libguile/ports.h

   1 /* classes: h_files */
   2
   3 #ifndef SCM_PORTS_H
   4 #define SCM_PORTS_H
   5
   6 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2003, 2004, 2006, 2008, 2009 Free Software Foundation, Inc.
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public License
  10  * as published by the Free Software Foundation; either version 3 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  21  * 02110-1301 USA
  22  */
  23
  24 \f
  25
  26 #include "libguile/__scm.h"
  27
  28 #include "libguile/print.h"
  29 #include "libguile/struct.h"
  30 #include "libguile/threads.h"
  31
  32 /* Not sure if this is a good idea.  We need it for off_t.  */
  33 #include <sys/types.h>
  34
  35 \f
  36
  37 #define SCM_INITIAL_PUTBACK_BUF_SIZE 4
  38
  39 /* values for the rw_active flag.  */
  40 typedef enum scm_t_port_rw_active {
  41   SCM_PORT_NEITHER = 0,
  42   SCM_PORT_READ = 1,
  43   SCM_PORT_WRITE = 2
  44 } scm_t_port_rw_active;
  45
  46 /* C representation of a Scheme port.  */
  47
  48 typedef struct
  49 {
  50   SCM port;                     /* Link back to the port object.  */
  51   int revealed;                 /* 0 not revealed, > 1 revealed.
  52                                  * Revealed ports do not get GC'd.
  53                                  */
  54   /* data for the underlying port implementation as a raw C value. */
  55   scm_t_bits stream;
  56
  57   SCM file_name;                /* debugging support.  */
  58   long line_number;             /* debugging support.  */
  59   int column_number;            /* debugging support.  */
  60
  61   /* port buffers.  the buffer(s) are set up for all ports.
  62      in the case of string ports, the buffer is the string itself.
  63      in the case of unbuffered file ports, the buffer is a
  64      single char: shortbuf.  */
  65
  66   /* this buffer is filled from read_buf to read_end using the ptob
  67      buffer_fill.  then input requests are taken from read_pos until
  68      it reaches read_end.  */
  69
  70   unsigned char *read_buf;      /* buffer start.  */
  71   const unsigned char *read_pos;/* the next unread char.  */
  72   unsigned char *read_end;      /* pointer to last buffered char + 1.  */
  73   off_t read_buf_size;          /* size of the buffer.  */
  74
  75   /* when chars are put back into the buffer, e.g., using peek-char or
  76      unread-string, the read-buffer pointers are switched to cbuf.
  77      the original pointers are saved here and restored when the put-back
  78      chars have been consumed.  */
  79   unsigned char *saved_read_buf;
  80   const unsigned char *saved_read_pos;
  81   unsigned char *saved_read_end;
  82   off_t saved_read_buf_size;
  83
  84   /* write requests are saved into this buffer at write_pos until it
  85      reaches write_buf + write_buf_size, then the ptob flush is
  86      called.  */
  87
  88   unsigned char *write_buf;     /* buffer start.  */
  89   unsigned char *write_pos;     /* pointer to last buffered char + 1.  */
  90   unsigned char *write_end;     /* pointer to end of buffer + 1.  */
  91   off_t write_buf_size;         /* size of the buffer.  */
  92
  93   unsigned char shortbuf;       /* buffer for "unbuffered" streams.  */
  94
  95   int rw_random;                /* true if the port is random access.
  96                                    implies that the buffers must be
  97                                    flushed before switching between
  98                                    reading and writing, seeking, etc.  */
  99
 100   scm_t_port_rw_active rw_active; /* for random access ports,
 101                                      indicates which of the buffers
 102                                      is currently in use.  can be
 103                                      SCM_PORT_WRITE, SCM_PORT_READ,
 104                                      or SCM_PORT_NEITHER.  */
 105
 106
 107   /* a buffer for un-read chars and strings.  */
 108   unsigned char *putback_buf;
 109   size_t putback_buf_size;        /* allocated size of putback_buf.  */
 110 } scm_t_port;
 111
 112
 113 SCM_INTERNAL scm_i_pthread_mutex_t scm_i_port_table_mutex;
 114 SCM_INTERNAL SCM scm_i_port_weak_hash;
 115
 116
 117 #define SCM_READ_BUFFER_EMPTY_P(c_port) (c_port->read_pos >= c_port->read_end)
 118
 119 \f
 120
 121 #define SCM_EOF_OBJECT_P(x) (scm_is_eq ((x), SCM_EOF_VAL))
 122
 123 /* PORT FLAGS
 124  * A set of flags characterizes a port.
 125  * Note that we reserve the bits 1 << 24 and above for use by the
 126  * routines in the port's scm_ptobfuns structure.
 127  */
 128 #define SCM_OPN         (1L<<16) /* Is the port open? */
 129 #define SCM_RDNG        (2L<<16) /* Is it a readable port? */
 130 #define SCM_WRTNG       (4L<<16) /* Is it writable? */
 131 #define SCM_BUF0        (8L<<16) /* Is it unbuffered? */
 132 #define SCM_BUFLINE     (64L<<16) /* Is it line-buffered? */
 133
 134 #define SCM_PORTP(x) (!SCM_IMP (x) && (SCM_TYP7 (x) == scm_tc7_port))
 135 #define SCM_OPPORTP(x) (!SCM_IMP(x) && (((0x7f | SCM_OPN) & SCM_CELL_WORD_0(x))==(scm_tc7_port | SCM_OPN)))
 136 #define SCM_OPINPORTP(x) (!SCM_IMP(x) && (((0x7f | SCM_OPN | SCM_RDNG) & SCM_CELL_WORD_0(x))==(scm_tc7_port | SCM_OPN | SCM_RDNG)))
 137 #define SCM_OPOUTPORTP(x) (!SCM_IMP(x) && (((0x7f | SCM_OPN | SCM_WRTNG) & SCM_CELL_WORD_0(x))==(scm_tc7_port | SCM_OPN | SCM_WRTNG)))
 138 #define SCM_INPUT_PORT_P(x) \
 139   (!SCM_IMP(x) \
 140    && (((0x7f | SCM_RDNG) & SCM_CELL_WORD_0(x)) == (scm_tc7_port | SCM_RDNG)))
 141 #define SCM_OUTPUT_PORT_P(x) \
 142   (!SCM_IMP(x) \
 143    && (((0x7f | SCM_WRTNG) & SCM_CELL_WORD_0(x))==(scm_tc7_port | SCM_WRTNG)))
 144 #define SCM_OPENP(x) (!SCM_IMP(x) && (SCM_OPN & SCM_CELL_WORD_0 (x)))
 145 #define SCM_CLOSEDP(x) (!SCM_OPENP(x))
 146 #define SCM_CLR_PORT_OPEN_FLAG(p) \
 147   SCM_SET_CELL_WORD_0 ((p), SCM_CELL_WORD_0 (p) & ~SCM_OPN)
 148
 149 #define SCM_PTAB_ENTRY(x)         ((scm_t_port *) SCM_CELL_WORD_1 (x))
 150 #define SCM_SETPTAB_ENTRY(x, ent)  (SCM_SET_CELL_WORD_1 ((x), (scm_t_bits) (ent)))
 151 #define SCM_STREAM(x)             (SCM_PTAB_ENTRY(x)->stream)
 152 #define SCM_SETSTREAM(x, s)        (SCM_PTAB_ENTRY(x)->stream = (scm_t_bits) (s))
 153 #define SCM_FILENAME(x)           (SCM_PTAB_ENTRY(x)->file_name)
 154 #define SCM_SET_FILENAME(x, n)    (SCM_PTAB_ENTRY(x)->file_name = (n))
 155 #define SCM_LINUM(x)              (SCM_PTAB_ENTRY(x)->line_number)
 156 #define SCM_COL(x)                (SCM_PTAB_ENTRY(x)->column_number)
 157 #define SCM_REVEALED(x)           (SCM_PTAB_ENTRY(x)->revealed)
 158 #define SCM_SETREVEALED(x, s)      (SCM_PTAB_ENTRY(x)->revealed = (s))
 159
 160 #define SCM_INCLINE(port)       {SCM_LINUM (port) += 1; SCM_COL (port) = 0;}
 161 #define SCM_ZEROCOL(port)       {SCM_COL (port) = 0;}
 162 #define SCM_INCCOL(port)        {SCM_COL (port) += 1;}
 163 #define SCM_DECCOL(port)        {if (SCM_COL (port) > 0) SCM_COL (port) -= 1;}
 164 #define SCM_TABCOL(port)        {SCM_COL (port) += 8 - SCM_COL (port) % 8;}
 165
 166 /* Maximum number of port types.  */
 167 #define SCM_I_MAX_PORT_TYPE_COUNT  256
 168
 169 \f
 170
 171 /* port-type description.  */
 172 typedef struct scm_t_ptob_descriptor
 173 {
 174   char *name;
 175   SCM (*mark) (SCM);
 176   size_t (*free) (SCM);
 177   int (*print) (SCM exp, SCM port, scm_print_state *pstate);
 178   SCM (*equalp) (SCM, SCM);
 179   int (*close) (SCM port);
 180
 181   void (*write) (SCM port, const void *data, size_t size);
 182   void (*flush) (SCM port);
 183
 184   void (*end_input) (SCM port, int offset);
 185   int (*fill_input) (SCM port);
 186   int (*input_waiting) (SCM port);
 187
 188   off_t (*seek) (SCM port, off_t OFFSET, int WHENCE);
 189   void (*truncate) (SCM port, off_t length);
 190
 191 } scm_t_ptob_descriptor;
 192
 193 #define SCM_TC2PTOBNUM(x) (0x0ff & ((x) >> 8))
 194 #define SCM_PTOBNUM(x) (SCM_TC2PTOBNUM (SCM_CELL_TYPE (x)))
 195 /* SCM_PTOBNAME can be 0 if name is missing */
 196 #define SCM_PTOBNAME(ptobnum) scm_ptobs[ptobnum].name
 197
 198 \f
 199
 200 SCM_API scm_t_ptob_descriptor *scm_ptobs;
 201 SCM_API long scm_numptob;
 202 SCM_INTERNAL long scm_i_port_table_room;
 203
 204 \f
 205
 206 SCM_API SCM scm_markstream (SCM ptr);
 207 SCM_API scm_t_bits scm_make_port_type (char *name,
 208                                        int (*fill_input) (SCM port),
 209                                        void (*write) (SCM port,
 210                                                       const void *data,
 211                                                       size_t size));
 212 SCM_API void scm_set_port_mark (scm_t_bits tc, SCM (*mark) (SCM));
 213 SCM_API void scm_set_port_free (scm_t_bits tc, size_t (*free) (SCM));
 214 SCM_API void scm_set_port_print (scm_t_bits tc,
 215                                  int (*print) (SCM exp,
 216                                                SCM port,
 217                                                scm_print_state *pstate));
 218 SCM_API void scm_set_port_equalp (scm_t_bits tc, SCM (*equalp) (SCM, SCM));
 219 SCM_API void scm_set_port_close (scm_t_bits tc, int (*close) (SCM));
 220
 221 SCM_API void scm_set_port_flush (scm_t_bits tc,
 222                                  void (*flush) (SCM port));
 223 SCM_API void scm_set_port_end_input (scm_t_bits tc,
 224                                      void (*end_input) (SCM port,
 225                                                         int offset));
 226 SCM_API void scm_set_port_seek (scm_t_bits tc,
 227                                 off_t (*seek) (SCM port,
 228                                                off_t OFFSET,
 229                                                int WHENCE));
 230 SCM_API void scm_set_port_truncate (scm_t_bits tc,
 231                                     void (*truncate) (SCM port,
 232                                                       off_t length));
 233 SCM_API void scm_set_port_input_waiting (scm_t_bits tc, int (*input_waiting) (SCM));
 234 SCM_API SCM scm_char_ready_p (SCM port);
 235 size_t scm_take_from_input_buffers (SCM port, char *dest, size_t read_len);
 236 SCM_API SCM scm_drain_input (SCM port);
 237 SCM_API SCM scm_current_input_port (void);
 238 SCM_API SCM scm_current_output_port (void);
 239 SCM_API SCM scm_current_error_port (void);
 240 SCM_API SCM scm_current_load_port (void);
 241 SCM_API SCM scm_set_current_input_port (SCM port);
 242 SCM_API SCM scm_set_current_output_port (SCM port);
 243 SCM_API SCM scm_set_current_error_port (SCM port);
 244 SCM_API void scm_dynwind_current_input_port (SCM port);
 245 SCM_API void scm_dynwind_current_output_port (SCM port);
 246 SCM_API void scm_dynwind_current_error_port (SCM port);
 247 SCM_API SCM scm_new_port_table_entry (scm_t_bits tag);
 248 SCM_INTERNAL void scm_i_remove_port (SCM port);
 249 SCM_API void scm_grow_port_cbuf (SCM port, size_t requested);
 250 SCM_API SCM scm_pt_size (void);
 251 SCM_API SCM scm_pt_member (SCM member);
 252 SCM_API void scm_port_non_buffer (scm_t_port *pt);
 253 SCM_API int scm_revealed_count (SCM port);
 254 SCM_API SCM scm_port_revealed (SCM port);
 255 SCM_API SCM scm_set_port_revealed_x (SCM port, SCM rcount);
 256 SCM_API long scm_mode_bits (char *modes);
 257 SCM_API SCM scm_port_mode (SCM port);
 258 SCM_API SCM scm_close_input_port (SCM port);
 259 SCM_API SCM scm_close_output_port (SCM port);
 260 SCM_API SCM scm_close_port (SCM port);
 261 SCM_API SCM scm_port_for_each (SCM proc);
 262 SCM_API void scm_c_port_for_each (void (*proc)(void *data, SCM p), void *data);
 263 SCM_API SCM scm_input_port_p (SCM x);
 264 SCM_API SCM scm_output_port_p (SCM x);
 265 SCM_API SCM scm_port_p (SCM x);
 266 SCM_API SCM scm_port_closed_p (SCM port);
 267 SCM_API SCM scm_eof_object_p (SCM x);
 268 SCM_API SCM scm_force_output (SCM port);
 269 SCM_API SCM scm_flush_all_ports (void);
 270 SCM_API SCM scm_read_char (SCM port);
 271 SCM_API size_t scm_c_read (SCM port, void *buffer, size_t size);
 272 SCM_API void scm_c_write (SCM port, const void *buffer, size_t size);
 273 SCM_API void scm_lfwrite (const char *ptr, size_t size, SCM port);
 274 SCM_API void scm_flush (SCM port);
 275 SCM_API void scm_end_input (SCM port);
 276 SCM_API int scm_fill_input (SCM port);
 277 SCM_API void scm_ungetc (int c, SCM port);
 278 SCM_API void scm_ungets (const char *s, int n, SCM port);
 279 SCM_API SCM scm_peek_char (SCM port);
 280 SCM_API SCM scm_unread_char (SCM cobj, SCM port);
 281 SCM_API SCM scm_unread_string (SCM str, SCM port);
 282 SCM_API SCM scm_seek (SCM object, SCM offset, SCM whence);
 283 SCM_API SCM scm_truncate_file (SCM object, SCM length);
 284 SCM_API SCM scm_port_line (SCM port);
 285 SCM_API SCM scm_set_port_line_x (SCM port, SCM line);
 286 SCM_API SCM scm_port_column (SCM port);
 287 SCM_API SCM scm_set_port_column_x (SCM port, SCM line);
 288 SCM_API SCM scm_port_filename (SCM port);
 289 SCM_API SCM scm_set_port_filename_x (SCM port, SCM filename);
 290 SCM_API int scm_port_print (SCM exp, SCM port, scm_print_state *);
 291 SCM_API void scm_print_port_mode (SCM exp, SCM port);
 292 SCM_API void scm_ports_prehistory (void);
 293 SCM_API SCM scm_void_port (char * mode_str);
 294 SCM_API SCM scm_sys_make_void_port (SCM mode);
 295 SCM_INTERNAL void scm_init_ports (void);
 296
 297
 298 #if SCM_ENABLE_DEPRECATED==1
 299 SCM_API scm_t_port * scm_add_to_port_table (SCM port);
 300 #endif
 301
 302 #ifdef GUILE_DEBUG
 303 SCM_API SCM scm_pt_size (void);
 304 SCM_API SCM scm_pt_member (SCM member);
 305 #endif /* GUILE_DEBUG */
 306
 307 /* internal */
 308
 309 SCM_INTERNAL long scm_i_mode_bits (SCM modes);
 310 SCM_INTERNAL void scm_i_dynwind_current_load_port (SCM port);
 311
 312
 313 #endif  /* SCM_PORTS_H */
 314
 315 /*
 316   Local Variables:
 317   c-file-style: "gnu"
 318   End:
 319 */