|
22 | 22 | import gzip |
23 | 23 | import io |
24 | 24 | import os |
| 25 | +import shutil |
25 | 26 | import struct |
26 | 27 | import sys |
27 | 28 | import time |
|
41 | 42 | READ_BUFFER_SIZE = 512 * 1024 |
42 | 43 |
|
43 | 44 | FTEXT, FHCRC, FEXTRA, FNAME, FCOMMENT = 1, 2, 4, 8, 16 |
44 | | -READ, WRITE = 1, 2 |
| 45 | +READ, WRITE = gzip.READ, gzip.WRITE |
45 | 46 |
|
46 | 47 | BadGzipFile = gzip.BadGzipFile # type: ignore |
47 | 48 |
|
@@ -180,50 +181,27 @@ def write(self, data): |
180 | 181 | _GzipNGReader = _GzipReader |
181 | 182 |
|
182 | 183 |
|
183 | | -def _create_simple_gzip_header(compresslevel: int, |
184 | | - mtime=None) -> bytes: |
185 | | - """ |
186 | | - Write a simple gzip header with no extra fields. |
187 | | - :param compresslevel: Compresslevel used to determine the xfl bytes. |
188 | | - :param mtime: The mtime (must support conversion to a 32-bit integer). |
189 | | - :return: A bytes object representing the gzip header. |
190 | | - """ |
191 | | - if mtime is None: |
192 | | - mtime = time.time() |
193 | | - if compresslevel == _COMPRESS_LEVEL_BEST: |
194 | | - xfl = 2 |
195 | | - elif compresslevel == _COMPRESS_LEVEL_FAST: |
196 | | - xfl = 4 |
197 | | - else: |
198 | | - xfl = 0 |
199 | | - # Pack ID1 and ID2 magic bytes, method (8=deflate), header flags (no extra |
200 | | - # fields added to header), mtime, xfl and os (255 for unknown OS). |
201 | | - return struct.pack("<BBBBLBB", 0x1f, 0x8b, 8, 0, int(mtime), xfl, 255) |
202 | | - |
203 | | - |
204 | 184 | def compress(data, compresslevel=_COMPRESS_LEVEL_BEST, *, mtime=None): |
205 | 185 | """Compress data in one shot and return the compressed string. |
206 | 186 | compresslevel sets the compression level in range of 0-9. |
207 | 187 | mtime can be used to set the modification time. The modification time is |
208 | 188 | set to the current time by default. |
209 | 189 | """ |
210 | | - if mtime == 0: |
211 | | - # Use zlib as it creates the header with 0 mtime by default. |
212 | | - # This is faster and with less overhead. |
213 | | - return zlib_ng.compress(data, level=compresslevel, wbits=31) |
214 | | - header = _create_simple_gzip_header(compresslevel, mtime) |
215 | | - trailer = struct.pack("<LL", zlib_ng.crc32(data), (len(data) & 0xffffffff)) |
216 | | - # Wbits=-15 creates a raw deflate block. |
217 | | - return (header + zlib_ng.compress(data, level=compresslevel, wbits=-15) + |
218 | | - trailer) |
| 190 | + # Wbits=31 automatically includes a gzip header and trailer. |
| 191 | + gzip_data = zlib_ng.compress(data, level=compresslevel, wbits=31) |
| 192 | + if mtime is None: |
| 193 | + mtime = time.time() |
| 194 | + # Reuse gzip header created by zlib_ng, replace mtime and OS byte for |
| 195 | + # consistency. |
| 196 | + header = struct.pack("<4sLBB", gzip_data, int(mtime), gzip_data[8], 255) |
| 197 | + return header + gzip_data[10:] |
219 | 198 |
|
220 | 199 |
|
221 | 200 | def decompress(data): |
222 | 201 | """Decompress a gzip compressed string in one shot. |
223 | 202 | Return the decompressed string. |
224 | 203 | """ |
225 | | - fp = io.BytesIO(data) |
226 | | - reader = _GzipReader(fp, max(len(data), 16)) |
| 204 | + reader = _GzipReader(data) |
227 | 205 | return reader.readall() |
228 | 206 |
|
229 | 207 |
|
@@ -325,11 +303,7 @@ def main(): |
325 | 303 | global READ_BUFFER_SIZE |
326 | 304 | READ_BUFFER_SIZE = args.buffer_size |
327 | 305 | try: |
328 | | - while True: |
329 | | - block = in_file.read(args.buffer_size) |
330 | | - if block == b"": |
331 | | - break |
332 | | - out_file.write(block) |
| 306 | + shutil.copyfileobj(in_file, out_file, args.buffer_size) |
333 | 307 | finally: |
334 | 308 | if in_file is not sys.stdin.buffer: |
335 | 309 | in_file.close() |
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