39bde82ff6
That is a better decission, as it reduces the number of stat() call needed, and anyway some Streams will need the size.
110 lines
2.9 KiB
C
110 lines
2.9 KiB
C
/*
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* Copyright (c) 2007 Vreixo Formoso
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*
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* This file is part of the libisofs project; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation. See COPYING file for details.
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*/
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#ifndef LIBISO_STREAM_H_
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#define LIBISO_STREAM_H_
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/*
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* Definitions of streams.
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*/
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#include "fsource.h"
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/*
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* Some functions here will be moved to libisofs.h when we expose
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* Streams.
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*/
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typedef struct Iso_Stream IsoStream;
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struct Iso_Stream
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{
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/**
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* Opens the stream.
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*
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* TODO it would be great to return a different success code if the
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* underlying source size has changed.
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* @return
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* 1 on success, < 0 on error
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*/
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int (*open)(IsoStream *stream);
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/**
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* Close the Stream.
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* @return 1 on success, < 0 on error
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*/
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int (*close)(IsoStream *stream);
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/**
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* Get the size (in bytes) of the stream. This function should always
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* return the same size, even if the underlying source size changes.
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*/
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off_t (*get_size)(IsoStream *stream);
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/**
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* Attempts to read up to count bytes from the given stream into
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* the buffer starting at buf.
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*
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* The stream must be open() before calling this, and close() when no
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* more needed.
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*
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* @return
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* number of bytes read, 0 if EOF, < 0 on error
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*/
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int (*read)(IsoStream *stream, void *buf, size_t count);
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/**
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* Whether this Stram can be read several times, with the same results.
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* For example, a regular file is repeatable, you can read it as many
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* times as you want. However, a pipe isn't.
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*
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* This function doesn't take into account if the file has been modified
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* between the two reads.
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*
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* @return
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* 1 if stream is repeatable, 0 if not, < 0 on error
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*/
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int (*is_repeatable)(IsoStream *stream);
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/**
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* Get an unique identifier for the IsoStream. If your implementation
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* is unable to return a valid identifier, this function should return
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* 0.
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*
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* @return
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* 1 on success, 0 if idenfier is not valid, < 0 error
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*/
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int (*get_id)(IsoStream *stream, unsigned int *fs_id, dev_t *dev_id,
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ino_t *ino_id);
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/**
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* Free implementation specific data. Should never be called by user.
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* Use iso_stream_unref() instead.
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*/
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void (*free)(IsoStream *stream);
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int refcount;
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void *data;
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};
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void iso_stream_ref(IsoStream *stream);
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void iso_stream_unref(IsoStream *stream);
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/**
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* Create a stream to read from a IsoFileSource.
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* The stream will take the ref. to the IsoFileSource, so after a successfully
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* exectution of this function, you musn't unref() the source, unless you
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* take an extra ref.
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*
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* @return
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* 1 sucess, < 0 error
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* Possible errors:
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*
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*/
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int iso_file_source_stream_new(IsoFileSource *src, IsoStream **stream);
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#endif /*STREAM_H_*/
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