X-Git-Url: https://git.distorted.org.uk/~mdw/dvdrip/blobdiff_plain/be15bd145f610c88dc2e17698b3863904872a3f0..refs/heads/mdw/cleanup:/lib.h

diff --git a/lib.h b/lib.h
index 5507f12..7c4a0cb 100644
--- a/lib.h
+++ b/lib.h
@@ -97,8 +97,16 @@
 /* Function attributes.  If you're not using GCC to build then you'll need to
  * say something different here.
  */
-#define PRINTF_LIKE(fmt, dots) __attribute__((format(printf, fmt, dots)))
-#define NORETURN __attribute__((noreturn))
+#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 ------------------------------*/
 
@@ -135,6 +143,75 @@ extern PRINTF_LIKE(2, 3) NORETURN
 	 * 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
@@ -152,11 +229,24 @@ extern long parse_int(const char **p_inout, unsigned f,
 
 /*----- 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
@@ -190,7 +280,7 @@ extern off_t device_size(int fd, const char *file, int *blksz_out);
 	 * 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.
+	 * fatal error quoting FILE as the name of the device.
 	 */
 
 /*----- Progress utilities ------------------------------------------------*/
@@ -211,19 +301,19 @@ extern void hide_banner(void);
 
 /*----- DVD utilities -----------------------------------------------------*/
 
-extern void open_dvd(const char *device, int mode,
-		     int *fd_out, dvd_reader_t **dvd_out);
+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?
+	 * 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 as
-	 * fatal errors.
+	 * wait for a medium to be inserted.  Other problems are reported to
+	 * stderr.
 	 */
 
 enum { RAW, IFO, VOB, BUP };