@@@ dvdrip-upload: change settings while i'm stealing someone else's internet

[dvdrip] / lib.h

/* -*-c-*-
 *
 * Common functions for the DVDrip C utilities.
 *
 * (c) 2022 Mark Wooding
 */

/*----- Licensing notice --------------------------------------------------*
 *
 * This file is part of the DVD ripping toolset.
 *
 * DVDrip is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 3 of the License, or (at your
 * option) any later version.
 *
 * DVDrip is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with DVDrip.  If not, see <https://www.gnu.org/licenses/>.
 */

#ifndef LIB_H
#define LIB_H

/*----- Preliminaries -----------------------------------------------------*/

#define _GNU_SOURCE
#define _FILE_OFFSET_BITS 64

/*----- Header files ------------------------------------------------------*/

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <float.h>
#include <inttypes.h>
#include <limits.h>
#include <locale.h>
#include <math.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <sys/time.h>

#include <getopt.h>

#include <linux/fs.h>

#include <dvdread/dvd_reader.h>
#include <dvdread/dvd_udf.h>
#include <dvdread/ifo_read.h>
#include <dvdread/ifo_types.h>

#include "multiprogress.h"

/*----- Various macros with wide applicability ----------------------------*/

/* `ctype.h' functions are troublesome: in particular, they don't handle
 * negative characters properly, if they're a thing that your platform
 * believes in.  So we have these macros which fix things up properly.
 */
#define CTYPE_HACK(fn, ch) fn((unsigned char)(ch))
#define ISDIGIT(ch) CTYPE_HACK(isdigit, ch)
#define ISSPACE(ch) CTYPE_HACK(isspace, ch)

/* It's easy to screw up the `foocmp' functions by leaving off the comparison
 * with zero.  These macros make it impossible to forget, and put the
 * relation in the right place syntactically.
 */
#define STRCMP(a, op, b) (strcmp((a), (b)) op 0)
#define STRNCMP(a, op, b, n) (strncmp((a), (b), (n)) op 0)
#define MEMCMP(a, op, b, n) (memcmp((a), (b), (n)) op 0)

/* Suppress some code unless we're debugging. */
#ifdef DEBUG
#  define D(x) x
#else
#  define D(x)
#endif

/* Count the number of elements in an array. */
#define N(v) (sizeof(v)/sizeof((v)[0]))

/* Function attributes.  If you're not using GCC to build then you'll need to
 * say something different here.
 */
#if (defined(__GNUC__) && (__GNUC__ > 2 ||                              \
                           (__GNUC__ == 2 && __GNUC_MINOR__ >= 5))) ||  \
    (defined(__clang__) && (__clang_major__ > 3 || \
                            (__clang_major__ == 3 && __clang_minor__ >= 3)))
#  define PRINTF_LIKE(fmt, dots) __attribute__((format(printf, fmt, dots)))
#  define NORETURN __attribute__((noreturn))
#else
#  define PRINTF_LIKE(fmt, dots)
#  define NORETURN
#endif

/*----- Definitions for low-level DVD access ------------------------------*/

#define SECTORSZ 2048                   /* the DVD sector size */
#define SECTORS(n) (((n) + (SECTORSZ - 1))/SECTORSZ)
                                /* convert bytes to * sectors, rounding up */
typedef uint_least32_t secaddr;         /* a type for sector numbers */
#define PRIuSEC PRIuLEAST32             /* how to print a sector number  */
#define SECLIMIT 0x00400000             /* upper bound on sector numbers */

/*----- Diagnostics -------------------------------------------------------*/

extern const char *prog;          /* the program name; set with `set_prog' */

extern void set_prog(const char *p);
        /* Set the program name to P, stripping any directory names. */

extern void vmoan(const char *fmt, va_list ap);
extern void vmoan_syserr(int err, const char *fmt, va_list ap);
        /* Low-level warning reporting.  See `moan' and `moan_syserr'. */

extern PRINTF_LIKE(1, 2) void moan(const char *fmt, ...);
extern PRINTF_LIKE(2, 3) void moan_syserr(int err, const char *fmt, ...);
        /* Print a warning message, given as a `printf'-like format string
         * FMT and arguments, to standard error.  If ERR is nonzero, then
         * append a colon and the human-readable description of the `errno'
         * value ERR.
         */

extern PRINTF_LIKE(1, 2) NORETURN void bail(const char *fmt, ...);
extern PRINTF_LIKE(2, 3) NORETURN
  void bail_syserr(int err, const char *fmt, ...);
        /* Like the corresponding `moan' functions, except that they also
         * exit with status code 2.
         */

/*----- Resizing buffers --------------------------------------------------*/

struct buf {
  /* A buffer for a string which can grow automatically. */

  char *p;                              /* pointer to the buffer */
  size_t n, sz;                         /* string length, buffer size */
};
#define BUF_INIT { 0, 0, 0 }

static inline void buf_rewind(struct buf *b) { b->n = 0; }
        /* Throw away the current contents of B so that new stuff gets added
         * to the beginning.
         */

static inline void buf_free(struct buf *b)
  { free(b->p); b->p = 0; b->n = b->sz = 0; }
        /* Release the memory allocated for B.  The buffer can be reused
         * immediately and/or freed again safely.
         */

extern void buf__grow(struct buf *b);
        /* Make B's buffer larger, so that (at least) one extra byte can be
         * written to it.  (Internal to `buf_putc'.)
         */

static inline void buf_putc(struct buf *b, int ch)
  { if (b->n >= b->sz) buf__grow(b); b->p[b->n++] = ch; }
        /* Append the character CH to the buffer B. */

static inline void buf_putz(struct buf *b)
  { if (b->n >= b->sz) buf__grow(b); b->p[b->n] = 0; }
        /* Append a zero byte to B without increasing the string length, so
         * that a future `buf_putc' will overwrite it.
         */

/*----- Resizing vectors --------------------------------------------------*/

#define DEFVEC(vtype, etype)                                            \
        typedef struct { etype *v; size_t n, sz; } vtype
#define VEC_INIT { 0, 0, 0 }
        /* Define VTYPE as a (structured) type for vectors holding elements
         * of ETYPE.
         *
         * A vector V has `V.n' elements, addressed as `V.v[0]' up to
         * `V.v[V.n - 1]'.
         */

#define VEC_FREE(vv) do {                                               \
  free((vv)->v); (vv)->v 0; (vv)->n = (vv)->sz = 0;                     \
} while (0)
        /* Free the vector VV.  It's safe to free a vector multiple times. */

extern void *vec__grow(void *p, size_t esz, size_t *sz_inout);
        /* Extend the buffer P, which currently has space for *SZ_INOUT
         * elements, each ESZ bytes in size, so that there's space for at
         * least one one more; return the new buffer address, and update
         * *SZ_INOUT with the new size.
         */

#define VEC_PUSH(p, vv) do {                                            \
  if ((vv)->n >= (vv)->sz)                                              \
    (vv)->v = vec__grow((vv)->v, sizeof(*(vv)->v), &(vv)->sz);          \
  (p) = &(vv)->v[(vv)->n++];                                            \
} while (0)
        /* Add an initialized element to the end of vector VV, storing its
         * address in P.
         */

/*----- Parsing utilities -------------------------------------------------*/

#define PNF_JUNK 1u
extern double parse_float(const char **p_inout, unsigned f,
                          double min, double max, const char *what);
extern long parse_int(const char **p_inout, unsigned f,
                      long min, long max, const char *what);
        /* Parse a number starting at *P_IN OUT, advancing that pointer past
         * it, and return the resulting value.  If no number can be read from
         * the string, or the resulting number is not between MIN and MAX
         * inclusive, or the `PNF_JUNK' bit is clear in F and the number is
         * followed by anything other than whitespace, then report a fatal
         * error, quoting WHAT as having been expected.
         */

/*----- System utilities --------------------------------------------------*/

extern double tvdiff(const struct timeval *tv_lo,
                     const struct timeval *tv_hi);
        /* Return the (signed) difference from TV_LO to TV_HI, as a floating-
         * point number of seconds.
         */

extern void sit(double t);
        /* Do nothing for T seconds.  As implied by the type, T may be
         * fractional.
         */

extern int read_line(FILE *fp, struct buf *b);
        /* Read a line from FP, appending it to the buffer B, leaving the
         * string in B null-terminated (as if by `buf_putz').  Return 0 on
         * success, or -1 if nothing was read (not even an empty line) before
         * we encountered end-of-file or a read error.
         */

extern void carefully_write(int fd, const void *buf, size_t sz);
        /* Write SZ bytes to file descriptor FD, starting at BUF.  Report a
         * fatal error if this fails.  Correctly handles short writes and
         * `EINTR'.
         */

extern void open_file_on_demand(const char *file, FILE **fp_inout,
                                const char *what);
        /* If *FP_INOUT is not null, then do nothing.  Otherwise, open FILE
         * for writing, storing the resulting stream handle in *FP_INOUT; if
         * this can't be done then report a fatal error, quoting WHAT as the
         * kind of file.
         */

extern void check_write(FILE *fp, const char *what);
        /* Flush any remaining output to FP and check that there were no
         * errors.  If there were problems, report a fatal error quoting WHAT
         * as the kind of file.
         */

extern void carefully_fclose(FILE *fp, const char *what);
        /* Flush output to FP and close it, reporting fatal errors as for
         * `check_write'.  If FP is null, then do nothing.
         */

extern off_t device_size(int fd, const char *file, int *blksz_out);
        /* Determine the size of the device referred to by FD.  Specifically,
         * if FD is a regular file, then this is simply the size of the file;
         * if FD is a block device, then this is the size of the block
         * device.  Return the resulting size, and, in the case of a block
         * device only, store the block size in *BLKSZ_OUT.  (Hence,
         * *BLKSZ_OUT will be left unchanged if FD is open on a regular
         * file.)  If FD refers to any other kind of object then report a
         * fatal error quoting FILE as the name of the device.
         */

/*----- Progress utilities ------------------------------------------------*/

struct banner_progress_item {
        /* A progress item which simply shows a banner message. */
  struct progress_item _base;
  const char *msg;
};

extern struct progress_state progress;  /* the shared progress reporter */

extern void show_banner(const char *msg);
extern void hide_banner(void);
        /* Show or hide a banner reporting a message.  If a banner is already
         * showing, then `show_banner' just changes the message.
         */

/*----- DVD utilities -----------------------------------------------------*/

extern int open_dvd(const char *device, int mode,
                    int *fd_out, dvd_reader_t **dvd_out);
        /* Open the DEVICE.  If FD_OUT is not null, then open a file
         * descriptor onto the device, with the given open(2)-style MODE,
         * storing the descriptor in *FD_OUT; if DVD_OUT is not null, then
         * open a `libdvdread' handle onto the devie and store it in
         * *DVD_OUT.  If both are null, then why are you calling this
         * function?  Returns 0 on success or -1 on failure.
         *
         * If DEVICE refers to an actual block device, and no medium is
         * currently inserted, then put up a banner prompting the user and
         * wait for a medium to be inserted.  Other problems are reported to
         * stderr.
         */

enum { RAW, IFO, VOB, BUP };
typedef uint_least32_t ident;
        /* A convenient name for interesting files on a DVD.  It consists of
         * three components:
         *
         *   * A `kind', which is `RAW', `IFO', `VOB', or `BUP'.  `RAW' is a
         *     special token which refers to the whole disc; the other kinds
         *     refer to files in the DVD filesystem with the corresponding
         *     extensions.
         *
         *   * A `title', which is a number between 0 and 99 inclusive.
         *     Title zero refers to the video management information and its
         *     corresponding menu; nonzero numbers refer to video titlesets.
         *
         *   * A `part', which is only relevant for `VOB' files; part 0
         *     refers to the menu data, while parts 1 to 9 inclusive refer to
         *     portions of the video titleset itself.
         *
         * Components which aren't applicable must be zero, so that idents
         * can conveniently be compared as integers (so, specifically, the
         * title, if kind is `RAW', and the part, if kind is not `VOB' or
         * title is zero.
         */

static inline ident mkident(unsigned kind, unsigned title, unsigned part)
  { return (((ident)kind << 0) | ((ident)title << 8) | ((ident)part << 16)); }
static inline unsigned id_kind(ident id) { return ((id >> 0)&0x0ff); }
static inline unsigned id_title(ident id) { return ((id >> 8)&0x0ff); }
static inline unsigned id_part(ident id) { return ((id >> 16)&0x0ff); }
        /* Functions for constructing and picking apart the fields of an
         * ident.
         */

#define MAXFNSZ (1 + 8 + 1 + 12 + 1)
extern void store_filename(char *buf, ident id);
        /* Store in BUF the filename corresponding to the ident ID.  The
         * filename will be at most `MAXFNSZ' bytes long, including the
         * terminating zero.
         */

#define DIF_MUSTVOLINF 1u
#define DIF_MUSTIFOHASH 2u
#define MAXIDSZ (32 + 1 + 32 + 1 + 32 + 1)
extern int dvd_id(char *p, dvd_reader_t *dvd, unsigned f, const char *file);
        /* Determine a (hopefully) unique identifier for DVD.  The identifier
         * consists of two parts:
         *
         *   * the volume name and serial number, from the volume
         *     information, and
         *
         *   * a cryptographic hash of the `.IFO' files on the disc.
         *
         * The identifier is written, as plain text, at P, and consists of at
         * most `MAXIDSZ' bytes, including the terminating zero.
         *
         * It's possible that determining either, or both, of these might
         * fail: the behaviour is controlled by the `DIF_MUSTVOLINF' and
         * `DIF_MUSTIFOHASH' flags in F: if the volume name/serial number, or
         * `.IFO' hash, respectively, can't be determined, and the
         * corresponding flag is clear, then a placeholder error message is
         * written to the output buffer in place of the correct data; if the
         * flag is set, then a warning message is printed to standard error
         * and -1 is returned.  In practice, the `.IFO' hash is more likely
         * to be computed successfully, and probably more likely to actually
         * be unique.
         *
         * Returns zero if the identifier was successfully determined, within
         * the parameters set by the flags.
         */

/*----- That's all, folks -------------------------------------------------*/

#endif