ntfs3/lib/lzx_decompress.c

4  * be used in "System Compressed" files.  This is based on the code from wimlib.
6  * this is the only size used in System Compression.
24 /* Number of match lengths for which no length symbol is required  */
46 /* Number of bits in which each precode codeword length is represented  */
62 /* Number of bits in which each aligned offset codeword length is represented  */
73  * in the LZX format used in WIM files and system-compressed files this value is
175 	 * A worthwhile optimization is to push the end-of-buffer check into the
176 	 * relatively rare E8 case.  This is possible if we replace the last six
180 	 * bytes because a 4-byte offset containing E8 as its high byte is a
181 	 * large negative number that is not valid for translation.  That is
208 					struct input_bitstream *is)
210 	return read_huffsym(is, d->precode_decode_table,
216 					 struct input_bitstream *is)
218 	return read_huffsym(is, d->maincode_decode_table,
224 					struct input_bitstream *is)
226 	return read_huffsym(is, d->lencode_decode_table,
232 					    struct input_bitstream *is)
234 	return read_huffsym(is, d->alignedcode_decode_table,
243  * @is:		The input bitstream.
247  *		if this is the first time.  This array must have at least
255 				  struct input_bitstream *is,
267 			bitstream_read_bits(is, LZX_PRECODE_ELEMENT_SIZE);
285 		presym = read_presym(d, is);
299 				run_len = 4 + bitstream_read_bits(is, 4);
303 				run_len = 20 + bitstream_read_bits(is, 5);
307 				run_len = 4 + bitstream_read_bits(is, 1);
308 				presym = read_presym(d, is);
319 			/* Worst case overrun is when presym == 18,
327 			 * generates overruns is invalid anyway.
339  * If the block is compressed, also update the Huffman decode @tables with the
340  * new Huffman codes.  If the block is uncompressed, also update the match
346 				 struct input_bitstream *is,
355 	bitstream_ensure_bits(is, 4);
357 	/* The first three bits tell us what kind of block it is, and should be
360 	block_type = bitstream_pop_bits(is, 3);
363 	if (bitstream_pop_bits(is, 1)) {
367 		block_size |= bitstream_read_bits(is, 8);
369 		block_size |= bitstream_read_bits(is, 8);
381 				bitstream_read_bits(is,
394 		 * blocks is the same as that for verbatim blocks.
407 		if (lzx_read_codeword_lens(d, is, d->maincode_lens,
411 		if (lzx_read_codeword_lens(d, is,
426 		if (lzx_read_codeword_lens(d, is, d->lencode_lens,
444 		 * boundary.  But if the stream is *already* aligned, then the
447 		bitstream_ensure_bits(is, 1);
448 		bitstream_align(is);
450 		recent_offsets[0] = bitstream_read_u32(is);
451 		recent_offsets[1] = bitstream_read_u32(is);
452 		recent_offsets[2] = bitstream_read_u32(is);
472 				struct input_bitstream *is,
487 		mainsym = read_mainsym(d, is);
503 			match_len += read_lensym(d, is);
512 			 * the same code.  (For R0, the swap is a no-op.)
535 					bitstream_read_bits(is, num_extra_bits -
538 				match_offset += read_alignedsym(d, is);
540 				match_offset += bitstream_read_bits(is, num_extra_bits);
598 	struct input_bitstream is;
602 	init_input_bitstream(&is, compressed_data, compressed_size);
614 		if (lzx_read_block_header(d, &is, &block_type, &block_size,
626 						 &is,
639 			out_next = bitstream_read_bytes(&is, out_next,
645 				bitstream_read_byte(&is);