=head1 PackFile Manipulation Functions

This file, C<packfile.c> contains all the functions required
for the processing of the structure of a PackFile. It is not
intended to understand the byte code stream itself, but merely
to dissect and reconstruct data from the various segments.
See L<parrotbyte> for information about the structure of the
frozen bycode.

=head2 PackFile Structure Functions

=over 4

=item new

Allocate a new empty PackFile.

=item destroy

Delete a PackFile.

=item unpack

Unpack a PackFile from a block of memory. The format is:

  opcode_t magic

  opcode_t segment_length
  *  fixup_segment

  opcode_t segment_length
  *  const_segment

  opcode_t segment_length
  *  byte_code

Checks to see if the magic matches the Parrot magic number for
Parrot PackFiles.

Returns one (1) if everything is OK, else zero (0).

=back

=head2 PackFile FixupTable Structure Functions

=over 4

=item clear

Clear a PackFile FixupTable.

=item unpack

Unpack a PackFile FixupTable from a block of memory.

NOTE: There is no format defined for FixupTables yet.

Returns one (1) if everything is OK, else zero (0).

=back

=head2 PackFile ConstTable Structure Functions

=over 4

=item clear

Clear a PackFile ConstTable.

=item unpack

Unpack a PackFile ConstTable from a block of memory. The format is:

  opcode_t const_count
  *  constants

Returns one (1) if everything is OK, else zero (0).

=back

=head2 PackFile Constant Structure Functions

=over 4

=item new

Allocate a new empty PackFile Constant.
This is only here so we can make a new one and then do an unpack.

=item destroy

Delete a PackFile Constant.

=item pack_size

Determine the size of the buffer needed in order to pack the PackFile Constant into a
contiguous region of memory.

=item unpack

Unpack a PackFile Constant from a block of memory. The format is:

  opcode_t type
  opcode_t size
  *  data

Returns one (1) if everything is OK, else zero (0).

=item unpack_number

Unpack a PackFile Constant number from a block of memory. The format is:

  FLOATVAL value

Returns one (1) if everything is OK, else zero (0).

=item unpack_string

Unpack a PackFile Constant from a block of memory. The format is:

  opcode_t flags
  opcode_t encoding
  opcode_t type
  opcode_t size
  *  data

The data is expected to be zero-padded to an opcode_t-boundary, so any
pad bytes are removed.

Returns one (1) if everything is OK, else zero (0).

=back