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/* Tarlz - Archiver with multimember lzip compression
Copyright (C) 2013-2021 Antonio Diaz Diaz.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
struct Archive_descriptor
{
const std::string name;
const char * const namep; // printable archive name
const int infd;
const Lzip_index lzip_index;
const bool seekable;
const bool indexed; // archive is a compressed regular file
Archive_descriptor( const std::string & archive_name )
: name( archive_name ), namep( name.empty() ? "(stdin)" : name.c_str() ),
infd( name.empty() ? STDIN_FILENO : open_instream( name ) ),
lzip_index( infd, true, false ),
seekable( lseek( infd, 0, SEEK_SET ) == 0 ),
indexed( seekable && lzip_index.retval() == 0 ) {}
};
class Archive_reader_base // base of serial and indexed readers
{
public:
const Archive_descriptor & ad;
protected:
LZ_Decoder * decoder; // destructor closes it if needed
const char * e_msg_; // message for show_file_error
int e_code_; // copy of errno
int e_size_; // partial size read in case of read error
bool e_skip_; // corrupt header skipped
bool fatal_;
int err( const int retval, const char * const msg = "", const int code = 0,
const int size = 0, const bool skip = false )
{ e_msg_ = msg; e_code_ = code; e_size_ = size; e_skip_ = skip;
if( retval == 2 ) { fatal_ = true; } return retval; }
Archive_reader_base( const Archive_descriptor & d )
: ad( d ), decoder( 0 ), e_msg_( "" ), e_code_( 0 ), e_size_( 0 ),
e_skip_( false ), fatal_( false ) {}
public:
virtual ~Archive_reader_base()
{ if( decoder != 0 ) LZ_decompress_close( decoder ); }
const char * e_msg() const { return e_msg_; }
int e_code() const { return e_code_; }
int e_size() const { return e_size_; }
bool e_skip() const { return e_skip_; }
bool fatal() const { return fatal_; }
/* Read 'size' uncompressed bytes, decompressing the input if needed.
Return value: 0 = OK, 1 = damaged member, 2 = fatal error.
If !OK, fills all the e_* variables. */
virtual int read( uint8_t * const buf, const int size ) = 0;
int parse_records( Extended & extended, const Tar_header header,
Resizable_buffer & rbuf, const bool permissive );
};
class Archive_reader : public Archive_reader_base // serial reader
{
bool first_read;
bool uncompressed_seekable; // value set by first read call
bool at_eof;
public:
Archive_reader( const Archive_descriptor & d )
: Archive_reader_base( d ), first_read( true ),
uncompressed_seekable( false ), at_eof( false ) {}
int read( uint8_t * const buf, const int size );
int skip_member( const Extended & extended );
};
/* If the archive is compressed seekable (indexed), several indexed readers
can be constructed sharing the same Archive_descriptor, for example to
decode the archive in parallel.
*/
class Archive_reader_i : public Archive_reader_base // indexed reader
{
long long data_pos_; // current decompressed position
long long mdata_end_; // current member decompressed end
long long archive_pos; // current position in archive for pread
long member_id; // current member unless reading beyond
public:
Archive_reader_i( const Archive_descriptor & d )
: Archive_reader_base( d ),
data_pos_( 0 ), mdata_end_( 0 ), archive_pos( 0 ), member_id( 0 )
{
decoder = LZ_decompress_open();
if( !decoder || LZ_decompress_errno( decoder ) != LZ_ok )
{ LZ_decompress_close( decoder ); decoder = 0; fatal_ = true; }
}
long long data_pos() const { return data_pos_; }
long long mdata_end() const { return mdata_end_; }
bool at_member_end() const { return data_pos_ == mdata_end_; }
// Resets decoder and sets position to the start of the member.
void set_member( const long i );
int read( uint8_t * const buf, const int size );
int skip_member( const Extended & extended );
};
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