97 lines
2.2 KiB
Python
97 lines
2.2 KiB
Python
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from datetime import datetime
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from .record import *
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class Reader(object):
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def __init__(self, file):
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self.stream = file
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def skip(self, n):
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self.stream.read(n)
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def read_int(self):
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temp = self.stream.read(4)
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if len(temp) != 4:
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return None
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return int(temp[3]) | int(temp[2]) << 8 | int(temp[1]) << 16 | int(temp[0]) << 24
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def read_short(self):
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temp = self.stream.read(2)
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if len(temp) != 2:
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return None
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return int(temp[1]) | int(temp[0]) << 8
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def read_double(self):
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temp = self.stream.read(8)
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if len(temp) != 8:
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return None
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result = 0
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for i in temp:
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if int(i) != 0:
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# read double
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result = 1
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for j in range(1,8):
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result += float(temp[8-j])/(2**(j*8))
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exp = int(temp[0]) & 0x7F
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exp -= 64
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result *= 16**exp
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if int(temp[0]) & 0x80:
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result += -1
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return result
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# double is Zero
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return 0
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def read_ascii(self, len):
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return self.stream.read(len).decode("ASCII").strip()
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def read_record(self):
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result = Record()
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try:
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result.len = self.read_short()
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result.ident = Records(self.read_short())
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except ValueError:
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return None
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result.len -= 4 # remove record header len
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return result
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def read_date(self):
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# date
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year = self.read_short()
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month = self.read_short()
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day = self.read_short()
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# time
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hour = self.read_short()
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minute = self.read_short()
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second = self.read_short()
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return datetime(year=year, month=month, day=day, hour=hour, minute=minute, second=second)
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def read_coord(self):
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X = self.read_int()
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Y = self.read_int()
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return (X,Y)
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def read_coords(self, len):
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len /= 8
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result = []
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while len > 0:
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point = self.read_coord()
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if not point:
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return None
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result.append(point)
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len -= 1
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return result
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