contiki/apps/antelope/storage-cfs.c

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/*
* 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
* Contiki File System (CFS) backend for the storage abstraction
* used by the database.
* \author
* Nicolas Tsiftes <nvt@sics.se>
*/
#include <stdio.h>
#include <string.h>
#include "cfs/cfs.h"
#include "cfs/cfs-coffee.h"
#include "lib/random.h"
#define DEBUG DEBUG_NONE
#include "net/ip/uip-debug.h"
#include "db-options.h"
#include "storage.h"
struct attribute_record {
char name[ATTRIBUTE_NAME_LENGTH];
uint8_t domain;
uint8_t element_size;
};
struct index_record {
char attribute_name[ATTRIBUTE_NAME_LENGTH];
char file_name[DB_MAX_FILENAME_LENGTH];
uint8_t type;
};
#if DB_FEATURE_COFFEE
#define DB_COFFEE_CATALOG_SIZE RELATION_NAME_LENGTH + \
(DB_MAX_ATTRIBUTES_PER_RELATION * \
sizeof(struct attribute_record))
#endif
#define ROW_XOR 0xf6U
static void
merge_strings(char *dest, char *prefix, char *suffix)
{
strcpy(dest, prefix);
strcat(dest, suffix);
}
char *
storage_generate_file(char *prefix, unsigned long size)
{
static char filename[ATTRIBUTE_NAME_LENGTH + sizeof(".ffff")];
#if !DB_FEATURE_COFFEE
int fd;
#endif
snprintf(filename, sizeof(filename), "%s.%x", prefix,
(unsigned)(random_rand() & 0xffff));
#if DB_FEATURE_COFFEE
PRINTF("DB: Reserving %lu bytes in %s\n", size, filename);
if(cfs_coffee_reserve(filename, size) < 0) {
PRINTF("DB: Failed to reserve\n");
return NULL;
}
return filename;
#else
fd = cfs_open(filename, CFS_WRITE);
cfs_close(fd);
return fd < 0 ? NULL : filename;
#endif /* DB_FEATURE_COFFEE */
}
db_result_t
storage_load(relation_t *rel)
{
PRINTF("DB: Opening the tuple file %s\n", rel->tuple_filename);
rel->tuple_storage = cfs_open(rel->tuple_filename,
CFS_READ | CFS_WRITE | CFS_APPEND);
if(rel->tuple_storage < 0) {
PRINTF("DB: Failed to open the tuple file\n");
return DB_STORAGE_ERROR;
}
return DB_OK;
}
void
storage_unload(relation_t *rel)
{
if(RELATION_HAS_TUPLES(rel)) {
PRINTF("DB: Unload tuple file %s\n", rel->tuple_filename);
cfs_close(rel->tuple_storage);
rel->tuple_storage = -1;
}
}
db_result_t
storage_get_relation(relation_t *rel, char *name)
{
int fd;
int r;
int i;
struct attribute_record record;
db_result_t result;
fd = cfs_open(name, CFS_READ);
if(fd < 0) {
return DB_STORAGE_ERROR;
}
r = cfs_read(fd, rel->name, sizeof(rel->name));
if(r != sizeof(rel->name)) {
cfs_close(fd);
PRINTF("DB: Failed to read name, got %d of %d bytes\n",
r, sizeof(rel->name));
return DB_STORAGE_ERROR;
}
r = cfs_read(fd, rel->tuple_filename, sizeof(rel->tuple_filename));
if(r != sizeof(rel->name)) {
cfs_close(fd);
PRINTF("DB: Failed to read tuple filename\n");
return DB_STORAGE_ERROR;
}
rel->tuple_filename[sizeof(rel->tuple_filename) - 1] ^= ROW_XOR;
/* Read attribute records. */
result = DB_OK;
for(i = 0;; i++) {
r = cfs_read(fd, &record, sizeof(record));
if(r == 0) {
break;
}
if(r != sizeof(record)) {
PRINTF("DB: Failed to read attribute record %d (r = %d)\n", i, r);
result = DB_STORAGE_ERROR;
break;
}
if(relation_attribute_add(rel, DB_MEMORY, record.name,
record.domain, record.element_size) == NULL) {
PRINTF("DB: Failed to add the attribute %s\n", record.name);
result = DB_STORAGE_ERROR;
break;
}
}
PRINTF("DB: Read %d attributes\n", i);
cfs_close(fd);
return result;
}
db_result_t
storage_put_relation(relation_t *rel)
{
int fd;
int r;
char *str;
unsigned char *last_byte;
PRINTF("DB: put_relation(%s)\n", rel->name);
cfs_remove(rel->name);
#if DB_FEATURE_COFFEE
cfs_coffee_reserve(rel->name, DB_COFFEE_CATALOG_SIZE);
#endif
fd = cfs_open(rel->name, CFS_WRITE | CFS_READ);
if(fd < 0) {
return DB_STORAGE_ERROR;
}
r = cfs_write(fd, rel->name, sizeof(rel->name));
if(r != sizeof(rel->name)) {
cfs_close(fd);
cfs_remove(rel->name);
return DB_STORAGE_ERROR;
}
if(rel->tuple_filename[0] == '\0') {
str = storage_generate_file("tuple", DB_COFFEE_RESERVE_SIZE);
if(str == NULL) {
cfs_close(fd);
cfs_remove(rel->name);
return DB_STORAGE_ERROR;
}
strncpy(rel->tuple_filename, str, sizeof(rel->tuple_filename) - 1);
rel->tuple_filename[sizeof(rel->tuple_filename) - 1] = '\0';
}
/*
* Encode the last byte to ensure that the filename is not
* null-terminated. This will make the Coffee FS determine
* the correct length when re-opening the file.
*/
last_byte = (unsigned char *)&rel->tuple_filename[sizeof(rel->tuple_filename) - 1];
*last_byte ^= ROW_XOR;
r = cfs_write(fd, rel->tuple_filename, sizeof(rel->tuple_filename));
*last_byte ^= ROW_XOR;
if(r != sizeof(rel->tuple_filename)) {
cfs_close(fd);
cfs_remove(rel->tuple_filename);
return DB_STORAGE_ERROR;
}
PRINTF("DB: Saved relation %s\n", rel->name);
cfs_close(fd);
return DB_OK;
}
db_result_t
storage_put_attribute(relation_t *rel, attribute_t *attr)
{
int fd;
struct attribute_record record;
int r;
PRINTF("DB: put_attribute(%s, %s)\n", rel->name, attr->name);
fd = cfs_open(rel->name, CFS_WRITE | CFS_APPEND);
if(fd < 0) {
return DB_STORAGE_ERROR;
}
memset(&record.name, 0, sizeof(record.name));
memcpy(record.name, attr->name, sizeof(record.name));
record.domain = attr->domain;
record.element_size = attr->element_size;
r = cfs_write(fd, &record, sizeof(record));
if(r != sizeof(record)) {
cfs_close(fd);
cfs_remove(rel->name);
return DB_STORAGE_ERROR;
}
cfs_close(fd);
return DB_OK;
}
db_result_t
storage_drop_relation(relation_t *rel, int remove_tuples)
{
if(remove_tuples && RELATION_HAS_TUPLES(rel)) {
cfs_remove(rel->tuple_filename);
}
return cfs_remove(rel->name) < 0 ? DB_STORAGE_ERROR : DB_OK;
}
#if DB_FEATURE_REMOVE
db_result_t
storage_rename_relation(char *old_name, char *new_name)
{
db_result_t result;
int old_fd;
int new_fd;
int r;
char buf[64];
result = DB_STORAGE_ERROR;
old_fd = new_fd = -1;
old_fd = cfs_open(old_name, CFS_READ);
new_fd = cfs_open(new_name, CFS_WRITE);
if(old_fd < 0 || new_fd < 0) {
goto error;
}
for(;;) {
r = cfs_read(old_fd, buf, sizeof(buf));
if(r < 0) {
goto error;
} else if(r == 0) {
break;
}
if(cfs_write(new_fd, buf, r) != r) {
goto error;
}
};
cfs_remove(old_name);
result = DB_OK;
error:
cfs_close(old_fd);
cfs_close(new_fd);
if(result != DB_OK) {
cfs_remove(new_name);
}
return result;
}
#endif /* DB_FEATURE_REMOVE */
db_result_t
storage_get_index(index_t *index, relation_t *rel, attribute_t *attr)
{
char filename[INDEX_NAME_LENGTH];
int fd;
int r;
struct index_record record;
db_result_t result;
merge_strings(filename, rel->name, INDEX_NAME_SUFFIX);
fd = cfs_open(filename, CFS_READ);
if(fd < 0) {
return DB_STORAGE_ERROR;
}
for(result = DB_STORAGE_ERROR;;) {
r = cfs_read(fd, &record, sizeof(record));
if(r < sizeof(record)) {
break;
}
if(strcmp(attr->name, record.attribute_name) == 0) {
PRINTF("DB: Found the index record for %s.%s: type %d, filename %s\n",
rel->name, attr->name, record.type, record.file_name);
index->type = record.type;
memcpy(index->descriptor_file, record.file_name,
sizeof(index->descriptor_file));
result = DB_OK;
}
}
cfs_close(fd);
return result;
}
db_result_t
storage_put_index(index_t *index)
{
char filename[INDEX_NAME_LENGTH];
int fd;
int r;
struct index_record record;
db_result_t result;
merge_strings(filename, index->rel->name, INDEX_NAME_SUFFIX);
fd = cfs_open(filename, CFS_WRITE | CFS_APPEND);
if(fd < 0) {
return DB_STORAGE_ERROR;
}
strcpy(record.attribute_name, index->attr->name);
memcpy(record.file_name, index->descriptor_file, sizeof(record.file_name));
record.type = index->type;
result = DB_OK;
r = cfs_write(fd, &record, sizeof(record));
if(r < sizeof(record)) {
result = DB_STORAGE_ERROR;
} else {
PRINTF("DB: Wrote an index record for %s.%s, type %d\n",
index->rel->name, index->attr->name, record.type);
}
cfs_close(fd);
return result;
}
db_result_t
storage_get_row(relation_t *rel, tuple_id_t *tuple_id, storage_row_t row)
{
int r;
tuple_id_t nrows;
if(DB_ERROR(storage_get_row_amount(rel, &nrows))) {
return DB_STORAGE_ERROR;
}
if(*tuple_id >= nrows) {
return DB_FINISHED;
}
if(cfs_seek(rel->tuple_storage, *tuple_id * rel->row_length, CFS_SEEK_SET) ==
(cfs_offset_t)-1) {
return DB_STORAGE_ERROR;
}
r = cfs_read(rel->tuple_storage, row, rel->row_length);
if(r < 0) {
PRINTF("DB: Reading failed on fd %d\n", rel->tuple_storage);
return DB_STORAGE_ERROR;
} else if(r == 0) {
return DB_FINISHED;
} else if(r < rel->row_length) {
PRINTF("DB: Incomplete record: %d < %d\n", r, rel->row_length);
return DB_STORAGE_ERROR;
}
row[rel->row_length - 1] ^= ROW_XOR;
PRINTF("DB: Read %d bytes from relation %s\n", rel->row_length, rel->name);
return DB_OK;
}
db_result_t
storage_put_row(relation_t *rel, storage_row_t row)
{
cfs_offset_t end;
unsigned remaining;
int r;
unsigned char *last_byte;
#if DB_FEATURE_INTEGRITY
int missing_bytes;
char buf[rel->row_length];
#endif
end = cfs_seek(rel->tuple_storage, 0, CFS_SEEK_END);
if(end == (cfs_offset_t)-1) {
return DB_STORAGE_ERROR;
}
#if DB_FEATURE_INTEGRITY
missing_bytes = end % rel->row_length;
if(missing_bytes > 0) {
memset(buf, 0xff, sizeof(buf));
r = cfs_write(rel->tuple_storage, buf, sizeof(buf));
if(r != missing_bytes) {
return DB_STORAGE_ERROR;
}
}
#endif
/* Ensure that last written byte is separated from 0, to make file
lengths correct in Coffee. */
last_byte = row + rel->row_length - 1;
*last_byte ^= ROW_XOR;
remaining = rel->row_length;
do {
r = cfs_write(rel->tuple_storage, row, remaining);
if(r < 0) {
PRINTF("DB: Failed to store %u bytes\n", remaining);
*last_byte ^= ROW_XOR;
return DB_STORAGE_ERROR;
}
row += r;
remaining -= r;
} while(remaining > 0);
PRINTF("DB: Stored a of %d bytes\n", rel->row_length);
*last_byte ^= ROW_XOR;
return DB_OK;
}
db_result_t
storage_get_row_amount(relation_t *rel, tuple_id_t *amount)
{
cfs_offset_t offset;
if(rel->row_length == 0) {
*amount = 0;
} else {
offset = cfs_seek(rel->tuple_storage, 0, CFS_SEEK_END);
if(offset == (cfs_offset_t)-1) {
return DB_STORAGE_ERROR;
}
*amount = (tuple_id_t)(offset / rel->row_length);
}
return DB_OK;
}
db_storage_id_t
storage_open(const char *filename)
{
int fd;
fd = cfs_open(filename, CFS_WRITE | CFS_READ);
#if DB_FEATURE_COFFEE
if(fd >= 0) {
cfs_coffee_set_io_semantics(fd, CFS_COFFEE_IO_FLASH_AWARE);
}
#endif
return fd;
}
void
storage_close(db_storage_id_t fd)
{
cfs_close(fd);
}
db_result_t
storage_read(db_storage_id_t fd,
void *buffer, unsigned long offset, unsigned length)
{
char *ptr;
int r;
/* Extend the file if necessary, so that previously unwritten bytes
will be read in as zeroes. */
if(cfs_seek(fd, offset + length, CFS_SEEK_SET) == (cfs_offset_t)-1) {
return DB_STORAGE_ERROR;
}
if(cfs_seek(fd, offset, CFS_SEEK_SET) == (cfs_offset_t)-1) {
return DB_STORAGE_ERROR;
}
ptr = buffer;
while(length > 0) {
r = cfs_read(fd, ptr, length);
if(r <= 0) {
return DB_STORAGE_ERROR;
}
ptr += r;
length -= r;
}
return DB_OK;
}
db_result_t
storage_write(db_storage_id_t fd,
void *buffer, unsigned long offset, unsigned length)
{
char *ptr;
int r;
if(cfs_seek(fd, offset, CFS_SEEK_SET) == (cfs_offset_t)-1) {
return DB_STORAGE_ERROR;
}
ptr = buffer;
while(length > 0) {
r = cfs_write(fd, ptr, length);
if(r <= 0) {
return DB_STORAGE_ERROR;
}
ptr += r;
length -= r;
}
return DB_OK;
}