pike.git/ src/ modules/ Gz/ module.pmod.in

2003-04-14

2003-04-14 17:10:57 by Marcus Comstedt <marcus@mc.pp.se>

• b8f765e69f60f9fd6452b30012faab7a640ecf33 (269 lines) (+262/-7) ^{[ Show | Annotate ]}
  Branch: 7.9

Removed Gz._file C code, since it can just as well be implemented in Pike.

Rev: src/modules/Gz/configure.in:1.25
Rev: src/modules/Gz/module.pmod.in:1.9
Rev: src/modules/Gz/zlibmod.c:1.63

1: - // $Id: module.pmod.in,v 1.8 2002/11/25 15:47:34 grubba Exp $ + // $Id: module.pmod.in,v 1.9 2003/04/14 17:10:57 marcus Exp $   #pike __REAL_VERSION__      inherit @module@;    - #if constant(@module@._file) + //! Low-level implementation of read/write support for GZip files + class _file {    -  +  static private Stdio.Stream f; +  static private inflate inf; +  static private deflate def; +  static private int level, strategy; +  static private string read_buf; +  static private int file_pos, crc, write_mode; +  +  constant SEEK_SET = 0; +  constant SEEK_CUR = 1; +  constant SEEK_END = 2; +  +  static int check_header() +  { +  int magic1, magic2, method, flags, len; +  +  if(sscanf(f->read(4), "%1c%1c%1c%1c", magic1, magic2, method, flags)!=4 || +  magic1 != 0x1f || magic2 != 0x8b) +  return 0; +  +  if(method != 8 || (flags & 0xe0)) +  return 0; +  +  if(sizeof(f->read(6)) != 6) +  return 0; +  +  if(flags & 4) +  if(sscanf(f->read(2), "%-2c", len) != 1 || +  sizeof(f->read(len)) != len) +  return 0; +  +  if(flags & 8) +  loop: for(;;) +  switch(f->read(1)) { +  case 0: case "": return 0; +  case "\0": break loop; +  } +  +  if(flags & 16) +  loop: for(;;) +  switch(f->read(1)) { +  case 0: case "": return 0; +  case "\0": break loop; +  } +  +  if(flags & 2) +  if(sizeof(f->read(2)) != 2) +  return 0; +  +  return 1; +  } +  +  static int make_header() +  { +  return f->write(sprintf("%1c%1c%1c%1c%4c%1c%1c", +  0x1f, 0x8b, 8, 0, 0, 0, 3)) == 10; +  } +  +  //! Opens a file for I/O. +  //! +  //! @param file +  //! The filename or an open filedescriptor or Stream for the GZip +  //! file to use. +  //! @param mode +  //! Mode for the fileoperations. Defaults to read only. +  //! +  //! @note +  //! If the object already has been opened, it will first be closed. +  int open(string|int|Stdio.Stream file, void|string mode) +  { +  close(); +  write_mode = 0; +  level = 6; +  strategy = DEFAULT_STRATEGY; +  if(mode) { +  mode = filter(mode, lambda(int n) { +  if(n == 'w' || n == 'a') +  write_mode = 1; +  if(n >= '0' && n <= '9') +  level = n - '0'; +  else if(n == 'f') +  strategy = FILTERED; +  else if(n == 'h') +  strategy = HUFFMAN_ONLY; +  else +  return 1; +  }); +  if(write_mode) { +  if(!has_value(mode, 'a')) +  mode += "t"; +  mode += "c"; +  } +  } +  file_pos = 0; +  if(objectp(file)) +  f = file; +  else { +  f = Stdio.File(); +  if(!f->open(file, mode||"rb")) +  return 0; +  } +  return write_mode? make_header() : check_header(); +  } +  +  //! Opens a gzip file for reading. +  static void create(void|string|Stdio.Stream gzFile, void|string mode) +  { +  if(!zero_type(gzFile) && !open(gzFile, mode)) +  error("Failed to open file.\n"); +  } +  +  //! closes the file +  //! @returns +  //! 1 if successful +  int close() +  { +  if(def) { +  string s = def->deflate("", FINISH); +  if(sizeof(s) && f->write(s) != sizeof(s)) +  return 0; +  if(f->write(sprintf("%-4c%-4c", crc, file_pos)) != 8) +  return 0; +  } +  inf = 0; +  def = 0; +  read_buf = ""; +  Stdio.File oldf = f; +  f = 0; +  return !oldf || oldf->close(); +  } +  +  //! Reads len (uncompressed) bytes from the file. +  //! If read is unsuccessful, 0 is returned. +  int|string read(int len) +  { +  if(!inf) inf = inflate(-15); +  while(sizeof(read_buf) < len) { +  string r = f->read(16384); +  if(!sizeof(r)) +  break; +  read_buf += inf->inflate(r); +  } +  string res = read_buf[..len-1]; +  read_buf = read_buf[len..]; +  file_pos += sizeof(res); +  return res; +  } +  +  //! Writes the data to the file. +  //! @returns +  //! the number of bytes written to the file. +  int write(string data) +  { +  if(!def) { def = deflate(-level, strategy); crc = crc32(""); } +  string comp = def->deflate(data, NO_FLUSH); +  if(f->write(comp) != sizeof(comp)) +  return 0; +  else { +  file_pos += sizeof(data); +  crc = crc32(data, crc); +  return sizeof(data); +  } +  } +  +  //! Seeks within the file. +  //! @param pos +  //! Position relative to the searchtype. +  //! @param type +  //! SEEK_SET = set current position in file to pos +  //! SEEK_CUR = new position is current+pos +  //! SEEK_END is not supported. +  //! @returns +  //! New position or negative number if seek failed. +  int seek(int pos, void|int type) +  { +  if(type != SEEK_SET && type != SEEK_CUR) +  return -1; +  if(write_mode) { +  if(type == SEEK_SET) +  pos -= file_pos; +  if(pos < 0) +  return -1; +  while(pos > 0) { +  int n = write("\0"*(pos>16384? 16384:pos)); +  if(!n) +  return -1; +  pos -= n; +  } +  return file_pos; +  } else { +  if(type == SEEK_CUR) +  pos += file_pos; +  if(pos < 0) +  return -1; +  if(!f->seek || f->seek(0)<0) +  return -1; +  file_pos = 0; +  read_buf = ""; +  while(pos > 0) { +  string r = read(pos>16384? 16384:pos); +  if(!sizeof(r)) +  return -1; +  pos -= sizeof(r); +  } +  return file_pos; +  } +  } +  +  //! @returns +  //! the current position within the file. +  int tell() +  { +  return file_pos; +  } +  +  //! @returns +  //! 1 if EOF has been reached. +  int(0..1) eof() +  { +  if(def || sizeof(read_buf)) return 0; +  if(!inf) inf = inflate(-15); +  string r = f->read(16384); +  if(!sizeof(r)) +  return 1; +  read_buf = inf->inflate(r); +  return !sizeof(read_buf); +  } +  +  //! Sets the encoding level and strategy +  //! @param level +  //! Level of the compression. +  //! 0 is the least compression, 9 is max. 8 is default. +  //! @param strategy +  //! Set strategy for encoding to one of the following: +  //! DEFAULT_STRATEGY +  //! FILTERED +  //! HUFFMAN_ONLY +  int setparams(int level, int strategy) +  { +  if(def) { +  string s = def->deflate("", FINISH); +  if(sizeof(s) && f->write(s) != sizeof(s)) +  return 0; +  def = 0; +  } +  _file::level = level; +  _file::strategy = strategy; +  return 1; +  } +  + } +  +    //! Allows the user to open a Gzip archive and read and write   //! it's contents in an uncompressed form, emulating the @[Stdio.File]   //! interface.
19:       private int is_open = 0;    -  //! @decl void create(void|string|int file, void|string mode) +  //! @decl void create(void|string|int|Stdio.Stream file, void|string mode)    //! @param file -  //! Filename or filedescriptor of the gzip file to open. +  //! Filename or filedescriptor of the gzip file to open, or an already +  //! open Stream.    //! @param mode    //! mode for the file. Defaults to "rb".    //! @seealso
57:    }       //! @param file -  //! Filename or filedescriptor of the gzip file to open. +  //! Filename or filedescriptor of the gzip file to open, or an already +  //! open Stream.    //! @param mode    //! mode for the file. Defaults to "rb".    //! May be one of the following:
73:    //! be specified. Please se zlib manual for more info.    //! @returns    //! non-zero if successful. -  int open(string|int file, void|string mode) { +  int open(string|int|Stdio.Stream file, void|string mode) {    string open_mode="rb";    if (is_open) {    ::close();
107:    }   }    - #endif /* constant(@module@._file) */ +