TileSupport.py

   1 # -*- coding: utf-8 -*-
   2 #######################################################################################
   3 #   Photo is a part of Plinn - http://plinn.org                                       #
   4 #   Copyright (C) 2004-2007  Benoît PIN <benoit.pin@ensmp.fr>                         #
   5 #                                                                                     #
   6 #   This program is free software; you can redistribute it and/or                     #
   7 #   modify it under the terms of the GNU General Public License                       #
   8 #   as published by the Free Software Foundation; either version 2                    #
   9 #   of the License, or (at your option) any later version.                            #
  10 #                                                                                     #
  11 #   This program is distributed in the hope that it will be useful,                   #
  12 #   but WITHOUT ANY WARRANTY; without even the implied warranty of                    #
  13 #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the                     #
  14 #   GNU General Public License for more details.                                      #
  15 #                                                                                     #
  16 #   You should have received a copy of the GNU General Public License                 #
  17 #   along with this program; if not, write to the Free Software                       #
  18 #   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.   #
  19 #######################################################################################
  20 """ Tile support module
  21
  22
  23
  24 """
  25
  26 from AccessControl import ClassSecurityInfo
  27 from AccessControl import Unauthorized
  28 from AccessControl import getSecurityManager
  29 from AccessControl.Permissions import view, change_images_and_files
  30 from PIL import Image as PILImage
  31 from math import ceil
  32 from blobbases import Image
  33 from xmputils import TIFF_ORIENTATIONS
  34 from cache import memoizedmethod
  35 from BTrees.OOBTree import OOBTree
  36 from BTrees.IOBTree import IOBTree
  37 from ppm import PPMFile
  38 from threading import Lock
  39 from subprocess import Popen, PIPE
  40 from tempfile import TemporaryFile
  41
  42 JPEG_ROTATE = 'jpegtran -rotate %d'
  43 JPEG_FLIP = 'jpegtran -flip horizontal'
  44
  45 def runOnce(lock):
  46         """ Decorator. exit if already running """
  47
  48         def wrapper(f):
  49                 def method(*args, **kw):
  50                         if not lock.locked() :
  51                                 lock.acquire()
  52                                 try:
  53                                         return f(*args, **kw)
  54                                 finally:
  55                                         lock.release()
  56                         else :
  57                                 return False
  58                 return method
  59         return wrapper
  60
  61
  62
  63 class TileSupport :
  64         """ Mixin class to generate tiles from image """
  65
  66         security = ClassSecurityInfo()
  67         tileSize = 256
  68         tileGenerationLock = Lock()
  69
  70         def __init__(self) :
  71                 self._tiles = OOBTree()
  72
  73         security.declarePrivate('makeTilesAt')
  74         @runOnce(tileGenerationLock)
  75         def makeTilesAt(self, zoom):
  76                 """generates tiles at zoom level"""
  77
  78                 if self._tiles.has_key(zoom) :
  79                         return True
  80
  81                 assert zoom <= 1, "zoom arg must be <= 1 found: %s" % zoom
  82
  83                 ppm = self._getPPM()
  84                 if zoom < 1 :
  85                         ppm = ppm.resize(ratio=zoom)
  86
  87                 self._makeTilesAt(zoom, ppm)
  88                 return True
  89
  90         def _getPPM(self) :
  91                 bf = self._getJpegBlob()
  92                 f = bf.open('r')
  93
  94                 orientation = self.tiffOrientation()
  95                 rotation, flip = TIFF_ORIENTATIONS.get(orientation, (0, False))
  96
  97                 if rotation and flip :
  98                         tf = TemporaryFile(mode='w+')
  99                         pRot = Popen(JPEG_ROTATE % rotation
 100                                         , stdin=f
 101                                         , stdout=PIPE
 102                                         , shell=True)
 103                         pFlip = Popen(JPEG_FLIP
 104                                                 , stdin=pRot.stdout
 105                                                 , stdout=tf
 106                                                 , shell=True)
 107                         pFlip.wait()
 108                         f.close()
 109                         tf.seek(0)
 110                         f = tf
 111
 112                 elif rotation :
 113                         tf = TemporaryFile(mode='w+')
 114                         pRot = Popen(JPEG_ROTATE % rotation
 115                                                 , stdin=f
 116                                                 , stdout=tf
 117                                                 , shell=True)
 118                         pRot.wait()
 119                         f.close()
 120                         tf.seek(0)
 121                         f = tf
 122
 123                 elif flip :
 124                         tf = TemporaryFile(mode='w+')
 125                         pFlip = Popen(JPEG_FLIP
 126                                                 , stdin=f
 127                                                 , stdout=tf
 128                                                 , shell=True)
 129                         pFlip.wait()
 130                         f.close()
 131                         tf.seek(0)
 132                         f = tf
 133
 134                 ppm = PPMFile(f, tileSize=self.tileSize)
 135                 f.close()
 136                 return ppm
 137
 138         def _makeTilesAt(self, zoom, ppm):
 139                 hooks = self._getAfterTilingHooks()
 140                 self._tiles[zoom] = IOBTree()
 141                 bgColor = getattr(self, 'tiles_background_color', '#fff')
 142
 143                 for x in xrange(ppm.tilesX) :
 144                         self._tiles[zoom][x] = IOBTree()
 145                         for y in xrange(ppm.tilesY) :
 146                                 tile = ppm.getTile(x, y)
 147                                 for hook in hooks :
 148                                         hook(self, tile)
 149
 150                                 # fill with solid color
 151                                 if min(tile.size) < self.tileSize :
 152                                         blankTile = PILImage.new('RGB', (self.tileSize, self.tileSize), bgColor)
 153                                         box = (0,0) + tile.size
 154                                         blankTile.paste(tile, box)
 155                                         tile = blankTile
 156
 157                                 zImg = Image('tile', 'tile', '', content_type='image/jpeg')
 158                                 out = zImg.open('w')
 159                                 tile.save(out, 'JPEG', quality=90)
 160                                 zImg.updateFormat(out.tell(), tile.size, 'image/jpeg')
 161                                 out.close()
 162
 163                                 self._tiles[zoom][x][y] = zImg
 164
 165         def _getAfterTilingHooks(self) :
 166                 return []
 167
 168
 169         security.declareProtected(view, 'getAvailableZooms')
 170         def getAvailableZooms(self):
 171                 zooms = list(self._tiles.keys())
 172                 zooms.sort()
 173                 return zooms
 174
 175         security.declareProtected(view, 'getTile')
 176         def getTile(self, REQUEST, RESPONSE, zoom=1, x=0, y=0):
 177                 """ publishes tile
 178                 """
 179                 zoom, x, y = float(zoom), int(x), int(y)
 180                 if not self._tiles.has_key(zoom) :
 181                         sm = getSecurityManager()
 182                         if not sm.checkPermission(change_images_and_files, self) :
 183                                 raise Unauthorized("Tiling arbitrary zoom unauthorized")
 184                         if self.makeTilesAt(zoom) :
 185                                 tile = self._tiles[zoom][x][y]
 186                                 return tile.index_html(REQUEST=REQUEST, RESPONSE=RESPONSE)
 187                 else :
 188                         tile = self._tiles[zoom][x][y]
 189                         return tile.index_html(REQUEST=REQUEST, RESPONSE=RESPONSE)
 190