+2002-12-06 Marcus Brinkmann <marcus@g10code.de>
+
+ * gpgme.texi (Memory Based Data Buffers): New subsection.
+ (File Based Data Buffers): Likewise.
+ (Callback Based Data Buffers): Likewise.
+ (Manipulating Data Buffers): Update interfaces. Add
+ gpgme_data_seek.
+ * gpgme.texi (Engine Version Check): Remove gpgme_chec_engine.
+
2002-11-21 Marcus Brinkmann <marcus@g10code.de>
* gpgme.texi (Verify): Document the new interface.
* Destroying Data Buffers:: Releasing data buffers.
* Manipulating Data Buffers:: Operations on data buffers.
+Creating Data Buffers
+
+* Memory Based Data Buffers:: Creating memory based data buffers.
+* File Based Data Buffers:: Creating file based data buffers.
+* Callback Based Data Buffers:: Creating callback based data buffers.
+
Contexts
* Creating Contexts:: Creating new @acronym{GPGME} contexts.
and @code{GPGME_Invalid_Engine} if it is not.
@end deftypefun
-@deftypefun GpgmeError gpgme_check_engine (void)
-The function @code{gpgme_check_engine} is equivalent to
-
-@example
-gpgme_engine_check_version (GPGME_PROTOCOL_OpenPGP);
-@end example
-
-This function is deprecated and provided for backwards compatibility
-only. It is obsoleted by @code{gpgme_engine_check_version}.
-@end deftypefun
-
@node Engine Information
@section Engine Information
@item GPGME_File_Error
This value means that a file I/O operation failed. The value of
-@code{errno} contains the system error value.
+@var{errno} contains the system error value.
@item GPGME_Decryption_Failed
This value indicates that a decryption operation was unsuccessful.
@section Creating Data Buffers
@cindex data buffer, creation
+Data objects can be based on memory, files, or callback functions
+provided by the user. Not all operations are supported by all
+objects.
+
+
+@menu
+* Memory Based Data Buffers:: Creating memory based data buffers.
+* File Based Data Buffers:: Creating file based data buffers.
+* Callback Based Data Buffers:: Creating callback based data buffers.
+@end menu
+
+
+@node Memory Based Data Buffers
+@subsection Memory Based Data Buffers
+
+Memory based data objects store all data in allocated memory. This is
+convenient, but only practical for an amount of data that is a
+fraction of the available physical memory. The data has to be copied
+from its source and to its destination, which can often be avoided by
+using one of the other data object
+
@deftypefun GpgmeError gpgme_data_new (@w{GpgmeData *@var{dh}})
The function @code{gpgme_data_new} creates a new @code{GpgmeData}
object and returns a handle for it in @var{dh}. The data object is
-initially empty.
+memory based and initially empty.
The function returns @code{GPGME_No_Error} if the data object was
successfully created, @code{GPGME_Invalid_Value} if @var{dh} is not a
@code{GPGME_Out_Of_Core} if not enough memory is available.
@end deftypefun
+
+@node File Based Data Buffers
+@subsection File Based Data Buffers
+
+File based data objects operate directly on file descriptors or
+streams. Only a small amount of data is stored in core at any time,
+so the size of the data objects is not limited by @acronym{GPGME}.
+
+@deftypefun GpgmeError gpgme_data_new_from_fd (@w{GpgmeData *@var{dh}}, @w{int @var{fd}})
+The function @code{gpgme_data_new_from_fd} creates a new
+@code{GpgmeData} object and uses the file descriptor @var{fd} to read
+from (if used as an input data object) and write to (if used as an
+output data object).
+
+When using the data object as an input buffer, the function might read
+a bit more from the file descriptor than is actually needed by the
+crypto engine in the desired operation because of internal buffering.
+
+The function returns @code{GPGME_No_Error} if the data object was
+successfully created, and @code{GPGME_Out_Of_Core} if not enough
+memory is available.
+@end deftypefun
+
+@deftypefun GpgmeError gpgme_data_new_from_stream (@w{GpgmeData *@var{dh}}, @w{FILE *@var{stream}})
+The function @code{gpgme_data_new_from_stream} creates a new
+@code{GpgmeData} object and uses the I/O stream @var{stream} to read
+from (if used as an input data object) and write to (if used as an
+output data object).
+
+When using the data object as an input buffer, the function might read
+a bit more from the stream than is actually needed by the crypto
+engine in the desired operation because of internal buffering.
+
+The function returns @code{GPGME_No_Error} if the data object was
+successfully created, and @code{GPGME_Out_Of_Core} if not enough
+memory is available.
+@end deftypefun
+
+
+@node Callback Based Data Buffers
+@subsection Callback Based Data Buffers
+
+If neither memory nor file based data objects are a good fit for your
+application, you can implement the functions a data object provides
+yourself and create a data object from these callback functions.
+
+@deftp {Data type} {ssize_t (*GpgmeDataReadCb) (@w{void *@var{handle}}, @w{void @var{*buffer}}, @w{size_t @var{size}})}
+@tindex GpgmeDataReadCb
+The @code{GpgmeDataReadCb} type is the type of functions which
+@acronym{GPGME} calls if it wants to read data from a user-implemented
+data object. The function should read up to @var{size} bytes from the
+current read position into the space starting at @var{buffer}. The
+@var{handle} is provided by the user at data object creation time.
+
+The function should return the number of bytes read, 0 on EOF, and -1
+on error. If an error occurs, @var{errno} should be set to describe
+the type of the error.
+@end deftp
+
+@deftp {Data type} {ssize_t (*GpgmeDataWriteCb) (@w{void *@var{handle}}, @w{const void @var{*buffer}}, @w{size_t @var{size}})}
+@tindex GpgmeDataWriteCb
+The @code{GpgmeDataWriteCb} type is the type of functions which
+@acronym{GPGME} calls if it wants to write data to a user-implemented
+data object. The function should write up to @var{size} bytes to the
+current write position from the space starting at @var{buffer}. The
+@var{handle} is provided by the user at data object creation time.
+
+The function should return the number of bytes written, and -1 on
+error. If an error occurs, @var{errno} should be set to describe the
+type of the error.
+@end deftp
+
+@deftp {Data type} {off_t (*GpgmeDataSeekCb) (@w{void *@var{handle}}, @w{off_t @var{offset}}, @w{int @var{whence}})}
+@tindex GpgmeDataSeekCb
+The @code{GpgmeDataSeekCb} type is the type of functions which
+@acronym{GPGME} calls if it wants to change the current read/write
+position in a user-implemented data object, just like the @code{lseek}
+function.
+
+The function should return the new read/write position, and -1 on
+error. If an error occurs, @var{errno} should be set to describe the
+type of the error.
+@end deftp
+
+@deftp {Data type} {void (*GpgmeDataReleaseCb) (@w{void *@var{handle}})
+@tindex GpgmeDataReleaseCb
+The @code{GpgmeDataReleaseCb} type is the type of functions which
+@acronym{GPGME} calls if it wants to destroy a user-implemented data
+object. The @var{handle} is provided by the user at data object
+creation time.
+@end deftp
+
+@deftp {Data type} {struct GpgmeDataCbs}
+This structure is used to store the data callback interface functions
+described above. It has the following members:
+
+@table @code
+@item GpgmeDataReadCb read
+This is the function called by @acronym{GPGME} to read data from the
+data object. It is only required for input data object.
+
+@item GpgmeDataReadCb write
+This is the function called by @acronym{GPGME} to write data to the
+data object. It is only required for output data object.
+
+@item GpgmeDataSeekCb seek
+This is the function called by @acronym{GPGME} to change the current
+read/write pointer in the data object (if available). It is optional.
+
+@item GpgmeDataReleaseCb release
+This is the function called by @acronym{GPGME} to release a data
+object. It is optional.
+@end table
+@end deftp
+
+@deftypefun GpgmeError gpgme_data_new_from_cbs (@w{GpgmeData *@var{dh}}, @w{struct GpgmeDataCbs *@var{cbs}}, @w{void *@var{handle}})
+The function @code{gpgme_data_new_from_cbs} creates a new
+@code{GpgmeData} object and uses the user-provided callback functions
+to operate on the data object.
+
+The handle @var{handle} is passed as first argument to the callback
+functions. This can be used to identify this data object.
+
+The function returns @code{GPGME_No_Error} if the data object was
+successfully created, and @code{GPGME_Out_Of_Core} if not enough
+memory is available.
+@end deftypefun
+
+The following interface is deprecated and only provided for backward
+compatibility. Don't use it. It will be removed in a future version
+of @acronym{GPGME}.
+
@deftypefun GpgmeError gpgme_data_new_with_read_cb (@w{GpgmeData *@var{dh}}, @w{int (*@var{readfunc})} (@w{void *@var{hook}}, @w{char *@var{buffer}}, @w{size_t @var{count}}, @w{size_t *@var{nread}}), @w{void *@var{hook_value}})
The function @code{gpgme_data_new_with_read_cb} creates a new
@code{GpgmeData} object and uses the callback function @var{readfunc}
@section Manipulating Data Buffers
@cindex data buffere, manipulation
-@deftypefun GpgmeError gpgme_data_read (@w{GpgmeData @var{dh}}, @w{void *@var{buffer}}, @w{size_t @var{length}}, @w{size_t *@var{nread}})
+@deftypefun ssize_t gpgme_data_read (@w{GpgmeData @var{dh}}, @w{void *@var{buffer}}, @w{size_t @var{length}})
The function @code{gpgme_data_read} reads up to @var{length} bytes
from the data object with the handle @var{dh} into the space starting
-at @var{buffer}. The actual amount read is returned in @var{nread}.
+at @var{buffer}.
-If @var{buffer} is @code{NULL}, the function returns the amount of
-bytes available in @var{nread} without changing the read pointer.
-This is not supported by all types of data objects. If this function
-is not supported, @code{GPGME_Invalid_Type} is returned.
+If no error occurs, the actual amount read is returned. If the end of
+the data object is reached, the function returns @code{GPGME_EOF} and
+sets @var{nread} to zero.
-If the end of the data object is reached, the function returns
-@code{GPGME_EOF} and sets @var{nread} to zero.
-
-In all other cases, the function returns @code{GPGME_No_Error} if the
-operation was successfully performed and @code{GPGME_Invalid_Value} if
-@var{dh} is not a valid pointer.
-@end deftypefun
-
-@deftypefun GpgmeError gpgme_data_rewind (@w{GpgmeData @var{dh}})
-The function @code{gpgme_data_rewind} resets the read pointer of the
-data object with the handle @var{dh}, so that a subsequent
-@code{gpgme_data_read} operation starts at the beginning of the data.
-
-The function returns @code{GPGME_No_Error} if the operation was
-successfully performed, @code{GPGME_Not_Implemented} if the operation
-is not supported (for example, by a read callback function supplied by
-the user) and @code{GPGME_Invalid_Value} if @var{dh} is not a valid
-pointer.
+In all other cases, the function returns -1 and sets @var{errno}.
@end deftypefun
-@deftypefun GpgmeError gpgme_data_write (@w{GpgmeData @var{dh}}, @w{const void *@var{buffer}}, @w{size_t @var{length}})
-The function @code{gpgme_data_write} writes @var{length} bytes
+@deftypefun ssize_t gpgme_data_write (@w{GpgmeData @var{dh}}, @w{const void *@var{buffer}}, @w{size_t @var{size}})
+The function @code{gpgme_data_write} writes up to @var{size} bytes
starting from @var{buffer} into the data object with the handle
@var{dh} at the current write position.
-The function returns @code{GPGME_No_Error} if the operation was
-successfully performed, @code{GPGME_Invalid_Value} if @var{dh} or
-@var{buffer} is not a valid pointer, @code{GPGME_Invalid_Type} or
-@code{GPGME_Invalid_Mode} if the data object type does not support
-writing, and @code{GPGME_Out_Of_Core} if not enough memory is
-available.
+The function returns the number of bytes actually written, or -1 if an
+error occurs. If an error occurs, @var{errno} is set.
@end deftypefun
-@c
-@c GpgmeDataType
-@c
-@deftp {Data type} {enum GpgmeDataType}
-@tindex GpgmeDataType
-The @code{GpgmeDataType} type specifies the type of a @code{GpgmeData} object.
-The following data types are available:
+/* Set the current position from where the next read or write starts
+ in the data object with the handle DH to OFFSET, relativ to
+ WHENCE. */
+off_t gpgme_data_seek (GpgmeData dh, off_t offset, int whence);
+
+@deftypefun off_t gpgme_data_seek (@w{GpgmeData @var{dh}}, @w{off_t *@var{offset}}, @w{int @var{whence}})
+The function @code{gpgme_data_seek} changes the current read/write
+position.
+
+The @var{whence} argument specifies how the @var{offset} should be
+interpreted. It must be one of the following symbolic constants:
@table @code
-@item GPGME_DATA_TYPE_NONE
-This specifies that the type is not yet determined.
+@item SEEK_SET
+Specifies that @var{whence} is a count of characters from the
+beginning of the data object.
+
+@item SEEK_CUR
+Specifies that @var{whence} is a count of characters from the current
+file position. This count may be positive or negative.
+
+@item SEEK_END
+Specifies that @var{whence} is a count of characters from the end of
+the data object. A negative count specifies a position within the
+current extent of the data object; a positive count specifies a
+position past the current end. If you set the position past the
+current end, and actually write data, you will extend the data object
+with zeros up to that position.
+@end table
-@item GPGME_DATA_TYPE_MEM
-This specifies that the data is stored in memory.
+If successful, the function returns the resulting file position,
+measured in bytes from the beginning of the data object. You can use
+this feature together with @code{SEEK_CUR} to read the current
+read/write position.
-@item GPGME_DATA_TYPE_FD
-This type is not implemented.
+If the function fails, -1 is returned and @var{errno} is set.
+@end deftypefun
-@item GPGME_DATA_TYPE_FILE
-This type is not implemented.
+The following function is deprecated and should not be used. It will
+be removed in a future version of @acronym{GPGME}.
-@item GPGME_DATA_TYPE_CB
-This type specifies that the data is provided by a callback function
-implemented by the user.
-@end table
-@end deftp
+@deftypefun GpgmeError gpgme_data_rewind (@w{GpgmeData @var{dh}})
+The function @code{gpgme_data_rewind} is equivalent to:
-@deftypefun GpgmeDataType gpgme_data_get_type (@w{GpgmeData @var{dh}})
-The function @code{gpgme_data_get_type} returns the type of the data
-object with the handle @var{dh}. If @var{dh} is not a valid pointer,
-@code{GPGME_DATA_TYPE_NONE} is returned.
+@example
+ return (gpgme_data_seek (dh, 0, SEEK_SET) == -1)
+ ? mk_error (File_Error) : 0;
+@end example
@end deftypefun
@c
+2002-12-06 Marcus Brinkmann <marcus@g10code.de>
+
+ * data.h (gpgme_data_release_cb): Change return type to void.
+ (gpgme_data_read_cb): Change return type to ssize_t.
+ * data.c (gpgme_data_read): Likewise.
+ * data-stream.c (stream_read): Likewise.
+ * data-fd.c (fd_read): Likewise.
+ * data-mem.c (mem_read): Likewise.
+ (mem_release): Change return type to void.
+ * data-user.c (user_read): Change return type to ssize_t.
+ (user_release): Change return type to void.
+ * data-compat.c (old_user_read): Change return type to ssize_t.
+ * gpgme.h (GpgmeDataReadCb): Likewise.
+ (gpgme_data_read): Likewise.
+ (GpgmeDataSeekCb): Change return type to off_t.
+
2002-12-04 Marcus Brinkmann <marcus@g10code.de>
* gpgme.h: Add prototype for gpgme_get_key.
-/* data-mem.c - A memory based data object.
- * Copyright (C) 2002 g10 Code GmbH
- *
- * This file is part of GPGME.
- *
- * GPGME is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * GPGME is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- */
+/* data-compat.c - Compatibility interfaces for data objects.
+ Copyright (C) 2002 g10 Code GmbH
+
+ This file is part of GPGME.
+
+ GPGME is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ GPGME is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with GPGME; if not, write to the Free Software Foundation,
+ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#if HAVE_CONFIG_H
#include <config.h>
}
}
-static int
+static ssize_t
old_user_read (GpgmeData dh, void *buffer, size_t size)
{
size_t amt;
/* data-fd.c - A file descripor based data object.
- * Copyright (C) 2002 g10 Code GmbH
- *
- * This file is part of GPGME.
- *
- * GPGME is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * GPGME is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- */
+ Copyright (C) 2002 g10 Code GmbH
+
+ This file is part of GPGME.
+
+ GPGME is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ GPGME is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with GPGME; if not, write to the Free Software Foundation,
+ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#if HAVE_CONFIG_H
#include <config.h>
#include "data.h"
\f
-static int
+static ssize_t
fd_read (GpgmeData dh, void *buffer, size_t size)
{
return read (dh->data.fd, buffer, size);
/* data-mem.c - A memory based data object.
- * Copyright (C) 2002 g10 Code GmbH
- *
- * This file is part of GPGME.
- *
- * GPGME is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * GPGME is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- */
+ Copyright (C) 2002 g10 Code GmbH
+
+ This file is part of GPGME.
+
+ GPGME is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ GPGME is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with GPGME; if not, write to the Free Software Foundation,
+ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#if HAVE_CONFIG_H
#include <config.h>
#include "util.h"
\f
-static int
+static ssize_t
mem_read (GpgmeData dh, void *buffer, size_t size)
{
size_t amt = dh->data.mem.length - dh->data.mem.offset;
}
-static int
+static void
mem_release (GpgmeData dh)
{
if (dh->data.mem.buffer)
-/* data-stream.c - A memory based data object.
- * Copyright (C) 2002 g10 Code GmbH
- *
- * This file is part of GPGME.
- *
- * GPGME is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * GPGME is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- */
+/* data-stream.c - A stream based data object.
+ Copyright (C) 2002 g10 Code GmbH
+
+ This file is part of GPGME.
+
+ GPGME is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ GPGME is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with GPGME; if not, write to the Free Software Foundation,
+ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#if HAVE_CONFIG_H
#include <config.h>
#include "data.h"
\f
-static int
+static ssize_t
stream_read (GpgmeData dh, void *buffer, size_t size)
{
size_t amt = fread (buffer, 1, size, dh->data.stream);
/* data-user.c - A user callback based data object.
- * Copyright (C) 2002 g10 Code GmbH
- *
- * This file is part of GPGME.
- *
- * GPGME is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * GPGME is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- */
+ Copyright (C) 2002 g10 Code GmbH
+
+ This file is part of GPGME.
+
+ GPGME is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ GPGME is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with GPGME; if not, write to the Free Software Foundation,
+ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#if HAVE_CONFIG_H
#include <config.h>
#include "data.h"
\f
-static int
+static ssize_t
user_read (GpgmeData dh, void *buffer, size_t size)
{
return (*dh->data.user.cbs->read) (dh->data.user.handle, buffer, size);
}
-static int
+static void
user_release (GpgmeData dh)
{
(*dh->data.user.cbs->release) (dh->data.user.handle);
/* Read up to SIZE bytes into buffer BUFFER from the data object with
the handle DH. Return the number of characters read, 0 on EOF and
-1 on error. If an error occurs, errno is set. */
-int
+ssize_t
gpgme_data_read (GpgmeData dh, void *buffer, size_t size)
{
if (!dh)
/* data.h - Internal data object abstraction interface.
- * Copyright (C) 2002 g10 Code GmbH
- *
- * This file is part of GPGME.
- *
- * GPGME is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * GPGME is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
- */
+ Copyright (C) 2002 g10 Code GmbH
+
+ This file is part of GPGME.
+
+ GPGME is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ GPGME is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with GPGME; if not, write to the Free Software Foundation,
+ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#ifndef DATA_H
#define DATA_H
/* Read up to SIZE bytes into buffer BUFFER from the data object with
the handle DH. Return the number of characters read, 0 on EOF and
-1 on error. If an error occurs, errno is set. */
-typedef int (*gpgme_data_read_cb) (GpgmeData dh, void *buffer, size_t size);
+typedef ssize_t (*gpgme_data_read_cb) (GpgmeData dh, void *buffer,
+ size_t size);
/* Write up to SIZE bytes from buffer BUFFER to the data object with
the handle DH. Return the number of characters written, or -1 on
typedef off_t (*gpgme_data_seek_cb) (GpgmeData dh, off_t offset, int whence);
/* Release the data object with the handle DH. */
-typedef int (*gpgme_data_release_cb) (GpgmeData dh);
+typedef void (*gpgme_data_release_cb) (GpgmeData dh);
struct gpgme_data_cbs
{
/* Read up to SIZE bytes into buffer BUFFER from the data object with
the handle HANDLE. Return the number of characters read, 0 on EOF
and -1 on error. If an error occurs, errno is set. */
-typedef int (*GpgmeDataReadCb) (void *handle, void *buffer, size_t size);
+typedef ssize_t (*GpgmeDataReadCb) (void *handle, void *buffer, size_t size);
/* Write up to SIZE bytes from buffer BUFFER to the data object with
the handle HANDLE. Return the number of characters written, or -1
/* Set the current position from where the next read or write starts
in the data object with the handle HANDLE to OFFSET, relativ to
WHENCE. */
-typedef int (*GpgmeDataSeekCb) (void *handle, off_t offset, int whence);
+typedef off_t (*GpgmeDataSeekCb) (void *handle, off_t offset, int whence);
/* Close the data object with the handle DL. */
typedef void (*GpgmeDataReleaseCb) (void *handle);
/* Read up to SIZE bytes into buffer BUFFER from the data object with
the handle DH. Return the number of characters read, 0 on EOF and
-1 on error. If an error occurs, errno is set. */
-int gpgme_data_read (GpgmeData dh, void *buffer, size_t size);
+ssize_t gpgme_data_read (GpgmeData dh, void *buffer, size_t size);
/* Write up to SIZE bytes from buffer BUFFER to the data object with
the handle DH. Return the number of characters written, or -1 on