Thuban/Model/data.py

# Copyright (C) 2003 by Intevation GmbH
# Authors:
# Bernhard Herzog <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with the software for details.

"""Data source abstractions"""

from __future__ import generators

__version__ = "$Revision$"
# $Source$
# $Id$

import os
import weakref
from math import ceil, log

import shapelib
import shptree
import table
import transientdb

from Thuban import _

# Shape type constants
SHAPETYPE_POLYGON = "polygon"
SHAPETYPE_ARC = "arc"
SHAPETYPE_POINT = "point"

# mapping from shapelib shapetype constants to our constants
shapelib_shapetypes = {shapelib.SHPT_POLYGON: SHAPETYPE_POLYGON,
                       shapelib.SHPT_ARC: SHAPETYPE_ARC,
                       shapelib.SHPT_POINT: SHAPETYPE_POINT}

#
# Raw shape data formats
#

# Raw data is the same as that returned by the points method.
RAW_PYTHON = "RAW_PYTHON"

# Raw data is a shapefile. The Shape object will use the shapeid as the
# raw data.
RAW_SHAPEFILE = "RAW_SHAPEFILE"


class ShapefileShape:

    """Represent one shape of a shapefile"""

    def __init__(self, shapefile, shapeid):
        self.shapefile = shapefile
        self.shapeid = shapeid

    def compute_bbox(self):
        """
        Return the bounding box of the shape as a tuple (minx,miny,maxx,maxy)
        """
        xs = []
        ys = []
        for part in self.Points():
            for x, y in part:
                xs.append(x)
                ys.append(y)
        return (min(xs), min(ys), max(xs), max(ys))

    def ShapeID(self):
        return self.shapeid

    def Points(self):
        """Return the coordinates of the shape as a list of lists of pairs"""
        shape = self.shapefile.read_object(self.shapeid)
        points = shape.vertices()
        if self.shapefile.info()[1] == shapelib.SHPT_POINT:
            points = [points]
        return points

    def RawData(self):
        """Return the shape id to use with the shapefile"""
        return self.shapeid

    def Shapefile(self):
        """Return the shapefile object"""
        return self.shapefile


class ShapeTable(transientdb.AutoTransientTable):

    """A Table that depends on a ShapefileStore

    Intended use is by the ShapefileStore for the table associated with
    the shapefiles.
    """

    def __init__(self, store, db, table):
        """Initialize the ShapeTable.

        Parameters:
            store -- the ShapefileStore the table is to depend on
            db -- The transient database to use
            table -- the table
        """
        transientdb.AutoTransientTable.__init__(self, db, table)
        self.store = weakref.ref(store)

    def Dependencies(self):
        """Return a tuple containing the shapestore"""
        return (self.store(),)


class ShapefileStore:

    """Combine a shapefile and the corresponding DBF file into one object"""

    def __init__(self, session, filename):
        # Make the filename absolute. The filename will be
        # interpreted relative to that anyway, but when saving a
        # session we need to compare absolute paths and it's usually
        # safer to always work with absolute paths.
        self.filename = os.path.abspath(filename)

        self.shapefile = shapelib.ShapeFile(self.filename)
        self.dbftable = table.DBFTable(filename)
        self.table = ShapeTable(self, session.TransientDB(), self.dbftable)

        self.numshapes, shapetype, mins, maxs = self.shapefile.info()
        if self.numshapes:
            self.bbox = mins[:2] + maxs[:2]
        else:
            self.bbox = None
        self.shapetype = shapelib_shapetypes[shapetype]

        # estimate a good depth for the quad tree. Each depth multiplies
        # the number of nodes by four, therefore we basically take the
        # base 4 logarithm of the number of shapes.
        if self.numshapes < 4:
            maxdepth = 1
        else:
            maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))

        self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,
                                         maxdepth)

    def Table(self):
        """Return the table containing the attribute data"""
        return self.table

    def Shapefile(self):
        """Return the shapefile object"""
        return self.shapefile

    def FileName(self):
        """Return the filename used to open the shapefile"""
        return self.filename

    def FileType(self):
        """Return the filetype. This is always the string 'shapefile'"""
        return "shapefile"

    def ShapeType(self):
        """Return the type of the shapes in the shapestore.

        This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
        """
        return self.shapetype

    def RawShapeFormat(self):
        """Return the raw data format of the shape data, i.e. RAW_SHAPEFILE"""
        return RAW_SHAPEFILE

    def NumShapes(self):
        """Return the number of shapes in the shape store"""
        return self.numshapes

    def Dependencies(self):
        """Return the empty tuple.

        The ShapefileStore doesn't depend on anything else.
        """
        return ()

    def OrigShapeStore(self):
        """Return None.

        The ShapefileStore was not derived from another shapestore.
        """
        return None

    def BoundingBox(self):
        """Return the bounding box of the shapes in the shapestore.

        The coordinate system used is whatever was used in the shapefile.
        If the shapefile is empty, return None.
        """
        return self.bbox

    def ShapesInRegion(self, bbox):
        """Return an iterable over the shapes that overlap the bounding box.

        The bbox parameter should be the bounding box as a tuple in the
        form (minx, miny, maxx, maxy) in the coordinate system of the
        shape store.
        """
        left, bottom, right, top = bbox
        for i in self.shapetree.find_shapes((left, bottom), (right, top)):
            yield ShapefileShape(self.shapefile, i)

    def AllShapes(self):
        """Return an iterable over the shapes in the shape store."""
        for i in xrange(self.NumShapes()):
            yield ShapefileShape(self.shapefile, i)

    def Shape(self, index):
        """Return the shape with index index"""
        return ShapefileShape(self.shapefile, index)


class DerivedShapeStore:

    """A ShapeStore derived from other shapestores or tables"""

    def __init__(self, shapestore, table):
        """Initialize the derived shapestore.

        The arguments are a shapestore for the shapedata and a table for
        the tabular data.

        Raises ValueError if the number of shapes in the shapestore
        is different from the number of rows in the table.
        """

        numShapes = shapestore.Shapefile().info()[0]
        if numShapes != table.NumRows():
            raise ValueError(_("Table not compatible with shapestore."))

        self.shapestore = shapestore
        self.table = table

    def Table(self):
        """Return the table"""
        return self.table

    def Shapefile(self):
        """Return the shapefile of the underlying shapestore"""
        return self.shapestore.Shapefile()

    def Dependencies(self):
        """Return a tuple containing the shapestore and the table"""
        return (self.shapestore, self.table)

    def OrigShapeStore(self):
        """
        Return the original shapestore the derived store was instantiated with
        """
        return self.shapestore

    def Shape(self, index):
        """Return the shape with index index"""
        return self.shapestore.Shape(index)

    def ShapesInRegion(self, bbox):
        """Return the ids of the shapes that overlap the box.

        This method is simply delegated to the shapestore the
        DerivedShapeStore was instantiated with.
        """
        return self.shapestore.ShapesInRegion(bbox)

    def AllShapes(self):
        """Return an iterable over the shapes in the shape store.

        This method is simply delegated to the shapestore the
        DerivedShapeStore was instantiated with.
        """
        return self.shapestore.AllShapes()

    def ShapeType(self):
        """Return the type of the shapes in the layer.

        This method is simply delegated to the shapestore the
        DerivedShapeStore was instantiated with.
        """
        return self.shapestore.ShapeType()

    def RawShapeFormat(self):
        """Return the raw data format of the shapes.

        This method is simply delegated to the shapestore the
        DerivedShapeStore was instantiated with.
        """
        return self.shapestore.RawShapeFormat()

    def NumShapes(self):
        """Return the number of shapes in the shapestore."""
        return self.shapestore.NumShapes()

    def BoundingBox(self):
        """Return the bounding box of the shapes in the shapestore.

        This method is simply delegated to the shapestore the
        DerivedShapeStore was instantiated with.
        """
        return self.shapestore.BoundingBox()
1	bh	723	# Copyright (C) 2003 by Intevation GmbH
2			# Authors:
3			# Bernhard Herzog <[email protected]>
4			#
5			# This program is free software under the GPL (>=v2)
6			# Read the file COPYING coming with the software for details.
7
8			"""Data source abstractions"""
9
10	bh	1593	from __future__ import generators
11
12	bh	723	__version__ = "$Revision$"
13			# $Source$
14			# $Id$
15
16			import os
17	bh	984	import weakref
18	bh	1535	from math import ceil, log
19	bh	723
20			import shapelib
21	bh	1535	import shptree
22	bh	723	import table
23	bh	765	import transientdb
24	bh	723
25	jonathan	1261	from Thuban import _
26	bh	765
27	bh	1535	# Shape type constants
28			SHAPETYPE_POLYGON = "polygon"
29			SHAPETYPE_ARC = "arc"
30			SHAPETYPE_POINT = "point"
31	jonathan	1261
32	bh	1535	# mapping from shapelib shapetype constants to our constants
33			shapelib_shapetypes = {shapelib.SHPT_POLYGON: SHAPETYPE_POLYGON,
34			shapelib.SHPT_ARC: SHAPETYPE_ARC,
35			shapelib.SHPT_POINT: SHAPETYPE_POINT}
36
37	bh	1559	#
38			# Raw shape data formats
39			#
40	bh	1535
41	bh	1559	# Raw data is the same as that returned by the points method.
42			RAW_PYTHON = "RAW_PYTHON"
43	bh	1535
44	bh	1559	# Raw data is a shapefile. The Shape object will use the shapeid as the
45			# raw data.
46			RAW_SHAPEFILE = "RAW_SHAPEFILE"
47	bh	1535
48
49	bh	1559	class ShapefileShape:
50
51			"""Represent one shape of a shapefile"""
52
53			def __init__(self, shapefile, shapeid):
54			self.shapefile = shapefile
55			self.shapeid = shapeid
56
57	bh	1535	def compute_bbox(self):
58	bh	1559	"""
59			Return the bounding box of the shape as a tuple (minx,miny,maxx,maxy)
60			"""
61	bh	1535	xs = []
62			ys = []
63	bh	1559	for part in self.Points():
64	bh	1551	for x, y in part:
65			xs.append(x)
66			ys.append(y)
67	bh	1559	return (min(xs), min(ys), max(xs), max(ys))
68	bh	1535
69	bh	1593	def ShapeID(self):
70			return self.shapeid
71
72	bh	1559	def Points(self):
73			"""Return the coordinates of the shape as a list of lists of pairs"""
74			shape = self.shapefile.read_object(self.shapeid)
75			points = shape.vertices()
76			if self.shapefile.info()[1] == shapelib.SHPT_POINT:
77			points = [points]
78			return points
79	bh	1535
80	bh	1559	def RawData(self):
81			"""Return the shape id to use with the shapefile"""
82			return self.shapeid
83	bh	1535
84	bh	1559	def Shapefile(self):
85			"""Return the shapefile object"""
86			return self.shapefile
87	bh	1535
88
89	bh	984	class ShapeTable(transientdb.AutoTransientTable):
90
91			"""A Table that depends on a ShapefileStore
92
93			Intended use is by the ShapefileStore for the table associated with
94			the shapefiles.
95			"""
96
97			def __init__(self, store, db, table):
98			"""Initialize the ShapeTable.
99
100			Parameters:
101			store -- the ShapefileStore the table is to depend on
102			db -- The transient database to use
103			table -- the table
104			"""
105			transientdb.AutoTransientTable.__init__(self, db, table)
106			self.store = weakref.ref(store)
107
108			def Dependencies(self):
109			"""Return a tuple containing the shapestore"""
110			return (self.store(),)
111
112
113	bh	723	class ShapefileStore:
114
115			"""Combine a shapefile and the corresponding DBF file into one object"""
116
117			def __init__(self, session, filename):
118			# Make the filename absolute. The filename will be
119			# interpreted relative to that anyway, but when saving a
120			# session we need to compare absolute paths and it's usually
121			# safer to always work with absolute paths.
122			self.filename = os.path.abspath(filename)
123
124			self.shapefile = shapelib.ShapeFile(self.filename)
125	bh	765	self.dbftable = table.DBFTable(filename)
126	bh	984	self.table = ShapeTable(self, session.TransientDB(), self.dbftable)
127	bh	723
128	bh	1535	self.numshapes, shapetype, mins, maxs = self.shapefile.info()
129			if self.numshapes:
130			self.bbox = mins[:2] + maxs[:2]
131			else:
132			self.bbox = None
133			self.shapetype = shapelib_shapetypes[shapetype]
134
135			# estimate a good depth for the quad tree. Each depth multiplies
136			# the number of nodes by four, therefore we basically take the
137			# base 4 logarithm of the number of shapes.
138			if self.numshapes < 4:
139			maxdepth = 1
140			else:
141			maxdepth = int(ceil(log(self.numshapes / 4.0) / log(4)))
142
143			self.shapetree = shptree.SHPTree(self.shapefile.cobject(), 2,
144			maxdepth)
145
146	bh	723	def Table(self):
147	bh	984	"""Return the table containing the attribute data"""
148	bh	723	return self.table
149
150			def Shapefile(self):
151	bh	984	"""Return the shapefile object"""
152	bh	723	return self.shapefile
153	bh	765
154	bh	984	def FileName(self):
155			"""Return the filename used to open the shapefile"""
156			return self.filename
157	bh	765
158	bh	984	def FileType(self):
159			"""Return the filetype. This is always the string 'shapefile'"""
160			return "shapefile"
161
162	bh	1535	def ShapeType(self):
163			"""Return the type of the shapes in the shapestore.
164
165			This is either SHAPETYPE_POINT, SHAPETYPE_ARC or SHAPETYPE_POLYGON.
166			"""
167			return self.shapetype
168
169	bh	1559	def RawShapeFormat(self):
170			"""Return the raw data format of the shape data, i.e. RAW_SHAPEFILE"""
171			return RAW_SHAPEFILE
172
173	bh	1535	def NumShapes(self):
174			"""Return the number of shapes in the shape store"""
175			return self.numshapes
176
177	bh	984	def Dependencies(self):
178			"""Return the empty tuple.
179
180			The ShapefileStore doesn't depend on anything else.
181			"""
182			return ()
183
184	bh	1074	def OrigShapeStore(self):
185			"""Return None.
186	bh	984
187	bh	1074	The ShapefileStore was not derived from another shapestore.
188			"""
189			return None
190
191	bh	1535	def BoundingBox(self):
192			"""Return the bounding box of the shapes in the shapestore.
193	bh	1074
194	bh	1535	The coordinate system used is whatever was used in the shapefile.
195			If the shapefile is empty, return None.
196			"""
197			return self.bbox
198
199	bh	1593	def ShapesInRegion(self, bbox):
200			"""Return an iterable over the shapes that overlap the bounding box.
201	bh	1535
202	bh	1593	The bbox parameter should be the bounding box as a tuple in the
203			form (minx, miny, maxx, maxy) in the coordinate system of the
204			shape store.
205	bh	1535	"""
206	bh	1593	left, bottom, right, top = bbox
207			for i in self.shapetree.find_shapes((left, bottom), (right, top)):
208			yield ShapefileShape(self.shapefile, i)
209	bh	1535
210	bh	1593	def AllShapes(self):
211			"""Return an iterable over the shapes in the shape store."""
212			for i in xrange(self.NumShapes()):
213			yield ShapefileShape(self.shapefile, i)
214
215	bh	1535	def Shape(self, index):
216			"""Return the shape with index index"""
217	bh	1559	return ShapefileShape(self.shapefile, index)
218	bh	1535
219
220
221	bh	984	class DerivedShapeStore:
222
223			"""A ShapeStore derived from other shapestores or tables"""
224
225			def __init__(self, shapestore, table):
226			"""Initialize the derived shapestore.
227
228			The arguments are a shapestore for the shapedata and a table for
229			the tabular data.
230	jonathan	1261
231			Raises ValueError if the number of shapes in the shapestore
232			is different from the number of rows in the table.
233	bh	984	"""
234	jonathan	1261
235			numShapes = shapestore.Shapefile().info()[0]
236			if numShapes != table.NumRows():
237			raise ValueError(_("Table not compatible with shapestore."))
238
239	bh	984	self.shapestore = shapestore
240			self.table = table
241
242			def Table(self):
243			"""Return the table"""
244			return self.table
245
246			def Shapefile(self):
247	bh	1074	"""Return the shapefile of the underlying shapestore"""
248	bh	984	return self.shapestore.Shapefile()
249
250			def Dependencies(self):
251			"""Return a tuple containing the shapestore and the table"""
252			return (self.shapestore, self.table)
253
254	bh	1074	def OrigShapeStore(self):
255			"""
256			Return the original shapestore the derived store was instantiated with
257			"""
258			return self.shapestore
259	bh	1535
260			def Shape(self, index):
261			"""Return the shape with index index"""
262			return self.shapestore.Shape(index)
263
264			def ShapesInRegion(self, bbox):
265			"""Return the ids of the shapes that overlap the box.
266
267			This method is simply delegated to the shapestore the
268			DerivedShapeStore was instantiated with.
269			"""
270			return self.shapestore.ShapesInRegion(bbox)
271
272	bh	1593	def AllShapes(self):
273			"""Return an iterable over the shapes in the shape store.
274
275			This method is simply delegated to the shapestore the
276			DerivedShapeStore was instantiated with.
277			"""
278			return self.shapestore.AllShapes()
279
280	bh	1535	def ShapeType(self):
281			"""Return the type of the shapes in the layer.
282
283			This method is simply delegated to the shapestore the
284			DerivedShapeStore was instantiated with.
285			"""
286			return self.shapestore.ShapeType()
287
288	bh	1564	def RawShapeFormat(self):
289			"""Return the raw data format of the shapes.
290
291			This method is simply delegated to the shapestore the
292			DerivedShapeStore was instantiated with.
293			"""
294			return self.shapestore.RawShapeFormat()
295
296	bh	1535	def NumShapes(self):
297			"""Return the number of shapes in the shapestore."""
298			return self.shapestore.NumShapes()
299
300			def BoundingBox(self):
301			"""Return the bounding box of the shapes in the shapestore.
302
303			This method is simply delegated to the shapestore the
304			DerivedShapeStore was instantiated with.
305			"""
306			return self.shapestore.BoundingBox()
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision