source: trunk/drmaa_utils/drmaa_utils/environ.c @ 1

/* $Id: environ.c 2 2009-10-12 09:51:22Z mamonski $ */
/*
 * FedStage DRMAA utilities library
 * Copyright (C) 2006-2008  FedStage Systems
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include <string.h>
#include <stdlib.h>

#include <drmaa_utils/common.h>
#include <drmaa_utils/environ.h>
#include <drmaa_utils/lookup3.h>

#ifndef lint
static char rcsid[]
#       ifdef __GNUC__
                __attribute__ ((unused))
#       endif
        = "$Id: environ.c 2 2009-10-12 09:51:22Z mamonski $";
#endif


static void
fsd_environ_destroy( fsd_environ_t *self )
{
        unsigned i;
        fsd_environ_item_t *j;
        if( self->_table )
         {
                for( i = 0;  i < self->_table_size;  i++ )
                        for( j = self->_table[i];  j != NULL; )
                         {
                                fsd_environ_item_t *to_delete = j;
                                j = j->next;
                                fsd_free( to_delete->name );
                                fsd_free( to_delete->value );
                                fsd_free( to_delete );
                         }
                fsd_free( self->_table );
         }
        fsd_free( self );
}

static const char *
fsd_environ_get( fsd_environ_t *self, const char *name )
{
        uint32_t hash;
        const fsd_environ_item_t *i;
        hash = hashstr( name, strlen(name), 0 );
        hash &= self->_table_size - 1;
        for( i = self->_table[hash];  i != NULL;  i = i->next )
                if( strcmp( i->name, name ) == 0 )
                        return i->value;
        return NULL;
}

static void
fsd_environ_set( fsd_environ_t *self, char *name, char *value )
{
        uint32_t hash;
        fsd_environ_item_t *i;
        fsd_environ_item_t *item = NULL;
        bool replaced = false;

        TRY
         {
                hash = hashstr( name, strlen(name), 0 );
                hash &= self->_table_size - 1;
                for( i = self->_table[hash];  i != NULL;  i = i->next )
                 {
                        if( strcmp( i->name, name ) == 0 )
                         {
                                fsd_free( i->value );
                                i->value = value;
                                replaced = true;
                                break;
                         }
                 }

                if( !replaced )
                 {
                        fsd_malloc( item, fsd_environ_item_t );
                        item->next = self->_table[hash];
                        item->name = name;
                        item->value = value;
                        self->_table[hash] = item;
                 }
         }
        EXCEPT_DEFAULT
         {
                fsd_free( name );
                fsd_free( value );
                fsd_exc_reraise();
         }
        END_TRY
}

static void
fsd_environ_update( fsd_environ_t *self, const char *const envp[] )
{
        const char *const *i;
        for( i = envp;  *i;  i++ )
         {
                const char *eq;
                char *volatile name = NULL;
                char *volatile value = NULL;
                eq = strchr( *i, '=' );
                if( eq == NULL )
                        fsd_exc_raise_code( FSD_ERRNO_INVALID_VALUE_FORMAT );
                name = fsd_strndup( *i, eq-*i );
                TRY
                 { value = fsd_strdup( eq+1 ); }
                EXCEPT_DEFAULT
                 { fsd_free(name); fsd_exc_reraise(); }
                END_TRY
                self->set( self, name, value );
         }
}

static char **
fsd_environ_list( fsd_environ_t *self )
{
        uint32_t i;
        const fsd_environ_item_t *j;
        char **volatile result = NULL;
        unsigned items = 0;

        TRY
         {
                for( i = 0;  i < self->_table_size;  i++ )
                        for( j = self->_table[i];  j != NULL;  j = j->next )
                         {
                                items++;
                                fsd_realloc( result, items+1, char* );
                                result[items] = NULL;
                                result[items-1] = fsd_asprintf( "%s=%s", j->name, j->value );
                         }
         }
        EXCEPT_DEFAULT
         {
                fsd_free_vector( result );
                fsd_exc_reraise();
         }
        END_TRY

        i = 0;
        while (result[i])
         {
                fsd_log_debug(("enc[%d]=%s",i, result[i]));
                i++;
         }

        return result;
}

static fsd_environ_t *
fsd_environ_apply( fsd_environ_t *self )
{
        uint32_t i;
        const fsd_environ_item_t *j;
        fsd_environ_t *volatile saved_state =NULL;
        TRY
         {
                saved_state = fsd_environ_new( NULL );
                for( i = 0;  i < self->_table_size;  i++ )
                        for( j = self->_table[i];  j != NULL;  j = j->next )
                         {
                                const char *value = getenv( j->name );
                                if( value )
                                        saved_state->set( saved_state,
                                                        fsd_strdup(j->name), fsd_strdup(value) );
                                setenv( j->name, j->value, 1 );
                         }
         }
        EXCEPT_DEFAULT
         {
                if( saved_state )
                        saved_state->destroy( saved_state );
                fsd_exc_reraise();
         }
        END_TRY
        return saved_state;
}

static void
fsd_environ_restore( fsd_environ_t *self, fsd_environ_t *saved_state )
{
        uint32_t i;
        const fsd_environ_item_t *j;
        for( i = 0;  i < self->_table_size;  i++ )
                for( j = self->_table[i];  j != NULL;  j = j->next )
                 {
                        const char *value = saved_state->get( saved_state, j->name );
                        if( value )
                                setenv( j->name, value, 1 );
                        else
                                unsetenv( j->name );
                 }
}

fsd_environ_t *
fsd_environ_new( const char *const envp[] )
{
        fsd_environ_t *volatile self = NULL;
        TRY
         {
                fsd_malloc( self, fsd_environ_t );
                self->destroy = fsd_environ_destroy;
                self->get = fsd_environ_get;
                self->set = fsd_environ_set;
                self->update = fsd_environ_update;
                self->list = fsd_environ_list;
                self->apply = fsd_environ_apply;
                self->restore = fsd_environ_restore;
                self->_table_size = 256;
                fsd_calloc( self->_table, self->_table_size, fsd_environ_item_t* );
                if( envp )
                        self->update( self, envp );
         }
        EXCEPT_DEFAULT
         {
                if( self )
                        self->destroy( self );
         }
        END_TRY
        return self;
}