test_zlib.py revision c72737e7b6ec3beeecafbef75fbc31e22e0d710b
1import zlib 2from test_support import TestFailed 3import sys 4import imp 5 6try: 7 t = imp.find_module('test_zlib') 8 file = t[0] 9except ImportError: 10 file = open(__file__) 11buf = file.read() * 8 12file.close() 13 14# test the checksums (hex so the test doesn't break on 64-bit machines) 15print hex(zlib.crc32('penguin')), hex(zlib.crc32('penguin', 1)) 16print hex(zlib.adler32('penguin')), hex(zlib.adler32('penguin', 1)) 17 18# make sure we generate some expected errors 19try: 20 zlib.compress('ERROR', zlib.MAX_WBITS + 1) 21except zlib.error, msg: 22 print "expecting", msg 23try: 24 zlib.compressobj(1, 8, 0) 25except ValueError, msg: 26 print "expecting", msg 27try: 28 zlib.decompressobj(0) 29except ValueError, msg: 30 print "expecting", msg 31 32x = zlib.compress(buf) 33y = zlib.decompress(x) 34if buf != y: 35 print "normal compression/decompression failed" 36else: 37 print "normal compression/decompression succeeded" 38 39buf = buf * 16 40 41co = zlib.compressobj(8, 8, -15) 42x1 = co.compress(buf) 43x2 = co.flush() 44try: 45 co.flush() 46 print "Oops - second flush worked when it should not have!" 47except zlib.error: 48 pass 49 50x = x1 + x2 51 52dc = zlib.decompressobj(-15) 53y1 = dc.decompress(x) 54y2 = dc.flush() 55y = y1 + y2 56if buf != y: 57 print "compress/decompression obj failed" 58else: 59 print "compress/decompression obj succeeded" 60 61co = zlib.compressobj(2, 8, -12, 9, 1) 62bufs = [] 63for i in range(0, len(buf), 256): 64 bufs.append(co.compress(buf[i:i+256])) 65bufs.append(co.flush()) 66combuf = ''.join(bufs) 67 68decomp1 = zlib.decompress(combuf, -12, -5) 69if decomp1 != buf: 70 print "decompress with init options failed" 71else: 72 print "decompress with init options succeeded" 73 74deco = zlib.decompressobj(-12) 75bufs = [] 76for i in range(0, len(combuf), 128): 77 bufs.append(deco.decompress(combuf[i:i+128])) 78bufs.append(deco.flush()) 79decomp2 = ''.join(bufs) 80if decomp2 != buf: 81 print "decompressobj with init options failed" 82else: 83 print "decompressobj with init options succeeded" 84 85print "should be '':", `deco.unconsumed_tail` 86 87# Check a decompression object with max_length specified 88deco = zlib.decompressobj(-12) 89cb = combuf 90bufs = [] 91while cb: 92 max_length = 1 + len(cb)/10 93 chunk = deco.decompress(cb, max_length) 94 if len(chunk) > max_length: 95 print 'chunk too big (%d>%d)' % (len(chunk),max_length) 96 bufs.append(chunk) 97 cb = deco.unconsumed_tail 98bufs.append(deco.flush()) 99decomp2 = ''.join(buf) 100if decomp2 != buf: 101 print "max_length decompressobj failed" 102else: 103 print "max_length decompressobj succeeded" 104 105# Misc tests of max_length 106deco = zlib.decompressobj(-12) 107try: 108 deco.decompress("", -1) 109except ValueError: 110 pass 111else: 112 print "failed to raise value error on bad max_length" 113print "unconsumed_tail should be '':", `deco.unconsumed_tail` 114 115# Test flush() with the various options, using all the different levels 116# in order to provide more variations. 117sync_opt = ['Z_NO_FLUSH', 'Z_SYNC_FLUSH', 'Z_FULL_FLUSH'] 118sync_opt = [getattr(zlib, opt) for opt in sync_opt if hasattr(zlib, opt)] 119 120for sync in sync_opt: 121 for level in range(10): 122 obj = zlib.compressobj( level ) 123 d = obj.compress( buf[:3000] ) 124 d = d + obj.flush( sync ) 125 d = d + obj.compress( buf[3000:] ) 126 d = d + obj.flush() 127 if zlib.decompress(d) != buf: 128 print "Decompress failed: flush mode=%i, level=%i" % (sync,level) 129 del obj 130 131# Test for the odd flushing bugs noted in 2.0, and hopefully fixed in 2.1 132 133import random 134random.seed(1) 135 136print 'Testing on 17K of random data' 137 138if hasattr(zlib, 'Z_SYNC_FLUSH'): 139 140 # Create compressor and decompressor objects 141 c=zlib.compressobj(9) 142 d=zlib.decompressobj() 143 144 # Try 17K of data 145 # generate random data stream 146 a="" 147 for i in range(17*1024): 148 a=a+chr(random.randint(0,255)) 149 150 # compress, sync-flush, and decompress 151 t = d.decompress( c.compress(a)+c.flush(zlib.Z_SYNC_FLUSH) ) 152 153 # if decompressed data is different from the input data, choke. 154 if len(t) != len(a): 155 print len(a),len(t),len(d.unused_data) 156 raise TestFailed, "output of 17K doesn't match" 157 158def ignore(): 159 """An empty function with a big string. 160 161 Make the compression algorithm work a little harder. 162 """ 163 164 """ 165LAERTES 166 167 O, fear me not. 168 I stay too long: but here my father comes. 169 170 Enter POLONIUS 171 172 A double blessing is a double grace, 173 Occasion smiles upon a second leave. 174 175LORD POLONIUS 176 177 Yet here, Laertes! aboard, aboard, for shame! 178 The wind sits in the shoulder of your sail, 179 And you are stay'd for. There; my blessing with thee! 180 And these few precepts in thy memory 181 See thou character. Give thy thoughts no tongue, 182 Nor any unproportioned thought his act. 183 Be thou familiar, but by no means vulgar. 184 Those friends thou hast, and their adoption tried, 185 Grapple them to thy soul with hoops of steel; 186 But do not dull thy palm with entertainment 187 Of each new-hatch'd, unfledged comrade. Beware 188 Of entrance to a quarrel, but being in, 189 Bear't that the opposed may beware of thee. 190 Give every man thy ear, but few thy voice; 191 Take each man's censure, but reserve thy judgment. 192 Costly thy habit as thy purse can buy, 193 But not express'd in fancy; rich, not gaudy; 194 For the apparel oft proclaims the man, 195 And they in France of the best rank and station 196 Are of a most select and generous chief in that. 197 Neither a borrower nor a lender be; 198 For loan oft loses both itself and friend, 199 And borrowing dulls the edge of husbandry. 200 This above all: to thine ownself be true, 201 And it must follow, as the night the day, 202 Thou canst not then be false to any man. 203 Farewell: my blessing season this in thee! 204 205LAERTES 206 207 Most humbly do I take my leave, my lord. 208 209LORD POLONIUS 210 211 The time invites you; go; your servants tend. 212 213LAERTES 214 215 Farewell, Ophelia; and remember well 216 What I have said to you. 217 218OPHELIA 219 220 'Tis in my memory lock'd, 221 And you yourself shall keep the key of it. 222 223LAERTES 224 225 Farewell. 226""" 227