X-Git-Url: https://git.sesse.net/?p=fjl;a=blobdiff_plain;f=dehuff.h;h=9243e101530018b346e80e2db8b64b96dee1db61;hp=224005f84ad3dcb2797c9086a11485c8269c825c;hb=8389f95d5750d6fcb202181005954829e64865b4;hpb=9d2d4ff08d760e0abd83d2cea03c77d5b752a400 diff --git a/dehuff.h b/dehuff.h index 224005f..9243e10 100644 --- a/dehuff.h +++ b/dehuff.h @@ -48,12 +48,11 @@ void read_huffman_tables(huffman_tables_t* dst, input_func_t* input_func, void* unsigned read_huffman_symbol_slow_path(const struct huffman_table* table, struct bit_source* source); -static inline unsigned read_huffman_symbol(const struct huffman_table* table, - struct bit_source* source) +static inline unsigned read_huffman_symbol_no_refill( + const struct huffman_table* table, + struct bit_source* source) { - // FIXME: We can read past the end of the stream here in some edge - // cases. We need to define some guarantees in the layers above. - possibly_refill(source, DEHUF_TABLE_BITS); + assert(source->bits_available >= DEHUF_TABLE_BITS); unsigned lookup = peek_bits(source, DEHUF_TABLE_BITS); int code = table->lookup_table_codes[lookup]; int length = table->lookup_table_length[lookup]; @@ -61,11 +60,18 @@ static inline unsigned read_huffman_symbol(const struct huffman_table* table, if (code == DEHUF_SLOW_PATH) { return read_huffman_symbol_slow_path(table, source); } - + read_bits(source, length); return code; } +static inline unsigned read_huffman_symbol(const struct huffman_table* table, + struct bit_source* source) +{ + possibly_refill(source, DEHUF_TABLE_BITS); + return read_huffman_symbol_no_refill(table, source); +} + // procedure EXTEND (figure F.12) // Fast lookup table for (1 << (bits - 1)).