From d8934e21344d51731ed7806ed600de1eeb8757ab Mon Sep 17 00:00:00 2001 From: Josh Coalson Date: Sat, 10 Jul 2004 00:37:02 +0000 Subject: [PATCH] add callback.h --- include/FLAC/all.h | 1 + include/FLAC/callback.h | 168 ++++++++++++++++++++++++++++++++++++++++ include/FLAC/metadata.h | 1 + 3 files changed, 170 insertions(+) create mode 100644 include/FLAC/callback.h diff --git a/include/FLAC/all.h b/include/FLAC/all.h index d25e8717..18d3f149 100644 --- a/include/FLAC/all.h +++ b/include/FLAC/all.h @@ -35,6 +35,7 @@ #include "export.h" #include "assert.h" +#include "callback.h" #include "file_decoder.h" #include "file_encoder.h" #include "format.h" diff --git a/include/FLAC/callback.h b/include/FLAC/callback.h new file mode 100644 index 00000000..1d794a93 --- /dev/null +++ b/include/FLAC/callback.h @@ -0,0 +1,168 @@ +/* libFLAC - Free Lossless Audio Codec library + * Copyright (C) 2004 Josh Coalson + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * - Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * - Neither the name of the Xiph.org Foundation nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef FLAC__CALLBACK_H +#define FLAC__CALLBACK_H + +#ifdef HAVE_CONFIG_H +#include +#endif + +#include "ordinals.h" +#include /* for size_t */ + +/** \file include/FLAC/callback.h + * + * \brief + * This module defines the structures for describing I/O callbacks + * to the other FLAC interfaces. + * + * See the detailed documentation for callbacks in the + * \link flac_callbacks callbacks \endlink module. + */ + +/** \defgroup flac_callbacks FLAC/callback.h: I/O callback structures + * \ingroup flac + * + * \brief + * This module defines the structures for describing I/O callbacks + * to the other FLAC interfaces. + * + * The purpose of the I/O callback functions is to create a common way + * for the metadata interfaces to handle I/O. + * + * Originally the metadata interfaces required filenames as the way of + * specifying FLAC files to operate on. This is problematic in some + * environments so there is an additional option to specify a set of + * callbacks for doing I/O on the FLAC file, instead of the filename. + * + * In addition to the callbacks, a FLAC__IOHandle type is defined as an + * opaque structure for a data source. + * + * The callback function prototypes are similar (but not identical) to the + * stdio functions fread, fwrite, fseek, ftell, and fclose. If you use stdio + * streams to implement the callbacks, you can pass fread, fwrite, and fclose + * anywhere a FLAC__IOCallback_Read, FLAC__IOCallback_Write, or + * FLAC__IOCallback_Close is required, and a FILE* anywhere a FLAC__IOHandle + * is required. \warning You generally can NOT directly use fseek or ftell + * for FLAC__IOCallback_Seek or FLAC__IOCallback_Tell since on most systems + * these use 32-bit offsets and FLAC requires 64-bit offsets to deal with + * large files. You will have to find an equivalent function (e.g. ftello), + * or write a wrapper. + */ + +#ifdef __cplusplus +extern "C" { +#endif + +typedef void* FLAC__IOHandle; + +/** Signature for the read callback. + * The signature and semantics match POSIX fread() implementations + * and can generally be used interchangeably. + * + * \param ptr The address of the read buffer. + * \param size The size of the records to be read. + * \param nmemb The number of records to be read. + * \param handle The handle to the data source. + * \retval size_t + * The number of records read. + */ +typedef size_t (*FLAC__IOCallback_Read) (void *ptr, size_t size, size_t nmemb, FLAC__IOHandle handle); + +/** Signature for the write callback. + * The signature and semantics match POSIX fwrite() implementations + * and can generally be used interchangeably. + * + * \param ptr The address of the write buffer. + * \param size The size of the records to be written. + * \param nmemb The number of records to be written. + * \param handle The handle to the data source. + * \retval size_t + * The number of records written. + */ +typedef size_t (*FLAC__IOCallback_Write) (const void *ptr, size_t size, size_t nmemb, FLAC__IOHandle handle); + +/** Signature for the seek callback. + * The signature and semantics mostly match POSIX fseek() WITH ONE IMPORTANT + * EXCEPTION: the offset is a 64-bit type whereas fseek() is generally 'long' + * and 32-bits wide. + * + * \param handle The handle to the data source. + * \param offset The new position, relative to \a whence + * \param whence \c SEEK_SET, \c SEEK_CUR, or \c SEEK_END + * \retval int + * \c 0 on success, \c -1 on error. + */ +typedef int (*FLAC__IOCallback_Seek) (FLAC__IOHandle handle, FLAC__int64 offset, int whence); + +/** Signature for the tell callback. + * The signature and semantics mostly match POSIX ftell() WITH ONE IMPORTANT + * EXCEPTION: the offset is a 64-bit type whereas ftell() is generally 'long' + * and 32-bits wide. + * + * \param handle The handle to the data source. + * \retval FLAC__int64 + * The current position on success, \c -1 on error. + */ +typedef FLAC__int64 (*FLAC__IOCallback_Tell) (FLAC__IOHandle handle); + +/** Signature for the close callback. + * The signature and semantics match POSIX fclose() implementations + * and can generally be used interchangeably. + * + * \param handle The handle to the data source. + * \retval int + * \c 0 on success, \c EOF on error. + */ +typedef int (*FLAC__IOCallback_Close) (FLAC__IOHandle handle); + +/** A structure for holding a set of callbacks. + * Each FLAC interface that requires a FLAC__IOCallbacks structure will + * describe which of the callbacks are required. The ones that are not + * required may be set to NULL. + * + * If the seek requirement for an interface is optional, you can signify that + * a data sorce is not seekable by setting the \a seek field to \c NULL. + */ +typedef struct { + FLAC__IOCallback_Read read; + FLAC__IOCallback_Write write; + FLAC__IOCallback_Seek seek; + FLAC__IOCallback_Tell tell; + FLAC__IOCallback_Close close; +} FLAC__IOCallbacks; + +#ifdef __cplusplus +} +#endif + +#endif diff --git a/include/FLAC/metadata.h b/include/FLAC/metadata.h index 6345ef14..3e72c67e 100644 --- a/include/FLAC/metadata.h +++ b/include/FLAC/metadata.h @@ -33,6 +33,7 @@ #define FLAC__METADATA_H #include "export.h" +#include "callback.h" #include "format.h" /******************************************************************************