Fastbufs now work better on unseekable files.

The seek callback returns success, bseek() and bsetpos() dies if seek
fails, bfilesize() returns -1 if the file is unseekable.

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;

diff --git a/lib/fastbuf.h b/lib/fastbuf.h
index 598a21d942f0c0997c31e0f0e2fb1d9f70d4492c..12bb5da2be3282a4ddee460b002ac85a1917b9d1 100644 (file)
--- a/lib/fastbuf.h
+++ b/lib/fastbuf.h
@@ -73,7 +73,7 @@ struct fastbuf {
   sh_off_t pos;                                /* Position of bstop in the file */
   int (*refill)(struct fastbuf *);     /* Get a buffer with new data */
   void (*spout)(struct fastbuf *);     /* Write buffer data to the file */
-  void (*seek)(struct fastbuf *, sh_off_t, int);  /* Slow path for bseek(), buffer already flushed */
+  int (*seek)(struct fastbuf *, sh_off_t, int);  /* Slow path for bseek(), buffer already flushed; returns success */
   void (*close)(struct fastbuf *);     /* Close the stream */
   int (*config)(struct fastbuf *, uns, int);   /* Configure the stream */
   int can_overwrite_buffer;            /* Can the buffer be altered? (see discussion above) 0=never, 1=temporarily, 2=permanently */
@@ -153,7 +153,7 @@ void bflush(struct fastbuf *f);
 void bseek(struct fastbuf *f, sh_off_t pos, int whence);
 void bsetpos(struct fastbuf *f, sh_off_t pos);
 void brewind(struct fastbuf *f);
-sh_off_t bfilesize(struct fastbuf *f);
+sh_off_t bfilesize(struct fastbuf *f);         // -1 if not seekable
 
 static inline sh_off_t btell(struct fastbuf *f)
 {

diff --git a/lib/fb-buffer.c b/lib/fb-buffer.c
index 09c7429357e6c518e9630b418067037e4986a43f..9ad248a289db329ecabec693c29f103c78e47965 100644 (file)
--- a/lib/fb-buffer.c
+++ b/lib/fb-buffer.c
@@ -18,7 +18,7 @@ fbbuf_refill(struct fastbuf *f UNUSED)
   return 0;
 }
 
-static void
+static int
 fbbuf_seek(struct fastbuf *f, sh_off_t pos, int whence)
 {
   /* Somebody might want to seek to the end of buffer, try to be nice to him. */
@@ -29,6 +29,7 @@ fbbuf_seek(struct fastbuf *f, sh_off_t pos, int whence)
   f->bptr = f->buffer + pos;
   f->bstop = f->bufend;
   f->pos = len;
+  return 1;
 }
 
 void

diff --git a/lib/fb-file.c b/lib/fb-file.c
index 0dcf22a958978a2d0fe0ea0ab97ca94137f27d62..c45432775ca2ba2349a05f4a2a7ffa4143e84cfd 100644 (file)
--- a/lib/fb-file.c
+++ b/lib/fb-file.c
@@ -53,16 +53,17 @@ bfd_spout(struct fastbuf *f)
   f->bptr = f->buffer = FB_BUFFER(f);
 }
 
-static void
+static int
 bfd_seek(struct fastbuf *f, sh_off_t pos, int whence)
 {
   if (whence == SEEK_SET && pos == f->pos)
-    return;
+    return 1;
 
   sh_off_t l = sh_seek(FB_FILE(f)->fd, pos, whence);
   if (l < 0)
-    die("lseek on %s: %m", f->name);
+    return 0;
   f->pos = l;
+  return 1;
 }
 
 static void

diff --git a/lib/fb-grow.c b/lib/fb-grow.c
index 0b04817fcc1caa6855845700ec175a911e4e4aab..1a10a50172cdb83e81ac40f671df80f17cc229dd 100644 (file)
--- a/lib/fb-grow.c
+++ b/lib/fb-grow.c
@@ -45,7 +45,7 @@ fbgrow_spout(struct fastbuf *b)
     }
 }
 
-static void
+static int
 fbgrow_seek(struct fastbuf *b, sh_off_t pos, int whence)
 {
   ASSERT(FB_GBUF(b)->last_written);    /* Seeks allowed only in read mode */
@@ -56,6 +56,7 @@ fbgrow_seek(struct fastbuf *b, sh_off_t pos, int whence)
   b->bptr = b->buffer + pos;
   b->bstop = FB_GBUF(b)->last_written;
   b->pos = len;
+  return 1;
 }
 
 static void

diff --git a/lib/fb-mem.c b/lib/fb-mem.c
index 0de590e04fb90b19cca2c567f2c7c338d75b4180..c3f104f13d47732403ef57cf96cf04dca624783b 100644 (file)
--- a/lib/fb-mem.c
+++ b/lib/fb-mem.c
@@ -93,7 +93,7 @@ fbmem_spout(struct fastbuf *f)
   FB_MEM(f)->block = bb;
 }
 
-static void
+static int
 fbmem_seek(struct fastbuf *f, sh_off_t pos, int whence)
 {
   struct memstream *m = FB_MEM(f)->stream;
@@ -115,7 +115,7 @@ fbmem_seek(struct fastbuf *f, sh_off_t pos, int whence)
          f->bufend = f->bstop = b->data + b->size;
          f->pos = b->pos + b->size;
          FB_MEM(f)->block = b;
-         return;
+         return 1;
        }
     }
   if (!m->first && !pos)
@@ -124,7 +124,7 @@ fbmem_seek(struct fastbuf *f, sh_off_t pos, int whence)
       f->buffer = f->bptr = f->bufend = NULL;
       f->pos = 0;
       FB_MEM(f)->block = NULL;
-      return;
+      return 1;
     }
   die("fbmem_seek to invalid offset");
 }

diff --git a/lib/fb-mmap.c b/lib/fb-mmap.c
index 85dc27ee2c10566e4d77d222acad39e87d495a4c..41e65832653c8c16180920d78172bc6221428e63 100644 (file)
--- a/lib/fb-mmap.c
+++ b/lib/fb-mmap.c
@@ -117,7 +117,7 @@ bfmm_spout(struct fastbuf *f)
   DBG(" -> %p %p %p(%x) %p", f->buffer, f->bptr, f->bstop, (int)f->pos, f->bufend);
 }
 
-static void
+static int
 bfmm_seek(struct fastbuf *f, sh_off_t pos, int whence)
 {
   if (whence == SEEK_END)
@@ -128,6 +128,7 @@ bfmm_seek(struct fastbuf *f, sh_off_t pos, int whence)
   f->pos = pos;
   f->bptr = f->bstop = f->bufend;      /* force refill/spout call */
   DBG("Seek -> %p %p %p(%x) %p", f->buffer, f->bptr, f->bstop, (int)f->pos, f->bufend);
+  return 1;
 }
 
 static void