reading file from disk into cache: %s" % file)
  45                         else:
  46                                 # log("Skipping read of unmodified file: %s %d <= %d " % (file, os.path.getmtime(file), self._mtimes.get(file, 0)))
  47                                 return
  48                 if file is not None and os.path.isfile(file):
  49                         self._order.append(file)
  50                         # TODO: lazy reading, only read() if, in the end, the whole request needs to be written into the cache
  51                         self._mtimes[file] = os.path.getmtime(file)
  52                         with open(file,"rb") as f:
  53                                 self._data[file] = f.read()
  54
  55         def getOutputFile(self):
  56                 """ Subclasses should implement this to add the proper extension """
  57                 fname_hash = hashlib.sha1(''.join(self._order)).hexdigest()
  58                 mtime_hash = hashlib.sha1(''.join([str(os.path.getmtime(f)) for f in self._order])).hexdigest()
  59                 return Settings.cacheDir+os.path.sep+"%s-%s" %(fname_hash, mtime_hash)
  60
  61         def saveContent(self):
  62                 f = self.getOutputFile()
  63                 if not os.path.isfile(f):
  64                         # remove stale cache files first
  65                         """DISABLED
  66                         key = f[6:10]
  67                         for file in os.listdir(Settings.cacheDir):
  68                                 if file == f:
  69                                         file = os.path.sep.join([Settings.cacheDir,file])
  70                                         log("Removing stale cache file: %s" % (file))
  71                                         os.remove(file)
  72                         """
  73                         # then write the fresh one
  74                         log("Writing files: [%s] to cache: %s" % (', '.join(self.order()), self.getOutputFile()))
  75                         leader = "/* Files: "+', '.join(self.order())+" */\n"
  76                         packed = ''.join([self.filter(self._data[key]) for key in self.order()])
  77                         with open(self.getOutputFile(),'wb') as f:
  78                                 f.write(leader)
  79                                 f.write(packed)
  80
  81         def order(self):
  82                 return self._order
  83
  84         def clear(self):
  85                 self._order = []
  86                 self._data.clear()
  87
  88         def getText(self):
  89                 self.saveContent()
  90                 with open(z_file,"rb") as f:
  91                         return f.read()
  92
  93         def filter(self, text):
  94                 """ Subclasses should implement this in order to do minification, compression, etc. """
  95                 return text
  96
  97 import jsmin, cssmin
  98
  99 class _JSFileSet(_AggreggateFileSet):
 100         def filter(self, text):
 101                 if Settings.developmentMode:
 102                         return text;
 103                 else:
 104                         return jsmin.jsmin(text)
 105         def getOutputFile(self):
 106                 return _AggreggateFileSet.getOutputFile(self)+".js"
 107
 108 class _CSSFileSet(_AggreggateFileSet):
 109         def filter(self, text):
 110                 if Settings.developmentMode:
 111                         return text;
 112                 else:
 113                         return cssmin.minimalize(text)
 114         def getOutputFile(self):
 115                 return _AggreggateFileSet.getOutputFile(self)+".css"
 116         def order(self):
 117                 return self._order
 118
 119 class Cache:
 120         CSS = _CSSFileSet()
 121         JS = _JSFileSet()