X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=ucw%2Ffastbuf.c;h=ac6eaea7272b44676ec37d0e55cba1181541d2b6;hb=5de81f1debc4341fb3af4e756b0a18e196d5ba13;hp=9ba01ef4c6c0126ef24e559f3d28bf8096df0056;hpb=1cf8ac51f5495ccd5187dc220ffc69e95d6e0cfc;p=libucw.git

diff --git a/ucw/fastbuf.c b/ucw/fastbuf.c
index 9ba01ef4..ac6eaea7 100644
--- a/ucw/fastbuf.c
+++ b/ucw/fastbuf.c
@@ -1,14 +1,19 @@
 /*
  *	UCW Library -- Fast Buffered I/O
  *
- *	(c) 1997--2007 Martin Mares <mj@ucw.cz>
+ *	(c) 1997--2011 Martin Mares <mj@ucw.cz>
  *
  *	This software may be freely distributed and used according to the terms
  *	of the GNU Lesser General Public License.
  */
 
-#include "ucw/lib.h"
-#include "ucw/fastbuf.h"
+#undef LOCAL_DEBUG
+
+#include <ucw/lib.h>
+#include <ucw/fastbuf.h>
+#include <ucw/resource.h>
+#include <ucw/trans.h>
+#include <ucw/stkstring.h>
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -18,29 +23,101 @@ void bclose(struct fastbuf *f)
   if (f)
     {
       bflush(f);
+      res_detach(f->res);
+      DBG("FB: closing", f);
       if (f->close)
-	f->close(f);
+	f->close(f); /* Should always free all internal resources, even if it throws an exception */
+    }
+}
+
+void NONRET bthrow(struct fastbuf *f, const char *id, const char *fmt, ...)
+{
+  DBG("FB: throwing %s", full_id);
+  char full_id[16];
+  snprintf(full_id, sizeof(full_id), "ucw.fb.%s", id);
+  ASSERT(!(f->flags & FB_DEAD)); /* Only one bthrow() is allowed before bclose() */
+  va_list args;
+  va_start(args, fmt);
+  if (!f->res)
+    die("Fastbuf %s error: %s", f->name ? : "<fb>", stk_vprintf(fmt, args));
+  f->flags |= FB_DEAD;
+  f->bptr = f->bstop = f->bufend; /* Reset the buffer to guard consecutive seek/read/write */
+  trans_vthrow(full_id, f, fmt, args);
+}
+
+int brefill(struct fastbuf *f, int allow_eof)
+{
+  DBG("FB: refill");
+  ASSERT(!(f->flags & FB_DEAD) && f->buffer <= f->bstop && f->bstop <= f->bptr && f->bptr <= f->bufend);
+  if (!f->refill)
+    bthrow(f, "read", "Stream not readable");
+  if (f->refill(f))
+    {
+      ASSERT(f->buffer <= f->bptr && f->bptr < f->bstop && f->bstop <= f->bufend);
+      return 1;
+    }
+  else
+    {
+      ASSERT(f->buffer <= f->bptr && f->bptr == f->bstop && f->bstop <= f->bufend);
+      if (!allow_eof && (f->flags & FB_DIE_ON_EOF))
+	bthrow(f, "eof", "Unexpected EOF");
+      return 0;
+    }
+}
+
+static void do_spout(struct fastbuf *f)
+{
+  DBG("FB: spout");
+  ASSERT(!(f->flags & FB_DEAD) && f->buffer <= f->bstop && f->bstop <= f->bptr && f->bptr <= f->bufend); /* Check write mode possibly with unflushed data */
+  if (!f->spout)
+    bthrow(f, "write", "Stream not writeable");
+  f->spout(f);
+  ASSERT(f->buffer <= f->bstop && f->bstop <= f->bptr && f->bptr <= f->bufend);
+}
+
+void bspout(struct fastbuf *f)
+{
+  do_spout(f);
+  if (f->bstop == f->bufend)
+    {
+      do_spout(f);
+      ASSERT(f->bstop < f->bufend);
     }
 }
 
 void bflush(struct fastbuf *f)
 {
   if (f->bptr > f->bstop)
-    f->spout(f);
-  else if (f->bstop > f->buffer)
-    f->bptr = f->bstop = f->buffer;
+    do_spout(f);
+  else
+    f->bptr = f->bstop; /* XXX: Skip the rest of the reading buffer ==> it breaks the position of the FE cursor */
+  DBG("FB: flushed");
+}
+
+static void do_seek(struct fastbuf *f, ucw_off_t pos, int whence)
+{
+  bflush(f);
+  DBG("FB: seeking to pos=%lld whence=%d %p %p %p %p", (long long)pos, whence, f->buffer, f->bstop, f->bptr, f->bufend);
+  if (!f->seek || !f->seek(f, pos, whence))
+    bthrow(f, "seek", "Stream not seekable");
+  DBG("FB: seeked %p %p %p %p", f->buffer, f->bstop, f->bptr, f->bufend);
+  ASSERT(f->buffer <= f->bstop && f->bstop <= f->bptr && f->bptr <= f->bufend);
+  if (whence == SEEK_SET)
+    ASSERT(pos == btell(f));
+  else
+    ASSERT(btell(f) >= 0);
 }
 
 inline void bsetpos(struct fastbuf *f, ucw_off_t pos)
 {
   /* We can optimize seeks only when reading */
-  if (pos >= f->pos - (f->bstop - f->buffer) && pos <= f->pos)
+  if (f->bptr < f->bstop && pos <= f->pos && pos >= f->pos - (f->bstop - f->buffer)) /* If bptr == bstop, then [buffer, bstop] may be undefined */
     f->bptr = f->bstop + (pos - f->pos);
-  else
+  else if (pos != btell(f))
     {
-      bflush(f);
-      if (!f->seek || !f->seek(f, pos, SEEK_SET))
-	die("bsetpos: stream not seekable");
+      if (pos < 0)
+	bthrow(f, "seek", "Seek out of range");
+      do_seek(f, pos, SEEK_SET);
     }
 }
 
@@ -49,13 +126,15 @@ void bseek(struct fastbuf *f, ucw_off_t pos, int whence)
   switch (whence)
     {
     case SEEK_SET:
-      return bsetpos(f, pos);
+      bsetpos(f, pos);
+      break;
     case SEEK_CUR:
-      return bsetpos(f, btell(f) + pos);
+      bsetpos(f, btell(f) + pos); /* btell() is non-negative, so an overflow will always throw "Seek out of range" in bsetpos() */
+      break;
     case SEEK_END:
-      bflush(f);
-      if (!f->seek || !f->seek(f, pos, SEEK_END))
-	die("bseek: stream not seekable");
+      if (pos > 0)
+	bthrow(f, "seek", "Seek out of range");
+      do_seek(f, pos, SEEK_END);
       break;
     default:
       die("bseek: invalid whence=%d", whence);
@@ -66,7 +145,7 @@ int bgetc_slow(struct fastbuf *f)
 {
   if (f->bptr < f->bstop)
     return *f->bptr++;
-  if (!f->refill(f))
+  if (!brefill(f, 0))
     return -1;
   return *f->bptr++;
 }
@@ -75,15 +154,20 @@ int bpeekc_slow(struct fastbuf *f)
 {
   if (f->bptr < f->bstop)
     return *f->bptr;
-  if (!f->refill(f))
+  if (!brefill(f, 0))
     return -1;
   return *f->bptr;
 }
 
+int beof_slow(struct fastbuf *f)
+{
+  return f->bptr >= f->bstop && !brefill(f, 1);
+}
+
 void bputc_slow(struct fastbuf *f, uns c)
 {
   if (f->bptr >= f->bufend)
-    f->spout(f);
+    bspout(f);
   *f->bptr++ = c;
 }
 
@@ -96,7 +180,7 @@ uns bread_slow(struct fastbuf *f, void *b, uns l, uns check)
 
       if (!k)
 	{
-	  f->refill(f);
+	  brefill(f, check);
 	  k = f->bstop - f->bptr;
 	  if (!k)
 	    break;
@@ -110,7 +194,7 @@ uns bread_slow(struct fastbuf *f, void *b, uns l, uns check)
       total += k;
     }
   if (check && total && l)
-    die("breadb: short read");
+    bthrow(f, "eof", "breadb: short read");
   return total;
 }
 
@@ -122,7 +206,7 @@ void bwrite_slow(struct fastbuf *f, const void *b, uns l)
 
       if (!k)
 	{
-	  f->spout(f);
+	  bspout(f);
 	  k = f->bufend - f->bptr;
 	}
       if (k > l)
@@ -134,8 +218,7 @@ void bwrite_slow(struct fastbuf *f, const void *b, uns l)
     }
 }
 
-void
-bbcopy_slow(struct fastbuf *f, struct fastbuf *t, uns l)
+void bbcopy_slow(struct fastbuf *f, struct fastbuf *t, uns l)
 {
   while (l)
     {
@@ -147,7 +230,7 @@ bbcopy_slow(struct fastbuf *f, struct fastbuf *t, uns l)
 	{
 	  if (l == ~0U)
 	    return;
-	  die("bbcopy: source exhausted");
+	  bthrow(f, "eof", "bbcopy: source exhausted");
 	}
       tavail = bdirect_write_prepare(t, &tptr);
       n = MIN(l, favail);
@@ -160,21 +243,18 @@ bbcopy_slow(struct fastbuf *f, struct fastbuf *t, uns l)
     }
 }
 
-int
-bconfig(struct fastbuf *f, uns item, int value)
+int bconfig(struct fastbuf *f, uns item, int value)
 {
-  return f->config ? f->config(f, item, value) : -1;
+  return (f->config && !(f->flags & FB_DEAD)) ? f->config(f, item, value) : -1;
 }
 
-void
-brewind(struct fastbuf *f)
+void brewind(struct fastbuf *f)
 {
   bflush(f);
   bsetpos(f, 0);
 }
 
-int
-bskip_slow(struct fastbuf *f, uns len)
+int bskip_slow(struct fastbuf *f, uns len)
 {
   while (len)
     {
@@ -189,11 +269,12 @@ bskip_slow(struct fastbuf *f, uns len)
   return 1;
 }
 
-ucw_off_t
-bfilesize(struct fastbuf *f)
+ucw_off_t bfilesize(struct fastbuf *f)
 {
   if (!f)
     return 0;
+  if (!f->seek)
+    return -1;
   ucw_off_t pos = btell(f);
   bflush(f);
   if (!f->seek(f, 0, SEEK_END))
@@ -202,3 +283,37 @@ bfilesize(struct fastbuf *f)
   bsetpos(f, pos);
   return len;
 }
+
+/* Resources */
+
+static void fb_res_detach(struct resource *r)
+{
+  struct fastbuf *f = r->priv;
+  f->res = NULL;
+}
+
+static void fb_res_free(struct resource *r)
+{
+  struct fastbuf *f = r->priv;
+  f->res = NULL;
+  bclose(f);
+}
+
+static void fb_res_dump(struct resource *r, uns indent UNUSED)
+{
+  struct fastbuf *f = r->priv;
+  printf(" name=%s\n", f->name);
+}
+
+static const struct res_class fb_res_class = {
+  .name = "fastbuf",
+  .detach = fb_res_detach,
+  .dump = fb_res_dump,
+  .free = fb_res_free,
+};
+
+struct fastbuf *fb_tie(struct fastbuf *f)
+{
+  f->res = res_new(&fb_res_class, f);
+  return f;
+}