sio.h
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- /* ***** BEGIN LICENSE BLOCK *****
- * Source last modified: $Id: sio.h,v 1.3.36.3 2004/07/09 01:44:45 hubbe Exp $
- *
- * Portions Copyright (c) 1995-2004 RealNetworks, Inc. All Rights Reserved.
- *
- * The contents of this file, and the files included with this file,
- * are subject to the current version of the RealNetworks Public
- * Source License (the "RPSL") available at
- * http://www.helixcommunity.org/content/rpsl unless you have licensed
- * the file under the current version of the RealNetworks Community
- * Source License (the "RCSL") available at
- * http://www.helixcommunity.org/content/rcsl, in which case the RCSL
- * will apply. You may also obtain the license terms directly from
- * RealNetworks. You may not use this file except in compliance with
- * the RPSL or, if you have a valid RCSL with RealNetworks applicable
- * to this file, the RCSL. Please see the applicable RPSL or RCSL for
- * the rights, obligations and limitations governing use of the
- * contents of the file.
- *
- * Alternatively, the contents of this file may be used under the
- * terms of the GNU General Public License Version 2 or later (the
- * "GPL") in which case the provisions of the GPL are applicable
- * instead of those above. If you wish to allow use of your version of
- * this file only under the terms of the GPL, and not to allow others
- * to use your version of this file under the terms of either the RPSL
- * or RCSL, indicate your decision by deleting the provisions above
- * and replace them with the notice and other provisions required by
- * the GPL. If you do not delete the provisions above, a recipient may
- * use your version of this file under the terms of any one of the
- * RPSL, the RCSL or the GPL.
- *
- * This file is part of the Helix DNA Technology. RealNetworks is the
- * developer of the Original Code and owns the copyrights in the
- * portions it created.
- *
- * This file, and the files included with this file, is distributed
- * and made available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY
- * KIND, EITHER EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS
- * ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES
- * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET
- * ENJOYMENT OR NON-INFRINGEMENT.
- *
- * Technology Compatibility Kit Test Suite(s) Location:
- * http://www.helixcommunity.org/content/tck
- *
- * Contributor(s):
- *
- * ***** END LICENSE BLOCK ***** */
- #ifndef _SIO_H_
- #define _SIO_H_
- #include "hlxclib/errno.h"
- #include "debug.h"
- #include "fio.h"
- class IO;
- class SIO
- {
- public:
- SIO();
- virtual ~SIO() = 0;
- int error();
- int end_of_file();
- Byte* read_alloc(int& size);
- virtual Byte* read_alloc(int& size, off_t seek, int whence)=0;
- Byte* read_realloc(Byte* buf, int oldsize, int& size);
- int read_undo(Byte* buf, int len);
- void read_free(Byte* buf);
- off_t read_offset();
- virtual off_t read_seek(off_t off, int whence) = 0;
- virtual int read_pushback(Byte* buf, int len) = 0;
- int read_count();
- Byte* write_alloc(int& size);
- virtual Byte* write_alloc(int& size, off_t seek, int whence)=0;
- Byte* write_realloc(Byte* buf, int oldsize, int& size);
- int write_undo(Byte* buf, int len);
- int write_free(Byte* buf);
- off_t write_offset();
- virtual off_t write_seek(off_t off, int whence) = 0;
- int write_flush();
- int write_flush_count();
- BOOL write_flush_needed();
- virtual off_t file_size() = 0;
- void unset_eof();
- virtual char * get_pathname() { return NULL;};
- virtual int get_would_block() {return 0;}
- void set_delete_io(int flag) { delete_io = flag; }
- struct Region
- {
- Region* next;
- Region* prev;
- off_t off; // offset into file
- off_t flush_off; // offset into file for writing
- Byte* base; // this is where data starts
- Byte* limit; // this is where data ends
- int refcount;
- Region();
- Region(Region* link);
- void set_buf(Byte* b, int size, off_t offset = 0);
- };
- protected:
- struct Region_list
- {
- off_t off; // current offset into file
- Byte* ptr; // ptr to data on next access
- Byte* end; // data ends here
- Region* regs; // list of regions
- Region* creg; // current region
- int eof; // 1 if end of file
- Region_list();
- ~Region_list();
- Region* find(Byte* buf, Region**& rp);
- Region* find(off_t offt, Region**& rp);
- Byte* remove(Region* reg);
- };
- IO* io; // object that does the real io
- int flags;
- off_t write_off; // data written up to this point
- Region_list reader;
- Region_list writer;
- int err; // last error
- int delete_io;
- virtual Byte* _read_alloc(int& size) = 0;
- virtual void _read_free(Byte* buf) = 0;
- int _read_count();
- int _read_space();
- virtual Byte* _write_alloc(int& size) = 0;
- virtual int _write_free(Byte* buf) = 0;
- virtual int _write_flush(Region* reg) = 0;
- int _write_count();
- int _write_space();
- };
- inline
- SIO::Region::Region() {
- next = 0;
- prev = 0;
- refcount = 0;
- }
- inline
- SIO::Region::Region(SIO::Region* link) {
- link->next = this;
- prev = link;
- next = 0;
- refcount = 0;
- }
- inline void
- SIO::Region::set_buf(Byte* b, int size, off_t offset) {
- base = b;
- limit = b + size;
- flush_off = off = offset;
- }
- inline
- SIO::Region_list::Region_list() {
- creg = regs = new Region;
- off = 0;
- eof = 0;
- }
- inline
- SIO::Region_list::~Region_list() {
- while (regs) {
- Region* next = regs->next;
- delete regs;
- regs = next;
- if (next) next->prev = 0;
- }
- }
- inline int
- SIO::error() {
- return err;
- }
- inline int
- SIO::end_of_file() {
- return reader.eof;
- }
- inline
- SIO::SIO() {
- err = 0;
- write_off = 0;
- delete_io = 1;
- }
- inline
- SIO::~SIO() {
- }
- inline int
- SIO::_read_count() {
- return reader.end - reader.ptr;
- }
- inline int
- SIO::_read_space() {
- return reader.creg->limit - reader.end;
- }
- inline off_t
- SIO::read_offset() {
- return reader.creg->off + (reader.ptr - reader.creg->base);
- }
- inline Byte*
- SIO::read_alloc(int& size) {
- if (size < 0) {
- DPRINTF(D_ERROR,("illegal read_alloc request %d bytesn", size));
- err = EINVAL;
- return 0;
- }
- Byte* p = reader.ptr + size;
- if (p <= reader.end) {
- reader.creg->refcount++;
-
- /*
- * Return the base of the region if the user requests a
- * read_alloc of 0 bytes. This avoids corrupting the region
- * list when the corresponding call to read_free is made
- *
- * NOTE: read_undo and read_realloc may NOT be performed on
- * the pointer returned
- */
- if (size == 0)
- return reader.creg->base;
- Byte* b = reader.ptr;
- reader.ptr = p;
- return b;
- }
- return _read_alloc(size);
- }
- inline Byte*
- SIO::read_realloc(Byte* buf, int oldsize, int& size)
- {
- // realloc allowed only on the very last allocation
- if (buf + oldsize != reader.ptr) {
- size = oldsize;
- return buf;
- }
- // shrink case is easy, just unread the bytes beyond size
- if (size <= oldsize) {
- reader.ptr -= oldsize - size;
- reader.eof = 0;
- return buf;
- }
- // essentially do an unread and a new read_alloc
- reader.ptr = buf;
- reader.creg->refcount--;
- return read_alloc(size);
- }
- inline void
- SIO::read_free(Byte* buf)
- {
- if (!buf)
- return;
- /*
- * If buf == reader.creg->base then it may have come from a read_alloc
- * of 0 bytes. We must free this pointer even if it has the same address
- * as reader.end
- */
- if (buf == reader.creg->base || (reader.creg->base < buf && buf < reader.end))
- {
- reader.creg->refcount--;
- return;
- }
- DPRINTF(D_ALLOC, ("freeing %pn", buf));
- _read_free(buf);
- }
- /*
- * read_undo is same as
- * buf = read_realloc(buf, len, 0); read_free(buf);
- */
- inline int
- SIO::read_undo(Byte* buf, int len)
- {
- // can not read undo in case of any error
- if (err)
- return -1;
- if (buf + len == reader.ptr) {
- reader.ptr = buf;
- reader.creg->refcount--;
- } else {
- DPRINTF(D_ALLOC, ("freeing %p count %dn", buf, len));
- _read_free(buf);
- }
- // XXX err may need to be cleared
- reader.eof = 0;
- return 0;
- }
- inline int
- SIO::_write_count() {
- return writer.end - writer.ptr;
- }
- inline int
- SIO::_write_space() {
- return writer.creg->limit - writer.ptr;
- }
- inline Byte*
- SIO::write_alloc(int& size) {
- // XXX this needs to be moved to the non file case.
- // sio is a generic interface and can not assume
- // any specific buffering scheme.
- Byte* p = writer.ptr + size;
- if (p <= writer.creg->limit) {
- writer.creg->refcount++;
- /*
- * Return the base of the region if the user requests a
- * write_alloc of 0 bytes. This keeps write_alloc orthogonal
- * with read_alloc
- *
- * NOTE: write_undo and write_realloc may NOT be performed on
- * the pointer returned
- */
- if (size == 0)
- return writer.creg->base;
- Byte* b = writer.ptr;
- writer.end = writer.ptr = p;
- return b;
- }
- return _write_alloc(size);
- }
- inline Byte*
- SIO::write_realloc(Byte* buf, int oldsize, int& size)
- {
- // XXX this code's been disabled since 1997 so it was removed
- // XXX unsupported
- return 0;
- }
- inline int
- SIO::write_free(Byte* buf)
- {
- //
- // let the derived class decide what to do with the data
- //
- return _write_free(buf);
- }
- /*
- * write_undo is same as
- * buf = write_realloc(buf, len, 0); write_free(buf);
- */
- inline int
- SIO::write_undo(Byte* buf, int len)
- {
- // XXX this code's been disabled since 1997 so it was removed
- // XXX unsupported
- return -1;
- }
- inline int
- SIO::write_flush()
- {
- Region* reg = writer.regs;
- if (reg == writer.creg)
- return 0;
- if (_write_flush(reg) < 0)
- {
- if (err)
- return -1;
- return 0;
- }
- writer.regs = reg->next;
- if (writer.regs) writer.regs->prev = 0;
- delete[] reg->base;
- delete reg;
-
- return 0;
- }
- inline off_t
- SIO::write_offset() {
- return writer.creg->off + (writer.ptr - writer.creg->base);
- }
- inline void
- SIO::unset_eof() {
- reader.eof = 0;
- }
- inline int
- SIO::read_count() {
- return _read_count();
- }
- #endif/*_SIO_H*/