nes-proj/os/storage/antelope/result.c
2017-09-22 17:09:54 +02:00

186 lines
5.1 KiB
C

/*
* Copyright (c) 2010, Swedish Institute of Computer Science
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions 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.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 INSTITUTE 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.
*/
/**
* \file
* Result acquisition interface for AQL queries.
* \author
* Nicolas Tsiftes <nvt@sics.se>
*/
#include <string.h>
#define DEBUG DEBUG_NONE
#include "net/ipv6/uip-debug.h"
#include "result.h"
#include "storage.h"
/* db_get_value: Retrieve the value of the specified attribute in
the current tuple. */
db_result_t
db_get_value(attribute_value_t *value, db_handle_t *handle, unsigned col)
{
attribute_t *attr;
unsigned char *buf;
if(col >= handle->ncolumns) {
PRINTF("DB: Requested value (%d) is out of bounds; max = (%d)\n",
col, handle->ncolumns);
return DB_LIMIT_ERROR;
}
buf = handle->tuple;
for(attr = list_head(handle->result_rel->attributes); attr != NULL; attr = attr->next) {
if(attr->flags & ATTRIBUTE_FLAG_NO_STORE) {
/* This attribute was used for processing only. */
continue;
}
PRINTF("Found attribute %s in the result. The element size is %d\n",
attr->name, attr->element_size);
if(col == 0) {
break;
}
--col;
buf += attr->element_size;
}
if(attr == NULL) {
return DB_NAME_ERROR;
}
return db_phy_to_value(value, attr, buf);
}
/* db_phy_to_value: Convert a value from the physical storage
representation to the internal RAM representation. */
db_result_t
db_phy_to_value(attribute_value_t *value, attribute_t *attr,
unsigned char *ptr)
{
int int_value;
long long_value;
value->domain = attr->domain;
switch(attr->domain) {
case DOMAIN_STRING:
ptr[attr->element_size - 1] = '\0';
VALUE_STRING(value) = ptr;
PRINTF("DB: %s = %s\n", attr->name, ptr);
break;
case DOMAIN_INT:
int_value = (ptr[0] << 8) | ((unsigned)ptr[1] & 0xff);
VALUE_INT(value) = int_value;
PRINTF("DB: %s = %d\n", attr->name, int_value);
break;
case DOMAIN_LONG:
long_value = (long)ptr[0] << 24 | (long)ptr[1] << 16 |
(long)ptr[2] << 8 | (long)ptr[3];
VALUE_LONG(value) = long_value;
PRINTF("DB: %s = %ld\n", attr->name, long_value);
break;
default:
return DB_TYPE_ERROR;
}
return DB_OK;
}
/* db_value_to_phy: Convert a value from the internal RAM representation
to the physical storage representation. */
db_result_t
db_value_to_phy(unsigned char *ptr, attribute_t *attr,
attribute_value_t *value)
{
int int_value;
long long_value;
switch(attr->domain) {
case DOMAIN_STRING:
memcpy(ptr, VALUE_STRING(value), attr->element_size);
ptr[attr->element_size - 1] = '\0';
break;
case DOMAIN_INT:
int_value = VALUE_INT(value);
ptr[0] = int_value >> 8;
ptr[1] = int_value & 0xff;
break;
case DOMAIN_LONG:
long_value = VALUE_LONG(value);
ptr[0] = long_value >> 24;
ptr[1] = long_value >> 16;
ptr[2] = long_value >> 8;
ptr[3] = long_value & 0xff;
break;
default:
return DB_TYPE_ERROR;
}
return DB_OK;
}
/* db_value_to_long: Convert an attribute value
to a value of the C long type. */
long
db_value_to_long(attribute_value_t *value)
{
switch(value->domain) {
case DOMAIN_INT:
return (long)VALUE_INT(value);
case DOMAIN_LONG:
return (long)VALUE_LONG(value);
default:
return 0;
}
}
/* db_free: Free all the resources that are referenced in a DB handle. */
db_result_t
db_free(db_handle_t *handle)
{
if(handle->rel != NULL) {
relation_release(handle->rel);
}
if(handle->result_rel != NULL) {
relation_release(handle->result_rel);
}
if(handle->left_rel != NULL) {
relation_release(handle->left_rel);
}
if(handle->right_rel != NULL) {
relation_release(handle->right_rel);
}
handle->flags = 0;
return DB_OK;
}