libguile/ports.h

   1 /* classes: h_files */
   2
   3 #ifndef PORTSH
   4 #define PORTSH
   5 /*      Copyright (C) 1995,1996,1997,1998,1999 Free Software Foundation, Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2, or (at your option)
  10  * any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this software; see the file COPYING.  If not, write to
  19  * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  20  * Boston, MA 02111-1307 USA
  21  *
  22  * As a special exception, the Free Software Foundation gives permission
  23  * for additional uses of the text contained in its release of GUILE.
  24  *
  25  * The exception is that, if you link the GUILE library with other files
  26  * to produce an executable, this does not by itself cause the
  27  * resulting executable to be covered by the GNU General Public License.
  28  * Your use of that executable is in no way restricted on account of
  29  * linking the GUILE library code into it.
  30  *
  31  * This exception does not however invalidate any other reasons why
  32  * the executable file might be covered by the GNU General Public License.
  33  *
  34  * This exception applies only to the code released by the
  35  * Free Software Foundation under the name GUILE.  If you copy
  36  * code from other Free Software Foundation releases into a copy of
  37  * GUILE, as the General Public License permits, the exception does
  38  * not apply to the code that you add in this way.  To avoid misleading
  39  * anyone as to the status of such modified files, you must delete
  40  * this exception notice from them.
  41  *
  42  * If you write modifications of your own for GUILE, it is your choice
  43  * whether to permit this exception to apply to your modifications.
  44  * If you do not wish that, delete this exception notice.  */
  45 \f
  46 #include "libguile/__scm.h"
  47
  48 #include "libguile/print.h"
  49 #include "libguile/struct.h"
  50
  51 /* Not sure if this is a good idea.  We need it for off_t.  */
  52 #include <sys/types.h>
  53
  54 \f
  55
  56 #define SCM_INITIAL_PUTBACK_BUF_SIZE 4
  57
  58 /* C representation of a Scheme port.  */
  59
  60 typedef struct
  61 {
  62   SCM port;                     /* Link back to the port object.  */
  63   int entry;                    /* Index in port table. */
  64   int revealed;                 /* 0 not revealed, > 1 revealed.
  65                                  * Revealed ports do not get GC'd.
  66                                  */
  67   /* data for the underlying port implementation.  may be an SCM cell or
  68      cast to a pointer to C data.  */
  69   SCM stream;
  70
  71   SCM file_name;                /* debugging support.  */
  72   int line_number;              /* debugging support.  */
  73   int column_number;            /* debugging support.  */
  74
  75   /* port buffers.  the buffer(s) are set up for all ports.
  76      in the case of string ports, the buffer is the string itself.
  77      in the case of unbuffered file ports, the buffer is a
  78      single char: shortbuf.  */
  79
  80   /* this buffer is filled from read_buf to read_end using the ptob
  81      buffer_fill.  then input requests are taken from read_pos until
  82      it reaches read_end.  */
  83
  84   unsigned char *read_buf;      /* buffer start.  */
  85   const unsigned char *read_pos;/* the next unread char.  */
  86   unsigned char *read_end;      /* pointer to last buffered char + 1.  */
  87   off_t read_buf_size;          /* size of the buffer.  */
  88
  89   /* when chars are put back into the buffer, e.g., using peek-char or
  90      unread-string, the read-buffer pointers are switched to cbuf.
  91      the original pointers are saved here and restored when the put-back
  92      chars have been consumed.  */
  93   unsigned char *saved_read_buf;
  94   const unsigned char *saved_read_pos;
  95   unsigned char *saved_read_end;
  96   off_t saved_read_buf_size;
  97
  98   /* write requests are saved into this buffer at write_pos until it
  99      reaches write_buf + write_buf_size, then the ptob flush is
 100      called.  */
 101
 102   unsigned char *write_buf;     /* buffer start.  */
 103   unsigned char *write_pos;     /* pointer to last buffered char + 1.  */
 104   unsigned char *write_end;     /* pointer to end of buffer + 1.  */
 105   off_t write_buf_size;         /* size of the buffer.  */
 106
 107   unsigned char shortbuf;       /* buffer for "unbuffered" streams.  */
 108
 109   int rw_random;                /* true if the port is bidirectional and
 110                                    random access.  implies that the buffers
 111                                    must be flushed before switching between
 112                                    reading and writing.  */
 113
 114   int rw_active;                /* for bidirectional random ports, indicates
 115                                    which of the buffers is currently in use.
 116                                    can be SCM_PORT_WRITE, SCM_PORT_READ,
 117                                    or 0.  */
 118
 119   /* a buffer for un-read chars and strings.  */
 120   unsigned char *putback_buf;
 121   int putback_buf_size;        /* allocated size of putback_buf.  */
 122 } scm_port;
 123
 124 /* values for the rw_active flag.  */
 125 #define SCM_PORT_READ 1
 126 #define SCM_PORT_WRITE 2
 127
 128 extern scm_port **scm_port_table;
 129 extern int scm_port_table_size; /* Number of ports in scm_port_table.  */
 130
 131
 132 \f
 133
 134 #define SCM_EOF_OBJECT_P(x) ((x) == SCM_EOF_VAL)
 135
 136 /* PORT FLAGS
 137  * A set of flags characterizes a port.
 138  * Note that we reserve the bits 1 << 24 and above for use by the
 139  * routines in the port's scm_ptobfuns structure.
 140  */
 141 #define SCM_OPN         (1L<<16) /* Is the port open? */
 142 #define SCM_RDNG        (2L<<16) /* Is it a readable port? */
 143 #define SCM_WRTNG       (4L<<16) /* Is it writable? */
 144 #define SCM_BUF0        (8L<<16) /* Is it unbuffered? */
 145 /* #define SCM_CRDY     (32L<<16)  obsolete, for pushed back characters  */
 146 #define SCM_BUFLINE     (64L<<16) /* Is it line-buffered? */
 147
 148 #define SCM_PORTP(x) (SCM_TYP7(x)==scm_tc7_port)
 149 #define SCM_OPPORTP(x) (((0x7f | SCM_OPN) & SCM_CAR(x))==(scm_tc7_port | SCM_OPN))
 150 #define SCM_OPINPORTP(x) (((0x7f | SCM_OPN | SCM_RDNG) & SCM_CAR(x))==(scm_tc7_port | SCM_OPN | SCM_RDNG))
 151 #define SCM_OPOUTPORTP(x) (((0x7f | SCM_OPN | SCM_WRTNG) & SCM_CAR(x))==(scm_tc7_port | SCM_OPN | SCM_WRTNG))
 152 #define SCM_INPORTP(x) (((0x7f | SCM_RDNG) & SCM_CAR(x))==(scm_tc7_port | SCM_RDNG))
 153 #define SCM_OUTPORTP(x) (((0x7f | SCM_WRTNG) & SCM_CAR(x))==(scm_tc7_port | SCM_WRTNG))
 154 #define SCM_OPENP(x) (SCM_OPN & SCM_CAR(x))
 155 #define SCM_CLOSEDP(x) (!SCM_OPENP(x))
 156 #define SCM_PTAB_ENTRY(x) ((scm_port *) SCM_CDR(x))
 157 #define SCM_SETPTAB_ENTRY(x,ent) SCM_SETCDR ((x), (SCM)(ent))
 158 #define SCM_STREAM(x) SCM_PTAB_ENTRY(x)->stream
 159 #define SCM_SETSTREAM(x,s) (SCM_PTAB_ENTRY(x)->stream = (SCM) s)
 160 #define SCM_FILENAME(x) SCM_PTAB_ENTRY(x)->file_name
 161 #define SCM_LINUM(x) SCM_PTAB_ENTRY(x)->line_number
 162 #define SCM_COL(x) SCM_PTAB_ENTRY(x)->column_number
 163 #define SCM_REVEALED(x) SCM_PTAB_ENTRY(x)->revealed
 164 #define SCM_SETREVEALED(x,s) (SCM_PTAB_ENTRY(x)->revealed = s)
 165
 166 #define SCM_INCLINE(port)       {SCM_LINUM (port) += 1; SCM_COL (port) = 0;}
 167 #define SCM_INCCOL(port)        {SCM_COL (port) += 1;}
 168 #define SCM_TABCOL(port)        {SCM_COL (port) += 8 - SCM_COL (port) % 8;}
 169
 170 \f
 171
 172 typedef struct scm_ptob_descriptor
 173 {
 174   char *name;
 175   SCM (*mark) (SCM);
 176   scm_sizet (*free) (SCM);
 177   int (*print) (SCM exp, SCM port, scm_print_state *pstate);
 178   SCM (*equalp) (SCM, SCM);
 179   void (*write) (SCM port, void *data, size_t size);
 180   void (*fflush) (SCM port);
 181   void (*read_flush) (SCM port, int offset);
 182   int (*fclose) (SCM port);
 183   int (*fill_buffer) (SCM port);
 184   off_t (*seek) (SCM port, off_t OFFSET, int WHENCE);
 185   void (*ftruncate) (SCM port, off_t length);
 186   int (*input_waiting_p) (SCM port);
 187 } scm_ptob_descriptor;
 188
 189 #define SCM_TC2PTOBNUM(x) (0x0ff & ((x) >> 8))
 190 #define SCM_PTOBNUM(x) (SCM_TC2PTOBNUM (SCM_CAR (x)))
 191 /* SCM_PTOBNAME can be 0 if name is missing */
 192 #define SCM_PTOBNAME(ptobnum) scm_ptobs[ptobnum].name
 193
 194 \f
 195
 196 extern scm_ptob_descriptor *scm_ptobs;
 197 extern int scm_numptob;
 198 extern int scm_port_table_room;
 199
 200 \f
 201
 202 extern SCM scm_markstream SCM_P ((SCM ptr));
 203 extern long scm_make_port_type (char *name,
 204                                 int (*fill_buffer) (SCM port),
 205                                 void (*write_flush) (SCM port));
 206 extern void scm_set_port_mark (long tc, SCM (*mark) (SCM));
 207 extern void scm_set_port_free (long tc, scm_sizet (*free) (SCM));
 208 extern void scm_set_port_print (long tc,
 209                                 int (*print) (SCM exp,
 210                                               SCM port,
 211                                               scm_print_state *pstate));
 212 extern void scm_set_port_equalp (long tc, SCM (*equalp) (SCM, SCM));
 213 extern void scm_set_port_write (long tc,
 214                                 void (*write_proc) (SCM port,
 215                                                     void *data,
 216                                                     size_t size));
 217 extern void scm_set_port_flush_input (long tc,
 218                                       void (*flush_input) (SCM port,
 219                                                            int offset));
 220 extern void scm_set_port_close (long tc, int (*close) (SCM));
 221 extern void scm_set_port_seek (long tc,
 222                                off_t (*seek) (SCM port,
 223                                               off_t OFFSET,
 224                                               int WHENCE));
 225 extern void scm_set_port_truncate (long tc,
 226                                    void (*truncate) (SCM port,
 227                                                      off_t length));
 228 extern void scm_set_port_input_waiting_p (long tc, int (*waitingp) (SCM));
 229 extern SCM scm_char_ready_p SCM_P ((SCM port));
 230 extern SCM scm_drain_input (SCM port);
 231 extern SCM scm_current_input_port SCM_P ((void));
 232 extern SCM scm_current_output_port SCM_P ((void));
 233 extern SCM scm_current_error_port SCM_P ((void));
 234 extern SCM scm_current_load_port SCM_P ((void));
 235 extern SCM scm_set_current_input_port SCM_P ((SCM port));
 236 extern SCM scm_set_current_output_port SCM_P ((SCM port));
 237 extern SCM scm_set_current_error_port SCM_P ((SCM port));
 238 extern scm_port * scm_add_to_port_table SCM_P ((SCM port));
 239 extern void scm_remove_from_port_table SCM_P ((SCM port));
 240 extern void scm_grow_port_cbuf SCM_P ((SCM port, size_t requested));
 241 extern SCM scm_pt_size SCM_P ((void));
 242 extern SCM scm_pt_member SCM_P ((SCM member));
 243 extern int scm_revealed_count SCM_P ((SCM port));
 244 extern SCM scm_port_revealed SCM_P ((SCM port));
 245 extern SCM scm_set_port_revealed_x SCM_P ((SCM port, SCM rcount));
 246 extern long scm_mode_bits SCM_P ((char *modes));
 247 extern SCM scm_port_mode SCM_P ((SCM port));
 248 extern SCM scm_close_port SCM_P ((SCM port));
 249 extern SCM scm_close_all_ports_except SCM_P ((SCM ports));
 250 extern SCM scm_input_port_p SCM_P ((SCM x));
 251 extern SCM scm_output_port_p SCM_P ((SCM x));
 252 extern SCM scm_eof_object_p SCM_P ((SCM x));
 253 extern SCM scm_force_output SCM_P ((SCM port));
 254 extern SCM scm_flush_all_ports SCM_P ((void));
 255 extern SCM scm_read_char SCM_P ((SCM port));
 256 extern void scm_putc SCM_P ((char c, SCM port));
 257 extern void scm_puts SCM_P ((char *str_data, SCM port));
 258 extern void scm_lfwrite SCM_P ((char *ptr, scm_sizet size, SCM port));
 259 extern void scm_fflush SCM_P ((SCM port));
 260 extern void scm_read_flush (SCM port);
 261 extern int scm_fill_buffer (SCM port);
 262 extern int scm_getc SCM_P ((SCM port));
 263 extern void scm_ungetc SCM_P ((int c, SCM port));
 264 extern void scm_ungets SCM_P ((char *s, int n, SCM port));
 265 extern SCM scm_peek_char SCM_P ((SCM port));
 266 extern SCM scm_unread_char SCM_P ((SCM cobj, SCM port));
 267 extern SCM scm_unread_string SCM_P ((SCM str, SCM port));
 268 extern char *scm_generic_fgets SCM_P ((SCM port, int *len));
 269 extern SCM scm_lseek (SCM object, SCM offset, SCM whence);
 270 extern SCM scm_truncate_file (SCM object, SCM length);
 271 extern SCM scm_port_line SCM_P ((SCM port));
 272 extern SCM scm_set_port_line_x SCM_P ((SCM port, SCM line));
 273 extern SCM scm_port_column SCM_P ((SCM port));
 274 extern SCM scm_set_port_column_x SCM_P ((SCM port, SCM line));
 275 extern SCM scm_port_filename SCM_P ((SCM port));
 276 extern SCM scm_set_port_filename_x SCM_P ((SCM port, SCM filename));
 277 extern int scm_port_print (SCM exp, SCM port, scm_print_state *);
 278 extern void scm_print_port_mode (SCM exp, SCM port);
 279 extern void scm_ports_prehistory SCM_P ((void));
 280 extern SCM scm_void_port SCM_P ((char * mode_str));
 281 extern SCM scm_sys_make_void_port SCM_P ((SCM mode));
 282 extern void scm_init_ports SCM_P ((void));
 283
 284 #ifdef GUILE_DEBUG
 285 extern SCM scm_pt_size SCM_P ((void));
 286 extern SCM scm_pt_member SCM_P ((SCM member));
 287 #endif /* GUILE_DEBUG */
 288
 289 #endif  /* PORTSH */