/OpenCV_231/opencv2_core/persistence.cpp

/*M///////////////////////////////////////////////////////////////////////////////////////
//
//  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
//
//  By downloading, copying, installing or using the software you agree to this license.
//  If you do not agree to this license, do not download, install,
//  copy or use the software.
//
//
//                           License Agreement
//                For Open Source Computer Vision Library
//
// Copyright (C) 2000-2008, Intel Corporation, all rights reserved.
// Copyright (C) 2009, Willow Garage Inc., all rights reserved.
// Third party copyrights are property of their respective owners.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
//
//   * Redistribution's of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
//
//   * Redistribution's 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.
//
//   * The name of the copyright holders may not 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 Intel Corporation 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.
//
//M*/

#include "precomp.hpp"
#include <ctype.h>
#include <wchar.h>
#include <zlib.h>

/****************************************************************************************\
*                            Common macros and type definitions                          *
\****************************************************************************************/

#define cv_isprint(c)     ((uchar)(c) >= (uchar)' ')
#define cv_isprint_or_tab(c)  ((uchar)(c) >= (uchar)' ' || (c) == '\t')

static inline bool cv_isalnum(char c)
{
    return ('0' <= c && c <= '9') || ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z');
}

static inline bool cv_isalpha(char c)
{
    return ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z');
}

static inline bool cv_isdigit(char c)
{
    return '0' <= c && c <= '9';
}

static inline bool cv_isspace(char c)
{
    return (9 <= c && c <= 13) || c == ' ';
}

static char* icv_itoa( int _val, char* buffer, int /*radix*/ )
{
    const int radix = 10;
    char* ptr=buffer + 23 /* enough even for 64-bit integers */;
    unsigned val = abs(_val);

    *ptr = '\0';
    do
    {
        unsigned r = val / radix;
        *--ptr = (char)(val - (r*radix) + '0');
        val = r;
    }
    while( val != 0 );

    if( _val < 0 )
        *--ptr = '-';

    return ptr;
}

cv::string cv::FileStorage::getDefaultObjectName(const string& _filename)
{
    static const char* stubname = "unnamed";
    const char* filename = _filename.c_str();
    const char* ptr2 = filename + _filename.size();
    const char* ptr = ptr2 - 1;
    cv::AutoBuffer<char> name_buf(_filename.size()+1);

    while( ptr >= filename && *ptr != '\\' && *ptr != '/' && *ptr != ':' )
    {
        if( *ptr == '.' && (!*ptr2 || strncmp(ptr2, ".gz", 3) == 0) )
            ptr2 = ptr;
        ptr--;
    }
    ptr++;
    if( ptr == ptr2 )
        CV_Error( CV_StsBadArg, "Invalid filename" );

    char* name = name_buf;

    // name must start with letter or '_'
    if( !cv_isalpha(*ptr) && *ptr!= '_' ){
        *name++ = '_';
    }

    while( ptr < ptr2 )
    {
        char c = *ptr++;
        if( !cv_isalnum(c) && c != '-' && c != '_' )
            c = '_';
        *name++ = c;
    }
    *name = '\0';
    name = name_buf;
    if( strcmp( name, "_" ) == 0 )
        strcpy( name, stubname );
    return cv::string(name);
}

namespace cv
{
#ifndef ANDROID //unsuported wcstombs on android
string fromUtf16(const WString& str)
{
    cv::AutoBuffer<char> _buf(str.size()*4 + 1);
    char* buf = _buf;
        
    size_t sz = wcstombs(buf, str.c_str(), str.size());
    if( sz == (size_t)-1 )
        return string();
    buf[sz] = '\0';
    return string(buf);
}

WString toUtf16(const string& str)
{
    cv::AutoBuffer<wchar_t> _buf(str.size() + 1);
    wchar_t* buf = _buf;
        
    size_t sz = mbstowcs(buf, str.c_str(), str.size());
    if( sz == (size_t)-1 )
        return WString();
    buf[sz] = '\0';
    return WString(buf);
}
#endif
}

typedef struct CvGenericHash
{
    CV_SET_FIELDS()
    int tab_size;
    void** table;
}
CvGenericHash;

typedef CvGenericHash CvStringHash;

typedef struct CvFileMapNode
{
    CvFileNode value;
    const CvStringHashNode* key;
    struct CvFileMapNode* next;
}
CvFileMapNode;

typedef struct CvXMLStackRecord
{
    CvMemStoragePos pos;
    CvString struct_tag;
    int struct_indent;
    int struct_flags;
}
CvXMLStackRecord;

#define CV_XML_OPENING_TAG 1
#define CV_XML_CLOSING_TAG 2
#define CV_XML_EMPTY_TAG 3
#define CV_XML_HEADER_TAG 4
#define CV_XML_DIRECTIVE_TAG 5

//typedef void (*CvParse)( struct CvFileStorage* fs );
typedef void (*CvStartWriteStruct)( struct CvFileStorage* fs, const char* key,
                                    int struct_flags, const char* type_name );
typedef void (*CvEndWriteStruct)( struct CvFileStorage* fs );
typedef void (*CvWriteInt)( struct CvFileStorage* fs, const char* key, int value );
typedef void (*CvWriteReal)( struct CvFileStorage* fs, const char* key, double value );
typedef void (*CvWriteString)( struct CvFileStorage* fs, const char* key,
                               const char* value, int quote );
typedef void (*CvWriteComment)( struct CvFileStorage* fs, const char* comment, int eol_comment );
typedef void (*CvStartNextStream)( struct CvFileStorage* fs );

typedef struct CvFileStorage
{
    int flags;
    int is_xml;
    int write_mode;
    int is_first;
    CvMemStorage* memstorage;
    CvMemStorage* dststorage;
    CvMemStorage* strstorage;
    CvStringHash* str_hash;
    CvSeq* roots;
    CvSeq* write_stack;
    int struct_indent;
    int struct_flags;
    CvString struct_tag;
    int space;
    char* filename;
    FILE* file;
    gzFile gzfile;
    char* buffer;
    char* buffer_start;
    char* buffer_end;
    int wrap_margin;
    int lineno;
    int dummy_eof;
    const char* errmsg;
    char errmsgbuf[128];

    CvStartWriteStruct start_write_struct;
    CvEndWriteStruct end_write_struct;
    CvWriteInt write_int;
    CvWriteReal write_real;
    CvWriteString write_string;
    CvWriteComment write_comment;
    CvStartNextStream start_next_stream;
    //CvParse parse;
}
CvFileStorage;

static void icvPuts( CvFileStorage* fs, const char* str )
{
    CV_Assert( fs->file || fs->gzfile );
    if( fs->file )
        fputs( str, fs->file );
    else
        gzputs( fs->gzfile, str );
}

static char* icvGets( CvFileStorage* fs, char* str, int maxCount )
{
    CV_Assert( fs->file || fs->gzfile );
    if( fs->file )
        return fgets( str, maxCount, fs->file );
    return gzgets( fs->gzfile, str, maxCount );
}

static int icvEof( CvFileStorage* fs )
{
    CV_Assert( fs->file || fs->gzfile );
    if( fs->file )
        return feof(fs->file);
    return gzeof(fs->gzfile);
}

static void icvClose( CvFileStorage* fs )
{
    if( fs->file )
        fclose( fs->file );
    if( fs->gzfile )
        gzclose( fs->gzfile );
    fs->file = 0;
    fs->gzfile = 0;
}

static void icvRewind( CvFileStorage* fs )
{
    CV_Assert( fs->file || fs->gzfile );
    if( fs->file )
        rewind(fs->file);
    else
        gzrewind(fs->gzfile);
}

#define CV_YML_INDENT  3
#define CV_XML_INDENT  2
#define CV_YML_INDENT_FLOW  1
#define CV_FS_MAX_LEN 4096

#define CV_FILE_STORAGE ('Y' + ('A' << 8) + ('M' << 16) + ('L' << 24))
#define CV_IS_FILE_STORAGE(fs) ((fs) != 0 && (fs)->flags == CV_FILE_STORAGE)

#define CV_CHECK_FILE_STORAGE(fs)                       \
{                                                       \
    if( !CV_IS_FILE_STORAGE(fs) )                       \
        CV_Error( (fs) ? CV_StsBadArg : CV_StsNullPtr,  \
                  "Invalid pointer to file storage" );  \
}

#define CV_CHECK_OUTPUT_FILE_STORAGE(fs)                \
{                                                       \
    CV_CHECK_FILE_STORAGE(fs);                          \
    if( !fs->write_mode )                               \
        CV_Error( CV_StsError, "The file storage is opened for reading" ); \
}

CV_IMPL const char*
cvAttrValue( const CvAttrList* attr, const char* attr_name )
{
    while( attr && attr->attr )
    {
        int i;
        for( i = 0; attr->attr[i*2] != 0; i++ )
        {
            if( strcmp( attr_name, attr->attr[i*2] ) == 0 )
                return attr->attr[i*2+1];
        }
        attr = attr->next;
    }

    return 0;
}


static CvGenericHash*
cvCreateMap( int flags, int header_size, int elem_size,
             CvMemStorage* storage, int start_tab_size )
{
    if( header_size < (int)sizeof(CvGenericHash) )
        CV_Error( CV_StsBadSize, "Too small map header_size" );

    if( start_tab_size <= 0 )
        start_tab_size = 16;

    CvGenericHash* map = (CvGenericHash*)cvCreateSet( flags, header_size, elem_size, storage );

    map->tab_size = start_tab_size;
    start_tab_size *= sizeof(map->table[0]);
    map->table = (void**)cvMemStorageAlloc( storage, start_tab_size );
    memset( map->table, 0, start_tab_size );

    return map;
}

#ifdef __GNUC__
#define CV_PARSE_ERROR( errmsg )                                    \
    icvParseError( fs, __func__, (errmsg), __FILE__, __LINE__ )
#else
#define CV_PARSE_ERROR( errmsg )                                    \
    icvParseError( fs, "", (errmsg), __FILE__, __LINE__ )
#endif

static void
icvParseError( CvFileStorage* fs, const char* func_name,
               const char* err_msg, const char* source_file, int source_line )
{
    char buf[1<<10];
    sprintf( buf, "%s(%d): %s", fs->filename, fs->lineno, err_msg );
    cvError( CV_StsParseError, func_name, buf, source_file, source_line );
}


static void
icvFSCreateCollection( CvFileStorage* fs, int tag, CvFileNode* collection )
{
    if( CV_NODE_IS_MAP(tag) )
    {
        if( collection->tag != CV_NODE_NONE )
        {
            assert( fs->is_xml != 0 );
            CV_PARSE_ERROR( "Sequence element should not have name (use <_></_>)" );
        }

        collection->data.map = cvCreateMap( 0, sizeof(CvFileNodeHash),
                            sizeof(CvFileMapNode), fs->memstorage, 16 );
    }
    else
    {
        CvSeq* seq;
        seq = cvCreateSeq( 0, sizeof(CvSeq), sizeof(CvFileNode), fs->memstorage );

        // if <collection> contains some scalar element, add it to the newly created collection
        if( CV_NODE_TYPE(collection->tag) != CV_NODE_NONE )
            cvSeqPush( seq, collection );

        collection->data.seq = seq;
    }

    collection->tag = tag;
    cvSetSeqBlockSize( collection->data.seq, 8 );
}


/*static void
icvFSReleaseCollection( CvSeq* seq )
{
    if( seq )
    {
        int is_map = CV_IS_SET(seq);
        CvSeqReader reader;
        int i, total = seq->total;
        cvStartReadSeq( seq, &reader, 0 );

        for( i = 0; i < total; i++ )
        {
            CvFileNode* node = (CvFileNode*)reader.ptr;

            if( (!is_map || CV_IS_SET_ELEM( node )) && CV_NODE_IS_COLLECTION(node->tag) )
            {
                if( CV_NODE_IS_USER(node->tag) && node->info && node->data.obj.decoded )
                    cvRelease( (void**)&node->data.obj.decoded );
                if( !CV_NODE_SEQ_IS_SIMPLE( node->data.seq ))
                    icvFSReleaseCollection( node->data.seq );
            }
            CV_NEXT_SEQ_ELEM( seq->elem_size, reader );
        }
    }
}*/


static char*
icvFSDoResize( CvFileStorage* fs, char* ptr, int len )
{
    char* new_ptr = 0;
    int written_len = (int)(ptr - fs->buffer_start);
    int new_size = (int)((fs->buffer_end - fs->buffer_start)*3/2);
    new_size = MAX( written_len + len, new_size );
    new_ptr = (char*)cvAlloc( new_size + 256 );
    fs->buffer = new_ptr + (fs->buffer - fs->buffer_start);
    if( written_len > 0 )
        memcpy( new_ptr, fs->buffer_start, written_len );
    fs->buffer_start = new_ptr;
    fs->buffer_end = fs->buffer_start + new_size;
    new_ptr += written_len;
    return new_ptr;
}


inline char* icvFSResizeWriteBuffer( CvFileStorage* fs, char* ptr, int len )
{
    return ptr + len < fs->buffer_end ? ptr : icvFSDoResize( fs, ptr, len );
}


static char*
icvFSFlush( CvFileStorage* fs )
{
    char* ptr = fs->buffer;
    int indent;

    if( ptr > fs->buffer_start + fs->space )
    {
        ptr[0] = '\n';
        ptr[1] = '\0';
        icvPuts( fs, fs->buffer_start );
        fs->buffer = fs->buffer_start;
    }

    indent = fs->struct_indent;

    if( fs->space != indent )
    {
        if( fs->space < indent )
            memset( fs->buffer_start + fs->space, ' ', indent - fs->space );
        fs->space = indent;
    }

    ptr = fs->buffer = fs->buffer_start + fs->space;

    return ptr;
}


/* closes file storage and deallocates buffers */
CV_IMPL  void
cvReleaseFileStorage( CvFileStorage** p_fs )
{
    if( !p_fs )
        CV_Error( CV_StsNullPtr, "NULL double pointer to file storage" );

    if( *p_fs )
    {
        CvFileStorage* fs = *p_fs;
        *p_fs = 0;

        if( fs->write_mode && (fs->file || fs->gzfile) )
        {
            if( fs->write_stack )
            {
                while( fs->write_stack->total > 0 )
                    cvEndWriteStruct(fs);
            }
            icvFSFlush(fs);
            if( fs->is_xml )
                icvPuts( fs, "</opencv_storage>\n" );
        }

        //icvFSReleaseCollection( fs->roots ); // delete all the user types recursively

        icvClose(fs);

        cvReleaseMemStorage( &fs->strstorage );

        cvFree( &fs->buffer_start );
        cvReleaseMemStorage( &fs->memstorage );

        memset( fs, 0, sizeof(*fs) );
        cvFree( &fs );
    }
}


#define CV_HASHVAL_SCALE 33

CV_IMPL CvStringHashNode*
cvGetHashedKey( CvFileStorage* fs, const char* str, int len, int create_missing )
{
    CvStringHashNode* node = 0;
    unsigned hashval = 0;
    int i, tab_size;
    CvStringHash* map = fs->str_hash;

    if( !fs )
        return 0;

    if( len < 0 )
    {
        for( i = 0; str[i] != '\0'; i++ )
            hashval = hashval*CV_HASHVAL_SCALE + (unsigned char)str[i];
        len = i;
    }
    else for( i = 0; i < len; i++ )
        hashval = hashval*CV_HASHVAL_SCALE + (unsigned char)str[i];

    hashval &= INT_MAX;
    tab_size = map->tab_size;
    if( (tab_size & (tab_size - 1)) == 0 )
        i = (int)(hashval & (tab_size - 1));
    else
        i = (int)(hashval % tab_size);

    for( node = (CvStringHashNode*)(map->table[i]); node != 0; node = node->next )
    {
        if( node->hashval == hashval &&
            node->str.len == len &&
            memcmp( node->str.ptr, str, len ) == 0 )
            break;
    }

    if( !node && create_missing )
    {
        node = (CvStringHashNode*)cvSetNew( (CvSet*)map );
        node->hashval = hashval;
        node->str = cvMemStorageAllocString( map->storage, str, len );
        node->next = (CvStringHashNode*)(map->table[i]);
        map->table[i] = node;
    }

    return node;
}


CV_IMPL CvFileNode*
cvGetFileNode( CvFileStorage* fs, CvFileNode* _map_node,
               const CvStringHashNode* key,
               int create_missing )
{
    CvFileNode* value = 0;
    int k = 0, attempts = 1;

    if( !fs )
        return 0;

    CV_CHECK_FILE_STORAGE(fs);

    if( !key )
        CV_Error( CV_StsNullPtr, "Null key element" );

    if( _map_node )
    {
        if( !fs->roots )
            return 0;
        attempts = fs->roots->total;
    }

    for( k = 0; k < attempts; k++ )
    {
        int i, tab_size;
        CvFileNode* map_node = _map_node;
        CvFileMapNode* another;
        CvFileNodeHash* map;

        if( !map_node )
            map_node = (CvFileNode*)cvGetSeqElem( fs->roots, k );

        if( !CV_NODE_IS_MAP(map_node->tag) )
        {
            if( (!CV_NODE_IS_SEQ(map_node->tag) || map_node->data.seq->total != 0) &&
                CV_NODE_TYPE(map_node->tag) != CV_NODE_NONE )
                CV_Error( CV_StsError, "The node is neither a map nor an empty collection" );
            return 0;
        }

        map = map_node->data.map;
        tab_size = map->tab_size;

        if( (tab_size & (tab_size - 1)) == 0 )
            i = (int)(key->hashval & (tab_size - 1));
        else
            i = (int)(key->hashval % tab_size);

        for( another = (CvFileMapNode*)(map->table[i]); another != 0; another = another->next )
            if( another->key == key )
            {
                if( !create_missing )
                {
                    value = &another->value;
                    return value;
                }
                CV_PARSE_ERROR( "Duplicated key" );
            }

        if( k == attempts - 1 && create_missing )
        {
            CvFileMapNode* node = (CvFileMapNode*)cvSetNew( (CvSet*)map );
            node->key = key;

            node->next = (CvFileMapNode*)(map->table[i]);
            map->table[i] = node;
            value = (CvFileNode*)node;
        }
    }

    return value;
}


CV_IMPL CvFileNode*
cvGetFileNodeByName( const CvFileStorage* fs, const CvFileNode* _map_node, const char* str )
{
    CvFileNode* value = 0;
    int i, len, tab_size;
    unsigned hashval = 0;
    int k = 0, attempts = 1;

    if( !fs )
        return 0;

    CV_CHECK_FILE_STORAGE(fs);

    if( !str )
        CV_Error( CV_StsNullPtr, "Null element name" );

    for( i = 0; str[i] != '\0'; i++ )
        hashval = hashval*CV_HASHVAL_SCALE + (unsigned char)str[i];
    hashval &= INT_MAX;
    len = i;

    if( !_map_node )
    {
        if( !fs->roots )
            return 0;
        attempts = fs->roots->total;
    }

    for( k = 0; k < attempts; k++ )
    {
        CvFileNodeHash* map;
        const CvFileNode* map_node = _map_node;
        CvFileMapNode* another;

        if( !map_node )
            map_node = (CvFileNode*)cvGetSeqElem( fs->roots, k );

        if( !CV_NODE_IS_MAP(map_node->tag) )
        {
            if( (!CV_NODE_IS_SEQ(map_node->tag) || map_node->data.seq->total != 0) &&
                CV_NODE_TYPE(map_node->tag) != CV_NODE_NONE )
                CV_Error( CV_StsError, "The node is neither a map nor an empty collection" );
            return 0;
        }

        map = map_node->data.map;
        tab_size = map->tab_size;

        if( (tab_size & (tab_size - 1)) == 0 )
            i = (int)(hashval & (tab_size - 1));
        else
            i = (int)(hashval % tab_size);

        for( another = (CvFileMapNode*)(map->table[i]); another != 0; another = another->next )
        {
            const CvStringHashNode* key = another->key;

            if( key->hashval == hashval &&
                key->str.len == len &&
                memcmp( key->str.ptr, str, len ) == 0 )
            {
                value = &another->value;
                return value;
            }
        }
    }

    return value;
}


CV_IMPL CvFileNode*
cvGetRootFileNode( const CvFileStorage* fs, int stream_index )
{
    CV_CHECK_FILE_STORAGE(fs);

    if( !fs->roots || (unsigned)stream_index >= (unsigned)fs->roots->total )
        return 0;

    return (CvFileNode*)cvGetSeqElem( fs->roots, stream_index );
}


/* returns the sequence element by its index */
/*CV_IMPL CvFileNode*
cvGetFileNodeFromSeq( CvFileStorage* fs,
                      CvFileNode* seq_node, int index )
{
    CvFileNode* value = 0;
    CvSeq* seq;

    if( !seq_node )
        seq = fs->roots;
    else if( !CV_NODE_IS_SEQ(seq_node->tag) )
    {
        if( CV_NODE_IS_MAP(seq_node->tag) )
            CV_Error( CV_StsError, "The node is map. Use cvGetFileNodeFromMap()." );
        if( CV_NODE_TYPE(seq_node->tag) == CV_NODE_NONE )
            CV_Error( CV_StsError, "The node is an empty object (None)." );
        if( index != 0 && index != -1 )
            CV_Error( CV_StsOutOfRange, "" );
        value = seq_node;
        EXIT;
    }
    else
        seq = seq_node->data.seq;

    if( !seq )
        CV_Error( CV_StsNullPtr, "The file storage is empty" );

    value = (CvFileNode*)cvGetSeqElem( seq, index, 0 );

    

    return value;
}*/


static char*
icvDoubleToString( char* buf, double value )
{
    Cv64suf val;
    unsigned ieee754_hi;

    val.f = value;
    ieee754_hi = (unsigned)(val.u >> 32);

    if( (ieee754_hi & 0x7ff00000) != 0x7ff00000 )
    {
        int ivalue = cvRound(value);
        if( ivalue == value )
            sprintf( buf, "%d.", ivalue );
        else
        {
            static const char* fmt = "%.16e";
            char* ptr = buf;
            sprintf( buf, fmt, value );
            if( *ptr == '+' || *ptr == '-' )
                ptr++;
            for( ; cv_isdigit(*ptr); ptr++ )
                ;
            if( *ptr == ',' )
                *ptr = '.';
        }
    }
    else
    {
        unsigned ieee754_lo = (unsigned)val.u;
        if( (ieee754_hi & 0x7fffffff) + (ieee754_lo != 0) > 0x7ff00000 )
            strcpy( buf, ".Nan" );
        else
            strcpy( buf, (int)ieee754_hi < 0 ? "-.Inf" : ".Inf" );
    }

    return buf;
}


static char*
icvFloatToString( char* buf, float value )
{
    Cv32suf val;
    unsigned ieee754;
    val.f = value;
    ieee754 = val.u;

    if( (ieee754 & 0x7f800000) != 0x7f800000 )
    {
        int ivalue = cvRound(value);
        if( ivalue == value )
            sprintf( buf, "%d.", ivalue );
        else
        {
            static const char* fmt = "%.8e";
            char* ptr = buf;
            sprintf( buf, fmt, value );
            if( *ptr == '+' || *ptr == '-' )
                ptr++;
            for( ; cv_isdigit(*ptr); ptr++ )
                ;
            if( *ptr == ',' )
                *ptr = '.';
        }
    }
    else
    {
        if( (ieee754 & 0x7fffffff) != 0x7f800000 )
            strcpy( buf, ".Nan" );
        else
            strcpy( buf, (int)ieee754 < 0 ? "-.Inf" : ".Inf" );
    }

    return buf;
}


static void
icvProcessSpecialDouble( CvFileStorage* fs, char* buf, double* value, char** endptr )
{
    char c = buf[0];
    int inf_hi = 0x7ff00000;

    if( c == '-' || c == '+' )
    {
        inf_hi = c == '-' ? 0xfff00000 : 0x7ff00000;
        c = *++buf;
    }

    if( c != '.' )
        CV_PARSE_ERROR( "Bad format of floating-point constant" );

    if( toupper(buf[1]) == 'I' && toupper(buf[2]) == 'N' && toupper(buf[3]) == 'F' )
        *(uint64*)value = ((uint64)inf_hi << 32);
    else if( toupper(buf[1]) == 'N' && toupper(buf[2]) == 'A' && toupper(buf[3]) == 'N' )
        *(uint64*)value = (uint64)-1;
    else
        CV_PARSE_ERROR( "Bad format of floating-point constant" );

    *endptr = buf + 4;
}


static double icv_strtod( CvFileStorage* fs, char* ptr, char** endptr )
{
    double fval = strtod( ptr, endptr );
    if( **endptr == '.' )
    {
        char* dot_pos = *endptr;
        *dot_pos = ',';
        double fval2 = strtod( ptr, endptr );
        *dot_pos = '.';
        if( *endptr > dot_pos )
            fval = fval2;
        else
            *endptr = dot_pos;
    }

    if( *endptr == ptr || cv_isalpha(**endptr) )
        icvProcessSpecialDouble( fs, ptr, &fval, endptr );

    return fval;
}


/****************************************************************************************\
*                                       YAML Parser                                      *
\****************************************************************************************/

static char*
icvYMLSkipSpaces( CvFileStorage* fs, char* ptr, int min_indent, int max_comment_indent )
{
    for(;;)
    {
        while( *ptr == ' ' )
            ptr++;
        if( *ptr == '#' )
        {
            if( ptr - fs->buffer_start > max_comment_indent )
                return ptr;
            *ptr = '\0';
        }
        else if( cv_isprint(*ptr) )
        {
            if( ptr - fs->buffer_start < min_indent )
                CV_PARSE_ERROR( "Incorrect indentation" );
            break;
        }
        else if( *ptr == '\0' || *ptr == '\n' || *ptr == '\r' )
        {
            int max_size = (int)(fs->buffer_end - fs->buffer_start);
            ptr = icvGets( fs, fs->buffer_start, max_size );
            if( !ptr )
            {
                // emulate end of stream
                ptr = fs->buffer_start;
                ptr[0] = ptr[1] = ptr[2] = '.';
                ptr[3] = '\0';
                fs->dummy_eof = 1;
                break;
            }
            else
            {
                int l = (int)strlen(ptr);
                if( ptr[l-1] != '\n' && ptr[l-1] != '\r' && !icvEof(fs) )
                    CV_PARSE_ERROR( "Too long string or a last string w/o newline" );
            }

            fs->lineno++;
        }
        else
            CV_PARSE_ERROR( *ptr == '\t' ? "Tabs are prohibited in YAML!" : "Invalid character" );
    }

    return ptr;
}


static char*
icvYMLParseKey( CvFileStorage* fs, char* ptr,
                CvFileNode* map_node, CvFileNode** value_placeholder )
{
    char c;
    char *endptr = ptr - 1, *saveptr;
    CvStringHashNode* str_hash_node;

    if( *ptr == '-' )
        CV_PARSE_ERROR( "Key may not start with \'-\'" );

    do c = *++endptr;
    while( cv_isprint(c) && c != ':' );

    if( c != ':' )
        CV_PARSE_ERROR( "Missing \':\'" );

    saveptr = endptr + 1;
    do c = *--endptr;
    while( c == ' ' );

    ++endptr;
    if( endptr == ptr )
        CV_PARSE_ERROR( "An empty key" );

    str_hash_node = cvGetHashedKey( fs, ptr, (int)(endptr - ptr), 1 );
    *value_placeholder = cvGetFileNode( fs, map_node, str_hash_node, 1 );
    ptr = saveptr;

    return ptr;
}


static char*
icvYMLParseValue( CvFileStorage* fs, char* ptr, CvFileNode* node,
                  int parent_flags, int min_indent )
{
    char buf[CV_FS_MAX_LEN + 1024];
    char* endptr = 0;
    char c = ptr[0], d = ptr[1];
    int is_parent_flow = CV_NODE_IS_FLOW(parent_flags);
    int value_type = CV_NODE_NONE;
    int len;

    memset( node, 0, sizeof(*node) );

    if( c == '!' ) // handle explicit type specification
    {
        if( d == '!' || d == '^' )
        {
            ptr++;
            value_type |= CV_NODE_USER;
        }

        endptr = ptr++;
        do d = *++endptr;
        while( cv_isprint(d) && d != ' ' );
        len = (int)(endptr - ptr);
        if( len == 0 )
            CV_PARSE_ERROR( "Empty type name" );
        d = *endptr;
        *endptr = '\0';

        if( len == 3 && !CV_NODE_IS_USER(value_type) )
        {
            if( memcmp( ptr, "str", 3 ) == 0 )
                value_type = CV_NODE_STRING;
            else if( memcmp( ptr, "int", 3 ) == 0 )
                value_type = CV_NODE_INT;
            else if( memcmp( ptr, "seq", 3 ) == 0 )
                value_type = CV_NODE_SEQ;
            else if( memcmp( ptr, "map", 3 ) == 0 )
                value_type = CV_NODE_MAP;
        }
        else if( len == 5 && !CV_NODE_IS_USER(value_type) )
        {
            if( memcmp( ptr, "float", 5 ) == 0 )
                value_type = CV_NODE_REAL;
        }
        else if( CV_NODE_IS_USER(value_type) )
        {
            node->info = cvFindType( ptr );
            if( !node->info )
                node->tag &= ~CV_NODE_USER;
        }

        *endptr = d;
        ptr = icvYMLSkipSpaces( fs, endptr, min_indent, INT_MAX );

        c = *ptr;

        if( !CV_NODE_IS_USER(value_type) )
        {
            if( value_type == CV_NODE_STRING && c != '\'' && c != '\"' )
                goto force_string;
            if( value_type == CV_NODE_INT )
                goto force_int;
            if( value_type == CV_NODE_REAL )
                goto force_real;
        }
    }

    if( cv_isdigit(c) ||
        ((c == '-' || c == '+') && (cv_isdigit(d) || d == '.')) ||
        (c == '.' && cv_isalnum(d))) // a number
    {
        double fval;
        int ival;
        endptr = ptr + (c == '-' || c == '+');
        while( cv_isdigit(*endptr) )
            endptr++;
        if( *endptr == '.' || *endptr == 'e' )
        {
force_real:
            fval = icv_strtod( fs, ptr, &endptr );
            /*if( endptr == ptr || cv_isalpha(*endptr) )
                icvProcessSpecialDouble( fs, endptr, &fval, &endptr ));*/

            node->tag = CV_NODE_REAL;
            node->data.f = fval;
        }
        else
        {
force_int:
            ival = (int)strtol( ptr, &endptr, 0 );
            node->tag = CV_NODE_INT;
            node->data.i = ival;
        }

        if( !endptr || endptr == ptr )
            CV_PARSE_ERROR( "Invalid numeric value (inconsistent explicit type specification?)" );

        ptr = endptr;
    }
    else if( c == '\'' || c == '\"' ) // an explicit string
    {
        node->tag = CV_NODE_STRING;
        if( c == '\'' )
            for( len = 0; len < CV_FS_MAX_LEN; )
            {
                c = *++ptr;
                if( cv_isalnum(c) || (c != '\'' && cv_isprint(c)))
                    buf[len++] = c;
                else if( c == '\'' )
                {
                    c = *++ptr;
                    if( c != '\'' )
                        break;
                    buf[len++] = c;
                }
                else
                    CV_PARSE_ERROR( "Invalid character" );
            }
        else
            for( len = 0; len < CV_FS_MAX_LEN; )
            {
                c = *++ptr;
                if( cv_isalnum(c) || (c != '\\' && c != '\"' && cv_isprint(c)))
                    buf[len++] = c;
                else if( c == '\"' )
                {
                    ++ptr;
                    break;
                }
                else if( c == '\\' )
                {
                    d = *++ptr;
                    if( d == '\'' )
                        buf[len++] = d;
                    else if( d == '\"' || d == '\\' || d == '\'' )
                        buf[len++] = d;
                    else if( d == 'n' )
                        buf[len++] = '\n';
                    else if( d == 'r' )
                        buf[len++] = '\r';
                    else if( d == 't' )
                        buf[len++] = '\t';
                    else if( d == 'x' || (cv_isdigit(d) && d < '8') )
                    {
                        int val, is_hex = d == 'x';
                        c = ptr[3];
                        ptr[3] = '\0';
                        val = strtol( ptr + is_hex, &endptr, is_hex ? 8 : 16 );
                        ptr[3] = c;
                        if( endptr == ptr + is_hex )
                            buf[len++] = 'x';
                        else
                        {
                            buf[len++] = (char)val;
                            ptr = endptr;
                        }
                    }
                }
                else
                    CV_PARSE_ERROR( "Invalid character" );
            }

        if( len >= CV_FS_MAX_LEN )
            CV_PARSE_ERROR( "Too long string literal" );

        node->data.str = cvMemStorageAllocString( fs->memstorage, buf, len );
    }
    else if( c == '[' || c == '{' ) // collection as a flow
    {
        int new_min_indent = min_indent + !is_parent_flow;
        int struct_flags = CV_NODE_FLOW + (c == '{' ? CV_NODE_MAP : CV_NODE_SEQ);
        int is_simple = 1;

        icvFSCreateCollection( fs, CV_NODE_TYPE(struct_flags) +
                                        (node->info ? CV_NODE_USER : 0), node );

        d = c == '[' ? ']' : '}';

        for( ++ptr ;;)
        {
            CvFileNode* elem = 0;

            ptr = icvYMLSkipSpaces( fs, ptr, new_min_indent, INT_MAX );
            if( *ptr == '}' || *ptr == ']' )
            {
                if( *ptr != d )
                    CV_PARSE_ERROR( "The wrong closing bracket" );
                ptr++;
                break;
            }

            if( node->data.seq->total != 0 )
            {
                if( *ptr != ',' )
                    CV_PARSE_ERROR( "Missing , between the elements" );
                ptr = icvYMLSkipSpaces( fs, ptr + 1, new_min_indent, INT_MAX );
            }

            if( CV_NODE_IS_MAP(struct_flags) )
            {
                ptr = icvYMLParseKey( fs, ptr, node, &elem );
                ptr = icvYMLSkipSpaces( fs, ptr, new_min_indent, INT_MAX );
            }
            else
            {
                if( *ptr == ']' )
                    break;
                elem = (CvFileNode*)cvSeqPush( node->data.seq, 0 );
            }
            ptr = icvYMLParseValue( fs, ptr, elem, struct_flags, new_min_indent );
            if( CV_NODE_IS_MAP(struct_flags) )
                elem->tag |= CV_NODE_NAMED;
            is_simple &= !CV_NODE_IS_COLLECTION(elem->tag);
        }
        node->data.seq->flags |= is_simple ? CV_NODE_SEQ_SIMPLE : 0;
    }
    else
    {
        int indent, struct_flags, is_simple;

        if( is_parent_flow || c != '-' )
        {
            // implicit (one-line) string or nested block-style collection
            if( !is_parent_flow )
            {
                if( c == '?' )
                    CV_PARSE_ERROR( "Complex keys are not supported" );
                if( c == '|' || c == '>' )
                    CV_PARSE_ERROR( "Multi-line text literals are not supported" );
            }

force_string:
            endptr = ptr - 1;

            do c = *++endptr;
            while( cv_isprint(c) &&
                   (!is_parent_flow || (c != ',' && c != '}' && c != ']')) &&
                   (is_parent_flow || c != ':' || value_type == CV_NODE_STRING));

            if( endptr == ptr )
                CV_PARSE_ERROR( "Invalid character" );

            if( is_parent_flow || c != ':' )
            {
                char* str_end = endptr;
                node->tag = CV_NODE_STRING;
                // strip spaces in the end of string
                do c = *--str_end;
                while( str_end > ptr && c == ' ' );
                str_end++;
                node->data.str = cvMemStorageAllocString( fs->memstorage, ptr, (int)(str_end - ptr) );
                ptr = endptr;
                return ptr;
            }
            struct_flags = CV_NODE_MAP;
        }
        else
            struct_flags = CV_NODE_SEQ;

        icvFSCreateCollection( fs, struct_flags +
                    (node->info ? CV_NODE_USER : 0), node );

        indent = (int)(ptr - fs->buffer_start);
        is_simple = 1;

        for(;;)
        {
            CvFileNode* elem = 0;

            if( CV_NODE_IS_MAP(struct_flags) )
            {
                ptr = icvYMLParseKey( fs, ptr, node, &elem );
            }
            else
            {
                c = *ptr++;
                if( c != '-' )
                    CV_PARSE_ERROR( "Block sequence elements must be preceded with \'-\'" );

                elem = (CvFileNode*)cvSeqPush( node->data.seq, 0 );
            }

            ptr = icvYMLSkipSpaces( fs, ptr, indent + 1, INT_MAX );
            ptr = icvYMLParseValue( fs, ptr, elem, struct_flags, indent + 1 );
            if( CV_NODE_IS_MAP(struct_flags) )
                elem->tag |= CV_NODE_NAMED;
            is_simple &= !CV_NODE_IS_COLLECTION(elem->tag);

            ptr = icvYMLSkipSpaces( fs, ptr, 0, INT_MAX );
            if( ptr - fs->buffer_start != indent )
            {
                if( ptr - fs->buffer_start < indent )
                    break;
                else
                    CV_PARSE_ERROR( "Incorrect indentation" );
            }
            if( memcmp( ptr, "...", 3 ) == 0 )
                break;
        }

        node->data.seq->flags |= is_simple ? CV_NODE_SEQ_SIMPLE : 0;
    }

    return ptr;
}


static void
icvYMLParse( CvFileStorage* fs )
{
    char* ptr = fs->buffer_start;
    int is_first = 1;

    for(;;)
    {
        // 0. skip leading comments and directives  and ...
        // 1. reach the first item
        for(;;)
        {
            ptr = icvYMLSkipSpaces( fs, ptr, 0, INT_MAX );
            if( !ptr )
                return;

            if( *ptr == '%' )
            {
                if( memcmp( ptr, "%YAML:", 6 ) == 0 &&
                    memcmp( ptr, "%YAML:1.", 8 ) != 0 )
                    CV_PARSE_ERROR( "Unsupported YAML version (it must be 1.x)" );
                *ptr = '\0';
            }
            else if( *ptr == '-' )
            {
                if( memcmp(ptr, "---", 3) == 0 )
                {
                    ptr += 3;
                    break;
                }
                else if( is_first )
                    break;
            }
            else if( cv_isalnum(*ptr) || *ptr=='_')
            {
                if( !is_first )
                    CV_PARSE_ERROR( "The YAML streams must start with '---', except the first one" );
                break;
            }
            else if( fs->dummy_eof )
                break;
            else
                CV_PARSE_ERROR( "Invalid or unsupported syntax" );
        }

        ptr = icvYMLSkipSpaces( fs, ptr, 0, INT_MAX );
        if( memcmp( ptr, "...", 3 ) != 0 )
        {
            // 2. parse the collection
            CvFileNode* root_node = (CvFileNode*)cvSeqPush( fs->roots, 0 );

            ptr = icvYMLParseValue( fs, ptr, root_node, CV_NODE_NONE, 0 );
            if( !CV_NODE_IS_COLLECTION(root_node->tag) )
                CV_PARSE_ERROR( "Only collections as YAML streams are supported by this parser" );

            // 3. parse until the end of file or next collection
            ptr = icvYMLSkipSpaces( fs, ptr, 0, INT_MAX );
            if( !ptr )
                return;
        }

        if( fs->dummy_eof )
            break;
        ptr += 3;
        is_first = 0;
    }
}


/****************************************************************************************\
*                                       YAML Emitter                                     *
\****************************************************************************************/

static void
icvYMLWrite( CvFileStorage* fs, const char* key, const char* data )
{
    int i, keylen = 0;
    int datalen = 0;
    int struct_flags;
    char* ptr;

    struct_flags = fs->struct_flags;

    if( key && key[0] == '\0' )
        key = 0;

    if( CV_NODE_IS_COLLECTION(struct_flags) )
    {
        if( (CV_NODE_IS_MAP(struct_flags) ^ (key != 0)) )
            CV_Error( CV_StsBadArg, "An attempt to add element without a key to a map, "
                                    "or add element with key to sequence" );
    }
    else
    {
        fs->is_first = 0;
        struct_flags = CV_NODE_EMPTY | (key ? CV_NODE_MAP : CV_NODE_SEQ);
    }

    if( key )
    {
        keylen = (int)strlen(key);
        if( keylen == 0 )
            CV_Error( CV_StsBadArg, "The key is an empty" );

        if( keylen > CV_FS_MAX_LEN )
            CV_Error( CV_StsBadArg, "The key is too long" );
    }

    if( data )
        datalen = (int)strlen(data);

    if( CV_NODE_IS_FLOW(struct_flags) )
    {
        int new_offset;
        ptr = fs->buffer;
        if( !CV_NODE_IS_EMPTY(struct_flags) )
            *ptr++ = ',';
        new_offset = (int)(ptr - fs->buffer_start) + keylen + datalen;
        if( new_offset > fs->wrap_margin && new_offset - fs->struct_indent > 10 )
        {
            fs->buffer = ptr;
            ptr = icvFSFlush(fs);
        }
        else
            *ptr++ = ' ';
    }
    else
    {
        ptr = icvFSFlush(fs);
        if( !CV_NODE_IS_MAP(struct_flags) )
        {
            *ptr++ = '-';
            if( data )
                *ptr++ = ' ';
        }
    }

    if( key )
    {
        if( !cv_isalpha(key[0]) && key[0] != '_' )
            CV_Error( CV_StsBadArg, "Key must start with a letter or _" );

        ptr = icvFSResizeWriteBuffer( fs, ptr, keylen );

        for( i = 0; i < keylen; i++ )
        {
            char c = key[i];

            ptr[i] = c;
            if( !cv_isalnum(c) && c != '-' && c != '_' && c != ' ' )
                CV_Error( CV_StsBadArg, "Key names may only contain alphanumeric characters [a-zA-Z0-9], '-', '_' and ' '" );
        }

        ptr += keylen;
        *ptr++ = ':';
        if( !CV_NODE_IS_FLOW(struct_flags) && data )
            *ptr++ = ' ';
    }

    if( data )
    {
        ptr = icvFSResizeWriteBuffer( fs, ptr, datalen );
        memcpy( ptr, data, datalen );
        ptr += datalen;
    }

    fs->buffer = ptr;
    fs->struct_flags = struct_flags & ~CV_NODE_EMPTY;
}


static void
icvYMLStartWriteStruct( CvFileStorage* fs, const char* key, int struct_flags,
                        const char* type_name CV_DEFAULT(0))
{
    int parent_flags;
    char buf[CV_FS_MAX_LEN + 1024];
    const char* data = 0;

    struct_flags = (struct_flags & (CV_NODE_TYPE_MASK|CV_NODE_FLOW)) | CV_NODE_EMPTY;
    if( !CV_NODE_IS_COLLECTION(struct_flags))
        CV_Error( CV_StsBadArg,
        "Some collection type - CV_NODE_SEQ or CV_NODE_MAP, must be specified" );

    if( CV_NODE_IS_FLOW(struct_flags) )
    {
        char c = CV_NODE_IS_MAP(struct_flags) ? '{' : '[';
        struct_flags |= CV_NODE_FLOW;

        if( type_name )
            sprintf( buf, "!!%s %c", type_name, c );
        else
        {
            buf[0] = c;
            buf[1] = '\0';
        }
        data = buf;
    }
    else if( type_name )
    {
        sprintf( buf, "!!%s", type_name );
        data = buf;
    }

    icvYMLWrite( fs, key, data );

    parent_flags = fs->struct_flags;
    cvSeqPush( fs->write_stack, &parent_flags );
    fs->struct_flags = struct_flags;

    if( !CV_NODE_IS_FLOW(parent_flags) )
        fs->struct_indent += CV_YML_INDENT + CV_NODE_IS_FLOW(struct_flags);
}


static void
icvYMLEndWriteStruct( CvFileStorage* fs )
{
    int parent_flags = 0, struct_flags;
    char* ptr;

    struct_flags = fs->struct_flags;
    if( fs->write_stack->total == 0 )
        CV_Error( CV_StsError, "EndWriteStruct w/o matching StartWriteStruct" );

    cvSeqPop( fs->write_stack, &parent_flags );

    if( CV_NODE_IS_FLOW(struct_flags) )
    {
        ptr = fs->buffer;
        if( ptr > fs->buffer_start + fs->struct_indent && !CV_NODE_IS_EMPTY(struct_flags) )
            *ptr++ = ' ';
        *ptr++ = CV_NODE_IS_MAP(struct_flags) ? '}' : ']';
        fs->buffer = ptr;
    }
    else if( CV_NODE_IS_EMPTY(struct_flags) )
    {
        ptr = icvFSFlush(fs);
        memcpy( ptr, CV_NODE_IS_MAP(struct_flags) ? "{}" : "[]", 2 );
        fs->buffer = ptr + 2;
    }

    if( !CV_NODE_IS_FLOW(parent_flags) )
        fs->struct_indent -= CV_YML_INDENT + CV_NODE_IS_FLOW(struct_flags);
    assert( fs->struct_indent >= 0 );

    fs->struct_flags = parent_flags;
}


static void
icvYMLStartNextStream( CvFileStorage* fs )
{
    if( !fs->is_first )
    {
        while( fs->write_stack->total > 0 )
            icvYMLEndWriteStruct(fs);

        fs->struct_indent = 0;
        icvFSFlush(fs);
        icvPuts( fs, "...\n" );
        icvPuts( fs, "---\n" );
        fs->buffer = fs->buffer_start;
    }
}


static void
icvYMLWriteInt( CvFileStorage* fs, const char* key, int value )
{
    char buf[128];
    icvYMLWrite( fs, key, icv_itoa( value, buf, 10 ));
}


static void
icvYMLWriteReal( CvFileStorage* fs, const char* key, double value )
{
    char buf[128];
    icvYMLWrite( fs, key, icvDoubleToString( buf, value ));
}


static void
icvYMLWriteString( CvFileStorage* fs, const char* key,
                   const char* str, int quote CV_DEFAULT(0))
{
    char buf[CV_FS_MAX_LEN*4+16];
    char* data = (char*)str;
    int i, len;

    if( !str )
        CV_Error( CV_StsNullPtr, "Null string pointer" );

    len = (int)strlen(str);
    if( len > CV_FS_MAX_LEN )
        CV_Error( CV_StsBadArg, "The written string is too long" );

    if( quote || len == 0 || str[0] != str[len-1] || (str[0] != '\"' && str[0] != '\'') )
    {
        int need_quote = quote || len == 0;
        data = buf;
        *data++ = '\"';
        for( i = 0; i < len; i++ )
        {
            char c = str[i];

            if( !need_quote && !cv_isalnum(c) && c != '_' && c != ' ' && c != '-' &&
                c != '(' && c != ')' && c != '/' && c != '+' && c != ';' )
                need_quote = 1;

            if( !cv_isalnum(c) && (!cv_isprint(c) || c == '\\' || c == '\'' || c == '\"') )
            {
                *data++ = '\\';
                if( cv_isprint(c) )
                    *data++ = c;
                else if( c == '\n' )
                    *data++ = 'n';
                else if( c == '\r' )
                    *data++ = 'r';
                else if( c == '\t' )
                    *data++ = 't';
                else
                {
                    sprintf( data, "x%02x", c );
                    data += 3;
                }
            }
            else
                *data++ = c;
        }
        if( !need_quote && (cv_isdigit(str[0]) ||
            str[0] == '+' || str[0] == '-' || str[0] == '.' ))
            need_quote = 1;

        if( need_quote )
            *data++ = '\"';
        *data++ = '\0';
        data = buf + !need_quote;
    }

    icvYMLWrite( fs, key, data );
}


static void
icvYMLWriteComment( CvFileStorage* fs, const char* comment, int eol_comment )
{
    int len; //, indent;
    int multiline;
    const char* eol;
    char* ptr;

    if( !comment )
        CV_Error( CV_StsNullPtr, "Null comment" );

    len = (int)strlen(comment);
    eol = strchr(comment, '\n');
    multiline = eol != 0;
    ptr = fs->buffer;

    if( !eol_comment || multiline ||
        fs->buffer_end - ptr < len || ptr == fs->buffer_start )
        ptr = icvFSFlush( fs );
    else
        *ptr++ = ' ';

    while( comment )
    {
        *ptr++ = '#';
        *ptr++ = ' ';
        if( eol )
        {
            ptr = icvFSResizeWriteBuffer( fs, ptr, (int)(eol - comment) + 1 );
            memcpy( ptr, comment, eol - comment + 1 );
            fs->buffer = ptr + (eol - comment);
            comment = eol + 1;
            eol = strchr( comment, '\n' );
        }
        else
        {
            len = (int)strlen(comment);
            ptr = icvFSResizeWriteBuffer( fs, ptr, len );
            memcpy( ptr, comment, len );
            fs->buffer = ptr + len;
            comment = 0;
        }
        ptr = icvFSFlush( fs );
    }
}


/****************************************************************************************\
*                                       XML Parser                                       *
\****************************************************************************************/

#define CV_XML_INSIDE_COMMENT 1
#define CV_XML_INSIDE_TAG 2
#define CV_XML_INSIDE_DIRECTIVE 3

static char*
icvXMLSkipSpaces( CvFileStorage* fs, char* ptr, int mode )
{
    int level = 0;

    for(;;)
    {
        char c;
        ptr--;

        if( mode == CV_XML_INSIDE_COMMENT )
        {
            do c = *++ptr;
            while( cv_isprint_or_tab(c) && (c != '-' || ptr[1] != '-' || ptr[2] != '>') );

            if( c == '-' )
            {
                assert( ptr[1] == '-' && ptr[2] == '>' );
                mode = 0;
                ptr += 3;
            }
        }
        else if( mode == CV_XML_INSIDE_DIRECTIVE )
        {
            // !!!NOTE!!! This is not quite correct, but should work in most cases
            do
            {
                c = *++ptr;
                level += c == '<';
                level -= c == '>';
                if( level < 0 )
                    return ptr;
            } while( cv_isprint_or_tab(c) );
        }
        else
        {
            do c = *++ptr;
            while( c == ' ' || c == '\t' );

            if( c == '<' && ptr[1] == '!' && ptr[2] == '-' && ptr[3] == '-' )
            {
                if( mode != 0 )
                    CV_PARSE_ERROR( "Comments are not allowed here" );
                mode = CV_XML_INSIDE_COMMENT;
                ptr += 4;
            }
            else if( cv_isprint(c) )
                break;
        }

        if( !cv_isprint(*ptr) )
        {
            int max_size = (int)(fs->buffer_end - fs->buffer_start);
            if( *ptr != '\0' && *ptr != '\n' && *ptr != '\r' )
                CV_PARSE_ERROR( "Invalid character in the stream" );
            ptr = icvGets( fs, fs->buffer_start, max_size );
            if( !ptr )
            {
                ptr = fs->buffer_start;
                *ptr = '\0';
                fs->dummy_eof = 1;
                break;
            }
            else
            {
                int l = (int)strlen(ptr);
                if( ptr[l-1] != '\n' && ptr[l-1] != '\r' && !icvEof(fs) )
                    CV_PARSE_ERROR( "Too long string or a last string w/o newline" );
            }
            fs->lineno++;
        }
    }
    return ptr;
}


static char*
icvXMLParseTag( CvFileStorage* fs, char* ptr, CvStringHashNode** _tag,
                CvAttrList** _list, int* _tag_type );

static char*
icvXMLParseValue( CvFileStorage* fs, char* ptr, CvFileNode* node,
                  int value_type CV_DEFAULT(CV_NODE_NONE))
{
    CvFileNode *elem = node;
    int have_space = 1, is_simple = 1;
    int is_user_type = CV_NODE_IS_USER(value_type);
    memset( node, 0, sizeof(*node) );

    value_type