Fastbufs now work better on unseekable files.

[libucw.git] / lib / fastbuf.c

diff --git a/lib/fastbuf.c b/lib/fastbuf.c
index 980d53aa619ceb0509d64987ef57765dc8f42199..79229d4e1d372bf981a92cd4c5adea28b3802b7c 100644 (file)
--- a/lib/fastbuf.c
+++ b/lib/fastbuf.c
@@ -38,7 +38,8 @@ inline void bsetpos(struct fastbuf *f, sh_off_t pos)
   else
     {
       bflush(f);
-      f->seek(f, pos, SEEK_SET);
+      if (!f->seek || !f->seek(f, pos, SEEK_SET))
+       die("bsetpos: stream not seekable");
     }
 }
 
@@ -52,7 +53,8 @@ void bseek(struct fastbuf *f, sh_off_t pos, int whence)
       return bsetpos(f, btell(f) + pos);
     case SEEK_END:
       bflush(f);
-      f->seek(f, pos, SEEK_END);
+      if (!f->seek || !f->seek(f, pos, SEEK_END))
+       die("bseek: stream not seekable");
       break;
     default:
       die("bseek: invalid whence=%d", whence);
@@ -192,7 +194,9 @@ bfilesize(struct fastbuf *f)
   if (!f)
     return 0;
   sh_off_t pos = btell(f);
-  bseek(f, 0, SEEK_END);
+  bflush(f);
+  if (!f->seek(f, pos, SEEK_END))
+    return -1;
   sh_off_t len = btell(f);
   bsetpos(f, pos);
   return len;