_IO_off64_t _IO_file_seekoff_mmap (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode) { _IO_off64_t result; /* If we are only interested in the current position, calculate it and return right now. This calculation does the right thing when we are using a pushback buffer, but in the usual case has the same value as (fp->_IO_read_ptr - fp->_IO_buf_base). */ if (mode == 0) return fp->_offset - (fp->_IO_read_end - fp->_IO_read_ptr); switch (dir) { case _IO_seek_cur: /* Adjust for read-ahead (bytes is buffer). */ offset += fp->_IO_read_ptr - fp->_IO_read_base; break; case _IO_seek_set: break; case _IO_seek_end: offset += fp->_IO_buf_end - fp->_IO_buf_base; break; } /* At this point, dir==_IO_seek_set. */ if (offset < 0) { /* No negative offsets are valid. */ __set_errno (EINVAL); return EOF; } result = _IO_SYSSEEK (fp, offset, 0); if (result < 0) return EOF; if (offset > fp->_IO_buf_end - fp->_IO_buf_base) /* One can fseek arbitrarily past the end of the file and it is meaningless until one attempts to read. Leave the buffer pointers in EOF state until underflow. */ _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_end, fp->_IO_buf_end); else /* Adjust the read pointers to match the file position, but so the next read attempt will call underflow. */ _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + offset, fp->_IO_buf_base + offset); fp->_offset = result; _IO_mask_flags (fp, 0, _IO_EOF_SEEN); return offset; }
static int attribute_compat_text_section old_do_write (_IO_FILE *fp, const char *data, _IO_size_t to_do) { _IO_size_t count; if (fp->_flags & _IO_IS_APPENDING) /* On a system without a proper O_APPEND implementation, you would need to sys_seek(0, SEEK_END) here, but is not needed nor desirable for Unix- or Posix-like systems. Instead, just indicate that offset (before and after) is unpredictable. */ fp->_old_offset = _IO_pos_BAD; else if (fp->_IO_read_end != fp->_IO_write_base) { _IO_off_t new_pos = _IO_SYSSEEK (fp, fp->_IO_write_base - fp->_IO_read_end, 1); if (new_pos == _IO_pos_BAD) return 0; fp->_old_offset = new_pos; } count = _IO_SYSWRITE (fp, data, to_do); if (fp->_cur_column && count) fp->_cur_column = _IO_adjust_column (fp->_cur_column - 1, data, count) + 1; _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base); fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_buf_base; fp->_IO_write_end = ((fp->_flags & (_IO_LINE_BUF | _IO_UNBUFFERED)) ? fp->_IO_buf_base : fp->_IO_buf_end); return count; }
int attribute_compat_text_section _IO_old_file_close_it (_IO_FILE *fp) { int write_status, close_status; if (!_IO_file_is_open (fp)) return EOF; write_status = _IO_old_do_flush (fp); _IO_unsave_markers (fp); close_status = ((fp->_flags2 & _IO_FLAGS2_NOCLOSE) == 0 ? _IO_SYSCLOSE (fp) : 0); /* Free buffer. */ _IO_setb (fp, NULL, NULL, 0); _IO_setg (fp, NULL, NULL, NULL); _IO_setp (fp, NULL, NULL); _IO_un_link ((struct _IO_FILE_plus *) fp); fp->_flags = _IO_MAGIC|CLOSED_FILEBUF_FLAGS; fp->_fileno = -1; fp->_old_offset = _IO_pos_BAD; return close_status ? close_status : write_status; }
int _IO_new_file_overflow (_IO_FILE *f, int ch) { if (f->_flags & _IO_NO_WRITES) /* SET ERROR */ { f->_flags |= _IO_ERR_SEEN; __set_errno (EBADF); return EOF; } /* If currently reading or no buffer allocated. */ if ((f->_flags & _IO_CURRENTLY_PUTTING) == 0 || f->_IO_write_base == NULL) { /* Allocate a buffer if needed. */ if (f->_IO_write_base == NULL) { _IO_doallocbuf (f); _IO_setg (f, f->_IO_buf_base, f->_IO_buf_base, f->_IO_buf_base); } /* Otherwise must be currently reading. If _IO_read_ptr (and hence also _IO_read_end) is at the buffer end, logically slide the buffer forwards one block (by setting the read pointers to all point at the beginning of the block). This makes room for subsequent output. Otherwise, set the read pointers to _IO_read_end (leaving that alone, so it can continue to correspond to the external position). */ if (__glibc_unlikely (_IO_in_backup (f))) { size_t nbackup = f->_IO_read_end - f->_IO_read_ptr; _IO_free_backup_area (f); f->_IO_read_base -= MIN (nbackup, f->_IO_read_base - f->_IO_buf_base); f->_IO_read_ptr = f->_IO_read_base; } if (f->_IO_read_ptr == f->_IO_buf_end) f->_IO_read_end = f->_IO_read_ptr = f->_IO_buf_base; f->_IO_write_ptr = f->_IO_read_ptr; f->_IO_write_base = f->_IO_write_ptr; f->_IO_write_end = f->_IO_buf_end; f->_IO_read_base = f->_IO_read_ptr = f->_IO_read_end; f->_flags |= _IO_CURRENTLY_PUTTING; if (f->_mode <= 0 && f->_flags & (_IO_LINE_BUF | _IO_UNBUFFERED)) f->_IO_write_end = f->_IO_write_ptr; } if (ch == EOF) return _IO_do_write (f, f->_IO_write_base, f->_IO_write_ptr - f->_IO_write_base); if (f->_IO_write_ptr == f->_IO_buf_end ) /* Buffer is really full */ if (_IO_do_flush (f) == EOF) return EOF; *f->_IO_write_ptr++ = ch; if ((f->_flags & _IO_UNBUFFERED) || ((f->_flags & _IO_LINE_BUF) && ch == '\n')) if (_IO_do_write (f, f->_IO_write_base, f->_IO_write_ptr - f->_IO_write_base) == EOF) return EOF; return (unsigned char) ch; }
int _IO_default_pbackfail (_IO_FILE *fp, int c) { if (fp->_IO_read_ptr > fp->_IO_read_base && !_IO_in_backup (fp) && (unsigned char) fp->_IO_read_ptr[-1] == c) --fp->_IO_read_ptr; else { /* Need to handle a filebuf in write mode (switch to read mode). FIXME!*/ if (!_IO_in_backup (fp)) { /* We need to keep the invariant that the main get area logically follows the backup area. */ if (fp->_IO_read_ptr > fp->_IO_read_base && _IO_have_backup (fp)) { if (save_for_backup (fp, fp->_IO_read_ptr)) return EOF; } else if (!_IO_have_backup (fp)) { /* No backup buffer: allocate one. */ /* Use nshort buffer, if unused? (probably not) FIXME */ int backup_size = 128; char *bbuf = (char *) malloc (backup_size); if (bbuf == NULL) return EOF; fp->_IO_save_base = bbuf; fp->_IO_save_end = fp->_IO_save_base + backup_size; fp->_IO_backup_base = fp->_IO_save_end; } fp->_IO_read_base = fp->_IO_read_ptr; _IO_switch_to_backup_area (fp); } else if (fp->_IO_read_ptr <= fp->_IO_read_base) { /* Increase size of existing backup buffer. */ _IO_size_t new_size; _IO_size_t old_size = fp->_IO_read_end - fp->_IO_read_base; char *new_buf; new_size = 2 * old_size; new_buf = (char *) malloc (new_size); if (new_buf == NULL) return EOF; memcpy (new_buf + (new_size - old_size), fp->_IO_read_base, old_size); free (fp->_IO_read_base); _IO_setg (fp, new_buf, new_buf + (new_size - old_size), new_buf + new_size); fp->_IO_backup_base = fp->_IO_read_ptr; } *--fp->_IO_read_ptr = c; } return (unsigned char) c; }
attribute_compat_text_section _IO_old_file_setbuf (_IO_FILE *fp, char *p, _IO_ssize_t len) { if (_IO_default_setbuf (fp, p, len) == NULL) return NULL; fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_write_end = fp->_IO_buf_base; _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base); return fp; }
_IO_FILE * _IO_new_file_setbuf (_IO_FILE *fp, char *p, _IO_ssize_t len) { if (_IO_default_setbuf (fp, p, len) == NULL) return NULL; fp->_IO_write_base = fp->_IO_write_ptr = fp->_IO_write_end = fp->_IO_buf_base; _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base); return fp; }
int _IO_new_file_close_it (_IO_FILE *fp) { int write_status; if (!_IO_file_is_open (fp)) return EOF; if ((fp->_flags & _IO_NO_WRITES) == 0 && (fp->_flags & _IO_CURRENTLY_PUTTING) != 0) write_status = _IO_do_flush (fp); else write_status = 0; _IO_unsave_markers (fp); int close_status = ((fp->_flags2 & _IO_FLAGS2_NOCLOSE) == 0 ? _IO_SYSCLOSE (fp) : 0); /* Free buffer. */ #if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T if (fp->_mode > 0) { if (_IO_have_wbackup (fp)) _IO_free_wbackup_area (fp); _IO_wsetb (fp, NULL, NULL, 0); _IO_wsetg (fp, NULL, NULL, NULL); _IO_wsetp (fp, NULL, NULL); } #endif _IO_setb (fp, NULL, NULL, 0); _IO_setg (fp, NULL, NULL, NULL); _IO_setp (fp, NULL, NULL); _IO_un_link ((struct _IO_FILE_plus *) fp); fp->_flags = _IO_MAGIC|CLOSED_FILEBUF_FLAGS; fp->_fileno = -1; fp->_offset = _IO_pos_BAD; return close_status ? close_status : write_status; }
_IO_off64_t attribute_compat_text_section _IO_old_file_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode) { _IO_off_t result; _IO_off64_t delta, new_offset; long count; /* POSIX.1 8.2.3.7 says that after a call the fflush() the file offset of the underlying file must be exact. */ int must_be_exact = (fp->_IO_read_base == fp->_IO_read_end && fp->_IO_write_base == fp->_IO_write_ptr); if (mode == 0) dir = _IO_seek_cur, offset = 0; /* Don't move any pointers. */ /* Flush unwritten characters. (This may do an unneeded write if we seek within the buffer. But to be able to switch to reading, we would need to set egptr to pptr. That can't be done in the current design, which assumes file_ptr() is eGptr. Anyway, since we probably end up flushing when we close(), it doesn't make much difference.) FIXME: simulate mem-mapped files. */ if (fp->_IO_write_ptr > fp->_IO_write_base || _IO_in_put_mode (fp)) if (_IO_switch_to_get_mode (fp)) return EOF; if (fp->_IO_buf_base == NULL) { /* It could be that we already have a pushback buffer. */ if (fp->_IO_read_base != NULL) { free (fp->_IO_read_base); fp->_flags &= ~_IO_IN_BACKUP; } _IO_doallocbuf (fp); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base); } switch (dir) { case _IO_seek_cur: /* Adjust for read-ahead (bytes is buffer). */ offset -= fp->_IO_read_end - fp->_IO_read_ptr; if (fp->_old_offset == _IO_pos_BAD) goto dumb; /* Make offset absolute, assuming current pointer is file_ptr(). */ offset += fp->_old_offset; dir = _IO_seek_set; break; case _IO_seek_set: break; case _IO_seek_end: { struct stat64 st; if (_IO_SYSSTAT (fp, &st) == 0 && S_ISREG (st.st_mode)) { offset += st.st_size; dir = _IO_seek_set; } else goto dumb; } } /* At this point, dir==_IO_seek_set. */ /* If we are only interested in the current position we've found it now. */ if (mode == 0) return offset; /* If destination is within current buffer, optimize: */ if (fp->_old_offset != _IO_pos_BAD && fp->_IO_read_base != NULL && !_IO_in_backup (fp)) { /* Offset relative to start of main get area. */ _IO_off_t rel_offset = (offset - fp->_old_offset + (fp->_IO_read_end - fp->_IO_read_base)); if (rel_offset >= 0) { #if 0 if (_IO_in_backup (fp)) _IO_switch_to_main_get_area (fp); #endif if (rel_offset <= fp->_IO_read_end - fp->_IO_read_base) { _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + rel_offset, fp->_IO_read_end); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); { _IO_mask_flags (fp, 0, _IO_EOF_SEEN); goto resync; } } #ifdef TODO /* If we have streammarkers, seek forward by reading ahead. */ if (_IO_have_markers (fp)) { int to_skip = rel_offset - (fp->_IO_read_ptr - fp->_IO_read_base); if (ignore (to_skip) != to_skip) goto dumb; _IO_mask_flags (fp, 0, _IO_EOF_SEEN); goto resync; } #endif } #ifdef TODO if (rel_offset < 0 && rel_offset >= Bbase () - Bptr ()) { if (!_IO_in_backup (fp)) _IO_switch_to_backup_area (fp); gbump (fp->_IO_read_end + rel_offset - fp->_IO_read_ptr); _IO_mask_flags (fp, 0, _IO_EOF_SEEN); goto resync; } #endif } #ifdef TODO _IO_unsave_markers (fp); #endif if (fp->_flags & _IO_NO_READS) goto dumb; /* Try to seek to a block boundary, to improve kernel page management. */ new_offset = offset & ~(fp->_IO_buf_end - fp->_IO_buf_base - 1); delta = offset - new_offset; if (delta > fp->_IO_buf_end - fp->_IO_buf_base) { new_offset = offset; delta = 0; } result = _IO_SYSSEEK (fp, new_offset, 0); if (result < 0) return EOF; if (delta == 0) count = 0; else { count = _IO_SYSREAD (fp, fp->_IO_buf_base, (must_be_exact ? delta : fp->_IO_buf_end - fp->_IO_buf_base)); if (count < delta) { /* We weren't allowed to read, but try to seek the remainder. */ offset = count == EOF ? delta : delta-count; dir = _IO_seek_cur; goto dumb; } } _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + delta, fp->_IO_buf_base + count); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); fp->_old_offset = result + count; _IO_mask_flags (fp, 0, _IO_EOF_SEEN); return offset; dumb: _IO_unsave_markers (fp); result = _IO_SYSSEEK (fp, offset, dir); if (result != EOF) { _IO_mask_flags (fp, 0, _IO_EOF_SEEN); fp->_old_offset = result; _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); } return result; resync: /* We need to do it since it is possible that the file offset in the kernel may be changed behind our back. It may happen when we fopen a file and then do a fork. One process may access the file and the kernel file offset will be changed. */ if (fp->_old_offset >= 0) _IO_SYSSEEK (fp, fp->_old_offset, 0); return offset; }
_IO_off64_t _IO_new_file_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode) { _IO_off64_t result; _IO_off64_t delta, new_offset; long count; /* Short-circuit into a separate function. We don't want to mix any functionality and we don't want to touch anything inside the FILE object. */ if (mode == 0) return do_ftell (fp); /* POSIX.1 8.2.3.7 says that after a call the fflush() the file offset of the underlying file must be exact. */ int must_be_exact = (fp->_IO_read_base == fp->_IO_read_end && fp->_IO_write_base == fp->_IO_write_ptr); bool was_writing = (fp->_IO_write_ptr > fp->_IO_write_base || _IO_in_put_mode (fp)); /* Flush unwritten characters. (This may do an unneeded write if we seek within the buffer. But to be able to switch to reading, we would need to set egptr to pptr. That can't be done in the current design, which assumes file_ptr() is eGptr. Anyway, since we probably end up flushing when we close(), it doesn't make much difference.) FIXME: simulate mem-mapped files. */ if (was_writing && _IO_switch_to_get_mode (fp)) return EOF; if (fp->_IO_buf_base == NULL) { /* It could be that we already have a pushback buffer. */ if (fp->_IO_read_base != NULL) { free (fp->_IO_read_base); fp->_flags &= ~_IO_IN_BACKUP; } _IO_doallocbuf (fp); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base); } switch (dir) { case _IO_seek_cur: /* Adjust for read-ahead (bytes is buffer). */ offset -= fp->_IO_read_end - fp->_IO_read_ptr; if (fp->_offset == _IO_pos_BAD) goto dumb; /* Make offset absolute, assuming current pointer is file_ptr(). */ offset += fp->_offset; if (offset < 0) { __set_errno (EINVAL); return EOF; } dir = _IO_seek_set; break; case _IO_seek_set: break; case _IO_seek_end: { struct stat64 st; if (_IO_SYSSTAT (fp, &st) == 0 && S_ISREG (st.st_mode)) { offset += st.st_size; dir = _IO_seek_set; } else goto dumb; } } /* At this point, dir==_IO_seek_set. */ /* If destination is within current buffer, optimize: */ if (fp->_offset != _IO_pos_BAD && fp->_IO_read_base != NULL && !_IO_in_backup (fp)) { _IO_off64_t start_offset = (fp->_offset - (fp->_IO_read_end - fp->_IO_buf_base)); if (offset >= start_offset && offset < fp->_offset) { _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + (offset - start_offset), fp->_IO_read_end); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); _IO_mask_flags (fp, 0, _IO_EOF_SEEN); goto resync; } } if (fp->_flags & _IO_NO_READS) goto dumb; /* Try to seek to a block boundary, to improve kernel page management. */ new_offset = offset & ~(fp->_IO_buf_end - fp->_IO_buf_base - 1); delta = offset - new_offset; if (delta > fp->_IO_buf_end - fp->_IO_buf_base) { new_offset = offset; delta = 0; } result = _IO_SYSSEEK (fp, new_offset, 0); if (result < 0) return EOF; if (delta == 0) count = 0; else { count = _IO_SYSREAD (fp, fp->_IO_buf_base, (must_be_exact ? delta : fp->_IO_buf_end - fp->_IO_buf_base)); if (count < delta) { /* We weren't allowed to read, but try to seek the remainder. */ offset = count == EOF ? delta : delta-count; dir = _IO_seek_cur; goto dumb; } } _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + delta, fp->_IO_buf_base + count); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); fp->_offset = result + count; _IO_mask_flags (fp, 0, _IO_EOF_SEEN); return offset; dumb: _IO_unsave_markers (fp); result = _IO_SYSSEEK (fp, offset, dir); if (result != EOF) { _IO_mask_flags (fp, 0, _IO_EOF_SEEN); fp->_offset = result; _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); } return result; resync: /* We need to do it since it is possible that the file offset in the kernel may be changed behind our back. It may happen when we fopen a file and then do a fork. One process may access the file and the kernel file offset will be changed. */ if (fp->_offset >= 0) _IO_SYSSEEK (fp, fp->_offset, 0); return offset; }
static void decide_maybe_mmap (_IO_FILE *fp) { /* We use the file in read-only mode. This could mean we can mmap the file and use it without any copying. But not all file descriptors are for mmap-able objects and on 32-bit machines we don't want to map files which are too large since this would require too much virtual memory. */ struct stat64 st; if (_IO_SYSSTAT (fp, &st) == 0 && S_ISREG (st.st_mode) && st.st_size != 0 /* Limit the file size to 1MB for 32-bit machines. */ && (sizeof (ptrdiff_t) > 4 || st.st_size < 1*1024*1024) /* Sanity check. */ && (fp->_offset == _IO_pos_BAD || fp->_offset <= st.st_size)) { /* Try to map the file. */ void *p; p = __mmap64 (NULL, st.st_size, PROT_READ, MAP_SHARED, fp->_fileno, 0); if (p != MAP_FAILED) { /* OK, we managed to map the file. Set the buffer up and use a special jump table with simplified underflow functions which never tries to read anything from the file. */ if (__lseek64 (fp->_fileno, st.st_size, SEEK_SET) != st.st_size) { (void) __munmap (p, st.st_size); fp->_offset = _IO_pos_BAD; } else { _IO_setb (fp, p, (char *) p + st.st_size, 0); if (fp->_offset == _IO_pos_BAD) fp->_offset = 0; _IO_setg (fp, p, p + fp->_offset, p + st.st_size); fp->_offset = st.st_size; if (fp->_mode <= 0) _IO_JUMPS_FILE_plus (fp) = &_IO_file_jumps_mmap; else _IO_JUMPS_FILE_plus (fp) = &_IO_wfile_jumps_mmap; fp->_wide_data->_wide_vtable = &_IO_wfile_jumps_mmap; return; } } } /* We couldn't use mmap, so revert to the vanilla file operations. */ if (fp->_mode <= 0) _IO_JUMPS_FILE_plus (fp) = &_IO_file_jumps; else _IO_JUMPS_FILE_plus (fp) = &_IO_wfile_jumps; fp->_wide_data->_wide_vtable = &_IO_wfile_jumps; }
/* Guts of underflow callback if we mmap the file. This stats the file and updates the stream state to match. In the normal case we return zero. If the file is no longer eligible for mmap, its jump tables are reset to the vanilla ones and we return nonzero. */ static int mmap_remap_check (_IO_FILE *fp) { struct stat64 st; if (_IO_SYSSTAT (fp, &st) == 0 && S_ISREG (st.st_mode) && st.st_size != 0 /* Limit the file size to 1MB for 32-bit machines. */ && (sizeof (ptrdiff_t) > 4 || st.st_size < 1*1024*1024)) { const size_t pagesize = __getpagesize (); # define ROUNDED(x) (((x) + pagesize - 1) & ~(pagesize - 1)) if (ROUNDED (st.st_size) < ROUNDED (fp->_IO_buf_end - fp->_IO_buf_base)) { /* We can trim off some pages past the end of the file. */ (void) __munmap (fp->_IO_buf_base + ROUNDED (st.st_size), ROUNDED (fp->_IO_buf_end - fp->_IO_buf_base) - ROUNDED (st.st_size)); fp->_IO_buf_end = fp->_IO_buf_base + st.st_size; } else if (ROUNDED (st.st_size) > ROUNDED (fp->_IO_buf_end - fp->_IO_buf_base)) { /* The file added some pages. We need to remap it. */ void *p; #ifdef _G_HAVE_MREMAP p = __mremap (fp->_IO_buf_base, ROUNDED (fp->_IO_buf_end - fp->_IO_buf_base), ROUNDED (st.st_size), MREMAP_MAYMOVE); if (p == MAP_FAILED) { (void) __munmap (fp->_IO_buf_base, fp->_IO_buf_end - fp->_IO_buf_base); goto punt; } #else (void) __munmap (fp->_IO_buf_base, fp->_IO_buf_end - fp->_IO_buf_base); p = __mmap64 (NULL, st.st_size, PROT_READ, MAP_SHARED, fp->_fileno, 0); if (p == MAP_FAILED) goto punt; #endif fp->_IO_buf_base = p; fp->_IO_buf_end = fp->_IO_buf_base + st.st_size; } else { /* The number of pages didn't change. */ fp->_IO_buf_end = fp->_IO_buf_base + st.st_size; } # undef ROUNDED fp->_offset -= fp->_IO_read_end - fp->_IO_read_ptr; _IO_setg (fp, fp->_IO_buf_base, fp->_offset < fp->_IO_buf_end - fp->_IO_buf_base ? fp->_IO_buf_base + fp->_offset : fp->_IO_buf_end, fp->_IO_buf_end); /* If we are already positioned at or past the end of the file, don't change the current offset. If not, seek past what we have mapped, mimicking the position left by a normal underflow reading into its buffer until EOF. */ if (fp->_offset < fp->_IO_buf_end - fp->_IO_buf_base) { if (__lseek64 (fp->_fileno, fp->_IO_buf_end - fp->_IO_buf_base, SEEK_SET) != fp->_IO_buf_end - fp->_IO_buf_base) fp->_flags |= _IO_ERR_SEEN; else fp->_offset = fp->_IO_buf_end - fp->_IO_buf_base; } return 0; } else { /* Life is no longer good for mmap. Punt it. */ (void) __munmap (fp->_IO_buf_base, fp->_IO_buf_end - fp->_IO_buf_base); punt: fp->_IO_buf_base = fp->_IO_buf_end = NULL; _IO_setg (fp, NULL, NULL, NULL); if (fp->_mode <= 0) _IO_JUMPS_FILE_plus (fp) = &_IO_file_jumps; else _IO_JUMPS_FILE_plus (fp) = &_IO_wfile_jumps; fp->_wide_data->_wide_vtable = &_IO_wfile_jumps; return 1; } }
_IO_size_t _IO_file_xsgetn (_IO_FILE *fp, void *data, _IO_size_t n) { _IO_size_t want, have; _IO_ssize_t count; char *s = data; want = n; if (fp->_IO_buf_base == NULL) { /* Maybe we already have a push back pointer. */ if (fp->_IO_save_base != NULL) { free (fp->_IO_save_base); fp->_flags &= ~_IO_IN_BACKUP; } _IO_doallocbuf (fp); } while (want > 0) { have = fp->_IO_read_end - fp->_IO_read_ptr; if (want <= have) { memcpy (s, fp->_IO_read_ptr, want); fp->_IO_read_ptr += want; want = 0; } else { if (have > 0) { #ifdef _LIBC s = __mempcpy (s, fp->_IO_read_ptr, have); #else memcpy (s, fp->_IO_read_ptr, have); s += have; #endif want -= have; fp->_IO_read_ptr += have; } /* Check for backup and repeat */ if (_IO_in_backup (fp)) { _IO_switch_to_main_get_area (fp); continue; } /* If we now want less than a buffer, underflow and repeat the copy. Otherwise, _IO_SYSREAD directly to the user buffer. */ if (fp->_IO_buf_base && want < (size_t) (fp->_IO_buf_end - fp->_IO_buf_base)) { if (__underflow (fp) == EOF) break; continue; } /* These must be set before the sysread as we might longjmp out waiting for input. */ _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); /* Try to maintain alignment: read a whole number of blocks. */ count = want; if (fp->_IO_buf_base) { _IO_size_t block_size = fp->_IO_buf_end - fp->_IO_buf_base; if (block_size >= 128) count -= want % block_size; } count = _IO_SYSREAD (fp, s, count); if (count <= 0) { if (count == 0) fp->_flags |= _IO_EOF_SEEN; else fp->_flags |= _IO_ERR_SEEN; break; } s += count; want -= count; if (fp->_offset != _IO_pos_BAD) _IO_pos_adjust (fp->_offset, count); } } return n - want; }
wint_t _IO_wfile_overflow (_IO_FILE *f, wint_t wch) { if (f->_flags & _IO_NO_WRITES) /* SET ERROR */ { f->_flags |= _IO_ERR_SEEN; __set_errno (EBADF); return WEOF; } /* If currently reading or no buffer allocated. */ if ((f->_flags & _IO_CURRENTLY_PUTTING) == 0) { /* Allocate a buffer if needed. */ if (f->_wide_data->_IO_write_base == 0) { _IO_wdoallocbuf (f); _IO_wsetg (f, f->_wide_data->_IO_buf_base, f->_wide_data->_IO_buf_base, f->_wide_data->_IO_buf_base); if (f->_IO_write_base == NULL) { _IO_doallocbuf (f); _IO_setg (f, f->_IO_buf_base, f->_IO_buf_base, f->_IO_buf_base); } } else { /* Otherwise must be currently reading. If _IO_read_ptr (and hence also _IO_read_end) is at the buffer end, logically slide the buffer forwards one block (by setting the read pointers to all point at the beginning of the block). This makes room for subsequent output. Otherwise, set the read pointers to _IO_read_end (leaving that alone, so it can continue to correspond to the external position). */ if (f->_wide_data->_IO_read_ptr == f->_wide_data->_IO_buf_end) { f->_IO_read_end = f->_IO_read_ptr = f->_IO_buf_base; f->_wide_data->_IO_read_end = f->_wide_data->_IO_read_ptr = f->_wide_data->_IO_buf_base; } } f->_wide_data->_IO_write_ptr = f->_wide_data->_IO_read_ptr; f->_wide_data->_IO_write_base = f->_wide_data->_IO_write_ptr; f->_wide_data->_IO_write_end = f->_wide_data->_IO_buf_end; f->_wide_data->_IO_read_base = f->_wide_data->_IO_read_ptr = f->_wide_data->_IO_read_end; f->_IO_write_ptr = f->_IO_read_ptr; f->_IO_write_base = f->_IO_write_ptr; f->_IO_write_end = f->_IO_buf_end; f->_IO_read_base = f->_IO_read_ptr = f->_IO_read_end; f->_flags |= _IO_CURRENTLY_PUTTING; if (f->_flags & (_IO_LINE_BUF | _IO_UNBUFFERED)) f->_wide_data->_IO_write_end = f->_wide_data->_IO_write_ptr; } if (wch == WEOF) return _IO_do_flush (f); if (f->_wide_data->_IO_write_ptr == f->_wide_data->_IO_buf_end) /* Buffer is really full */ if (_IO_do_flush (f) == EOF) return WEOF; *f->_wide_data->_IO_write_ptr++ = wch; if ((f->_flags & _IO_UNBUFFERED) || ((f->_flags & _IO_LINE_BUF) && wch == L'\n')) if (_IO_do_flush (f) == EOF) return WEOF; return wch; }