X-Git-Url: https://git.distorted.org.uk/~mdw/dvdrip/blobdiff_plain/513eba4411f9c6f8b09375734fdaafc49a962eae..d935b4815a7e314cfe75f46ad6eb9bfb6f5f447b:/dvd-sector-copy.c

diff --git a/dvd-sector-copy.c b/dvd-sector-copy.c
index 28a4943..177ce94 100644
--- a/dvd-sector-copy.c
+++ b/dvd-sector-copy.c
@@ -379,18 +379,6 @@ static void report_progress(secaddr pos)
 #undef BETA
 }
 
-static void report_bad_blocks_progress(secaddr lo, secaddr hi, int err)
-{
-  report_progress(hi);
-
-  if (lo == hi) append_progress(": retrying bad sector");
-  else
-    append_progress(": %"PRIuSEC" bad %s",
-		    hi - lo, hi == lo + 1 ? "sector" : "sectors");
-  if (err != EIO) append_progress(" (%s)", strerror(err));
-  fflush(stdout);
-}
-
 static dvd_reader_t *dvd;
 static int dvdfd = -1, outfd = -1;
 static dvd_file_t *vob;
@@ -415,9 +403,11 @@ static int compare_badblock(const void *a, const void *b)
 
 static ssize_t read_sectors(secaddr pos, void *buf, secaddr want)
 {
-  ssize_t n;
+  ssize_t n, done;
   size_t lo, mid, hi;
+  int fakeerr = 0;
   struct badblock *bad, *best;
+  unsigned char *p = buf;
 
   best = 0; lo = 0; hi = badblocks.n;
 #ifdef DEBUG
@@ -440,22 +430,290 @@ static ssize_t read_sectors(secaddr pos, void *buf, secaddr want)
     printf(";;   next is %"PRIuSEC" .. %"PRIuSEC"\n",
 	   best->start, best->end);
 #endif
-  if (best && pos + want > best->start) want = best->start - pos;
+  if (best && pos + want > best->start)
+    { want = best->start - pos; fakeerr = EIO; }
+
+  done = 0;
+  while (want) {
+    if (vob)
+      { errno = 0; n = DVDReadBlocks(vob, pos - file->start, want, p); }
+    else if (file) {
+      if (lseek(dvdfd, (off_t)pos*SECTORSZ, SEEK_SET) < 0)
+	bail_syserr(errno, "failed to seek to sector %"PRIuSEC"", pos);
+      errno = 0; n = read(dvdfd, p, want*SECTORSZ);
+      if (n >= 0) n /= SECTORSZ;
+    } else {
+      memset(p, 0, want*SECTORSZ);
+      n = want;
+    }
 
-again:
-  if (vob)
-    n = DVDReadBlocks(vob, pos - file->start, want, buf);
-  else if (file) {
-    if (lseek(dvdfd, (off_t)pos*SECTORSZ, SEEK_SET) < 0)
-      bail_syserr(errno, "failed to seek to sector %"PRIuSEC"", pos);
-    n = read(dvdfd, buf, want*SECTORSZ);
-    if (n >= 0) n /= SECTORSZ;
-  } else {
-    memset(buf, 0, want*SECTORSZ);
-    n = want;
+    if (n > 0) { done += n; pos += n; p += n*SECTORSZ; want -= n; }
+    else if (!n || errno != EINTR) break;
   }
+  if (fakeerr && !errno) errno = fakeerr;
+  return (!done && errno ? -1 : done);
+}
+
+static void report_bad_blocks_progress(secaddr lo, secaddr hi, int err)
+{
+  report_progress(hi);
+
+  if (lo == hi) append_progress(": retrying bad sector");
+  else
+    append_progress(": %"PRIuSEC" bad %s",
+		    hi - lo, hi == lo + 1 ? "sector" : "sectors");
+  if (err && err != EIO) append_progress(" (%s)", strerror(err));
+  fflush(stdout);
+}
+
+static void recovered(secaddr bad_lo, secaddr bad_hi)
+{
+  clear_progress();
+  moan("skipping %"PRIuSEC" bad sectors (%"PRIuSEC" .. %"PRIuSEC")",
+       bad_hi - bad_lo, bad_lo, bad_hi);
+  if (mapfile) {
+    if (!mapfp) {
+      mapfp = fopen(mapfile, "w");
+      if (!mapfp)
+	bail_syserr(errno, "failed to open bad-sector map file `%s'",
+		    optarg);
+      fprintf(mapfp, "## bad sector map\n\n");
+    }
+    fprintf(mapfp, "%"PRIuSEC" %"PRIuSEC"\n", bad_lo, bad_hi);
+    fflush(mapfp);
+    if (ferror(mapfp))
+      bail_syserr(errno, "error writing bad-sector map file");
+  }
+  if (lseek(outfd, (off_t)(bad_hi - bad_lo)*SECTORSZ, SEEK_CUR) < 0)
+    bail_syserr(errno, "failed to seek past bad sectors");
+  status = 1;
+}
 
-  if (n < 0 && errno == EINTR) goto again;
+struct recoverybuf {
+  unsigned char *buf;
+  secaddr sz, pos, start, end;
+};
+
+static void rearrange_sectors(struct recoverybuf *r,
+			      secaddr dest, secaddr src, secaddr len)
+{
+  assert(dest + len <= r->sz);
+  assert(src + len <= r->sz);
+  memmove(r->buf + dest*SECTORSZ, r->buf + src*SECTORSZ, len*SECTORSZ);
+}
+
+#ifdef DEBUG
+__attribute__((format(printf, 2, 3)))
+static void show_recovery_buffer_map(const struct recoverybuf *r,
+				     const char *what, ...)
+{
+  va_list ap;
+
+  va_start(ap, what);
+  clear_progress();
+  printf(";; recovery buffer (");
+  vprintf(what, ap);
+  printf("): "
+	 "(%"PRIuSEC") ..%"PRIuSEC".. "
+	 "[%"PRIuSEC" ..%"PRIuSEC".. %"PRIuSEC"] "
+	 "..%"PRIuSEC".. (%"PRIuSEC")\n",
+	 r->pos, r->start,
+	 r->pos + r->start, r->end - r->start, r->pos + r->end,
+	 r->sz - r->end, r->pos + r->sz);
+  va_end(ap);
+  assert(r->start <= r->end);
+  assert(r->end <= r->sz);
+}
+#endif
+
+static ssize_t recovery_read_sectors(struct recoverybuf *r,
+				     secaddr pos, secaddr off, secaddr want)
+{
+  ssize_t n;
+
+  assert(off + want <= r->sz);
+  n = read_sectors(pos, r->buf + off*SECTORSZ, want);
+  return (n);
+}
+
+static ssize_t recovery_read(struct recoverybuf *r,
+			     secaddr pos, secaddr want)
+{
+  secaddr diff, pp, nn;
+  ssize_t n;
+
+#ifdef DEBUG
+  clear_progress();
+  show_recovery_buffer_map(r, "begin(%"PRIuSEC", %"PRIuSEC")", pos, want);
+#endif
+
+  if (pos < r->pos) {
+    diff = r->pos - pos;
+    if (r->start + diff >= r->sz) {
+      r->pos = pos; r->start = r->end = 0;
+#ifdef DEBUG
+      show_recovery_buffer_map(r, "cleared; shift up by %"PRIuSEC"", diff);
+#endif
+    } else {
+      if (r->end + diff > r->sz) r->end = r->sz - diff;
+      rearrange_sectors(r, r->start + diff, r->start, r->end - r->start);
+      r->pos -= diff; r->start += diff; r->end += diff;
+#ifdef DEBUG
+      show_recovery_buffer_map(r, "shifted up by %"PRIuSEC"", diff);
+#endif
+    }
+  } else if (pos > r->pos + r->end) {
+      r->pos = pos; r->start = r->end = 0;
+#ifdef DEBUG
+      show_recovery_buffer_map(r, "cleared; beyond previous region");
+#endif
+  } else if (pos + want > r->pos + r->sz) {
+    diff = (pos + want) - (r->pos + r->sz);
+    if (r->end <= diff) {
+      r->pos = pos; r->start = r->end = 0;
+#ifdef DEBUG
+      show_recovery_buffer_map(r, "cleared; shift down by %"PRIuSEC"", diff);
+#endif
+    } else {
+      if (r->start < diff) r->start = diff;
+      rearrange_sectors(r, r->start - diff, r->start, r->end - r->start);
+      r->pos += diff; r->start -= diff; r->end -= diff;
+#ifdef DEBUG
+      show_recovery_buffer_map(r, "shifted down by %"PRIuSEC"", diff);
+#endif
+    }
+  }
+
+  if (pos < r->pos + r->start) {
+    pp = pos - r->pos; nn = r->start - pp;
+#ifdef DEBUG
+    printf(";; read low (%"PRIuSEC"@%"PRIuSEC", %"PRIuSEC")", pos, pp, nn);
+    fflush(stdout);
+#endif
+    n = recovery_read_sectors(r, pos, pp, nn);
+#ifdef DEBUG
+    printf(" -> %zd\n", n);
+#endif
+    if (n != nn) {
+      if (n >= 0 && n > want) n = want;
+      goto end;
+    }
+    r->start = pp;
+#ifdef DEBUG
+    show_recovery_buffer_map(r, "joined new region");
+#endif
+  }
+
+  if (pos + want > r->pos + r->end) {
+    pp = r->end; nn = (pos + want) - (r->pos + r->end);
+#ifdef DEBUG
+    printf(";; read high (%"PRIuSEC"@%"PRIuSEC", %"PRIuSEC")",
+	   r->pos + pp, pp, nn);
+fflush(stdout);
+#endif
+    n = recovery_read_sectors(r, pos, pp, nn);
+#ifdef DEBUG
+    printf(" -> %zd\n", n);
+#endif
+    if (n > 0) {
+      r->end += n;
+#ifdef DEBUG
+      show_recovery_buffer_map(r, "joined new region");
+#endif
+    }
+  }
+
+  n = r->pos + r->end - pos;
+  if (!n && want) n = -1;
+
+end:
+#ifdef DEBUG
+  show_recovery_buffer_map(r, "done; return %zd", n);
+#endif
+  return (n);
+}
+
+static secaddr run_length_wanted(secaddr pos, secaddr badlen,
+				 secaddr sz, secaddr end)
+{
+  secaddr want;
+
+  want = 3*badlen/2;
+  if (!want) want = 1;
+  if (want > end - pos) want = end - pos;
+  if (want > sz) want = sz;
+  return (want);
+}
+
+static ssize_t find_good_sector(secaddr *pos_inout, secaddr end,
+				unsigned char *buf, secaddr sz)
+{
+  int i;
+  secaddr pos = *pos_inout, bad_lo, bad_hi, good, step, want;
+  struct recoverybuf r;
+  ssize_t n;
+
+  r.buf = buf; r.sz = sz; r.pos = r.start = r.end = 0;
+  report_bad_blocks_progress(pos, pos, errno);
+
+  want = sz; if (want > end - pos) want = end - pos;
+  for (i = 0; i < 4; i++) {
+    n = recovery_read(&r, pos, want);
+#ifdef DEBUG
+    clear_progress();
+    printf(";; [retry] try reading %"PRIuSEC" .. %"PRIuSEC" -> %zd\n",
+	   pos, pos + want, n);
+#endif
+    if (n > 0) {
+      clear_progress();
+      moan("sector %"PRIuSEC" read ok after retry", pos);
+      return (n);
+    }
+  }
+
+  bad_lo = pos; bad_hi = pos + 1;
+  for (;;) {
+    report_bad_blocks_progress(bad_lo, bad_hi, errno);
+    if (bad_hi >= end) {
+      clear_progress();
+      moan("giving up on this extent");
+      recovered(bad_lo, end); *pos_inout = end; return (0);
+    }
+    step = 2*(bad_hi - bad_lo); if (step > end - bad_lo) step = end - bad_lo;
+    pos = bad_lo + step - 1;
+    want = run_length_wanted(pos, step, sz, end);
+    n = recovery_read(&r, pos, want);
+#ifdef DEBUG
+    clear_progress();
+    printf(";; [bound] try reading %"PRIuSEC" .. %"PRIuSEC" -> %zd\n",
+	   pos, pos + want, n);
+#endif
+    if (n == want) break;
+    if (n < 0) n = 0;
+    bad_hi = pos + n + 1;
+  }
+
+  good = pos;
+  while (good > bad_hi) {
+    report_bad_blocks_progress(bad_lo, bad_hi, errno);
+    pos = bad_hi + (good - bad_hi)/2;
+    step = pos - bad_lo;
+    want = run_length_wanted(pos, step, sz, end);
+    n = recovery_read(&r, pos, want);
+#ifdef DEBUG
+    clear_progress();
+    printf(";; [limit] try reading %"PRIuSEC" .. %"PRIuSEC" -> %zd\n",
+	   pos, pos + want, n);
+#endif
+    if (n < 0) n = 0;
+    if (n == want) good = pos;
+    else bad_hi = pos + n + 1;
+  }
+  recovered(bad_lo, bad_hi); *pos_inout = good;
+  if (r.pos + r.start <= good && good <= r.pos + r.end) {
+    rearrange_sectors(&r, 0, good - r.pos, r.pos + r.end - good);
+  } else
+    n = 0;
   return (n);
 }
 
@@ -463,10 +721,9 @@ static void emit(secaddr start, secaddr end)
 {
 #define BUFSECTORS 512
 
-  int least, i;
+  int least;
   unsigned char buf[BUFSECTORS*SECTORSZ];
   secaddr pos;
-  secaddr bad_lo, bad_hi, good, step;
   size_t want;
   ssize_t n;
   static int first_time = 1;
@@ -474,6 +731,7 @@ static void emit(secaddr start, secaddr end)
   struct file *f;
   char fn[MAXFNSZ];
   int act = -1;
+  int i;
 #endif
 
   least = least_live();
@@ -521,67 +779,7 @@ static void emit(secaddr start, secaddr end)
     want = end - pos; if (want > BUFSECTORS) want = BUFSECTORS;
     n = read_sectors(pos, buf, want);
 
-    if (n <= 0) {
-      report_bad_blocks_progress(pos, pos, errno);
-      for (i = 0; i < 4; i++) {
-	n = read_sectors(pos, buf, 1);
-	if (n > 0) {
-	  clear_progress();
-	  moan("sector %"PRIuSEC" read ok after retry", pos);
-	  bad_lo = bad_hi = pos;
-	  goto recovered;
-	}
-      }
-
-      bad_lo = pos; step = 1; bad_hi = pos + 1;
-      for (;;) {
-	report_bad_blocks_progress(bad_lo, bad_hi, errno);
-	if (bad_hi >= end) {
-	  clear_progress();
-	  moan("giving up on this extent");
-	  n = 0; goto recovered;
-	}
-	step *= 2;
-	if (step > end - bad_lo) step = end - bad_lo;
-	pos = bad_lo + step - 1;
-	n = read_sectors(pos, buf, 1);
-	if (n > 0) break;
-	bad_hi = pos + 1;
-      }
-
-      good = pos;
-      while (good > bad_hi) {
-	report_bad_blocks_progress(bad_lo, bad_hi, errno);
-	pos = bad_hi + (good - bad_hi)/2;
-	n = read_sectors(pos, buf, 1);
-	if (n > 0) good = pos;
-	else bad_hi = pos + 1;
-      }
-    recovered:
-      if (bad_hi > bad_lo) {
-	clear_progress();
-	moan("skipping %"PRIuSEC" bad sectors (%"PRIuSEC" .. %"PRIuSEC")",
-	     bad_hi - bad_lo, bad_lo, bad_hi);
-	if (mapfile) {
-	  if (!mapfp) {
-	    mapfp = fopen(mapfile, "w");
-	    if (!mapfp)
-	      bail_syserr(errno, "failed to open bad-sector map file `%s'",
-			  optarg);
-	    fprintf(mapfp, "## bad sector map\n\n");
-	  }
-	  fprintf(mapfp, "%"PRIuSEC" %"PRIuSEC"\n", bad_lo, bad_hi);
-	  fflush(mapfp);
-	  if (ferror(mapfp))
-	    bail_syserr(errno, "error writing bad-sector map file");
-	}
-	if (lseek(outfd, (off_t)(bad_hi - bad_lo)*SECTORSZ, SEEK_CUR) < 0)
-	  bail_syserr(errno, "failed to seek past bad sectors");
-	status = 1;
-      }
-      pos = bad_hi;
-    }
-
+    if (n <= 0) n = find_good_sector(&pos, end, buf, BUFSECTORS);
     if (n > 0) { carefully_write(outfd, buf, n*SECTORSZ); pos += n; }
     report_progress(pos); fflush(stdout);
   }