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 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
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but 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 02110-1301 USA
  21  */
  22
  23 \f
  24
  25 #include "libguile/__scm.h"
  26
  27 #include "libguile/print.h"
  28 #include "libguile/struct.h"
  29 #include "libguile/threads.h"
  30
  31 /* Not sure if this is a good idea.  We need it for off_t.  */
  32 #include <sys/types.h>
  33
  34 \f
  35
  36 #define SCM_INITIAL_PUTBACK_BUF_SIZE 4
  37
  38 /* values for the rw_active flag.  */
  39 typedef enum scm_t_port_rw_active {
  40   SCM_PORT_NEITHER = 0,
  41   SCM_PORT_READ = 1,
  42   SCM_PORT_WRITE = 2
  43 } scm_t_port_rw_active;
  44
  45 /* C representation of a Scheme port.  */
  46
  47 typedef struct
  48 {
  49   SCM port;                     /* Link back to the port object.  */
  50   int revealed;                 /* 0 not revealed, > 1 revealed.
  51                                  * Revealed ports do not get GC'd.
  52                                  */
  53   /* data for the underlying port implementation as a raw C value. */
  54   scm_t_bits stream;
  55
  56   SCM file_name;                /* debugging support.  */
  57   long line_number;             /* debugging support.  */
  58   int column_number;            /* debugging support.  */
  59
  60   /* port buffers.  the buffer(s) are set up for all ports.
  61      in the case of string ports, the buffer is the string itself.
  62      in the case of unbuffered file ports, the buffer is a
  63      single char: shortbuf.  */
  64
  65   /* this buffer is filled from read_buf to read_end using the ptob
  66      buffer_fill.  then input requests are taken from read_pos until
  67      it reaches read_end.  */
  68
  69   unsigned char *read_buf;      /* buffer start.  */
  70   const unsigned char *read_pos;/* the next unread char.  */
  71   unsigned char *read_end;      /* pointer to last buffered char + 1.  */
  72   off_t read_buf_size;          /* size of the buffer.  */
  73
  74   /* when chars are put back into the buffer, e.g., using peek-char or
  75      unread-string, the read-buffer pointers are switched to cbuf.
  76      the original pointers are saved here and restored when the put-back
  77      chars have been consumed.  */
  78   unsigned char *saved_read_buf;
  79   const unsigned char *saved_read_pos;
  80   unsigned char *saved_read_end;
  81   off_t saved_read_buf_size;
  82
  83   /* write requests are saved into this buffer at write_pos until it
  84      reaches write_buf + write_buf_size, then the ptob flush is
  85      called.  */
  86
  87   unsigned char *write_buf;     /* buffer start.  */
  88   unsigned char *write_pos;     /* pointer to last buffered char + 1.  */
  89   unsigned char *write_end;     /* pointer to end of buffer + 1.  */
  90   off_t write_buf_size;         /* size of the buffer.  */
  91
  92   unsigned char shortbuf;       /* buffer for "unbuffered" streams.  */
  93
  94   int rw_random;                /* true if the port is random access.
  95                                    implies that the buffers must be
  96                                    flushed before switching between
  97                                    reading and writing, seeking, etc.  */
  98
  99   scm_t_port_rw_active rw_active; /* for random access ports,
 100                                      indicates which of the buffers
 101                                      is currently in use.  can be
 102                                      SCM_PORT_WRITE, SCM_PORT_READ,
 103                                      or SCM_PORT_NEITHER.  */
 104
 105
 106   /* a buffer for un-read chars and strings.  */
 107   unsigned char *putback_buf;
 108   size_t putback_buf_size;        /* allocated size of putback_buf.  */
 109 } scm_t_port;
 110
 111
 112 SCM_API scm_i_pthread_mutex_t scm_i_port_table_mutex;
 113 SCM_API SCM scm_i_port_weak_hash;
 114
 115
 116 #define SCM_READ_BUFFER_EMPTY_P(c_port) (c_port->read_pos >= c_port->read_end)
 117
 118 \f
 119
 120 #define SCM_EOF_OBJECT_P(x) (scm_is_eq ((x), SCM_EOF_VAL))
 121
 122 /* PORT FLAGS
 123  * A set of flags characterizes a port.
 124  * Note that we reserve the bits 1 << 24 and above for use by the
 125  * routines in the port's scm_ptobfuns structure.
 126  */
 127 #define SCM_OPN         (1L<<16) /* Is the port open? */
 128 #define SCM_RDNG        (2L<<16) /* Is it a readable port? */
 129 #define SCM_WRTNG       (4L<<16) /* Is it writable? */
 130 #define SCM_BUF0        (8L<<16) /* Is it unbuffered? */
 131 #define SCM_BUFLINE     (64L<<16) /* Is it line-buffered? */
 132
 133 #define SCM_PORTP(x) (!SCM_IMP (x) && (SCM_TYP7 (x) == scm_tc7_port))
 134 #define SCM_OPPORTP(x) (!SCM_IMP(x) && (((0x7f | SCM_OPN) & SCM_CELL_WORD_0(x))==(scm_tc7_port | SCM_OPN)))
 135 #define SCM_OPINPORTP(x) (!SCM_IMP(x) && (((0x7f | SCM_OPN | SCM_RDNG) & SCM_CELL_WORD_0(x))==(scm_tc7_port | SCM_OPN | SCM_RDNG)))
 136 #define SCM_OPOUTPORTP(x) (!SCM_IMP(x) && (((0x7f | SCM_OPN | SCM_WRTNG) & SCM_CELL_WORD_0(x))==(scm_tc7_port | SCM_OPN | SCM_WRTNG)))
 137 #define SCM_INPUT_PORT_P(x) \
 138   (!SCM_IMP(x) \
 139    && (((0x7f | SCM_RDNG) & SCM_CELL_WORD_0(x)) == (scm_tc7_port | SCM_RDNG)))
 140 #define SCM_OUTPUT_PORT_P(x) \
 141   (!SCM_IMP(x) \
 142    && (((0x7f | SCM_WRTNG) & SCM_CELL_WORD_0(x))==(scm_tc7_port | SCM_WRTNG)))
 143 #define SCM_OPENP(x) (!SCM_IMP(x) && (SCM_OPN & SCM_CELL_WORD_0 (x)))
 144 #define SCM_CLOSEDP(x) (!SCM_OPENP(x))
 145 #define SCM_CLR_PORT_OPEN_FLAG(p) \
 146   SCM_SET_CELL_WORD_0 ((p), SCM_CELL_WORD_0 (p) & ~SCM_OPN)
 147
 148 #define SCM_PTAB_ENTRY(x)         ((scm_t_port *) SCM_CELL_WORD_1 (x))
 149 #define SCM_SETPTAB_ENTRY(x, ent)  (SCM_SET_CELL_WORD_1 ((x), (scm_t_bits) (ent)))
 150 #define SCM_STREAM(x)             (SCM_PTAB_ENTRY(x)->stream)
 151 #define SCM_SETSTREAM(x, s)        (SCM_PTAB_ENTRY(x)->stream = (scm_t_bits) (s))
 152 #define SCM_FILENAME(x)           (SCM_PTAB_ENTRY(x)->file_name)
 153 #define SCM_SET_FILENAME(x, n)    (SCM_PTAB_ENTRY(x)->file_name = (n))
 154 #define SCM_LINUM(x)              (SCM_PTAB_ENTRY(x)->line_number)
 155 #define SCM_COL(x)                (SCM_PTAB_ENTRY(x)->column_number)
 156 #define SCM_REVEALED(x)           (SCM_PTAB_ENTRY(x)->revealed)
 157 #define SCM_SETREVEALED(x, s)      (SCM_PTAB_ENTRY(x)->revealed = (s))
 158
 159 #define SCM_INCLINE(port)       {SCM_LINUM (port) += 1; SCM_COL (port) = 0;}
 160 #define SCM_ZEROCOL(port)       {SCM_COL (port) = 0;}
 161 #define SCM_INCCOL(port)        {SCM_COL (port) += 1;}
 162 #define SCM_DECCOL(port)        {if (SCM_COL (port) > 0) SCM_COL (port) -= 1;}
 163 #define SCM_TABCOL(port)        {SCM_COL (port) += 8 - SCM_COL (port) % 8;}
 164
 165 \f
 166
 167 /* port-type description.  */
 168 typedef struct scm_t_ptob_descriptor
 169 {
 170   char *name;
 171   SCM (*mark) (SCM);
 172   size_t (*free) (SCM);
 173   int (*print) (SCM exp, SCM port, scm_print_state *pstate);
 174   SCM (*equalp) (SCM, SCM);
 175   int (*close) (SCM port);
 176
 177   void (*write) (SCM port, const void *data, size_t size);
 178   void (*flush) (SCM port);
 179
 180   void (*end_input) (SCM port, int offset);
 181   int (*fill_input) (SCM port);
 182   int (*input_waiting) (SCM port);
 183
 184   off_t (*seek) (SCM port, off_t OFFSET, int WHENCE);
 185   void (*truncate) (SCM port, off_t length);
 186
 187 } scm_t_ptob_descriptor;
 188
 189 #define SCM_TC2PTOBNUM(x) (0x0ff & ((x) >> 8))
 190 #define SCM_PTOBNUM(x) (SCM_TC2PTOBNUM (SCM_CELL_TYPE (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 SCM_API scm_t_ptob_descriptor *scm_ptobs;
 197 SCM_API long scm_numptob;
 198 SCM_API long scm_i_port_table_room;
 199
 200 \f
 201
 202 SCM_API SCM scm_markstream (SCM ptr);
 203 SCM_API scm_t_bits scm_make_port_type (char *name,
 204                                        int (*fill_input) (SCM port),
 205                                        void (*write) (SCM port,
 206                                                       const void *data,
 207                                                       size_t size));
 208 SCM_API void scm_set_port_mark (scm_t_bits tc, SCM (*mark) (SCM));
 209 SCM_API void scm_set_port_free (scm_t_bits tc, size_t (*free) (SCM));
 210 SCM_API void scm_set_port_print (scm_t_bits tc,
 211                                  int (*print) (SCM exp,
 212                                                SCM port,
 213                                                scm_print_state *pstate));
 214 SCM_API void scm_set_port_equalp (scm_t_bits tc, SCM (*equalp) (SCM, SCM));
 215 SCM_API void scm_set_port_close (scm_t_bits tc, int (*close) (SCM));
 216
 217 SCM_API void scm_set_port_flush (scm_t_bits tc,
 218                                  void (*flush) (SCM port));
 219 SCM_API void scm_set_port_end_input (scm_t_bits tc,
 220                                      void (*end_input) (SCM port,
 221                                                         int offset));
 222 SCM_API void scm_set_port_seek (scm_t_bits tc,
 223                                 off_t (*seek) (SCM port,
 224                                                off_t OFFSET,
 225                                                int WHENCE));
 226 SCM_API void scm_set_port_truncate (scm_t_bits tc,
 227                                     void (*truncate) (SCM port,
 228                                                       off_t length));
 229 SCM_API void scm_set_port_input_waiting (scm_t_bits tc, int (*input_waiting) (SCM));
 230 SCM_API SCM scm_char_ready_p (SCM port);
 231 size_t scm_take_from_input_buffers (SCM port, char *dest, size_t read_len);
 232 SCM_API SCM scm_drain_input (SCM port);
 233 SCM_API SCM scm_current_input_port (void);
 234 SCM_API SCM scm_current_output_port (void);
 235 SCM_API SCM scm_current_error_port (void);
 236 SCM_API SCM scm_current_load_port (void);
 237 SCM_API SCM scm_set_current_input_port (SCM port);
 238 SCM_API SCM scm_set_current_output_port (SCM port);
 239 SCM_API SCM scm_set_current_error_port (SCM port);
 240 SCM_API void scm_dynwind_current_input_port (SCM port);
 241 SCM_API void scm_dynwind_current_output_port (SCM port);
 242 SCM_API void scm_dynwind_current_error_port (SCM port);
 243 SCM_API SCM scm_new_port_table_entry (scm_t_bits tag);
 244 SCM_API void scm_i_remove_port (SCM port);
 245 SCM_API void scm_grow_port_cbuf (SCM port, size_t requested);
 246 SCM_API SCM scm_pt_size (void);
 247 SCM_API SCM scm_pt_member (SCM member);
 248 SCM_API void scm_port_non_buffer (scm_t_port *pt);
 249 SCM_API int scm_revealed_count (SCM port);
 250 SCM_API SCM scm_port_revealed (SCM port);
 251 SCM_API SCM scm_set_port_revealed_x (SCM port, SCM rcount);
 252 SCM_API long scm_mode_bits (char *modes);
 253 SCM_API SCM scm_port_mode (SCM port);
 254 SCM_API SCM scm_close_input_port (SCM port);
 255 SCM_API SCM scm_close_output_port (SCM port);
 256 SCM_API SCM scm_close_port (SCM port);
 257 SCM_API SCM scm_port_for_each (SCM proc);
 258 SCM_API void scm_c_port_for_each (void (*proc)(void *data, SCM p), void *data);
 259 SCM_API SCM scm_input_port_p (SCM x);
 260 SCM_API SCM scm_output_port_p (SCM x);
 261 SCM_API SCM scm_port_p (SCM x);
 262 SCM_API SCM scm_port_closed_p (SCM port);
 263 SCM_API SCM scm_eof_object_p (SCM x);
 264 SCM_API SCM scm_force_output (SCM port);
 265 SCM_API SCM scm_flush_all_ports (void);
 266 SCM_API SCM scm_read_char (SCM port);
 267 SCM_API void scm_putc (char c, SCM port);
 268 SCM_API void scm_puts (const char *str_data, SCM port);
 269 SCM_API size_t scm_c_read (SCM port, void *buffer, size_t size);
 270 SCM_API void scm_c_write (SCM port, const void *buffer, size_t size);
 271 SCM_API void scm_lfwrite (const char *ptr, size_t size, SCM port);
 272 SCM_API void scm_flush (SCM port);
 273 SCM_API void scm_end_input (SCM port);
 274 SCM_API int scm_fill_input (SCM port);
 275 SCM_API int scm_getc (SCM port);
 276 SCM_API void scm_ungetc (int c, SCM port);
 277 SCM_API void scm_ungets (const char *s, int n, SCM port);
 278 SCM_API SCM scm_peek_char (SCM port);
 279 SCM_API SCM scm_unread_char (SCM cobj, SCM port);
 280 SCM_API SCM scm_unread_string (SCM str, SCM port);
 281 SCM_API SCM scm_seek (SCM object, SCM offset, SCM whence);
 282 SCM_API SCM scm_truncate_file (SCM object, SCM length);
 283 SCM_API SCM scm_port_line (SCM port);
 284 SCM_API SCM scm_set_port_line_x (SCM port, SCM line);
 285 SCM_API SCM scm_port_column (SCM port);
 286 SCM_API SCM scm_set_port_column_x (SCM port, SCM line);
 287 SCM_API SCM scm_port_filename (SCM port);
 288 SCM_API SCM scm_set_port_filename_x (SCM port, SCM filename);
 289 SCM_API int scm_port_print (SCM exp, SCM port, scm_print_state *);
 290 SCM_API void scm_print_port_mode (SCM exp, SCM port);
 291 SCM_API void scm_ports_prehistory (void);
 292 SCM_API SCM scm_void_port (char * mode_str);
 293 SCM_API SCM scm_sys_make_void_port (SCM mode);
 294 SCM_API void scm_init_ports (void);
 295
 296
 297 #if SCM_ENABLE_DEPRECATED==1
 298 SCM_API scm_t_port * scm_add_to_port_table (SCM port);
 299 #endif
 300
 301 #ifdef GUILE_DEBUG
 302 SCM_API SCM scm_pt_size (void);
 303 SCM_API SCM scm_pt_member (SCM member);
 304 #endif /* GUILE_DEBUG */
 305
 306 /* internal */
 307
 308 SCM_API long scm_i_mode_bits (SCM modes);
 309 SCM_API void scm_i_dynwind_current_load_port (SCM port);
 310
 311
 312 #endif  /* SCM_PORTS_H */
 313
 314 /*
 315   Local Variables:
 316   c-file-style: "gnu"
 317   End:
 318 */