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_ptobfuns
 173 {
 174   SCM (*mark) (SCM);
 175   int (*free) (SCM);
 176   int (*print) (SCM exp, SCM port, scm_print_state *pstate);
 177   SCM (*equalp) (SCM, SCM);
 178   void (*fflush) (SCM port);
 179   void (*read_flush) (SCM port);
 180   int (*fclose) (SCM port);
 181   int (*fill_buffer) (SCM port);
 182   off_t (*seek) (SCM port, off_t OFFSET, int WHENCE);
 183   void (*ftruncate) (SCM port, off_t length);
 184   int (*input_waiting_p) (SCM port);
 185 } scm_ptobfuns;
 186
 187 #define SCM_PTOBNUM(x) (0x0ff & (SCM_CAR(x)>>8))
 188
 189 \f
 190
 191 extern scm_ptobfuns *scm_ptobs;
 192 extern int scm_numptob;
 193 extern int scm_port_table_room;
 194
 195 \f
 196
 197 extern SCM scm_markstream SCM_P ((SCM ptr));
 198 extern long scm_newptob SCM_P ((scm_ptobfuns *ptob));
 199 extern SCM scm_char_ready_p SCM_P ((SCM port));
 200 extern SCM scm_drain_input (SCM port);
 201 extern SCM scm_current_input_port SCM_P ((void));
 202 extern SCM scm_current_output_port SCM_P ((void));
 203 extern SCM scm_current_error_port SCM_P ((void));
 204 extern SCM scm_current_load_port SCM_P ((void));
 205 extern SCM scm_set_current_input_port SCM_P ((SCM port));
 206 extern SCM scm_set_current_output_port SCM_P ((SCM port));
 207 extern SCM scm_set_current_error_port SCM_P ((SCM port));
 208 extern scm_port * scm_add_to_port_table SCM_P ((SCM port));
 209 extern void scm_remove_from_port_table SCM_P ((SCM port));
 210 extern void scm_grow_port_cbuf SCM_P ((SCM port, size_t requested));
 211 extern SCM scm_pt_size SCM_P ((void));
 212 extern SCM scm_pt_member SCM_P ((SCM member));
 213 extern int scm_revealed_count SCM_P ((SCM port));
 214 extern SCM scm_port_revealed SCM_P ((SCM port));
 215 extern SCM scm_set_port_revealed_x SCM_P ((SCM port, SCM rcount));
 216 extern long scm_mode_bits SCM_P ((char *modes));
 217 extern SCM scm_port_mode SCM_P ((SCM port));
 218 extern SCM scm_close_port SCM_P ((SCM port));
 219 extern SCM scm_close_all_ports_except SCM_P ((SCM ports));
 220 extern SCM scm_input_port_p SCM_P ((SCM x));
 221 extern SCM scm_output_port_p SCM_P ((SCM x));
 222 extern SCM scm_eof_object_p SCM_P ((SCM x));
 223 extern SCM scm_force_output SCM_P ((SCM port));
 224 extern SCM scm_flush_all_ports SCM_P ((void));
 225 extern SCM scm_read_char SCM_P ((SCM port));
 226 extern void scm_putc SCM_P ((int c, SCM port));
 227 extern void scm_puts SCM_P ((char *str_data, SCM port));
 228 extern void scm_lfwrite SCM_P ((char *ptr, scm_sizet size, SCM port));
 229 extern void scm_fflush SCM_P ((SCM port));
 230 extern int scm_fill_buffer (SCM port, scm_port *pt);
 231 extern int scm_getc SCM_P ((SCM port));
 232 extern void scm_ungetc SCM_P ((int c, SCM port));
 233 extern void scm_ungets SCM_P ((char *s, int n, SCM port));
 234 extern SCM scm_peek_char SCM_P ((SCM port));
 235 extern SCM scm_unread_char SCM_P ((SCM cobj, SCM port));
 236 extern SCM scm_unread_string SCM_P ((SCM str, SCM port));
 237 extern char *scm_generic_fgets SCM_P ((SCM port, int *len));
 238 extern SCM scm_lseek (SCM object, SCM offset, SCM whence);
 239 extern SCM scm_ftruncate (SCM port, SCM length);
 240 extern SCM scm_port_line SCM_P ((SCM port));
 241 extern SCM scm_set_port_line_x SCM_P ((SCM port, SCM line));
 242 extern SCM scm_port_column SCM_P ((SCM port));
 243 extern SCM scm_set_port_column_x SCM_P ((SCM port, SCM line));
 244 extern SCM scm_port_filename SCM_P ((SCM port));
 245 extern SCM scm_set_port_filename_x SCM_P ((SCM port, SCM filename));
 246 extern void scm_prinport SCM_P ((SCM exp, SCM port, char *type));
 247 extern void scm_ports_prehistory SCM_P ((void));
 248 extern SCM scm_void_port SCM_P ((char * mode_str));
 249 extern SCM scm_sys_make_void_port SCM_P ((SCM mode));
 250 extern void scm_init_ports SCM_P ((void));
 251
 252 #ifdef GUILE_DEBUG
 253 extern SCM scm_pt_size SCM_P ((void));
 254 extern SCM scm_pt_member SCM_P ((SCM member));
 255 #endif /* GUILE_DEBUG */
 256
 257 #endif  /* PORTSH */