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-rw-r--r--libio/libio.h3
-rw-r--r--libio/strfile.h4
-rw-r--r--libio/strops.c119
3 files changed, 66 insertions, 60 deletions
diff --git a/libio/libio.h b/libio/libio.h
index 0cd6b39c24..7dd47db9fa 100644
--- a/libio/libio.h
+++ b/libio/libio.h
@@ -303,6 +303,9 @@ extern int _IO_vfprintf __P((_IO_FILE*, const char*, _IO_va_list));
 extern _IO_ssize_t _IO_padn __P((_IO_FILE *, int, _IO_ssize_t));
 extern _IO_size_t _IO_sgetn __P((_IO_FILE *, void*, _IO_size_t));
 
+extern _IO_fpos_t _IO_seekoff __P((_IO_FILE*, _IO_off_t, int, int));
+extern _IO_fpos_t _IO_seekpos __P((_IO_FILE*, _IO_fpos_t, int));
+
 extern void _IO_free_backup_area __P((_IO_FILE*));
 
 #ifdef __cplusplus
diff --git a/libio/strfile.h b/libio/strfile.h
index 55783bb5c1..4934a06e3c 100644
--- a/libio/strfile.h
+++ b/libio/strfile.h
@@ -1,4 +1,4 @@
-/* 
+/*
 Copyright (C) 1993 Free Software Foundation
 
 This file is part of the GNU IO Library.  This library is free
@@ -32,8 +32,6 @@ typedef void (*_IO_free_type) __P((void*));
 
 struct _IO_str_fields
 {
-  /* The current length is max(_len, _IO_write_ptr-_IO_write_base). */
-  _IO_size_t _len;
   _IO_alloc_type _allocate_buffer;
   _IO_free_type _free_buffer;
 };
diff --git a/libio/strops.c b/libio/strops.c
index 464063322d..8a6c56d055 100644
--- a/libio/strops.c
+++ b/libio/strops.c
@@ -26,7 +26,31 @@ the executable file might be covered by the GNU General Public License. */
 #include "libioP.h"
 #include <string.h>
 
-#define LEN(fp) (((_IO_strfile*)(fp))->_s._len)
+#if 0
+/* The following definitions are for exposition only.
+   They map the terminlogy used in the ANSI/ISO C++ draft standard
+   to the implementation. */
+
+/* allocated:  set  when a dynamic array object has been allocated, and
+   hence should be freed by the destructor for the strstreambuf object. */
+#define ALLOCATED(FP) ((FP)->_f._IO_buf_base && DYNAMIC(FP))
+
+/* constant:  set when the array object has const elements,
+   so the output sequence cannot be written. */
+#define CONSTANT(FP) ((FP)->_f._IO_file_flags & _IO_NO_WRITES)
+
+/* alsize:  the suggested minimum size for a dynamic array object. */
+#define ALSIZE(FP) ??? /* not stored */
+
+/* palloc: points to the function to call to allocate a dynamic array object.*/
+#define PALLOC(FP) \
+  ((FP)->_s._allocate_buffer == default_alloc ? 0 : (FP)->_s._allocate_buffer)
+
+/* pfree: points  to  the  function  to call to free a dynamic array object. */
+#define PFREE(FP) \
+  ((FP)->_s._free_buffer == default_free ? 0 : (FP)->_s._free_buffer)
+
+#endif
 
 #ifdef TODO
 /* An "unbounded buffer" is when a buffer is supplied, but with no
@@ -44,27 +68,17 @@ DEFUN(_IO_str_init_static, (fp, ptr, size, pstart),
     {
       /* If size is negative 'the characters are assumed to
 	 continue indefinitely.'  This is kind of messy ... */
-#if 1
       int s;
       size = 512;
-      /* Try increasing powers of 2, as long as we don't wrap around.
-	 This can lose in pathological cases (ptr near the end
-	 of the address space).  A better solution might be to
-	 adjust the size on underflow/overflow.  FIXME. */
-      for ( ; s = 2*size, s > 0 && ptr + s > ptr && s < 0x4000000L; )
+      /* Try increasing powers of 2, as long as we don't wrap around. */
+      for (; s = 2*size, s > 0 && ptr + s > ptr && s < 0x4000000L; )
 	size = s;
-      size = s;
-#else
-      /* The following semi-portable kludge assumes that
-	 sizeof(unsigned long) == sizeof(char*). Hence,
-	 (unsigned long)(-1) should be the largest possible address. */
-      unsigned long highest = (unsigned long)(-1);
-      /* Pointers are signed on some brain-damaged systems, in
-	 which case we divide by two to get the maximum signed address. */
-      if  ((char*)highest < ptr)
-	highest >>= 1;
-      size = (char*)highest - ptr;
-#endif
+      /* Try increasing size as much as we can without wrapping around. */
+      for (s = size >> 1; s > 0; s >>= 1)
+	{
+	  if (ptr + size + s > ptr)
+	    size += s;
+	}
     }
   _IO_setb(fp, ptr, ptr+size, 0);
 
@@ -83,7 +97,6 @@ DEFUN(_IO_str_init_static, (fp, ptr, size, pstart),
       fp->_IO_write_end = ptr;
       fp->_IO_read_end = ptr+size;
     }
-  LEN(fp) = size;
   /* A null _allocate_buffer function flags the strfile as being static. */
   (((_IO_strfile*)(fp))->_s._allocate_buffer) =  (_IO_alloc_type)0;
 }
@@ -101,34 +114,25 @@ DEFUN(_IO_str_overflow, (fp, c),
       register _IO_FILE* fp AND int c)
 {
   int flush_only = c == EOF;
-  _IO_size_t pos = fp->_IO_write_ptr - fp->_IO_write_base;
-  _IO_size_t get_pos = fp->_IO_read_ptr - fp->_IO_read_base;
+  _IO_size_t pos;
   if (fp->_flags & _IO_NO_WRITES)
       return flush_only ? 0 : EOF;
-  if (pos > LEN(fp)) LEN(fp) = pos;
   if ((fp->_flags & _IO_TIED_PUT_GET) && !(fp->_flags & _IO_CURRENTLY_PUTTING))
     {
-      pos = get_pos;
       fp->_flags |= _IO_CURRENTLY_PUTTING;
-      get_pos = LEN(fp);
+      fp->_IO_write_ptr = fp->_IO_read_ptr;
+      fp->_IO_read_ptr = fp->_IO_read_end;
     }
-  if (pos >= (_IO_size_t) (_IO_blen(fp) + flush_only))
+  pos =  fp->_IO_write_ptr - fp->_IO_write_base;
+  if (pos >= _IO_blen(fp) + flush_only)
     {
       if (fp->_flags & _IO_USER_BUF) /* not allowed to enlarge */
-	{
-#ifdef TODO
-	  if (indefinite size)
-	    {
-	      fp->_IO_buf_end += 512;
-	    }
-	  else
-#endif
-	  return EOF;
-	}
+	return EOF;
       else
 	{
 	  char *new_buf;
-	  _IO_size_t new_size = 2 * _IO_blen(fp);
+	  char *old_buf = fp->_IO_buf_base;
+	  _IO_size_t new_size = 2 * _IO_blen(fp) + 100;
 	  new_buf
 	    = (char*)(*((_IO_strfile*)fp)->_s._allocate_buffer)(new_size);
 	  if (new_buf == NULL)
@@ -136,31 +140,32 @@ DEFUN(_IO_str_overflow, (fp, c),
 	      /*	  __ferror(fp) = 1; */
 	      return EOF;
 	    }
-	  memcpy(new_buf, fp->_IO_buf_base, _IO_blen(fp));
-#if 0
-	  if (lenp == &LEN(fp)) /* use '\0'-filling */
-	      memset(new_buf + pos, 0, blen() - pos);
-#endif
 	  if (fp->_IO_buf_base)
 	    {
+	      memcpy(new_buf, old_buf, _IO_blen(fp));
 	      (*((_IO_strfile*)fp)->_s._free_buffer)(fp->_IO_buf_base);
 	      /* Make sure _IO_setb won't try to delete _IO_buf_base. */
 	      fp->_IO_buf_base = NULL;
 	    }
+#if 0
+	  if (lenp == &LEN(fp)) /* use '\0'-filling */
+	      memset(new_buf + pos, 0, blen() - pos);
+#endif
 	  _IO_setb(fp, new_buf, new_buf + new_size, 1);
+	  fp->_IO_read_base = new_buf + (fp->_IO_read_base - old_buf);
+	  fp->_IO_read_ptr = new_buf + (fp->_IO_read_ptr - old_buf);
+	  fp->_IO_read_end = new_buf + (fp->_IO_read_end - old_buf);
+	  fp->_IO_write_ptr = new_buf + (fp->_IO_write_ptr - old_buf);
+
 	  fp->_IO_write_base = new_buf;
+	  fp->_IO_write_end = fp->_IO_buf_end;
 	}
-      fp->_IO_write_end = fp->_IO_buf_end;
     }
 
-  fp->_IO_write_ptr = fp->_IO_buf_base + pos;
-
-  fp->_IO_read_base = fp->_IO_buf_base;
-  fp->_IO_read_ptr = fp->_IO_buf_base + get_pos;
-  fp->_IO_read_end = fp->_IO_buf_base + LEN(fp);
-
   if (!flush_only)
     *fp->_IO_write_ptr++ = (unsigned char) c;
+  if (fp->_IO_write_ptr > fp->_IO_read_end)
+    fp->_IO_read_end = fp->_IO_write_ptr;
   return c;
 }
 
@@ -168,28 +173,29 @@ int
 DEFUN(_IO_str_underflow, (fp),
       register _IO_FILE* fp)
 {
-  _IO_size_t ppos = fp->_IO_write_ptr - fp->_IO_write_base;
-  if (ppos > LEN(fp)) LEN(fp) = ppos;
+  if (fp->_IO_write_ptr > fp->_IO_read_end)
+    fp->_IO_read_end = fp->_IO_write_ptr;
   if ((fp->_flags & _IO_TIED_PUT_GET) && (fp->_flags & _IO_CURRENTLY_PUTTING))
     {
       fp->_flags &= ~_IO_CURRENTLY_PUTTING;
+      fp->_IO_read_ptr = fp->_IO_write_ptr;
       fp->_IO_write_ptr = fp->_IO_write_end;
     }
-  fp->_IO_read_end = fp->_IO_read_base + LEN(fp);
   if (fp->_IO_read_ptr < fp->_IO_read_end)
     return *fp->_IO_read_ptr;
   else
     return EOF;
 }
 
+/* The size of the valid part of the buffer.  */
+
 _IO_ssize_t
 DEFUN(_IO_str_count, (fp),
       register _IO_FILE *fp)
 {
-  _IO_ssize_t put_len = fp->_IO_write_ptr - fp->_IO_write_base;
-  if (put_len < (_IO_ssize_t) LEN(fp))
-    put_len = LEN(fp);
-  return put_len;
+  return (fp->_IO_write_ptr > fp->_IO_read_end ? fp->_IO_write_ptr
+	  : fp->_IO_read_end)
+    - fp->_IO_read_base;
 }
 
 _IO_pos_t
@@ -236,7 +242,6 @@ DEFUN(_IO_str_seekoff, (fp, offset, dir, mode),
 	}
       if (offset < 0 || (_IO_ssize_t)offset > cur_size)
 	return EOF;
-      LEN(fp) = cur_size;
       fp->_IO_write_ptr = fp->_IO_write_base + offset;
       new_pos = offset;
     }