/***************************************************************************** * vlc_block_helper.h: Helper functions for data blocks management. ***************************************************************************** * Copyright (C) 2003 the VideoLAN team * $Id: 376c2b4d751d861a3cb33324834fb37e324a4eab $ * * Authors: Gildas Bazin <gbazin@netcourrier.com> * * This program 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. * * This program 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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA. *****************************************************************************/#ifndef VLC_BLOCK_HELPER_H#define VLC_BLOCK_HELPER_H 1#include <vlc_block.h>typedef struct block_bytestream_t{    block_t             *p_chain;    block_t             *p_block;    size_t              i_offset;} block_bytestream_t;/***************************************************************************** * block_bytestream_t management *****************************************************************************/static inline block_bytestream_t block_BytestreamInit( void ){    block_bytestream_t bytestream;    bytestream.i_offset = 0;    bytestream.p_chain = bytestream.p_block = NULL;    return bytestream;}static inline void block_BytestreamRelease( block_bytestream_t *p_bytestream ){    while( p_bytestream->p_chain )    {        block_t *p_next;        p_next = p_bytestream->p_chain->p_next;        p_bytestream->p_chain->pf_release( p_bytestream->p_chain );        p_bytestream->p_chain = p_next;    }    p_bytestream->i_offset = 0;    p_bytestream->p_chain = p_bytestream->p_block = NULL;}static inline void block_BytestreamFlush( block_bytestream_t *p_bytestream ){    while( p_bytestream->p_chain != p_bytestream->p_block )    {        block_t *p_next;        p_next = p_bytestream->p_chain->p_next;        p_bytestream->p_chain->pf_release( p_bytestream->p_chain );        p_bytestream->p_chain = p_next;    }    while( p_bytestream->p_block &&           (p_bytestream->p_block->i_buffer - p_bytestream->i_offset) == 0 )    {        block_t *p_next;        p_next = p_bytestream->p_chain->p_next;        p_bytestream->p_chain->pf_release( p_bytestream->p_chain );        p_bytestream->p_chain = p_bytestream->p_block = p_next;        p_bytestream->i_offset = 0;    }}static inline void block_BytestreamPush( block_bytestream_t *p_bytestream,                                         block_t *p_block ){    block_ChainAppend( &p_bytestream->p_chain, p_block );    if( !p_bytestream->p_block ) p_bytestream->p_block = p_block;}LIBVLC_USEDstatic inline block_t *block_BytestreamPop( block_bytestream_t *p_bytestream ){    block_t *p_block;    block_BytestreamFlush( p_bytestream );    p_block = p_bytestream->p_block;    if( p_block == NULL )    {        return NULL;    }    else if( !p_block->p_next )    {        p_block->p_buffer += p_bytestream->i_offset;        p_block->i_buffer -= p_bytestream->i_offset;        p_bytestream->i_offset = 0;        p_bytestream->p_chain = p_bytestream->p_block = NULL;        return p_block;    }    while( p_block->p_next && p_block->p_next->p_next )        p_block = p_block->p_next;    {        block_t *p_block_old = p_block;        p_block = p_block->p_next;        p_block_old->p_next = NULL;    }    return p_block;}static inline int block_SkipByte( block_bytestream_t *p_bytestream ){    /* Most common case first */    if( p_bytestream->p_block->i_buffer - p_bytestream->i_offset )    {        p_bytestream->i_offset++;        return VLC_SUCCESS;    }    else    {        block_t *p_block;        /* Less common case which is also slower */        for( p_block = p_bytestream->p_block->p_next;             p_block != NULL; p_block = p_block->p_next )        {            if( p_block->i_buffer )            {                p_bytestream->i_offset = 1;                p_bytestream->p_block = p_block;                return VLC_SUCCESS;            }        }    }    /* Not enough data, bail out */    return VLC_EGENERIC;}static inline int block_PeekByte( block_bytestream_t *p_bytestream,                                  uint8_t *p_data ){    /* Most common case first */    if( p_bytestream->p_block->i_buffer - p_bytestream->i_offset )    {        *p_data = p_bytestream->p_block->p_buffer[p_bytestream->i_offset];        return VLC_SUCCESS;    }    else    {        block_t *p_block;        /* Less common case which is also slower */        for( p_block = p_bytestream->p_block->p_next;             p_block != NULL; p_block = p_block->p_next )        {            if( p_block->i_buffer )            {                *p_data = p_block->p_buffer[0];                return VLC_SUCCESS;            }        }    }    /* Not enough data, bail out */    return VLC_EGENERIC;}static inline int block_GetByte( block_bytestream_t *p_bytestream,                                 uint8_t *p_data ){    /* Most common case first */    if( p_bytestream->p_block->i_buffer - p_bytestream->i_offset )    {        *p_data = p_bytestream->p_block->p_buffer[p_bytestream->i_offset];        p_bytestream->i_offset++;        return VLC_SUCCESS;    }    else    {        block_t *p_block;        /* Less common case which is also slower */        for( p_block = p_bytestream->p_block->p_next;             p_block != NULL; p_block = p_block->p_next )        {            if( p_block->i_buffer )            {                *p_data = p_block->p_buffer[0];                p_bytestream->i_offset = 1;                p_bytestream->p_block = p_block;                return VLC_SUCCESS;            }        }    }    /* Not enough data, bail out */    return VLC_EGENERIC;}static inline int block_WaitBytes( block_bytestream_t *p_bytestream,                                   size_t i_data ){    block_t *p_block;    size_t i_offset, i_copy, i_size;    /* Check we have that much data */    i_offset = p_bytestream->i_offset;    i_size = i_data;    i_copy = 0;    for( p_block = p_bytestream->p_block;         p_block != NULL; p_block = p_block->p_next )    {        i_copy = __MIN( i_size, p_block->i_buffer - i_offset );        i_size -= i_copy;        i_offset = 0;        if( !i_size ) break;    }    if( i_size )    {        /* Not enough data, bail out */        return VLC_EGENERIC;    }    return VLC_SUCCESS;}static inline int block_SkipBytes( block_bytestream_t *p_bytestream,                                   size_t i_data ){    block_t *p_block;    size_t i_offset, i_copy;    /* Check we have that much data */    i_offset = p_bytestream->i_offset;    i_copy = 0;    for( p_block = p_bytestream->p_block;         p_block != NULL; p_block = p_block->p_next )    {        i_copy = __MIN( i_data, p_block->i_buffer - i_offset );        i_data -= i_copy;        if( !i_data ) break;        i_offset = 0;    }    if( i_data )    {        /* Not enough data, bail out */        return VLC_EGENERIC;    }    p_bytestream->p_block = p_block;    p_bytestream->i_offset = i_offset + i_copy;    return VLC_SUCCESS;}static inline int block_PeekBytes( block_bytestream_t *p_bytestream,                                   uint8_t *p_data, size_t i_data ){    block_t *p_block;    size_t i_offset, i_copy, i_size;    /* Check we have that much data */    i_offset = p_bytestream->i_offset;    i_size = i_data;    i_copy = 0;    for( p_block = p_bytestream->p_block;         p_block != NULL; p_block = p_block->p_next )    {        i_copy = __MIN( i_size, p_block->i_buffer - i_offset );        i_size -= i_copy;        i_offset = 0;        if( !i_size ) break;    }    if( i_size )    {        /* Not enough data, bail out */        return VLC_EGENERIC;    }    /* Copy the data */    i_offset = p_bytestream->i_offset;    i_size = i_data;    i_copy = 0;    for( p_block = p_bytestream->p_block;         p_block != NULL; p_block = p_block->p_next )    {        i_copy = __MIN( i_size, p_block->i_buffer - i_offset );        i_size -= i_copy;        if( i_copy )        {            memcpy( p_data, p_block->p_buffer + i_offset, i_copy );            p_data += i_copy;        }        i_offset = 0;        if( !i_size ) break;    }    return VLC_SUCCESS;}static inline int block_GetBytes( block_bytestream_t *p_bytestream,                                  uint8_t *p_data, size_t i_data ){    block_t *p_block;    size_t i_offset, i_copy, i_size;    /* Check we have that much data */    i_offset = p_bytestream->i_offset;    i_size = i_data;    i_copy = 0;    for( p_block = p_bytestream->p_block;         p_block != NULL; p_block = p_block->p_next )    {        i_copy = __MIN( i_size, p_block->i_buffer - i_offset );        i_size -= i_copy;        i_offset = 0;        if( !i_size ) break;    }    if( i_size )    {        /* Not enough data, bail out */        return VLC_EGENERIC;    }    /* Copy the data */    i_offset = p_bytestream->i_offset;    i_size = i_data;    i_copy = 0;    for( p_block = p_bytestream->p_block;         p_block != NULL; p_block = p_block->p_next )    {        i_copy = __MIN( i_size, p_block->i_buffer - i_offset );        i_size -= i_copy;        if( i_copy )        {            memcpy( p_data, p_block->p_buffer + i_offset, i_copy );            p_data += i_copy;        }        if( !i_size ) break;        i_offset = 0;    }    /* No buffer given, just skip the data */    p_bytestream->p_block = p_block;    p_bytestream->i_offset = i_offset + i_copy;    return VLC_SUCCESS;}static inline int block_PeekOffsetBytes( block_bytestream_t *p_bytestream,    size_t i_peek_offset, uint8_t *p_data, size_t i_data ){    block_t *p_block;    size_t i_offset, i_copy, i_size;    /* Check we have that much data */    i_offset = p_bytestream->i_offset;    i_size = i_data + i_peek_offset;    i_copy = 0;    for( p_block = p_bytestream->p_block;         p_block != NULL; p_block = p_block->p_next )    {        i_copy = __MIN( i_size, p_block->i_buffer - i_offset );        i_size -= i_copy;        i_offset = 0;        if( !i_size ) break;    }    if( i_size )    {        /* Not enough data, bail out */        return VLC_EGENERIC;    }    /* Find the right place */    i_offset = p_bytestream->i_offset;    i_size = i_peek_offset;    i_copy = 0;    for( p_block = p_bytestream->p_block;         p_block != NULL; p_block = p_block->p_next )    {        i_copy = __MIN( i_size, p_block->i_buffer - i_offset );        i_size -= i_copy;        if( !i_size ) break;        i_offset = 0;    }    /* Copy the data */    i_offset += i_copy;    i_size = i_data;    i_copy = 0;    for( ; p_block != NULL; p_block = p_block->p_next )    {        i_copy = __MIN( i_size, p_block->i_buffer - i_offset );        i_size -= i_copy;        if( i_copy )        {            memcpy( p_data, p_block->p_buffer + i_offset, i_copy );            p_data += i_copy;        }        i_offset = 0;        if( !i_size ) break;    }    return VLC_SUCCESS;}static inline int block_FindStartcodeFromOffset(    block_bytestream_t *p_bytestream, size_t *pi_offset,    const uint8_t *p_startcode, int i_startcode_length ){    block_t *p_block, *p_block_backup = 0;    int i_size = 0;    size_t i_offset, i_offset_backup = 0;    int i_caller_offset_backup = 0, i_match;    /* Find the right place */    i_size = *pi_offset + p_bytestream->i_offset;    for( p_block = p_bytestream->p_block;         p_block != NULL; p_block = p_block->p_next )    {        i_size -= p_block->i_buffer;        if( i_size < 0 ) break;    }    if( i_size >= 0 )    {        /* Not enough data, bail out */        return VLC_EGENERIC;    }    /* Begin the search.     * We first look for an occurrence of the 1st startcode byte and     * if found, we do a more thorough check. */    i_size += p_block->i_buffer;    *pi_offset -= i_size;    i_match = 0;    for( ; p_block != NULL; p_block = p_block->p_next )    {        for( i_offset = i_size; i_offset < p_block->i_buffer; i_offset++ )        {            if( p_block->p_buffer[i_offset] == p_startcode[i_match] )            {                if( !i_match )                {                    p_block_backup = p_block;                    i_offset_backup = i_offset;                    i_caller_offset_backup = *pi_offset;                }                if( i_match + 1 == i_startcode_length )                {                    /* We have it */                    *pi_offset += i_offset - i_match;                    return VLC_SUCCESS;                }                i_match++;            }            else if ( i_match )            {                /* False positive */                p_block = p_block_backup;                i_offset = i_offset_backup;                *pi_offset = i_caller_offset_backup;                i_match = 0;            }        }        i_size = 0;        *pi_offset += i_offset;    }    *pi_offset -= i_match;    return VLC_EGENERIC;}#endif /* VLC_BLOCK_HELPER_H */