pragma Style_Checks (Off);

with Interfaces.C; use Interfaces.C;
with Ada.Streams;
with Lzma.Base;

package Lzma.Vli is

   --  unsupported macro: LZMA_VLI_MAX (UINT64_MAX / 2)
   --  unsupported macro: LZMA_VLI_UNKNOWN UINT64_MAX

   LZMA_VLI_BYTES_MAX : constant := 9;  --  /usr/include/lzma/vli.h:44
   --  arg-macro: procedure LZMA_VLI_C UINT64_C(n)
   --    UINT64_C(n)
   --  arg-macro: function lzma_vli_is_valid ((vli) <= LZMA_VLI_MAX  or else  (vli) = LZMA_VLI_UNKNOWN
   --    return (vli) <= LZMA_VLI_MAX  or else  (vli) = LZMA_VLI_UNKNOWN;

  --*
  -- * \file        lzma/vli.h
  -- * \brief       Variable-length integer handling
  -- *
  -- * In the .xz format, most integers are encoded in a variable-length
  -- * representation, which is sometimes called little endian base-128 encoding.
  -- * 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. 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 less than or equal to UINT64_MAX / 2. You
  -- * should use LZMA_VLI_MAX for clarity.
  --

  -- * Author: Lasse Collin
  -- *
  -- * This file has been put into the public domain.
  -- * You can do whatever you want with this file.
  -- *
  -- * See ../lzma.h for information about liblzma as a whole.
  --

  --*
  -- * \brief       Maximum supported value of a variable-length integer
  --

  --*
  -- * \brief       VLI value to denote that the value is unknown
  --

  --*
  -- * \brief       Maximum supported encoded length of variable length integers
  --

  --*
  -- * \brief       VLI constant suffix
  --

  --*
  -- * \brief       Variable-length integer type
  -- *
  -- * Valid VLI values are in the range [0, LZMA_VLI_MAX]. Unknown value is
  -- * indicated with LZMA_VLI_UNKNOWN, which is the maximum value of the
  -- * underlaying integer type.
  -- *
  -- * lzma_vli will be uint64_t for the foreseeable future. If a bigger size
  -- * is needed in the future, it is guaranteed that 2 * LZMA_VLI_MAX will
  -- * not overflow lzma_vli. This simplifies integer overflow detection.
  --

   subtype lzma_vli is Long_Long_Integer;  -- /usr/include/lzma/vli.h:63

  --*
  -- * \brief       Validate a 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.
  --

  --*
  -- * \brief       Encode a variable-length integer
  -- *
  -- * 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
  -- *                        out. When starting to encode a new integer in
  -- *                        multi-call mode, *vli_pos must be set to zero.
  -- *                        To use single-call encoding, set vli_pos to NULL.
  -- * \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      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_BUF_ERROR: No output space was provided.
  -- *              - LZMA_PROG_ERROR: Arguments are not sane.
  --

   function lzma_vli_encode
     (vli : lzma_vli;
      vli_pos : access Interfaces.C.size_t;
      c_out : access Ada.Streams.Stream_Element;
      out_pos : access Interfaces.C.size_t;
      out_size : Interfaces.C.size_t) return Lzma.Base.lzma_ret;  -- /usr/include/lzma/vli.h:115
   pragma Import (C, lzma_vli_encode, "lzma_vli_encode");

  --*
  -- * \brief       Decode a 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.
  -- * \param       vli_pos   How many bytes have already been decoded. When
  -- *                        starting to decode a new integer in multi-call
  -- *                        mode, *vli_pos must be initialized to zero. To
  -- *                        use single-call decoding, set vli_pos to NULL.
  -- * \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      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_BUF_ERROR: No input was provided.
  -- *              - LZMA_PROG_ERROR: Arguments are not sane.
  --

   function lzma_vli_decode
     (vli : access lzma_vli;
      vli_pos : access Interfaces.C.size_t;
      c_in : access Ada.Streams.Stream_Element;
      in_pos : access Interfaces.C.size_t;
      in_size : Interfaces.C.size_t) return Lzma.Base.lzma_ret;  -- /usr/include/lzma/vli.h:154
   pragma Import (C, lzma_vli_decode, "lzma_vli_decode");

  --*
  -- * \brief       Get the number of bytes required to encode a VLI
  -- *
  -- * \return      Number of bytes on success (1-9). If vli isn't valid,
  -- *              zero is returned.
  --

   function lzma_vli_size (vli : lzma_vli) return Interfaces.C.unsigned;  -- /usr/include/lzma/vli.h:165
   pragma Import (C, lzma_vli_size, "lzma_vli_size");

end Lzma.Vli;