diff options
Diffstat (limited to '')
| -rw-r--r-- | src/liblzma/api/lzma/vli.h | 131 |
1 files changed, 34 insertions, 97 deletions
diff --git a/src/liblzma/api/lzma/vli.h b/src/liblzma/api/lzma/vli.h index 15a9d0bf..294e5cdd 100644 --- a/src/liblzma/api/lzma/vli.h +++ b/src/liblzma/api/lzma/vli.h @@ -72,90 +72,24 @@ typedef uint64_t lzma_vli; /** - * \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 + * In the .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. + * number of bytes required to represent the given value. Encodings that use + * non-minimum number of bytes are invalid, thus every integer has exactly + * one encoded representation. The maximum number of bits in a VLI is 63, + * thus the vli argument must be at maximum of UINT64_MAX / 2. You should + * use LZMA_VLI_VALUE_MAX for clarity. + * + * This function has two modes: single-call and multi-call. Single-call mode + * encodes the whole integer at once; it is an error if the output buffer is + * too small. Multi-call mode saves the position in *vli_pos, and thus it is + * possible to continue encoding if the buffer becomes full before the whole + * integer has been encoded. * * \param vli Integer to be encoded * \param vli_pos How many VLI-encoded bytes have already been written @@ -170,19 +104,19 @@ typedef uint64_t lzma_vli; * \return Slightly different return values are used in multi-call and * single-call modes. * + * Single-call (vli_pos == NULL): + * - LZMA_OK: Integer successfully encoded. + * - LZMA_PROG_ERROR: Arguments are not sane. This can be due + * to too little output space; single-call mode doesn't use + * LZMA_BUF_ERROR, since the application should have checked + * the encoded size with lzma_vli_size(). + * * Multi-call (vli_pos != NULL): * - LZMA_OK: So far all OK, but the integer is not * completely written out yet. * - LZMA_STREAM_END: Integer successfully encoded. - * - LZMA_PROG_ERROR: Arguments are not sane. This can be due - * to no *out_pos == out_size; this function doesn't use - * LZMA_BUF_ERROR. - * - * Single-call (vli_pos == NULL): - * - LZMA_OK: Integer successfully encoded. - * - LZMA_PROG_ERROR: Arguments are not sane. This can be due - * to too little output space; this function doesn't use - * LZMA_BUF_ERROR. + * - LZMA_BUF_ERROR: No output space was provided. + * - LZMA_PROG_ERROR: Arguments are not sane. */ extern lzma_ret lzma_vli_encode( lzma_vli vli, size_t *lzma_restrict vli_pos, @@ -193,6 +127,8 @@ extern lzma_ret lzma_vli_encode( /** * \brief Decodes variable-length integer * + * Like lzma_vli_encode(), this function has single-call and multi-call modes. + * * \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. @@ -208,20 +144,20 @@ extern lzma_ret lzma_vli_encode( * \return Slightly different return values are used in multi-call and * single-call modes. * + * Single-call (vli_pos == NULL): + * - LZMA_OK: Integer successfully decoded. + * - LZMA_DATA_ERROR: Integer is corrupt. This includes hitting + * the end of the input buffer before the whole integer was + * decoded; providing no input at all will use LZMA_DATA_ERROR. + * - LZMA_PROG_ERROR: Arguments are not sane. + * * Multi-call (vli_pos != NULL): * - LZMA_OK: So far all OK, but the integer is not * completely decoded yet. * - LZMA_STREAM_END: Integer successfully decoded. * - LZMA_DATA_ERROR: Integer is corrupt. - * - LZMA_PROG_ERROR: Arguments are not sane. This can be - * due to *in_pos == in_size; this function doesn't use - * LZMA_BUF_ERROR. - * - * Single-call (vli_pos == NULL): - * - LZMA_OK: Integer successfully decoded. - * - LZMA_DATA_ERROR: Integer is corrupt. - * - LZMA_PROG_ERROR: Arguments are not sane. This can be due to - * too little input; this function doesn't use LZMA_BUF_ERROR. + * - LZMA_BUF_ERROR: No input was provided. + * - 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, @@ -234,4 +170,5 @@ extern lzma_ret lzma_vli_decode(lzma_vli *lzma_restrict vli, * \return Number of bytes on success (1-9). If vli isn't valid, * zero is returned. */ -extern uint32_t lzma_vli_size(lzma_vli vli); +extern uint32_t lzma_vli_size(lzma_vli vli) + lzma_attr_pure; |