Libc-1244.50.9.tar.gz

[apple/libc.git] / stdio / FreeBSD / fread.c

diff --git a/stdio/FreeBSD/fread.c b/stdio/FreeBSD/fread.c
index ad5d81bf3e84b538f13d96a91e15b26a8875f221..b02257b8bb8114a8f06ad979fe55c3cf8c67354a 100644 (file)
--- a/stdio/FreeBSD/fread.c
+++ b/stdio/FreeBSD/fread.c
@@ -13,10 +13,6 @@
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.

- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *     This product includes software developed by the University of
- *     California, Berkeley and its contributors.

  * 4. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  * 4. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.


@@ -38,7 +34,7 @@
 static char sccsid[] = "@(#)fread.c    8.2 (Berkeley) 12/11/93";
 #endif /* LIBC_SCCS and not lint */
 #include <sys/cdefs.h>
 static char sccsid[] = "@(#)fread.c    8.2 (Berkeley) 12/11/93";
 #endif /* LIBC_SCCS and not lint */
 #include <sys/cdefs.h>

-__FBSDID("$FreeBSD: src/lib/libc/stdio/fread.c,v 1.12 2002/10/12 16:13:37 mike Exp $");
+__FBSDID("$FreeBSD: src/lib/libc/stdio/fread.c,v 1.16 2009/07/12 13:09:43 ed Exp $");

 
 #include "namespace.h"
 #include <stdio.h>
 
 #include "namespace.h"
 #include <stdio.h>


@@ -47,45 +43,124 @@ __FBSDID("$FreeBSD: src/lib/libc/stdio/fread.c,v 1.12 2002/10/12 16:13:37 mike E
 #include "local.h"
 #include "libc_private.h"
 
 #include "local.h"
 #include "libc_private.h"
 

+/*
+ * MT-safe version
+ */
+

 size_t
 size_t

-fread(buf, size, count, fp)
-       void * __restrict buf;
-       size_t size, count;
-       FILE * __restrict fp;
+fread(void * __restrict buf, size_t size, size_t count, FILE * __restrict fp)

 {
 {

-       size_t resid;
-       char *p;
-       int r;
-       size_t total;
+       size_t ret;

 
 

-       /*
-        * The ANSI standard requires a return value of 0 for a count
-        * or a size of 0.  Peculiarily, it imposes no such requirements
-        * on fwrite; it only requires fread to be broken.
-        */
-       if ((resid = count * size) == 0)
-               return (0);

        FLOCKFILE(fp);
        FLOCKFILE(fp);

-       ORIENT(fp, -1);
-       if (fp->_r < 0)
-               fp->_r = 0;
-       total = resid;
+       ret = __fread(buf, size, count, fp);
+       FUNLOCKFILE(fp);
+       return (ret);
+}
+
+/*
+ * The maximum amount to read to avoid integer overflow.  INT_MAX is odd,
+ * so it make sense to make it even.  We subtract (BUFSIZ - 1) to get a
+ * whole number of BUFSIZ chunks.
+ */
+#define MAXREAD        (INT_MAX - (BUFSIZ - 1))
+
+/* __fread0: int sized, with size = 1 */
+static inline int
+__fread0(void * __restrict buf, int count, FILE * __restrict fp)
+{
+       int resid;
+       char *p;
+       int r, ret;
+
+       resid = count;

        p = buf;
        p = buf;

+       /* first deal with anything left in buffer, plus any ungetc buffers */

        while (resid > (r = fp->_r)) {
                (void)memcpy((void *)p, (void *)fp->_p, (size_t)r);
                fp->_p += r;
                /* fp->_r = 0 ... done in __srefill */
                p += r;
                resid -= r;
        while (resid > (r = fp->_r)) {
                (void)memcpy((void *)p, (void *)fp->_p, (size_t)r);
                fp->_p += r;
                /* fp->_r = 0 ... done in __srefill */
                p += r;
                resid -= r;

-               if (__srefill(fp)) {
+               if ((ret = __srefill0(fp)) > 0)
+                       break;
+               else if (ret) {

                        /* no more input: return partial result */
                        /* no more input: return partial result */

-                       FUNLOCKFILE(fp);
-                       return ((total - resid) / size);
+                       return (count - resid);
+               }
+       }
+       /*
+        * 5980080: don't use optimization if __SMBF not set (meaning setvbuf
+        * was called, and the buffer belongs to the user).
+        * 6180417: but for unbuffered (__SMBF is not set), so specifically
+        * test for it.
+        */
+       if ((fp->_flags & (__SMBF | __SNBF)) && resid > fp->_bf._size) {
+               struct __sbuf save;
+               size_t n;
+
+               save = fp->_bf;
+               fp->_bf._base = (unsigned char *)p;
+               fp->_bf._size = resid;
+               while (fp->_bf._size > 0) {
+                       if ((ret = __srefill1(fp)) != 0) {
+                               /* no more input: return partial result */
+                               resid = fp->_bf._size;
+                               fp->_bf = save;
+                               fp->_p = fp->_bf._base;
+                               /* fp->_r = 0;  already set in __srefill1 */
+                               return (count - resid);
+                       }
+                       fp->_bf._base += fp->_r;
+                       fp->_bf._size -= fp->_r;
+               }
+               fp->_bf = save;
+               n = fp->_bf._size * ((resid - 1) / fp->_bf._size);
+               r = resid - n;
+               (void)memcpy((void *)fp->_bf._base, (void *)(p + n), (size_t)r);
+               fp->_p = fp->_bf._base + r;
+               fp->_r = 0;
+       } else {
+               while (resid > (r = fp->_r)) {
+                       (void)memcpy((void *)p, (void *)fp->_p, (size_t)r);
+                       fp->_p += r;
+                       /* fp->_r = 0 ... done in __srefill */
+                       p += r;
+                       resid -= r;
+                       if (__srefill1(fp)) {
+                               /* no more input: return partial result */
+                               return (count - resid);
+                       }
+               }
+               (void)memcpy((void *)p, (void *)fp->_p, resid);
+               fp->_r -= resid;
+               fp->_p += resid;
+       }
+       return (count);
+}
+
+size_t
+__fread(void * __restrict buf, size_t size, size_t count, FILE * __restrict fp)
+{
+       size_t resid;
+       int r, ret;
+       size_t total;
+
+       /*
+        * ANSI and SUSv2 require a return value of 0 if size or count are 0.
+        */
+       if ((resid = count * size) == 0)
+               return (0);
+       ORIENT(fp, -1);
+       if (fp->_r < 0)
+               fp->_r = 0;
+
+       for (total = resid; resid > 0; buf += r, resid -= r) {
+               r = resid > INT_MAX ? MAXREAD : (int)resid;
+               if ((ret = __fread0(buf, r, fp)) != r) {
+                       count = (total - resid + ret) / size;
+                       break;

                }
        }
                }
        }

-       (void)memcpy((void *)p, (void *)fp->_p, resid);
-       fp->_r -= resid;
-       fp->_p += resid;
-       FUNLOCKFILE(fp);

        return (count);
 }
        return (count);
 }