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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-09-05 13:14:37 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-09-05 13:14:37 +0000
commitfd3b2704efc2b206784615c1a23eb25501842259 (patch)
tree61ba3a8af2a0ae2ac9ec362bbf18b038f5dc0448 /include/FLAC/callback.h
parentInitial commit. (diff)
downloadflac-upstream.tar.xz
flac-upstream.zip
Adding upstream version 1.4.3+ds.upstream/1.4.3+dsupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+/* libFLAC - Free Lossless Audio Codec library
+ * Copyright (C) 2004-2009 Josh Coalson
+ * Copyright (C) 2011-2023 Xiph.Org Foundation
+ *
+ * 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
+
+#include "ordinals.h"
+#include <stdlib.h> /* 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, feof, 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 CANNOT 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. The same is true for feof() since this is usually
+ * implemented as a macro, not as a function whose address can be taken.
+ *
+ * \{
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** This is the opaque handle type used by the callbacks. Typically
+ * this is a \c FILE* or address of a file descriptor.
+ */
+typedef void* FLAC__IOHandle;
+
+/** Signature for the read callback.
+ * The signature and semantics match POSIX fread() implementations
+ * and can generally be used interchangeably. Note that the global
+ * variable errno from errno.h is read by some libFLAC functions to
+ * detect read errors.
+ *
+ * \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 EOF callback.
+ * The signature and semantics mostly match POSIX feof() but WATCHOUT:
+ * on many systems, feof() is a macro, so in this case a wrapper function
+ * must be provided instead.
+ *
+ * \param handle The handle to the data source.
+ * \retval int
+ * \c 0 if not at end of file, nonzero if at end of file.
+ */
+typedef int (*FLAC__IOCallback_Eof) (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 source is not seekable by setting the \a seek field to \c NULL.
+ *
+ * See the detailed documentation for callbacks in the
+ * \link flac_callbacks callbacks \endlink module.
+ */
+typedef struct {
+ FLAC__IOCallback_Read read; /**< See FLAC__IOCallbacks */
+ FLAC__IOCallback_Write write; /**< See FLAC__IOCallbacks */
+ FLAC__IOCallback_Seek seek; /**< See FLAC__IOCallbacks */
+ FLAC__IOCallback_Tell tell; /**< See FLAC__IOCallbacks */
+ FLAC__IOCallback_Eof eof; /**< See FLAC__IOCallbacks */
+ FLAC__IOCallback_Close close; /**< See FLAC__IOCallbacks */
+} FLAC__IOCallbacks;
+
+/* \} */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif