mirror of
https://github.com/videolan/vlc.git
synced 2025-01-10 17:58:22 +08:00
* B-search macro
* Redo dictionnary handling to remove recursion and bugs
This commit is contained in:
Clément Stenac
parent
2c2ebc9c31
commit
23d27c9c9c
@ -203,7 +203,8 @@ typedef struct libvlc_t libvlc_t;
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typedef struct vlc_t vlc_t;
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typedef struct variable_t variable_t;
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typedef struct date_t date_t;
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typedef struct hashtable_entry_t hashtable_entry_t;
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typedef struct dict_entry_t dict_entry_t;
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typedef struct dict_t dict_t;
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typedef struct gc_object_t gc_object_t ;
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/* Messages */
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@ -717,19 +718,44 @@ static int64_t GCD( int64_t a, int64_t b )
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} \
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}
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/* Hash tables handling */
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struct hashtable_entry_t
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/* Binary search in an array */
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#define BSEARCH( entries, count, elem, zetype, key, answer ) { \
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int low = 0, high = count - 1; \
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answer = -1; \
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while( low <= high ) {\
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int mid = (low + high ) / 2; /* Just don't care about 2^30 tables */ \
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zetype mid_val = entries[mid] elem;\
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if( mid_val < key ) \
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low = mid + 1; \
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else if ( mid_val > key ) \
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high = mid -1; \
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else \
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{ \
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answer = mid; break; \
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}\
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} \
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}
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/* Dictionnary handling */
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struct dict_entry_t
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{
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int i_id;
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char *psz_name;
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int i_int;
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char *psz_string;
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uint64_t i_hash;
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void *p_data;
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};
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VLC_EXPORT( void, vlc_HashInsert, (hashtable_entry_t **, int *, int, const char *, void *));
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VLC_EXPORT( void*, vlc_HashRetrieve, (hashtable_entry_t*, int, int, const char *) );
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VLC_EXPORT( int, vlc_HashLookup, (hashtable_entry_t *, int, int, const char *) );
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struct dict_t
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{
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dict_entry_t *p_entries;
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int i_entries;
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};
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VLC_EXPORT( dict_t *, vlc_DictNew, (void) );
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VLC_EXPORT( void, vlc_DictClear, (dict_t * ) );
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VLC_EXPORT( void, vlc_DictInsert, (dict_t *, int, const char *, void * ) );
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VLC_EXPORT( void*, vlc_DictGet, (dict_t *, int, const char * ) );
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VLC_EXPORT( int, vlc_DictLookup, (dict_t *, int, const char * ) );
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/* MSB (big endian)/LSB (little endian) conversions - network order is always
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* MSB, and should be used for both network communications and files. Note that
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@ -463,9 +463,9 @@ struct module_symbols_t
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unsigned int (*update_iterator_ChooseMirrorAndFile_inner) (update_iterator_t *, int, int, int);
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update_t * (*__update_New_inner) (vlc_object_t *);
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void (*update_download_inner) (update_iterator_t *, char *);
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void (*vlc_HashInsert_inner) (hashtable_entry_t **, int *, int, const char *, void *);
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int (*vlc_HashLookup_inner) (hashtable_entry_t *, int, int, const char *);
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void* (*vlc_HashRetrieve_inner) (hashtable_entry_t*, int, int, const char *);
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void *vlc_HashInsert_deprecated;
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void *vlc_HashLookup_deprecated;
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void *vlc_HashRetrieve_deprecated;
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void * (*utf8_opendir_inner) (const char *dirname);
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FILE * (*utf8_fopen_inner) (const char *filename, const char *mode);
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const char * (*utf8_readdir_inner) (void *dir);
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@ -525,6 +525,11 @@ struct module_symbols_t
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int (*__intf_Progress_inner) (vlc_object_t*, const char*, const char*, float, int);
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void (*__intf_ProgressUpdate_inner) (vlc_object_t*, int, const char*, float, int);
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int (*playlist_AddInput_inner) (playlist_t *, input_item_t *,int , int, vlc_bool_t);
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void (*vlc_DictInsert_inner) (dict_t *, int, const char *, void *);
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void* (*vlc_DictGet_inner) (dict_t *, int, const char *);
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int (*vlc_DictLookup_inner) (dict_t *, int, const char *);
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void (*vlc_DictClear_inner) (dict_t *);
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dict_t * (*vlc_DictNew_inner) (void);
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};
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# if defined (__PLUGIN__)
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# define aout_FiltersCreatePipeline (p_symbols)->aout_FiltersCreatePipeline_inner
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@ -936,9 +941,6 @@ struct module_symbols_t
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# define update_iterator_ChooseMirrorAndFile (p_symbols)->update_iterator_ChooseMirrorAndFile_inner
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# define __update_New (p_symbols)->__update_New_inner
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# define update_download (p_symbols)->update_download_inner
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# define vlc_HashInsert (p_symbols)->vlc_HashInsert_inner
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# define vlc_HashLookup (p_symbols)->vlc_HashLookup_inner
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# define vlc_HashRetrieve (p_symbols)->vlc_HashRetrieve_inner
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# define utf8_opendir (p_symbols)->utf8_opendir_inner
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# define utf8_fopen (p_symbols)->utf8_fopen_inner
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# define utf8_readdir (p_symbols)->utf8_readdir_inner
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@ -988,6 +990,11 @@ struct module_symbols_t
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# define __intf_Progress (p_symbols)->__intf_Progress_inner
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# define __intf_ProgressUpdate (p_symbols)->__intf_ProgressUpdate_inner
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# define playlist_AddInput (p_symbols)->playlist_AddInput_inner
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# define vlc_DictInsert (p_symbols)->vlc_DictInsert_inner
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# define vlc_DictGet (p_symbols)->vlc_DictGet_inner
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# define vlc_DictLookup (p_symbols)->vlc_DictLookup_inner
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# define vlc_DictClear (p_symbols)->vlc_DictClear_inner
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# define vlc_DictNew (p_symbols)->vlc_DictNew_inner
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# elif defined (HAVE_DYNAMIC_PLUGINS) && !defined (__BUILTIN__)
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/******************************************************************
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* STORE_SYMBOLS: store VLC APIs into p_symbols for plugin access.
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@ -1402,9 +1409,6 @@ struct module_symbols_t
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((p_symbols)->update_iterator_ChooseMirrorAndFile_inner) = update_iterator_ChooseMirrorAndFile; \
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((p_symbols)->__update_New_inner) = __update_New; \
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((p_symbols)->update_download_inner) = update_download; \
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((p_symbols)->vlc_HashInsert_inner) = vlc_HashInsert; \
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((p_symbols)->vlc_HashLookup_inner) = vlc_HashLookup; \
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((p_symbols)->vlc_HashRetrieve_inner) = vlc_HashRetrieve; \
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((p_symbols)->utf8_opendir_inner) = utf8_opendir; \
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((p_symbols)->utf8_fopen_inner) = utf8_fopen; \
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((p_symbols)->utf8_readdir_inner) = utf8_readdir; \
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@ -1454,6 +1458,11 @@ struct module_symbols_t
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((p_symbols)->__intf_Progress_inner) = __intf_Progress; \
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((p_symbols)->__intf_ProgressUpdate_inner) = __intf_ProgressUpdate; \
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((p_symbols)->playlist_AddInput_inner) = playlist_AddInput; \
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((p_symbols)->vlc_DictInsert_inner) = vlc_DictInsert; \
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((p_symbols)->vlc_DictGet_inner) = vlc_DictGet; \
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((p_symbols)->vlc_DictLookup_inner) = vlc_DictLookup; \
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((p_symbols)->vlc_DictClear_inner) = vlc_DictClear; \
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((p_symbols)->vlc_DictNew_inner) = vlc_DictNew; \
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(p_symbols)->net_ConvertIPv4_deprecated = NULL; \
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(p_symbols)->__playlist_ItemNew_deprecated = NULL; \
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(p_symbols)->__playlist_ItemCopy_deprecated = NULL; \
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@ -1489,6 +1498,9 @@ struct module_symbols_t
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(p_symbols)->__stats_CounterGet_deprecated = NULL; \
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(p_symbols)->stats_HandlerDestroy_deprecated = NULL; \
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(p_symbols)->__stats_TimerDumpAll_deprecated = NULL; \
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(p_symbols)->vlc_HashInsert_deprecated = NULL; \
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(p_symbols)->vlc_HashLookup_deprecated = NULL; \
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(p_symbols)->vlc_HashRetrieve_deprecated = NULL; \
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(p_symbols)->playlist_ItemNewFromInput_deprecated = NULL; \
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(p_symbols)->playlist_PlaylistAdd_deprecated = NULL; \
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(p_symbols)->playlist_PlaylistAddExt_deprecated = NULL; \
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@ -325,7 +325,7 @@ SOURCES_libvlc_common = \
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misc/update.c \
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misc/vlm.c \
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misc/xml.c \
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misc/hashtables.c \
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misc/dict.c \
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misc/devices.c \
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extras/libc.c \
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control/core.c \
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@ -70,7 +70,7 @@ char *vlc_input_item_GetInfo( input_item_t *p_i,
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static void vlc_input_item_Destroy ( gc_object_t *p_this )
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{
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vlc_object_t *p_obj = (vlc_object_t *)p_this->p_destructor_arg;
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int i, i_top, i_bottom;
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int i;
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input_item_t *p_input = (input_item_t *) p_this;
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playlist_t *p_playlist = (playlist_t *)vlc_object_find( p_obj,
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163
src/misc/dict.c
Normal file
163
src/misc/dict.c
Normal file
@ -0,0 +1,163 @@
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/*****************************************************************************
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* dict.c: Dictionnary handling
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*****************************************************************************
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* Copyright (C) 2002-2004 the VideoLAN team
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* $Id: variables.c 13991 2006-01-22 17:12:24Z zorglub $
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*
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* Authors: Samuel Hocevar <sam@zoy.org>
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* Clément Stenac <zorglub@videolan.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
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*****************************************************************************/
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#include <vlc/vlc.h>
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#include <assert.h>
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/*****************************************************************************
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* Associative array
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*****************************************************************************
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* This is quite a weak implementation of an associative array.
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* It hashes the key and stores the entry in a sorted array that gets
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* reallocated to insert new entries (so, this is SLOW)
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* Lookup is done by using binary search on the array
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*/
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static uint64_t DoHash ( const char *, int );
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#define DARRAY p_dict->p_entries
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#define DSIZE p_dict->i_entries
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dict_t *vlc_DictNew()
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{
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DECMALLOC_NULL( p_dict, dict_t );
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p_dict->i_entries = 0;
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p_dict->p_entries = NULL;
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return p_dict;
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}
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void vlc_DictClear( dict_t *p_dict )
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{
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int i = 0;
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for( i = 0 ; i< DSIZE; i++ )
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{
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FREE( DARRAY[i].psz_string );
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}
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free( DARRAY );
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free( p_dict );
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}
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void vlc_DictInsert( dict_t *p_dict, int i_int, const char *psz_string,
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void *p_data )
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{
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uint64_t i_hash = DoHash( psz_string, i_int );
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int i_new;
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/* Find a free slot */
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if( DSIZE == 0 || i_hash <= DARRAY[0].i_hash )
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i_new = 0;
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else if( i_hash >= DARRAY[DSIZE-1].i_hash )
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i_new = DSIZE;
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else
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{
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int i_low = 0, i_high = DSIZE;
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while( i_low != i_high )
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{
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int i_mid = (i_low + i_high)/2;
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if( DARRAY[i_mid].i_hash < i_hash )
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i_low = i_mid + 1;
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if( DARRAY[i_mid].i_hash > i_hash )
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i_high = i_low + 1;
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}
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i_new = i_low;
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}
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DARRAY = realloc( DARRAY, (DSIZE + 1) * sizeof( dict_entry_t ) );
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DSIZE++;
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if( i_new != DSIZE -1 )
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memmove( DARRAY + i_new + 1 , DARRAY + i_new, ( DSIZE - i_new - 1 ) *
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sizeof( dict_entry_t ) );
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DARRAY[i_new].i_hash = i_hash;
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DARRAY[i_new].i_int = i_int;
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if( psz_string )
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DARRAY[i_new].psz_string = strdup( psz_string );
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else
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DARRAY[i_new].psz_string = NULL;
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DARRAY[i_new].p_data = p_data;
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}
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void * vlc_DictGet( dict_t *p_dict, int i_int, const char *psz_string )
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{
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int i_new = vlc_DictLookup( p_dict, i_int, psz_string );
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if( i_new >= 0 )
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return DARRAY[i_new].p_data;
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return NULL;
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}
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int vlc_DictLookup( dict_t *p_dict, int i_int, const char *psz_string )
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{
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uint64_t i_hash;
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int i, i_pos;
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if( DSIZE == 0 ) return -1;
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i_hash = DoHash( psz_string, i_int );
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BSEARCH( p_dict->p_entries, p_dict->i_entries, .i_hash, uint64_t,
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i_hash, i_pos );
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if( i_pos == -1 ) return -1;
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/* Hash found, let's check it looks like the entry */
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if( !strcmp( psz_string, DARRAY[i_pos].psz_string ) )
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return i_pos;
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/* Hash collision! This should be very rare, but we cannot guarantee
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* it will never happen. Just do an exhaustive search amongst all
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* entries with the same hash. */
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for( i = i_pos - 1 ; i > 0 && i_hash == DARRAY[i].i_hash ; i-- )
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{
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if( !strcmp( psz_string, DARRAY[i].psz_string ) &&
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DARRAY[i].i_int == i_int )
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return i;
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}
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for( i = i_pos + 1 ; i < DSIZE && i_hash == DARRAY[i].i_hash ; i++ )
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{
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if( !strcmp( psz_string, DARRAY[i].psz_string ) &&
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DARRAY[i].i_int == i_int )
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return i;
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}
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/* Hash found, but entry not found (quite strange !) */
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assert( 0 );
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return -1;
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}
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/*****************************************************************************
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* DoHash: our cool hash function
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*****************************************************************************
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* This function is not intended to be crypto-secure, we only want it to be
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* fast and not suck too much. This one is pretty fast and did 0 collisions
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* in wenglish's dictionary.
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*****************************************************************************/
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static uint64_t DoHash( const char *psz_string, int i_int )
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{
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uint64_t i_hash = 0;
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if( psz_string )
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{
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while( *psz_string )
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{
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i_hash += *psz_string++;
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i_hash += i_hash << 10;
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i_hash ^= i_hash >> 8;
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}
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}
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return i_hash + ( (uint64_t)i_int << 32 );
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}
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@ -1,223 +0,0 @@
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/*****************************************************************************
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* hashtables.c: Hash tables handling
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*****************************************************************************
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* Copyright (C) 2002-2004 the VideoLAN team
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* $Id: variables.c 13991 2006-01-22 17:12:24Z zorglub $
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*
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* Authors: Samuel Hocevar <sam@zoy.org>
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* Clément Stenac <zorglub@videolan.org>
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*
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* This program is free software; you can redistribute it and/or modify
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||||
* 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.
|
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*
|
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* 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.
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*****************************************************************************/
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/*****************************************************************************
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* Preamble
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*****************************************************************************/
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#include <vlc/vlc.h>
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static uint64_t HashString ( const char *, int );
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static int FindSlot ( hashtable_entry_t *, int, uint64_t );
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static int LookupInner ( hashtable_entry_t *, int, uint64_t );
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void vlc_HashInsert( hashtable_entry_t **pp_array, int *pi_count, int i_id,
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const char *psz_name, void *p_data )
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{
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hashtable_entry_t *p_new;
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int64_t i_hash = HashString( psz_name, i_id );
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int i_new = FindSlot( *pp_array, *pi_count, i_hash );
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*pp_array = realloc( *pp_array, ( *pi_count + 2) * sizeof( hashtable_entry_t ) );
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memmove( *pp_array + i_new + 1 , *pp_array + i_new, ( *pi_count - i_new ) *
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sizeof( hashtable_entry_t ) );
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(*pi_count)++;
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p_new = &((*pp_array)[i_new]);
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p_new->i_hash = i_hash;
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p_new->i_id = i_id;
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p_new->psz_name = strdup( psz_name );
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p_new->p_data = p_data;
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}
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void * vlc_HashRetrieve( hashtable_entry_t *p_array, int i_count, int i_id,
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const char *psz_name )
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{
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int i_new = vlc_HashLookup( p_array, i_count, i_id, psz_name );
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if( i_new >= 0 && i_new < i_count )
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{
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return p_array[i_new].p_data;
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}
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return NULL;
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}
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/*****************************************************************************
|
||||
* FindSlot: find an empty slot to insert a new variable
|
||||
*****************************************************************************
|
||||
* We use a recursive inner function indexed on the hash. This function does
|
||||
* nothing in the rare cases where a collision may occur, see Lookup()
|
||||
* to see how we handle them.
|
||||
* XXX: does this really need to be written recursively?
|
||||
*****************************************************************************/
|
||||
static int FindSlot( hashtable_entry_t *p_array, int i_count, uint64_t i_hash )
|
||||
{
|
||||
int i_middle;
|
||||
|
||||
if( i_count == 0 || i_hash <= p_array[0].i_hash )
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
if( i_hash >= p_array[i_count - 1].i_hash )
|
||||
{
|
||||
return i_count;
|
||||
}
|
||||
|
||||
i_middle = i_count / 2;
|
||||
|
||||
/* We know that 0 < i_middle */
|
||||
if( i_hash < p_array[i_middle].i_hash )
|
||||
{
|
||||
return FindSlot( p_array, i_middle, i_hash );
|
||||
}
|
||||
|
||||
/* We know that i_middle + 1 < i_count */
|
||||
if( i_hash > p_array[i_middle + 1].i_hash )
|
||||
{
|
||||
return i_middle + 1 + FindSlot( p_array + i_middle + 1,
|
||||
i_count - i_middle - 1,
|
||||
i_hash );
|
||||
}
|
||||
|
||||
return i_middle + 1;
|
||||
}
|
||||
|
||||
/*****************************************************************************
|
||||
* Lookup: find an existing variable given its name and id
|
||||
*****************************************************************************
|
||||
* We use a recursive inner function indexed on the hash. Care is taken of
|
||||
* possible hash collisions.
|
||||
* XXX: does this really need to be written recursively?
|
||||
*****************************************************************************/
|
||||
int vlc_HashLookup( hashtable_entry_t *p_array, int i_count,
|
||||
int i_id, const char *psz_name )
|
||||
{
|
||||
uint64_t i_hash;
|
||||
int i, i_pos;
|
||||
|
||||
if( i_count == 0 )
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
i_hash = HashString( psz_name, i_id );
|
||||
|
||||
i_pos = LookupInner( p_array, i_count, i_hash );
|
||||
|
||||
/* Hash not found */
|
||||
if( i_hash != p_array[i_pos].i_hash )
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* Hash found, let's check it looks like the entry
|
||||
* We don't check the whole entry, this could lead to bad surprises :( */
|
||||
if( psz_name[0] == p_array[i_pos].psz_name[0] )
|
||||
{
|
||||
return i_pos;
|
||||
}
|
||||
|
||||
/* Hash collision! This should be very rare, but we cannot guarantee
|
||||
* it will never happen. Just do an exhaustive search amongst all
|
||||
* entries with the same hash. */
|
||||
for( i = i_pos - 1 ; i > 0 && i_hash == p_array[i].i_hash ; i-- )
|
||||
{
|
||||
if( !strcmp( psz_name, p_array[i].psz_name ) && p_array[i].i_id == i_id )
|
||||
{
|
||||
return i;
|
||||
}
|
||||
}
|
||||
|
||||
for( i = i_pos + 1 ; i < i_count && i_hash == p_array[i].i_hash ; i++ )
|
||||
{
|
||||
if( !strcmp( psz_name, p_array[i].psz_name ) && p_array[i].i_id == i_id )
|
||||
{
|
||||
return i;
|
||||
}
|
||||
}
|
||||
|
||||
/* Hash found, but entry not found */
|
||||
return -1;
|
||||
}
|
||||
|
||||
static int LookupInner( hashtable_entry_t *p_array, int i_count, uint64_t i_hash )
|
||||
{
|
||||
int i_middle;
|
||||
|
||||
if( i_hash <= p_array[0].i_hash )
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
if( i_hash >= p_array[i_count-1].i_hash )
|
||||
{
|
||||
return i_count - 1;
|
||||
}
|
||||
|
||||
i_middle = i_count / 2;
|
||||
|
||||
/* We know that 0 < i_middle */
|
||||
if( i_hash < p_array[i_middle].i_hash )
|
||||
{
|
||||
return LookupInner( p_array, i_middle, i_hash );
|
||||
}
|
||||
|
||||
/* We know that i_middle + 1 < i_count */
|
||||
if( i_hash > p_array[i_middle].i_hash )
|
||||
{
|
||||
return i_middle + LookupInner( p_array + i_middle,
|
||||
i_count - i_middle,
|
||||
i_hash );
|
||||
}
|
||||
|
||||
return i_middle;
|
||||
}
|
||||
|
||||
|
||||
/*****************************************************************************
|
||||
* HashString: our cool hash function
|
||||
*****************************************************************************
|
||||
* This function is not intended to be crypto-secure, we only want it to be
|
||||
* fast and not suck too much. This one is pretty fast and did 0 collisions
|
||||
* in wenglish's dictionary.
|
||||
*****************************************************************************/
|
||||
static uint64_t HashString( const char *psz_string, int i_id )
|
||||
{
|
||||
uint64_t i_hash = 0;
|
||||
|
||||
while( *psz_string )
|
||||
{
|
||||
i_hash += *psz_string++;
|
||||
i_hash += i_hash << 10;
|
||||
i_hash ^= i_hash >> 8;
|
||||
}
|
||||
|
||||
i_hash += ( (uint64_t)i_id << 32 );
|
||||
|
||||
return i_hash;
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user