1- import sys
2-
3- from cffi import FFI
4-
5- if sys .hexversion > 0x03000000 :
6- unicode = str
7-
8- ffi = FFI ()
9-
10- ffi .cdef ('''
11- typedef enum {
12- SNAPPY_OK = 0,
13- SNAPPY_INVALID_INPUT = 1,
14- SNAPPY_BUFFER_TOO_SMALL = 2
15- } snappy_status;
16-
17- typedef uint32_t crc_t;
18-
19- int snappy_compress(const char* input,
20- size_t input_length,
21- char* compressed,
22- size_t* compressed_length);
23-
24- int snappy_uncompress(const char* compressed,
25- size_t compressed_length,
26- char* uncompressed,
27- size_t* uncompressed_length);
28-
29- size_t snappy_max_compressed_length(size_t source_length);
30-
31- int snappy_uncompressed_length(const char* compressed,
32- size_t compressed_length,
33- size_t* result);
34-
35- int snappy_validate_compressed_buffer(const char* compressed,
36- size_t compressed_length);
37-
38- crc_t crc_init(void);
39-
40- crc_t crc_finalize(crc_t crc);
41-
42- crc_t crc_reflect(crc_t data, size_t data_len);
43-
44- crc_t crc_update(crc_t crc, const unsigned char *data, size_t data_len);
45-
46- crc_t _crc32c(const char *input, int input_size);
47-
48- ''' )
49-
50- C = ffi .verify ('''
51- #include <stdint.h>
52- #include <stdlib.h>
53- #include "snappy-c.h"
54-
55- /*
56- * COPY of crc32c
57- * This is allowed since all crc code is self contained
58- */
59-
60- typedef uint32_t crc_t;
61-
62- uint32_t crc_table[256] = {
63- 0x00000000, 0xf26b8303, 0xe13b70f7, 0x1350f3f4,
64- 0xc79a971f, 0x35f1141c, 0x26a1e7e8, 0xd4ca64eb,
65- 0x8ad958cf, 0x78b2dbcc, 0x6be22838, 0x9989ab3b,
66- 0x4d43cfd0, 0xbf284cd3, 0xac78bf27, 0x5e133c24,
67- 0x105ec76f, 0xe235446c, 0xf165b798, 0x030e349b,
68- 0xd7c45070, 0x25afd373, 0x36ff2087, 0xc494a384,
69- 0x9a879fa0, 0x68ec1ca3, 0x7bbcef57, 0x89d76c54,
70- 0x5d1d08bf, 0xaf768bbc, 0xbc267848, 0x4e4dfb4b,
71- 0x20bd8ede, 0xd2d60ddd, 0xc186fe29, 0x33ed7d2a,
72- 0xe72719c1, 0x154c9ac2, 0x061c6936, 0xf477ea35,
73- 0xaa64d611, 0x580f5512, 0x4b5fa6e6, 0xb93425e5,
74- 0x6dfe410e, 0x9f95c20d, 0x8cc531f9, 0x7eaeb2fa,
75- 0x30e349b1, 0xc288cab2, 0xd1d83946, 0x23b3ba45,
76- 0xf779deae, 0x05125dad, 0x1642ae59, 0xe4292d5a,
77- 0xba3a117e, 0x4851927d, 0x5b016189, 0xa96ae28a,
78- 0x7da08661, 0x8fcb0562, 0x9c9bf696, 0x6ef07595,
79- 0x417b1dbc, 0xb3109ebf, 0xa0406d4b, 0x522bee48,
80- 0x86e18aa3, 0x748a09a0, 0x67dafa54, 0x95b17957,
81- 0xcba24573, 0x39c9c670, 0x2a993584, 0xd8f2b687,
82- 0x0c38d26c, 0xfe53516f, 0xed03a29b, 0x1f682198,
83- 0x5125dad3, 0xa34e59d0, 0xb01eaa24, 0x42752927,
84- 0x96bf4dcc, 0x64d4cecf, 0x77843d3b, 0x85efbe38,
85- 0xdbfc821c, 0x2997011f, 0x3ac7f2eb, 0xc8ac71e8,
86- 0x1c661503, 0xee0d9600, 0xfd5d65f4, 0x0f36e6f7,
87- 0x61c69362, 0x93ad1061, 0x80fde395, 0x72966096,
88- 0xa65c047d, 0x5437877e, 0x4767748a, 0xb50cf789,
89- 0xeb1fcbad, 0x197448ae, 0x0a24bb5a, 0xf84f3859,
90- 0x2c855cb2, 0xdeeedfb1, 0xcdbe2c45, 0x3fd5af46,
91- 0x7198540d, 0x83f3d70e, 0x90a324fa, 0x62c8a7f9,
92- 0xb602c312, 0x44694011, 0x5739b3e5, 0xa55230e6,
93- 0xfb410cc2, 0x092a8fc1, 0x1a7a7c35, 0xe811ff36,
94- 0x3cdb9bdd, 0xceb018de, 0xdde0eb2a, 0x2f8b6829,
95- 0x82f63b78, 0x709db87b, 0x63cd4b8f, 0x91a6c88c,
96- 0x456cac67, 0xb7072f64, 0xa457dc90, 0x563c5f93,
97- 0x082f63b7, 0xfa44e0b4, 0xe9141340, 0x1b7f9043,
98- 0xcfb5f4a8, 0x3dde77ab, 0x2e8e845f, 0xdce5075c,
99- 0x92a8fc17, 0x60c37f14, 0x73938ce0, 0x81f80fe3,
100- 0x55326b08, 0xa759e80b, 0xb4091bff, 0x466298fc,
101- 0x1871a4d8, 0xea1a27db, 0xf94ad42f, 0x0b21572c,
102- 0xdfeb33c7, 0x2d80b0c4, 0x3ed04330, 0xccbbc033,
103- 0xa24bb5a6, 0x502036a5, 0x4370c551, 0xb11b4652,
104- 0x65d122b9, 0x97baa1ba, 0x84ea524e, 0x7681d14d,
105- 0x2892ed69, 0xdaf96e6a, 0xc9a99d9e, 0x3bc21e9d,
106- 0xef087a76, 0x1d63f975, 0x0e330a81, 0xfc588982,
107- 0xb21572c9, 0x407ef1ca, 0x532e023e, 0xa145813d,
108- 0x758fe5d6, 0x87e466d5, 0x94b49521, 0x66df1622,
109- 0x38cc2a06, 0xcaa7a905, 0xd9f75af1, 0x2b9cd9f2,
110- 0xff56bd19, 0x0d3d3e1a, 0x1e6dcdee, 0xec064eed,
111- 0xc38d26c4, 0x31e6a5c7, 0x22b65633, 0xd0ddd530,
112- 0x0417b1db, 0xf67c32d8, 0xe52cc12c, 0x1747422f,
113- 0x49547e0b, 0xbb3ffd08, 0xa86f0efc, 0x5a048dff,
114- 0x8ecee914, 0x7ca56a17, 0x6ff599e3, 0x9d9e1ae0,
115- 0xd3d3e1ab, 0x21b862a8, 0x32e8915c, 0xc083125f,
116- 0x144976b4, 0xe622f5b7, 0xf5720643, 0x07198540,
117- 0x590ab964, 0xab613a67, 0xb831c993, 0x4a5a4a90,
118- 0x9e902e7b, 0x6cfbad78, 0x7fab5e8c, 0x8dc0dd8f,
119- 0xe330a81a, 0x115b2b19, 0x020bd8ed, 0xf0605bee,
120- 0x24aa3f05, 0xd6c1bc06, 0xc5914ff2, 0x37faccf1,
121- 0x69e9f0d5, 0x9b8273d6, 0x88d28022, 0x7ab90321,
122- 0xae7367ca, 0x5c18e4c9, 0x4f48173d, 0xbd23943e,
123- 0xf36e6f75, 0x0105ec76, 0x12551f82, 0xe03e9c81,
124- 0x34f4f86a, 0xc69f7b69, 0xd5cf889d, 0x27a40b9e,
125- 0x79b737ba, 0x8bdcb4b9, 0x988c474d, 0x6ae7c44e,
126- 0xbe2da0a5, 0x4c4623a6, 0x5f16d052, 0xad7d5351
127- };
128-
129- crc_t crc_init(void)
130- {
131- return 0xffffffff;
132- }
133-
134- crc_t crc_finalize(crc_t crc)
135- {
136- return crc ^ 0xffffffff;
137- }
138-
139- crc_t crc_reflect(crc_t data, size_t data_len)
140- {
141- unsigned int i;
142- crc_t ret;
143-
144- ret = data & 0x01;
145- for (i = 1; i < data_len; i++) {
146- data >>= 1;
147- ret = (ret << 1) | (data & 0x01);
148- }
149- return ret;
150- }
151-
152- crc_t crc_update(crc_t crc, const unsigned char *data, size_t data_len)
153- {
154- unsigned int tbl_idx;
155-
156- while (data_len--) {
157- tbl_idx = (crc ^ *data) & 0xff;
158- crc = (crc_table[tbl_idx] ^ (crc >> 8)) & 0xffffffff;
159-
160- data++;
161- }
162- return crc & 0xffffffff;
163- }
164-
165- uint32_t _crc32c(const char *input, int input_size) {
166- return crc_finalize(crc_update(crc_init(), input, input_size));
167- }
168-
169- ''' , libraries = ["snappy" ])
170-
1+ from _snappy_cffi import ffi , lib
1712
1723class UncompressError (Exception ):
1734 pass
@@ -192,14 +23,14 @@ def compress(data):
19223
19324 _input_data , _input_size = prepare (data )
19425
195- max_compressed = C .snappy_max_compressed_length (_input_size )
26+ max_compressed = lib .snappy_max_compressed_length (_input_size )
19627
19728 _out_data = ffi .new ('char[]' , max_compressed )
19829 _out_size = ffi .new ('size_t*' , max_compressed )
19930
200- rc = C .snappy_compress (_input_data , _input_size , _out_data , _out_size )
31+ rc = lib .snappy_compress (_input_data , _input_size , _out_data , _out_size )
20132
202- if rc != C .SNAPPY_OK :
33+ if rc != lib .SNAPPY_OK :
20334 raise SnappyBufferSmallError ()
20435
20536 value = ffi .buffer (ffi .cast ('char*' , _out_data ), _out_size [0 ])
@@ -212,23 +43,23 @@ def uncompress(data):
21243
21344 result = ffi .new ('size_t*' , 0 )
21445
215- rc = C .snappy_validate_compressed_buffer (_out_data , _out_size )
46+ rc = lib .snappy_validate_compressed_buffer (_out_data , _out_size )
21647
217- if not rc == C .SNAPPY_OK :
48+ if not rc == lib .SNAPPY_OK :
21849 raise UncompressError ()
21950
220- rc = C .snappy_uncompressed_length (_out_data ,
51+ rc = lib .snappy_uncompressed_length (_out_data ,
22152 _out_size ,
22253 result )
22354
224- if not rc == C .SNAPPY_OK :
55+ if not rc == lib .SNAPPY_OK :
22556 raise UncompressError ()
22657
22758 _uncompressed_data = ffi .new ('char[]' , result [0 ])
22859
229- rc = C .snappy_uncompress (_out_data , _out_size , _uncompressed_data , result )
60+ rc = lib .snappy_uncompress (_out_data , _out_size , _uncompressed_data , result )
23061
231- if rc != C .SNAPPY_OK :
62+ if rc != lib .SNAPPY_OK :
23263 raise UncompressError ()
23364
23465 buf = ffi .buffer (ffi .cast ('char*' , _uncompressed_data ), result [0 ])
@@ -242,14 +73,13 @@ def isValidCompressed(data):
24273
24374 _out_data , _out_size = prepare (data )
24475
245- rc = C .snappy_validate_compressed_buffer (_out_data , _out_size )
76+ rc = lib .snappy_validate_compressed_buffer (_out_data , _out_size )
24677
247- return rc == C .SNAPPY_OK
78+ return rc == lib .SNAPPY_OK
24879
24980decompress = uncompress
25081
25182def _crc32c (data ):
25283 c_data = ffi .new ('char[]' , data )
25384 size = ffi .cast ('int' , len (data ))
254- return int (C ._crc32c (c_data , size ))
255-
85+ return int (lib ._crc32c (c_data , size ))
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