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,
   7  *   2006, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public License
  11  * as published by the Free Software Foundation; either version 3 of
  12  * the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  22  * 02110-1301 USA
  23  */
  24
  25 \f
  26
  27 #include "libguile/__scm.h"
  28
  29 #include <unistd.h>
  30 #include "libguile/print.h"
  31 #include "libguile/struct.h"
  32 #include "libguile/threads.h"
  33 #include "libguile/strings.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   /* Character encoding support  */
  62   char *encoding;
  63   scm_t_string_failed_conversion_handler ilseq_handler;
  64
  65   /* port buffers.  the buffer(s) are set up for all ports.
  66      in the case of string ports, the buffer is the string itself.
  67      in the case of unbuffered file ports, the buffer is a
  68      single char: shortbuf.  */
  69
  70   /* this buffer is filled from read_buf to read_end using the ptob
  71      buffer_fill.  then input requests are taken from read_pos until
  72      it reaches read_end.  */
  73
  74   unsigned char *read_buf;      /* buffer start.  */
  75   const unsigned char *read_pos;/* the next unread char.  */
  76   unsigned char *read_end;      /* pointer to last buffered char + 1.  */
  77   scm_t_off read_buf_size;              /* size of the buffer.  */
  78
  79   /* when chars are put back into the buffer, e.g., using peek-char or
  80      unread-string, the read-buffer pointers are switched to cbuf.
  81      the original pointers are saved here and restored when the put-back
  82      chars have been consumed.  */
  83   unsigned char *saved_read_buf;
  84   const unsigned char *saved_read_pos;
  85   unsigned char *saved_read_end;
  86   scm_t_off saved_read_buf_size;
  87
  88   /* write requests are saved into this buffer at write_pos until it
  89      reaches write_buf + write_buf_size, then the ptob flush is
  90      called.  */
  91
  92   unsigned char *write_buf;     /* buffer start.  */
  93   unsigned char *write_pos;     /* pointer to last buffered char + 1.  */
  94   unsigned char *write_end;     /* pointer to end of buffer + 1.  */
  95   scm_t_off write_buf_size;             /* size of the buffer.  */
  96
  97   unsigned char shortbuf;       /* buffer for "unbuffered" streams.  */
  98
  99   int rw_random;                /* true if the port is random access.
 100                                    implies that the buffers must be
 101                                    flushed before switching between
 102                                    reading and writing, seeking, etc.  */
 103
 104   scm_t_port_rw_active rw_active; /* for random access ports,
 105                                      indicates which of the buffers
 106                                      is currently in use.  can be
 107                                      SCM_PORT_WRITE, SCM_PORT_READ,
 108                                      or SCM_PORT_NEITHER.  */
 109
 110
 111   /* a buffer for un-read chars and strings.  */
 112   unsigned char *putback_buf;
 113   size_t putback_buf_size;        /* allocated size of putback_buf.  */
 114
 115   /* input/output iconv conversion descriptors */
 116   void *input_cd;
 117   void *output_cd;
 118 } scm_t_port;
 119
 120
 121 SCM_INTERNAL scm_i_pthread_mutex_t scm_i_port_table_mutex;
 122 SCM_INTERNAL SCM scm_i_port_weak_hash;
 123
 124
 125 #define SCM_READ_BUFFER_EMPTY_P(c_port) (c_port->read_pos >= c_port->read_end)
 126
 127 \f
 128
 129 #define SCM_EOF_OBJECT_P(x) (scm_is_eq ((x), SCM_EOF_VAL))
 130
 131 /* PORT FLAGS
 132  * A set of flags characterizes a port.
 133  * Note that we reserve the bits 1 << 24 and above for use by the
 134  * routines in the port's scm_ptobfuns structure.
 135  */
 136 #define SCM_OPN         (1L<<16) /* Is the port open? */
 137 #define SCM_RDNG        (2L<<16) /* Is it a readable port? */
 138 #define SCM_WRTNG       (4L<<16) /* Is it writable? */
 139 #define SCM_BUF0        (8L<<16) /* Is it unbuffered? */
 140 #define SCM_BUFLINE     (64L<<16) /* Is it line-buffered? */
 141
 142 #define SCM_PORTP(x) (!SCM_IMP (x) && (SCM_TYP7 (x) == scm_tc7_port))
 143 #define SCM_OPPORTP(x) (!SCM_IMP(x) && (((0x7f | SCM_OPN) & SCM_CELL_WORD_0(x))==(scm_tc7_port | SCM_OPN)))
 144 #define SCM_OPINPORTP(x) (!SCM_IMP(x) && (((0x7f | SCM_OPN | SCM_RDNG) & SCM_CELL_WORD_0(x))==(scm_tc7_port | SCM_OPN | SCM_RDNG)))
 145 #define SCM_OPOUTPORTP(x) (!SCM_IMP(x) && (((0x7f | SCM_OPN | SCM_WRTNG) & SCM_CELL_WORD_0(x))==(scm_tc7_port | SCM_OPN | SCM_WRTNG)))
 146 #define SCM_INPUT_PORT_P(x) \
 147   (!SCM_IMP(x) \
 148    && (((0x7f | SCM_RDNG) & SCM_CELL_WORD_0(x)) == (scm_tc7_port | SCM_RDNG)))
 149 #define SCM_OUTPUT_PORT_P(x) \
 150   (!SCM_IMP(x) \
 151    && (((0x7f | SCM_WRTNG) & SCM_CELL_WORD_0(x))==(scm_tc7_port | SCM_WRTNG)))
 152 #define SCM_OPENP(x) (!SCM_IMP(x) && (SCM_OPN & SCM_CELL_WORD_0 (x)))
 153 #define SCM_CLOSEDP(x) (!SCM_OPENP(x))
 154 #define SCM_CLR_PORT_OPEN_FLAG(p) \
 155   SCM_SET_CELL_WORD_0 ((p), SCM_CELL_WORD_0 (p) & ~SCM_OPN)
 156
 157 #define SCM_PTAB_ENTRY(x)         ((scm_t_port *) SCM_CELL_WORD_1 (x))
 158 #define SCM_SETPTAB_ENTRY(x, ent)  (SCM_SET_CELL_WORD_1 ((x), (scm_t_bits) (ent)))
 159 #define SCM_STREAM(x)             (SCM_PTAB_ENTRY(x)->stream)
 160 #define SCM_SETSTREAM(x, s)        (SCM_PTAB_ENTRY(x)->stream = (scm_t_bits) (s))
 161 #define SCM_FILENAME(x)           (SCM_PTAB_ENTRY(x)->file_name)
 162 #define SCM_SET_FILENAME(x, n)    (SCM_PTAB_ENTRY(x)->file_name = (n))
 163 #define SCM_LINUM(x)              (SCM_PTAB_ENTRY(x)->line_number)
 164 #define SCM_COL(x)                (SCM_PTAB_ENTRY(x)->column_number)
 165 #define SCM_REVEALED(x)           (SCM_PTAB_ENTRY(x)->revealed)
 166 #define SCM_SETREVEALED(x, s)      (SCM_PTAB_ENTRY(x)->revealed = (s))
 167
 168 #define SCM_INCLINE(port)       do {SCM_LINUM (port) += 1; SCM_COL (port) = 0;} while (0)
 169 #define SCM_ZEROCOL(port)       do {SCM_COL (port) = 0;} while (0)
 170 #define SCM_INCCOL(port)        do {SCM_COL (port) += 1;} while (0)
 171 #define SCM_DECCOL(port)        do {if (SCM_COL (port) > 0) SCM_COL (port) -= 1;} while (0)
 172 #define SCM_TABCOL(port)        do {SCM_COL (port) += 8 - SCM_COL (port) % 8;} while (0)
 173
 174 /* Maximum number of port types.  */
 175 #define SCM_I_MAX_PORT_TYPE_COUNT  256
 176
 177 \f
 178
 179 /* port-type description.  */
 180 typedef struct scm_t_ptob_descriptor
 181 {
 182   char *name;
 183   SCM (*mark) (SCM);
 184   size_t (*free) (SCM);
 185   int (*print) (SCM exp, SCM port, scm_print_state *pstate);
 186   SCM (*equalp) (SCM, SCM);
 187   int (*close) (SCM port);
 188
 189   void (*write) (SCM port, const void *data, size_t size);
 190   void (*flush) (SCM port);
 191
 192   void (*end_input) (SCM port, int offset);
 193   int (*fill_input) (SCM port);
 194   int (*input_waiting) (SCM port);
 195
 196   scm_t_off (*seek) (SCM port, scm_t_off OFFSET, int WHENCE);
 197   void (*truncate) (SCM port, scm_t_off length);
 198
 199 } scm_t_ptob_descriptor;
 200
 201 #define SCM_TC2PTOBNUM(x) (0x0ff & ((x) >> 8))
 202 #define SCM_PTOBNUM(x) (SCM_TC2PTOBNUM (SCM_CELL_TYPE (x)))
 203 /* SCM_PTOBNAME can be 0 if name is missing */
 204 #define SCM_PTOBNAME(ptobnum) scm_ptobs[ptobnum].name
 205
 206 \f
 207
 208 SCM_API scm_t_ptob_descriptor *scm_ptobs;
 209 SCM_API long scm_numptob;
 210
 211 \f
 212
 213 SCM_API SCM scm_markstream (SCM ptr);
 214 SCM_API scm_t_bits scm_make_port_type (char *name,
 215                                        int (*fill_input) (SCM port),
 216                                        void (*write) (SCM port,
 217                                                       const void *data,
 218                                                       size_t size));
 219 SCM_API void scm_set_port_mark (scm_t_bits tc, SCM (*mark) (SCM));
 220 SCM_API void scm_set_port_free (scm_t_bits tc, size_t (*free) (SCM));
 221 SCM_API void scm_set_port_print (scm_t_bits tc,
 222                                  int (*print) (SCM exp,
 223                                                SCM port,
 224                                                scm_print_state *pstate));
 225 SCM_API void scm_set_port_equalp (scm_t_bits tc, SCM (*equalp) (SCM, SCM));
 226 SCM_API void scm_set_port_close (scm_t_bits tc, int (*close) (SCM));
 227
 228 SCM_API void scm_set_port_flush (scm_t_bits tc,
 229                                  void (*flush) (SCM port));
 230 SCM_API void scm_set_port_end_input (scm_t_bits tc,
 231                                      void (*end_input) (SCM port,
 232                                                         int offset));
 233 SCM_API void scm_set_port_seek (scm_t_bits tc,
 234                                 scm_t_off (*seek) (SCM port,
 235                                                    scm_t_off OFFSET,
 236                                                    int WHENCE));
 237 SCM_API void scm_set_port_truncate (scm_t_bits tc,
 238                                     void (*truncate) (SCM port,
 239                                                       scm_t_off length));
 240 SCM_API void scm_set_port_input_waiting (scm_t_bits tc, int (*input_waiting) (SCM));
 241 SCM_API SCM scm_char_ready_p (SCM port);
 242 size_t scm_take_from_input_buffers (SCM port, char *dest, size_t read_len);
 243 SCM_API SCM scm_drain_input (SCM port);
 244 SCM_API SCM scm_current_input_port (void);
 245 SCM_API SCM scm_current_output_port (void);
 246 SCM_API SCM scm_current_error_port (void);
 247 SCM_API SCM scm_current_load_port (void);
 248 SCM_API SCM scm_set_current_input_port (SCM port);
 249 SCM_API SCM scm_set_current_output_port (SCM port);
 250 SCM_API SCM scm_set_current_error_port (SCM port);
 251 SCM_API void scm_dynwind_current_input_port (SCM port);
 252 SCM_API void scm_dynwind_current_output_port (SCM port);
 253 SCM_API void scm_dynwind_current_error_port (SCM port);
 254 SCM_API SCM scm_new_port_table_entry (scm_t_bits tag);
 255 SCM_INTERNAL void scm_i_remove_port (SCM port);
 256 SCM_API void scm_grow_port_cbuf (SCM port, size_t requested);
 257 SCM_API SCM scm_pt_size (void);
 258 SCM_API SCM scm_pt_member (SCM member);
 259 SCM_API void scm_port_non_buffer (scm_t_port *pt);
 260 SCM_API int scm_revealed_count (SCM port);
 261 SCM_API SCM scm_port_revealed (SCM port);
 262 SCM_API SCM scm_set_port_revealed_x (SCM port, SCM rcount);
 263 SCM_API long scm_mode_bits (char *modes);
 264 SCM_API SCM scm_port_mode (SCM port);
 265 SCM_API SCM scm_close_input_port (SCM port);
 266 SCM_API SCM scm_close_output_port (SCM port);
 267 SCM_API SCM scm_close_port (SCM port);
 268 SCM_API SCM scm_port_for_each (SCM proc);
 269 SCM_API void scm_c_port_for_each (void (*proc)(void *data, SCM p), void *data);
 270 SCM_API SCM scm_input_port_p (SCM x);
 271 SCM_API SCM scm_output_port_p (SCM x);
 272 SCM_API SCM scm_port_p (SCM x);
 273 SCM_API SCM scm_port_closed_p (SCM port);
 274 SCM_API SCM scm_eof_object_p (SCM x);
 275 SCM_API SCM scm_force_output (SCM port);
 276 SCM_API SCM scm_flush_all_ports (void);
 277 SCM_API SCM scm_read_char (SCM port);
 278 SCM_API scm_t_wchar scm_getc (SCM port);
 279 SCM_API size_t scm_c_read (SCM port, void *buffer, size_t size);
 280 SCM_API void scm_c_write (SCM port, const void *buffer, size_t size);
 281 SCM_API void scm_lfwrite (const char *ptr, size_t size, SCM port);
 282 SCM_INTERNAL void scm_lfwrite_substr (SCM str, size_t start, size_t end,
 283                                       SCM port);
 284 SCM_API void scm_flush (SCM port);
 285 SCM_API void scm_end_input (SCM port);
 286 SCM_API int scm_fill_input (SCM port);
 287 SCM_INTERNAL void scm_unget_byte (int c, SCM port);
 288 SCM_API void scm_ungetc (scm_t_wchar c, SCM port);
 289 SCM_API void scm_ungets (const char *s, int n, SCM port);
 290 SCM_API SCM scm_peek_char (SCM port);
 291 SCM_API SCM scm_unread_char (SCM cobj, SCM port);
 292 SCM_API SCM scm_unread_string (SCM str, SCM port);
 293 SCM_API SCM scm_seek (SCM object, SCM offset, SCM whence);
 294 SCM_API SCM scm_truncate_file (SCM object, SCM length);
 295 SCM_API SCM scm_port_line (SCM port);
 296 SCM_API SCM scm_set_port_line_x (SCM port, SCM line);
 297 SCM_API SCM scm_port_column (SCM port);
 298 SCM_API SCM scm_set_port_column_x (SCM port, SCM line);
 299 SCM_API SCM scm_port_filename (SCM port);
 300 SCM_API SCM scm_set_port_filename_x (SCM port, SCM filename);
 301 SCM_INTERNAL const char *scm_i_default_port_encoding (void);
 302 SCM_INTERNAL void scm_i_set_default_port_encoding (const char *);
 303 SCM_INTERNAL void scm_i_set_port_encoding_x (SCM port, const char *str);
 304 SCM_API SCM scm_port_encoding (SCM port);
 305 SCM_API SCM scm_set_port_encoding_x (SCM port, SCM encoding);
 306 SCM_INTERNAL scm_t_string_failed_conversion_handler scm_i_get_conversion_strategy (SCM port);
 307 SCM_INTERNAL void scm_i_set_conversion_strategy_x (SCM port,
 308                                                    scm_t_string_failed_conversion_handler h);
 309 SCM_API SCM scm_port_conversion_strategy (SCM port);
 310 SCM_API SCM scm_set_port_conversion_strategy_x (SCM port, SCM behavior);
 311 SCM_API int scm_port_print (SCM exp, SCM port, scm_print_state *);
 312 SCM_API void scm_print_port_mode (SCM exp, SCM port);
 313 SCM_API SCM scm_void_port (char * mode_str);
 314 SCM_API SCM scm_sys_make_void_port (SCM mode);
 315 SCM_INTERNAL void scm_init_ports (void);
 316
 317 #if SCM_ENABLE_DEPRECATED==1
 318 SCM_DEPRECATED scm_t_port * scm_add_to_port_table (SCM port);
 319 #endif
 320
 321 #ifdef GUILE_DEBUG
 322 SCM_API SCM scm_pt_size (void);
 323 SCM_API SCM scm_pt_member (SCM member);
 324 #endif /* GUILE_DEBUG */
 325
 326 /* internal */
 327
 328 SCM_INTERNAL long scm_i_mode_bits (SCM modes);
 329 SCM_INTERNAL void scm_i_dynwind_current_load_port (SCM port);
 330
 331
 332 #endif  /* SCM_PORTS_H */
 333
 334 /*
 335   Local Variables:
 336   c-file-style: "gnu"
 337   End:
 338 */