scripts/khr_util/registry_cache.py

   1 # -*- coding: utf-8 -*-
   2
   3 import os
   4 import urllib2
   5 import hashlib
   6
   7 import registry
   8
   9 BASE_URL = ""
  10
  11 class RegistrySource:
  12         def __init__(self, filename, revision, checksum):
  13                 self.filename   = filename
  14                 self.revision   = revision
  15                 self.checksum   = checksum
  16
  17         def __hash__(self):
  18                 return hash((self.filename, self.revision, self.checksum))
  19
  20         def __eq__(self, other):
  21                 return (self.filename, self.revision, self.checksum) == (other.filename, other.revision, other.checksum)
  22
  23         def getFilename (self):
  24                 return self.filename
  25
  26         def getCacheFilename (self):
  27                 return "r%d-%s" % (self.revision, self.filename)
  28
  29         def getChecksum (self):
  30                 return self.checksum
  31
  32         def getRevision (self):
  33                 return self.revision
  34
  35         def getSourceUrl (self):
  36                 return "https://cvs.khronos.org/svn/repos/ogl/trunk/doc/registry/public/api/%s?r=%d" % (self.filename, self.revision)
  37
  38 def computeChecksum (data):
  39         return hashlib.sha256(data).hexdigest()
  40
  41 def fetchUrl (url):
  42         req             = urllib2.urlopen(url)
  43         data    = req.read()
  44         return data
  45
  46 def fetchFile (dstPath, url, checksum):
  47         def writeFile (filename, data):
  48                 f = open(filename, 'wb')
  49                 f.write(data)
  50                 f.close()
  51
  52         if not os.path.exists(os.path.dirname(dstPath)):
  53                 os.makedirs(os.path.dirname(dstPath))
  54
  55         print "Fetching %s" % url
  56         data            = fetchUrl(url)
  57         gotChecksum     = computeChecksum(data)
  58
  59         if checksum != gotChecksum:
  60                 raise Exception("Checksum mismatch, exepected %s, got %s" % (checksum, gotChecksum))
  61
  62         writeFile(dstPath, data)
  63
  64 def checkFile (filename, checksum):
  65         def readFile (filename):
  66                 f = open(filename, 'rb')
  67                 data = f.read()
  68                 f.close()
  69                 return data
  70
  71         if os.path.exists(filename):
  72                 return computeChecksum(readFile(filename)) == checksum
  73         else:
  74                 return False
  75
  76 g_registryCache = {}
  77
  78 def getRegistry (source):
  79         global g_registryCache
  80
  81         if source in g_registryCache:
  82                 return g_registryCache[source]
  83
  84         cacheDir        = os.path.join(os.path.dirname(__file__), "cache")
  85         cachePath       = os.path.join(cacheDir, source.getCacheFilename())
  86
  87         if not checkFile(cachePath, source.checksum):
  88                 fetchFile(cachePath, source.getSourceUrl(), source.getChecksum())
  89
  90         parsedReg       = registry.parse(cachePath)
  91
  92         g_registryCache[source] = parsedReg
  93
  94         return parsedReg