| /** |
| * \file lzma/vli.h |
| * \brief Variable-length integer handling |
| * |
| * \author Copyright (C) 1999-2006 Igor Pavlov |
| * \author Copyright (C) 2007 Lasse Collin |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| */ |
| |
| #ifndef LZMA_H_INTERNAL |
| # error Never include this file directly. Use <lzma.h> instead. |
| #endif |
| |
| |
| /** |
| * \brief Maximum supported value of variable-length integer |
| */ |
| #define LZMA_VLI_VALUE_MAX (UINT64_MAX / 2) |
| |
| /** |
| * \brief VLI value to denote that the value is unknown |
| */ |
| #define LZMA_VLI_VALUE_UNKNOWN UINT64_MAX |
| |
| /** |
| * \brief Maximum supported length of variable length integers |
| */ |
| #define LZMA_VLI_BYTES_MAX 9 |
| |
| |
| /** |
| * \brief VLI constant suffix |
| */ |
| #define LZMA_VLI_C(n) UINT64_C(n) |
| |
| |
| /** |
| * \brief Variable-length integer type |
| * |
| * This will always be unsigned integer. Valid VLI values are in the range |
| * [0, LZMA_VLI_VALUE_MAX]. Unknown value is indicated with |
| * LZMA_VLI_VALUE_UNKNOWN, which is the maximum value of the underlaying |
| * integer type (this feature is useful in several situations). |
| * |
| * In future, even if lzma_vli is typdefined to something else than uint64_t, |
| * it is guaranteed that 2 * LZMA_VLI_VALUE_MAX will not overflow lzma_vli. |
| * This simplifies integer overflow detection. |
| */ |
| typedef uint64_t lzma_vli; |
| |
| |
| /** |
| * \brief Simple macro to validate variable-length integer |
| * |
| * This is useful to test that application has given acceptable values |
| * for example in the uncompressed_size and compressed_size variables. |
| * |
| * \return True if the integer is representable as VLI or if it |
| * indicates unknown value. |
| */ |
| #define lzma_vli_is_valid(vli) \ |
| ((vli) <= LZMA_VLI_VALUE_MAX || (vli) == LZMA_VLI_VALUE_UNKNOWN) |
| |
| |
| /** |
| * \brief Sets VLI to given value with error checking |
| * |
| * \param dest Target variable which must have type of lzma_vli. |
| * \param src New value to be stored to dest. |
| * \param limit Maximum allowed value for src. |
| * |
| * \return False on success, true on error. If an error occurred, |
| * dest is left in undefined state (i.e. it's possible that |
| * it will be different in newer liblzma versions). |
| */ |
| #define lzma_vli_set_lim(dest, src, limit) \ |
| ((src) > (limit) || ((dest) = (src)) > (limit)) |
| |
| /** |
| * \brief |
| */ |
| #define lzma_vli_add_lim(dest, src, limit) \ |
| ((src) > (limit) || ((dest) += (src)) > (limit)) |
| |
| #define lzma_vli_add2_lim(dest, src1, src2, limit) \ |
| (lzma_vli_add_lim(dest, src1, limit) \ |
| || lzma_vli_add_lim(dest, src2, limit)) |
| |
| #define lzma_vli_add3_lim(dest, src1, src2, src3, limit) \ |
| (lzma_vli_add_lim(dest, src1, limit) \ |
| || lzma_vli_add_lim(dest, src2, limit) \ |
| || lzma_vli_add_lim(dest, src3, limit)) |
| |
| #define lzma_vli_add4_lim(dest, src1, src2, src3, src4, limit) \ |
| (lzma_vli_add_lim(dest, src1, limit) \ |
| || lzma_vli_add_lim(dest, src2, limit) \ |
| || lzma_vli_add_lim(dest, src3, limit) \ |
| || lzma_vli_add_lim(dest, src4, limit)) |
| |
| #define lzma_vli_sum_lim(dest, src1, src2, limit) \ |
| (lzma_vli_set_lim(dest, src1, limit) \ |
| || lzma_vli_add_lim(dest, src2, limit)) |
| |
| #define lzma_vli_sum3_lim(dest, src1, src2, src3, limit) \ |
| (lzma_vli_set_lim(dest, src1, limit) \ |
| || lzma_vli_add_lim(dest, src2, limit) \ |
| || lzma_vli_add_lim(dest, src3, limit)) |
| |
| #define lzma_vli_sum4_lim(dest, src1, src2, src3, src4, limit) \ |
| (lzma_vli_set_lim(dest, src1, limit) \ |
| || lzma_vli_add_lim(dest, src2, limit) \ |
| || lzma_vli_add_lim(dest, src3, limit) \ |
| || lzma_vli_add_lim(dest, src4, limit)) |
| |
| #define lzma_vli_set(dest, src) lzma_vli_set_lim(dest, src, LZMA_VLI_VALUE_MAX) |
| |
| #define lzma_vli_add(dest, src) lzma_vli_add_lim(dest, src, LZMA_VLI_VALUE_MAX) |
| |
| #define lzma_vli_add2(dest, src1, src2) \ |
| lzma_vli_add2_lim(dest, src1, src2, LZMA_VLI_VALUE_MAX) |
| |
| #define lzma_vli_add3(dest, src1, src2, src3) \ |
| lzma_vli_add3_lim(dest, src1, src2, src3, LZMA_VLI_VALUE_MAX) |
| |
| #define lzma_vli_add4(dest, src1, src2, src3, src4) \ |
| lzma_vli_add4_lim(dest, src1, src2, src3, src4, LZMA_VLI_VALUE_MAX) |
| |
| #define lzma_vli_sum(dest, src1, src2) \ |
| lzma_vli_sum_lim(dest, src1, src2, LZMA_VLI_VALUE_MAX) |
| |
| #define lzma_vli_sum3(dest, src1, src2, src3) \ |
| lzma_vli_sum3_lim(dest, src1, src2, src3, LZMA_VLI_VALUE_MAX) |
| |
| #define lzma_vli_sum4(dest, src1, src2, src3, src4) \ |
| lzma_vli_sum4_lim(dest, src1, src2, src3, src4, LZMA_VLI_VALUE_MAX) |
| |
| |
| /** |
| * \brief Encodes variable-length integer |
| * |
| * In the new .lzma format, most integers are encoded in variable-length |
| * representation. This saves space when smaller values are more likely |
| * than bigger values. |
| * |
| * The encoding scheme encodes seven bits to every byte, using minimum |
| * number of bytes required to represent the given value. In other words, |
| * it puts 7-63 bits into 1-9 bytes. This implementation limits the number |
| * of bits used to 63, thus num must be at maximum of UINT64_MAX / 2. You |
| * may use LZMA_VLI_VALUE_MAX for clarity. |
| * |
| * \param vli Integer to be encoded |
| * \param vli_pos How many bytes have already been written out. This |
| * must be less than 9 before calling this function. |
| * \param vli_size Minimum size that the variable-length representation |
| * must take. This is useful if you want to use |
| * variable-length integers as padding. Usually you want |
| * to set this to zero. The maximum allowed value is 9. |
| * \param out Beginning of the output buffer |
| * \param out_pos The next byte will be written to out[*out_pos]. |
| * \param out_size Size of the out buffer; the first byte into |
| * which no data is written to is out[out_size]. |
| * |
| * \return - LZMA_OK: So far all OK, but the integer is not |
| * completely written out yet. |
| * - LZMA_STREAM_END: Integer successfully encoded. |
| * - LZMA_BUF_ERROR: No output space (*out_pos == out_size) |
| * - LZMA_PROG_ERROR: Arguments are not sane. |
| */ |
| extern lzma_ret lzma_vli_encode( |
| lzma_vli vli, size_t *lzma_restrict vli_pos, size_t vli_size, |
| uint8_t *lzma_restrict out, size_t *lzma_restrict out_pos, |
| size_t out_size); |
| |
| |
| /** |
| * \brief Decodes variable-length integer |
| * |
| * \param vli Pointer to decoded integer. The decoder will |
| * initialize it to zero when *vli_pos == 0, so |
| * application isn't required to initialize *vli. |
| * \param vli_pos How many bytes have already been decoded. When |
| * starting to decode a new integer, *vli_pos must |
| * be initialized to zero. |
| * \param in Beginning of the input buffer |
| * \param in_pos The next byte will be read from in[*in_pos]. |
| * \param in_size Size of the input buffer; the first byte that |
| * won't be read is in[in_size]. |
| * |
| * \return - LZMA_OK: So far all OK, but the integer is not |
| * completely decoded yet. |
| * - LZMA_STREAM_END: Integer successfully decoded. |
| * - LZMA_BUF_ERROR: No input data (*in_pos == in_size) |
| * - LZMA_DATA_ERROR: Integer is longer than nine bytes. |
| * - LZMA_PROG_ERROR: Arguments are not sane. |
| */ |
| extern lzma_ret lzma_vli_decode(lzma_vli *lzma_restrict vli, |
| size_t *lzma_restrict vli_pos, const uint8_t *lzma_restrict in, |
| size_t *lzma_restrict in_pos, size_t in_size); |
| |
| |
| /** |
| * \brief Decodes variable-length integer reading buffer backwards |
| * |
| * The variable-length integer encoding is designed so that it can be read |
| * either from the beginning to the end, or from the end to the beginning. |
| * This feature is needed to make the Stream parseable backwards; |
| * specifically, to read the Backward Size field in Stream Footer. |
| * |
| * \param vli Pointer to variable to hold the decoded integer. |
| * \param in Beginning of the input buffer |
| * \param in_size Number of bytes available in the in[] buffer. |
| * On successful decoding, this is updated to match |
| * the number of bytes used. (in[*in_size - 1] is the |
| * first byte to process. After successful decoding, |
| * in[*in_size] will point to the first byte of the |
| * variable-length integer.) |
| * |
| * \return - LZMA_OK: Decoding successful |
| * - LZMA_DATA_ERROR: No valid variable-length integer was found. |
| * - LZMA_BUF_ERROR: Not enough input. Note that in practice, |
| * this tends to be a sign of broken input, because the |
| * applications usually do give as much input to this function |
| * as the applications have available. |
| */ |
| extern lzma_ret lzma_vli_reverse_decode( |
| lzma_vli *vli, const uint8_t *in, size_t *in_size); |
| |
| |
| /** |
| * \brief Gets the minimum number of bytes required to encode vli |
| * |
| * \return Number of bytes on success (1-9). If vli isn't valid, |
| * zero is returned. |
| */ |
| extern size_t lzma_vli_size(lzma_vli vli); |
