diff options
Diffstat (limited to 'libio/strops.c')
| -rw-r--r-- | libio/strops.c | 91 |
1 files changed, 82 insertions, 9 deletions
diff --git a/libio/strops.c b/libio/strops.c index da60e9319f..05270ce407 100644 --- a/libio/strops.c +++ b/libio/strops.c @@ -25,6 +25,7 @@ This exception applies to code released by its copyright holders in files containing the exception. */ +#include <assert.h> #include "strfile.h" #include "libioP.h" #include <string.h> @@ -102,7 +103,7 @@ _IO_str_overflow (fp, c) fp->_IO_write_ptr = fp->_IO_read_ptr; fp->_IO_read_ptr = fp->_IO_read_end; } - pos = fp->_IO_write_ptr - fp->_IO_write_base; + pos = fp->_IO_write_ptr - fp->_IO_write_base; if (pos >= (_IO_size_t) (_IO_blen (fp) + flush_only)) { if (fp->_flags & _IO_USER_BUF) /* not allowed to enlarge */ @@ -111,7 +112,10 @@ _IO_str_overflow (fp, c) { char *new_buf; char *old_buf = fp->_IO_buf_base; - _IO_size_t new_size = 2 * _IO_blen (fp) + 100; + size_t old_blen = _IO_blen (fp); + _IO_size_t new_size = 2 * old_blen + 100; + if (new_size < old_blen) + return EOF; new_buf = (char *) (*((_IO_strfile *) fp)->_s._allocate_buffer) (new_size); if (new_buf == NULL) @@ -121,15 +125,13 @@ _IO_str_overflow (fp, c) } if (old_buf) { - memcpy (new_buf, old_buf, _IO_blen (fp)); + memcpy (new_buf, old_buf, old_blen); (*((_IO_strfile *) fp)->_s._free_buffer) (old_buf); /* 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 + memset (new_buf + old_blen, '\0', new_size - old_blen); + INTUSE(_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); @@ -179,6 +181,71 @@ _IO_str_count (fp) - fp->_IO_read_base); } + +static int +enlarge_userbuf (_IO_FILE *fp, _IO_off64_t offset, int reading) +{ + if ((_IO_ssize_t) offset <= _IO_blen (fp)) + return 0; + + _IO_ssize_t oldend = fp->_IO_write_end - fp->_IO_write_base; + + /* Try to enlarge the buffer. */ + if (fp->_flags & _IO_USER_BUF) + /* User-provided buffer. */ + return 1; + + _IO_size_t newsize = offset + 100; + char *oldbuf = fp->_IO_buf_base; + char *newbuf + = (char *) (*((_IO_strfile *) fp)->_s._allocate_buffer) (newsize); + if (newbuf == NULL) + return 1; + + if (oldbuf != NULL) + { + memcpy (newbuf, oldbuf, _IO_blen (fp)); + (*((_IO_strfile *) fp)->_s._free_buffer) (oldbuf); + /* Make sure _IO_setb won't try to delete + _IO_buf_base. */ + fp->_IO_buf_base = NULL; + } + + INTUSE(_IO_setb) (fp, newbuf, newbuf + newsize, 1); + + if (reading) + { + fp->_IO_write_base = newbuf + (fp->_IO_write_base - oldbuf); + fp->_IO_write_ptr = newbuf + (fp->_IO_write_ptr - oldbuf); + fp->_IO_write_end = newbuf + (fp->_IO_write_end - oldbuf); + fp->_IO_read_ptr = newbuf + (fp->_IO_read_ptr - oldbuf); + + fp->_IO_read_base = newbuf; + fp->_IO_read_end = fp->_IO_buf_end; + } + else + { + fp->_IO_read_base = newbuf + (fp->_IO_read_base - oldbuf); + fp->_IO_read_ptr = newbuf + (fp->_IO_read_ptr - oldbuf); + fp->_IO_read_end = newbuf + (fp->_IO_read_end - oldbuf); + fp->_IO_write_ptr = newbuf + (fp->_IO_write_ptr - oldbuf); + + fp->_IO_write_base = newbuf; + fp->_IO_write_end = fp->_IO_buf_end; + } + + /* Clear the area between the last write position and th + new position. */ + assert (offset >= oldend); + if (reading) + memset (fp->_IO_read_base + oldend, '\0', offset - oldend); + else + memset (fp->_IO_write_base + oldend, '\0', offset - oldend); + + return 0; +} + + _IO_off64_t _IO_str_seekoff (fp, offset, dir, mode) _IO_FILE *fp; @@ -219,7 +286,10 @@ _IO_str_seekoff (fp, offset, dir, mode) default: /* case _IO_seek_set: */ break; } - if (offset < 0 || (_IO_ssize_t) offset > cur_size) + if (offset < 0) + return EOF; + if ((_IO_ssize_t) offset > cur_size + && enlarge_userbuf (fp, offset, 1) != 0) return EOF; fp->_IO_read_ptr = fp->_IO_read_base + offset; fp->_IO_read_end = fp->_IO_read_base + cur_size; @@ -240,7 +310,10 @@ _IO_str_seekoff (fp, offset, dir, mode) default: /* case _IO_seek_set: */ break; } - if (offset < 0 || (_IO_ssize_t) offset > cur_size) + if (offset < 0) + return EOF; + if ((_IO_ssize_t) offset > cur_size + && enlarge_userbuf (fp, offset, 0) != 0) return EOF; fp->_IO_write_ptr = fp->_IO_write_base + offset; new_pos = offset; |