/***************************************************************************** * variables.c: routines for object variables handling ***************************************************************************** * Copyright (C) 2002 VideoLAN * $Id: variables.c,v 1.25 2003/05/24 23:40:11 gbazin Exp $ * * Authors: Samuel Hocevar * * 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., 59 Temple Place - Suite 330, Boston, MA 02111, USA. *****************************************************************************/ /***************************************************************************** * Preamble *****************************************************************************/ #include #ifdef HAVE_STDLIB_H # include /* realloc() */ #endif /***************************************************************************** * Private types *****************************************************************************/ struct callback_entry_t { vlc_callback_t pf_callback; void * p_data; }; /***************************************************************************** * Local comparison functions, returns 0 if v == w, < 0 if v < w, > 0 if v > w *****************************************************************************/ static int CmpBool( vlc_value_t v, vlc_value_t w ) { return v.b_bool ? w.b_bool ? 0 : 1 : w.b_bool ? -1 : 0; } static int CmpInt( vlc_value_t v, vlc_value_t w ) { return v.i_int == w.i_int ? 0 : v.i_int > w.i_int ? 1 : -1; } static int CmpTime( vlc_value_t v, vlc_value_t w ) { mtime_t v_time,w_time; v_time = ( (mtime_t)v.time.i_high << 32 ) + v.time.i_low; w_time = ( (mtime_t)w.time.i_high << 32 ) + w.time.i_low; return v_time == w_time ? 0 : v_time > w_time ? 1 : -1; } static int CmpString( vlc_value_t v, vlc_value_t w ) { return strcmp( v.psz_string, w.psz_string ); } static int CmpFloat( vlc_value_t v, vlc_value_t w ) { return v.f_float == w.f_float ? 0 : v.f_float > w.f_float ? 1 : -1; } static int CmpAddress( vlc_value_t v, vlc_value_t w ) { return v.p_address == w.p_address ? 0 : v.p_address > w.p_address ? 1 : -1; } /***************************************************************************** * Local duplication functions, and local deallocation functions *****************************************************************************/ static void DupDummy( vlc_value_t *p_val ) { (void)p_val; /* unused */ } static void DupString( vlc_value_t *p_val ) { p_val->psz_string = strdup( p_val->psz_string ); } static void DupList( vlc_value_t *p_val ) { int i; vlc_list_t *p_list = malloc( sizeof(vlc_list_t) ); if( p_val->p_list->i_count ) { p_list->i_count = p_val->p_list->i_count; p_list->p_values = malloc( p_list->i_count * sizeof(vlc_value_t) ); p_list->pi_types = malloc( p_list->i_count * sizeof(int) ); } for( i = 0; i < p_list->i_count; i++ ) { p_list->p_values[i] = p_val->p_list->p_values[i]; switch( p_val->p_list->pi_types[i] & VLC_VAR_TYPE ) { case VLC_VAR_STRING: DupString( &p_list->p_values[i] ); break; default: break; } } p_val->p_list = p_list; } static void FreeDummy( vlc_value_t *p_val ) { (void)p_val; /* unused */ } static void FreeString( vlc_value_t *p_val ) { free( p_val->psz_string ); } static void FreeMutex( vlc_value_t *p_val ) { vlc_mutex_destroy( (vlc_mutex_t*)p_val->p_address ); free( p_val->p_address ); } static void FreeList( vlc_value_t *p_val ) { int i; for( i = 0; i < p_val->p_list->i_count; i++ ) { switch( p_val->p_list->pi_types[i] & VLC_VAR_TYPE ) { case VLC_VAR_STRING: FreeString( &p_val->p_list->p_values[i] ); break; case VLC_VAR_MUTEX: FreeMutex( &p_val->p_list->p_values[i] ); break; default: break; } } if( p_val->p_list->i_count ) { free( p_val->p_list->p_values ); free( p_val->p_list->pi_types ); } free( p_val->p_list ); } /***************************************************************************** * Local prototypes *****************************************************************************/ static int GetUnused ( vlc_object_t *, const char * ); static uint32_t HashString ( const char * ); static int Insert ( variable_t *, int, const char * ); static int InsertInner ( variable_t *, int, uint32_t ); static int Lookup ( variable_t *, int, const char * ); static int LookupInner ( variable_t *, int, uint32_t ); static void CheckValue ( variable_t *, vlc_value_t * ); static int InheritValue( vlc_object_t *, const char *, vlc_value_t *, int ); /***************************************************************************** * var_Create: initialize a vlc variable ***************************************************************************** * We hash the given string and insert it into the sorted list. The insertion * may require slow memory copies, but think about what we gain in the log(n) * lookup phase when setting/getting the variable value! *****************************************************************************/ int __var_Create( vlc_object_t *p_this, const char *psz_name, int i_type ) { int i_new; variable_t *p_var; static vlc_list_t dummy_null_list = {0, NULL, NULL}; vlc_mutex_lock( &p_this->var_lock ); /* FIXME: if the variable already exists, we don't duplicate it. But we * duplicate the lookups. It's not that serious, but if anyone finds some * time to rework Insert() so that only one lookup has to be done, feel * free to do so. */ i_new = Lookup( p_this->p_vars, p_this->i_vars, psz_name ); if( i_new >= 0 ) { /* If the types differ, variable creation failed. */ if( i_type != p_this->p_vars[i_new].i_type ) { vlc_mutex_unlock( &p_this->var_lock ); return VLC_EBADVAR; } p_this->p_vars[i_new].i_usage++; vlc_mutex_unlock( &p_this->var_lock ); return VLC_SUCCESS; } i_new = Insert( p_this->p_vars, p_this->i_vars, psz_name ); if( (p_this->i_vars & 15) == 15 ) { p_this->p_vars = realloc( p_this->p_vars, (p_this->i_vars+17) * sizeof(variable_t) ); } memmove( p_this->p_vars + i_new + 1, p_this->p_vars + i_new, (p_this->i_vars - i_new) * sizeof(variable_t) ); p_this->i_vars++; p_var = &p_this->p_vars[i_new]; p_var->i_hash = HashString( psz_name ); p_var->psz_name = strdup( psz_name ); p_var->psz_text = NULL; p_var->i_type = i_type; memset( &p_var->val, 0, sizeof(vlc_value_t) ); p_var->pf_dup = DupDummy; p_var->pf_free = FreeDummy; p_var->i_usage = 1; p_var->i_default = -1; p_var->choices.i_count = 0; p_var->choices.p_values = NULL; p_var->choices_text.i_count = 0; p_var->choices_text.p_values = NULL; p_var->b_incallback = VLC_FALSE; p_var->i_entries = 0; p_var->p_entries = NULL; /* Always initialize the variable, even if it is a list variable; this * will lead to errors if the variable is not initialized, but it will * not cause crashes in the variable handling. */ switch( i_type & VLC_VAR_TYPE ) { case VLC_VAR_BOOL: p_var->pf_cmp = CmpBool; p_var->val.b_bool = VLC_FALSE; break; case VLC_VAR_INTEGER: p_var->pf_cmp = CmpInt; p_var->val.i_int = 0; break; case VLC_VAR_STRING: case VLC_VAR_MODULE: case VLC_VAR_FILE: case VLC_VAR_DIRECTORY: case VLC_VAR_VARIABLE: p_var->pf_cmp = CmpString; p_var->pf_dup = DupString; p_var->pf_free = FreeString; p_var->val.psz_string = ""; break; case VLC_VAR_FLOAT: p_var->pf_cmp = CmpFloat; p_var->val.f_float = 0.0; break; case VLC_VAR_TIME: p_var->pf_cmp = CmpTime; p_var->val.time.i_low = 0; p_var->val.time.i_high = 0; break; case VLC_VAR_ADDRESS: p_var->pf_cmp = CmpAddress; p_var->val.p_address = NULL; break; case VLC_VAR_MUTEX: p_var->pf_cmp = CmpAddress; p_var->pf_free = FreeMutex; p_var->val.p_address = malloc( sizeof(vlc_mutex_t) ); vlc_mutex_init( p_this, (vlc_mutex_t*)p_var->val.p_address ); break; case VLC_VAR_LIST: p_var->pf_cmp = CmpAddress; p_var->pf_dup = DupList; p_var->pf_free = FreeList; p_var->val.p_list = &dummy_null_list; break; } /* Duplicate the default data we stored. */ p_var->pf_dup( &p_var->val ); vlc_mutex_unlock( &p_this->var_lock ); return VLC_SUCCESS; } /***************************************************************************** * var_Destroy: destroy a vlc variable ***************************************************************************** * Look for the variable and destroy it if it is found. As in var_Create we * do a call to memmove() but we have performance counterparts elsewhere. *****************************************************************************/ int __var_Destroy( vlc_object_t *p_this, const char *psz_name ) { int i_var, i; variable_t *p_var; vlc_mutex_lock( &p_this->var_lock ); i_var = GetUnused( p_this, psz_name ); if( i_var < 0 ) { vlc_mutex_unlock( &p_this->var_lock ); return i_var; } p_var = &p_this->p_vars[i_var]; if( p_var->i_usage > 1 ) { p_var->i_usage--; vlc_mutex_unlock( &p_this->var_lock ); return VLC_SUCCESS; } /* Free value if needed */ p_var->pf_free( &p_var->val ); /* Free choice list if needed */ if( p_var->choices.i_count ) { for( i = 0 ; i < p_var->choices.i_count ; i++ ) { p_var->pf_free( &p_var->choices.p_values[i] ); } free( p_var->choices.p_values ); } /* Free callbacks if needed */ if( p_var->p_entries ) { free( p_var->p_entries ); } free( p_var->psz_name ); if( p_var->psz_text ) free( p_var->psz_text ); memmove( p_this->p_vars + i_var, p_this->p_vars + i_var + 1, (p_this->i_vars - i_var - 1) * sizeof(variable_t) ); if( (p_this->i_vars & 15) == 0 ) { p_this->p_vars = realloc( p_this->p_vars, (p_this->i_vars) * sizeof( variable_t ) ); } p_this->i_vars--; vlc_mutex_unlock( &p_this->var_lock ); return VLC_SUCCESS; } /***************************************************************************** * var_Change: perform an action on a variable ***************************************************************************** * *****************************************************************************/ int __var_Change( vlc_object_t *p_this, const char *psz_name, int i_action, vlc_value_t *p_val, vlc_value_t *p_val2 ) { int i_var, i; variable_t *p_var; vlc_value_t oldval; vlc_mutex_lock( &p_this->var_lock ); i_var = Lookup( p_this->p_vars, p_this->i_vars, psz_name ); if( i_var < 0 ) { vlc_mutex_unlock( &p_this->var_lock ); return VLC_ENOVAR; } p_var = &p_this->p_vars[i_var]; switch( i_action ) { case VLC_VAR_SETMIN: if( p_var->i_type & VLC_VAR_HASMIN ) { p_var->pf_free( &p_var->min ); } p_var->i_type |= VLC_VAR_HASMIN; p_var->min = *p_val; p_var->pf_dup( &p_var->min ); CheckValue( p_var, &p_var->val ); break; case VLC_VAR_SETMAX: if( p_var->i_type & VLC_VAR_HASMAX ) { p_var->pf_free( &p_var->max ); } p_var->i_type |= VLC_VAR_HASMAX; p_var->max = *p_val; p_var->pf_dup( &p_var->max ); CheckValue( p_var, &p_var->val ); break; case VLC_VAR_SETSTEP: if( p_var->i_type & VLC_VAR_HASSTEP ) { p_var->pf_free( &p_var->step ); } p_var->i_type |= VLC_VAR_HASSTEP; p_var->step = *p_val; p_var->pf_dup( &p_var->step ); CheckValue( p_var, &p_var->val ); break; case VLC_VAR_ADDCHOICE: /* FIXME: the list is sorted, dude. Use something cleverer. */ for( i = p_var->choices.i_count ; i-- ; ) { if( p_var->pf_cmp( p_var->choices.p_values[i], *p_val ) < 0 ) { break; } } /* The new place is i+1 */ i++; if( p_var->i_default >= i ) { p_var->i_default++; } INSERT_ELEM( p_var->choices.p_values, p_var->choices.i_count, i, *p_val ); INSERT_ELEM( p_var->choices_text.p_values, p_var->choices_text.i_count, i, *p_val ); p_var->pf_dup( &p_var->choices.p_values[i] ); p_var->choices_text.p_values[i].psz_string = ( p_val2 && p_val2->psz_string ) ? strdup( p_val2->psz_string ) : NULL; CheckValue( p_var, &p_var->val ); break; case VLC_VAR_DELCHOICE: /* FIXME: the list is sorted, dude. Use something cleverer. */ for( i = 0 ; i < p_var->choices.i_count ; i++ ) { if( p_var->pf_cmp( p_var->choices.p_values[i], *p_val ) == 0 ) { break; } } if( i == p_var->choices.i_count ) { /* Not found */ vlc_mutex_unlock( &p_this->var_lock ); return VLC_EGENERIC; } if( p_var->i_default > i ) { p_var->i_default--; } else if( p_var->i_default == i ) { p_var->i_default = -1; } p_var->pf_free( &p_var->choices.p_values[i] ); if( p_var->choices_text.p_values[i].psz_string ) free( p_var->choices_text.p_values[i].psz_string ); REMOVE_ELEM( p_var->choices.p_values, p_var->choices.i_count, i ); REMOVE_ELEM( p_var->choices_text.p_values, p_var->choices_text.i_count, i ); CheckValue( p_var, &p_var->val ); break; case VLC_VAR_CHOICESCOUNT: p_val->i_int = p_var->choices.i_count; break; case VLC_VAR_CLEARCHOICES: for( i = 0 ; i < p_var->choices.i_count ; i++ ) { p_var->pf_free( &p_var->choices.p_values[i] ); } if( p_var->choices.i_count ) free( p_var->choices.p_values ); p_var->choices.i_count = 0; p_var->choices.p_values = NULL; p_var->i_default = -1; break; case VLC_VAR_SETDEFAULT: /* FIXME: the list is sorted, dude. Use something cleverer. */ for( i = 0 ; i < p_var->choices.i_count ; i++ ) { if( p_var->pf_cmp( p_var->choices.p_values[i], *p_val ) == 0 ) { break; } } if( i == p_var->choices.i_count ) { /* Not found */ break; } p_var->i_default = i; CheckValue( p_var, &p_var->val ); break; case VLC_VAR_SETVALUE: /* Duplicate data if needed */ p_var->pf_dup( p_val ); /* Backup needed stuff */ oldval = p_var->val; /* Check boundaries and list */ CheckValue( p_var, p_val ); /* Set the variable */ p_var->val = *p_val; /* Free data if needed */ p_var->pf_free( &oldval ); break; case VLC_VAR_GETCHOICES: case VLC_VAR_GETLIST: p_val->p_list = malloc( sizeof(vlc_list_t) ); if( p_val2 ) p_val2->p_list = malloc( sizeof(vlc_list_t) ); if( p_var->choices.i_count ) { p_val->p_list->p_values = malloc( p_var->choices.i_count * sizeof(vlc_value_t) ); p_val->p_list->pi_types = malloc( p_var->choices.i_count * sizeof(int) ); if( p_val2 ) { p_val2->p_list->p_values = malloc( p_var->choices.i_count * sizeof(vlc_value_t) ); p_val2->p_list->pi_types = malloc( p_var->choices.i_count * sizeof(int) ); } } p_val->p_list->i_count = p_var->choices.i_count; if( p_val2 ) p_val2->p_list->i_count = p_var->choices.i_count; for( i = 0 ; i < p_var->choices.i_count ; i++ ) { p_val->p_list->p_values[i] = p_var->choices.p_values[i]; p_val->p_list->pi_types[i] = p_var->i_type; p_var->pf_dup( &p_val->p_list->p_values[i] ); if( p_val2 ) { p_val2->p_list->p_values[i].psz_string = p_var->choices_text.p_values[i].psz_string ? strdup(p_var->choices_text.p_values[i].psz_string) : NULL; p_val2->p_list->pi_types[i] = VLC_VAR_STRING; } } break; case VLC_VAR_FREELIST: FreeList( p_val ); break; case VLC_VAR_SETTEXT: if( p_var->psz_text ) free( p_var->psz_text ); if( p_val && p_val->psz_string ) p_var->psz_text = strdup( p_val->psz_string ); break; case VLC_VAR_GETTEXT: p_val->psz_string = NULL; if( p_var->psz_text ) { p_val->psz_string = strdup( p_var->psz_text ); } break; case VLC_VAR_INHERITVALUE: { vlc_value_t val; if( InheritValue( p_this, psz_name, &val, p_var->i_type ) == VLC_SUCCESS ); { /* Duplicate already done */ /* Backup needed stuff */ oldval = p_var->val; /* Check boundaries and list */ CheckValue( p_var, &val ); /* Set the variable */ p_var->val = val; /* Free data if needed */ p_var->pf_free( &oldval ); } } break; default: break; } vlc_mutex_unlock( &p_this->var_lock ); return VLC_SUCCESS; } /***************************************************************************** * var_Type: request a variable's type ***************************************************************************** * This function returns the variable type if it exists, or 0 if the * variable could not be found. *****************************************************************************/ int __var_Type( vlc_object_t *p_this, const char *psz_name ) { int i_var, i_type; vlc_mutex_lock( &p_this->var_lock ); i_var = Lookup( p_this->p_vars, p_this->i_vars, psz_name ); if( i_var < 0 ) { vlc_mutex_unlock( &p_this->var_lock ); return 0; } i_type = p_this->p_vars[i_var].i_type; vlc_mutex_unlock( &p_this->var_lock ); return i_type; } /***************************************************************************** * var_Set: set a variable's value ***************************************************************************** * *****************************************************************************/ int __var_Set( vlc_object_t *p_this, const char *psz_name, vlc_value_t val ) { int i_var; variable_t *p_var; vlc_value_t oldval; vlc_mutex_lock( &p_this->var_lock ); i_var = GetUnused( p_this, psz_name ); if( i_var < 0 ) { vlc_mutex_unlock( &p_this->var_lock ); return i_var; } p_var = &p_this->p_vars[i_var]; /* Duplicate data if needed */ p_var->pf_dup( &val ); /* Backup needed stuff */ oldval = p_var->val; /* Check boundaries and list */ CheckValue( p_var, &val ); /* Set the variable */ p_var->val = val; /* Deal with callbacks. Tell we're in a callback, release the lock, * call stored functions, retake the lock. */ if( p_var->i_entries ) { int i_var; int i_entries = p_var->i_entries; callback_entry_t *p_entries = p_var->p_entries; p_var->b_incallback = VLC_TRUE; vlc_mutex_unlock( &p_this->var_lock ); /* The real calls */ for( ; i_entries-- ; ) { p_entries[i_entries].pf_callback( p_this, psz_name, oldval, val, p_entries[i_entries].p_data ); } vlc_mutex_lock( &p_this->var_lock ); i_var = Lookup( p_this->p_vars, p_this->i_vars, psz_name ); if( i_var < 0 ) { msg_Err( p_this, "variable %s has disappeared", psz_name ); vlc_mutex_unlock( &p_this->var_lock ); return VLC_ENOVAR; } p_var = &p_this->p_vars[i_var]; p_var->b_incallback = VLC_FALSE; } /* Free data if needed */ p_var->pf_free( &oldval ); vlc_mutex_unlock( &p_this->var_lock ); return VLC_SUCCESS; } /***************************************************************************** * var_Get: get a variable's value ***************************************************************************** * *****************************************************************************/ int __var_Get( vlc_object_t *p_this, const char *psz_name, vlc_value_t *p_val ) { int i_var; variable_t *p_var; vlc_mutex_lock( &p_this->var_lock ); i_var = Lookup( p_this->p_vars, p_this->i_vars, psz_name ); if( i_var < 0 ) { vlc_mutex_unlock( &p_this->var_lock ); return VLC_ENOVAR; } p_var = &p_this->p_vars[i_var]; /* Really get the variable */ *p_val = p_var->val; /* Duplicate value if needed */ p_var->pf_dup( p_val ); vlc_mutex_unlock( &p_this->var_lock ); return VLC_SUCCESS; } /***************************************************************************** * var_AddCallback: register a callback in a variable ***************************************************************************** * We store a function pointer pf_callback that will be called upon variable * modification. p_data is a generic pointer that will be passed as additional * argument to the callback function. *****************************************************************************/ int __var_AddCallback( vlc_object_t *p_this, const char *psz_name, vlc_callback_t pf_callback, void *p_data ) { int i_var; variable_t *p_var; callback_entry_t entry; entry.pf_callback = pf_callback; entry.p_data = p_data; vlc_mutex_lock( &p_this->var_lock ); i_var = GetUnused( p_this, psz_name ); if( i_var < 0 ) { vlc_mutex_unlock( &p_this->var_lock ); return i_var; } p_var = &p_this->p_vars[i_var]; INSERT_ELEM( p_var->p_entries, p_var->i_entries, p_var->i_entries, entry ); vlc_mutex_unlock( &p_this->var_lock ); return VLC_SUCCESS; } /***************************************************************************** * var_DelCallback: remove a callback from a variable ***************************************************************************** * pf_callback and p_data have to be given again, because different objects * might have registered the same callback function. *****************************************************************************/ int __var_DelCallback( vlc_object_t *p_this, const char *psz_name, vlc_callback_t pf_callback, void *p_data ) { int i_entry, i_var; variable_t *p_var; vlc_mutex_lock( &p_this->var_lock ); i_var = GetUnused( p_this, psz_name ); if( i_var < 0 ) { vlc_mutex_unlock( &p_this->var_lock ); return i_var; } p_var = &p_this->p_vars[i_var]; for( i_entry = p_var->i_entries ; i_entry-- ; ) { if( p_var->p_entries[i_entry].pf_callback == pf_callback && p_var->p_entries[i_entry].p_data == p_data ) { break; } } if( i_entry < 0 ) { vlc_mutex_unlock( &p_this->var_lock ); return VLC_EGENERIC; } REMOVE_ELEM( p_var->p_entries, p_var->i_entries, i_entry ); vlc_mutex_unlock( &p_this->var_lock ); return VLC_SUCCESS; } /* Following functions are local */ /***************************************************************************** * GetUnused: find an unused variable from its name ***************************************************************************** * We do i_tries tries before giving up, just in case the variable is being * modified and called from a callback. *****************************************************************************/ static int GetUnused( vlc_object_t *p_this, const char *psz_name ) { int i_var, i_tries = 0; while( VLC_TRUE ) { i_var = Lookup( p_this->p_vars, p_this->i_vars, psz_name ); if( i_var < 0 ) { return VLC_ENOVAR; } if( ! p_this->p_vars[i_var].b_incallback ) { return i_var; } if( i_tries++ > 100 ) { msg_Err( p_this, "caught in a callback deadlock?" ); return VLC_ETIMEOUT; } vlc_mutex_unlock( &p_this->var_lock ); msleep( THREAD_SLEEP ); vlc_mutex_lock( &p_this->var_lock ); } } /***************************************************************************** * 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 uint32_t HashString( const char *psz_string ) { uint32_t i_hash = 0; while( *psz_string ) { i_hash += *psz_string++; i_hash += i_hash << 10; i_hash ^= i_hash >> 8; } return i_hash; } /***************************************************************************** * Insert: 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 Insert( variable_t *p_vars, int i_count, const char *psz_name ) { if( i_count == 0 ) { return 0; } return InsertInner( p_vars, i_count, HashString( psz_name ) ); } static int InsertInner( variable_t *p_vars, int i_count, uint32_t i_hash ) { int i_middle; if( i_hash <= p_vars[0].i_hash ) { return 0; } if( i_hash >= p_vars[i_count - 1].i_hash ) { return i_count; } i_middle = i_count / 2; /* We know that 0 < i_middle */ if( i_hash < p_vars[i_middle].i_hash ) { return InsertInner( p_vars, i_middle, i_hash ); } /* We know that i_middle + 1 < i_count */ if( i_hash > p_vars[i_middle + 1].i_hash ) { return i_middle + 1 + InsertInner( p_vars + i_middle + 1, i_count - i_middle - 1, i_hash ); } return i_middle + 1; } /***************************************************************************** * Lookup: find an existing variable given its name ***************************************************************************** * 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? *****************************************************************************/ static int Lookup( variable_t *p_vars, int i_count, const char *psz_name ) { uint32_t i_hash; int i, i_pos; if( i_count == 0 ) { return -1; } i_hash = HashString( psz_name ); i_pos = LookupInner( p_vars, i_count, i_hash ); /* Hash not found */ if( i_hash != p_vars[i_pos].i_hash ) { return -1; } /* Hash found, entry found */ if( !strcmp( psz_name, p_vars[i_pos].psz_name ) ) { 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_vars[i].i_hash ; i-- ) { if( !strcmp( psz_name, p_vars[i].psz_name ) ) { return i; } } for( i = i_pos + 1 ; i < i_count && i_hash == p_vars[i].i_hash ; i++ ) { if( !strcmp( psz_name, p_vars[i].psz_name ) ) { return i; } } /* Hash found, but entry not found */ return -1; } static int LookupInner( variable_t *p_vars, int i_count, uint32_t i_hash ) { int i_middle; if( i_hash <= p_vars[0].i_hash ) { return 0; } if( i_hash >= p_vars[i_count-1].i_hash ) { return i_count - 1; } i_middle = i_count / 2; /* We know that 0 < i_middle */ if( i_hash < p_vars[i_middle].i_hash ) { return LookupInner( p_vars, i_middle, i_hash ); } /* We know that i_middle + 1 < i_count */ if( i_hash > p_vars[i_middle].i_hash ) { return i_middle + LookupInner( p_vars + i_middle, i_count - i_middle, i_hash ); } return i_middle; } /***************************************************************************** * CheckValue: check that a value is valid wrt. a variable ***************************************************************************** * This function checks p_val's value against p_var's limitations such as * minimal and maximal value, step, in-list position, and modifies p_val if * necessary. *****************************************************************************/ static void CheckValue ( variable_t *p_var, vlc_value_t *p_val ) { /* Check that our variable is in the list */ if( p_var->i_type & VLC_VAR_HASCHOICE && p_var->choices.i_count ) { int i; /* FIXME: the list is sorted, dude. Use something cleverer. */ for( i = p_var->choices.i_count ; i-- ; ) { if( p_var->pf_cmp( *p_val, p_var->choices.p_values[i] ) == 0 ) { break; } } /* If not found, change it to anything vaguely valid */ if( i < 0 ) { /* Free the old variable, get the new one, dup it */ p_var->pf_free( p_val ); *p_val = p_var->choices.p_values[p_var->i_default >= 0 ? p_var->i_default : 0 ]; p_var->pf_dup( p_val ); } } /* Check that our variable is within the bounds */ switch( p_var->i_type & VLC_VAR_TYPE ) { case VLC_VAR_INTEGER: if( p_var->i_type & VLC_VAR_HASSTEP && p_var->step.i_int && (p_val->i_int % p_var->step.i_int) ) { p_val->i_int = (p_val->i_int + (p_var->step.i_int / 2)) / p_var->step.i_int * p_var->step.i_int; } if( p_var->i_type & VLC_VAR_HASMIN && p_val->i_int < p_var->min.i_int ) { p_val->i_int = p_var->min.i_int; } if( p_var->i_type & VLC_VAR_HASMAX && p_val->i_int > p_var->max.i_int ) { p_val->i_int = p_var->max.i_int; } break; case VLC_VAR_FLOAT: if( p_var->i_type & VLC_VAR_HASSTEP && p_var->step.f_float ) { float f_round = p_var->step.f_float * (float)(int)( 0.5 + p_val->f_float / p_var->step.f_float ); if( p_val->f_float != f_round ) { p_val->f_float = f_round; } } if( p_var->i_type & VLC_VAR_HASMIN && p_val->f_float < p_var->min.f_float ) { p_val->f_float = p_var->min.f_float; } if( p_var->i_type & VLC_VAR_HASMAX && p_val->f_float > p_var->max.f_float ) { p_val->f_float = p_var->max.f_float; } break; case VLC_VAR_TIME: /* FIXME: TODO */ break; } } /***************************************************************************** * InheritValue: try to inherit the value of this variable from the same one * in our closest parent. *****************************************************************************/ static int InheritValue( vlc_object_t *p_this, const char *psz_name, vlc_value_t *p_val, int i_type ) { int i_var; variable_t *p_var; /* No need to take the structure lock, * we are only looking for our parents */ if( !p_this->p_parent ) { switch( i_type & VLC_VAR_TYPE ) { case VLC_VAR_STRING: p_val->psz_string = config_GetPsz( p_this, psz_name ); if( !p_val->psz_string ) p_val->psz_string = strdup(""); break; case VLC_VAR_FLOAT: p_val->f_float = config_GetFloat( p_this, psz_name ); break; case VLC_VAR_INTEGER: p_val->i_int = config_GetInt( p_this, psz_name ); break; case VLC_VAR_BOOL: p_val->b_bool = config_GetInt( p_this, psz_name ); break; default: return VLC_ENOOBJ; break; } return VLC_SUCCESS; } /* Look for the variable */ vlc_mutex_lock( &p_this->p_parent->var_lock ); i_var = Lookup( p_this->p_parent->p_vars, p_this->p_parent->i_vars, psz_name ); if( i_var >= 0 ) { /* We found it! */ p_var = &p_this->p_parent->p_vars[i_var]; /* Really get the variable */ *p_val = p_var->val; /* Duplicate value if needed */ p_var->pf_dup( p_val ); vlc_mutex_unlock( &p_this->p_parent->var_lock ); return VLC_SUCCESS; } vlc_mutex_unlock( &p_this->p_parent->var_lock ); /* We're still not there */ return InheritValue( p_this->p_parent, psz_name, p_val, i_type ); }