diff options
Diffstat (limited to 'libio/strops.c')
| -rw-r--r-- | libio/strops.c | 119 |
1 files changed, 62 insertions, 57 deletions
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; } |