RetroArch/rarchdb/rarchdb.c
2015-01-09 17:55:56 +01:00

396 lines
8.9 KiB
C

#include "rarchdb.h"
#include <sys/types.h>
#ifdef _WIN32
#include <direct.h>
#else
#include <unistd.h>
#endif
#include <string.h>
#include <errno.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <fcntl.h>
#include <stdio.h>
#include "rmsgpack_dom.h"
#include "rmsgpack.h"
#include "bintree.h"
#include "rarchdb_endian.h"
#define MAGIC_NUMBER "RARCHDB"
struct rarchdb_header
{
char magic_number[sizeof(MAGIC_NUMBER)-1];
uint64_t metadata_offset;
};
struct rarchdb_metadata
{
uint64_t count;
};
struct rarchdb_index
{
char name[50];
uint64_t key_size;
uint64_t next;
};
struct node_iter_ctx
{
struct rarchdb *db;
struct rarchdb_index *idx;
};
static struct rmsgpack_dom_value sentinal;
static int rarchdb_read_metadata(int fd, struct rarchdb_metadata *md)
{
return rmsgpack_dom_read_into(fd, "count", &md->count, NULL);
}
static int rarchdb_write_metadata(int fd, struct rarchdb_metadata *md)
{
rmsgpack_write_map_header(fd, 1);
rmsgpack_write_string(fd, "count", strlen("count"));
return rmsgpack_write_uint(fd, md->count);
}
int rarchdb_create(int fd, rarchdb_value_provider value_provider, void *ctx)
{
int rv;
uint64_t item_count = 0;
struct rmsgpack_dom_value item = {};
struct rarchdb_header header = {};
struct rarchdb_metadata md;
memcpy(header.magic_number, MAGIC_NUMBER, sizeof(MAGIC_NUMBER)-1);
off_t root = lseek(fd, 0, SEEK_CUR);
// We write the header in the end because we need to know the size of
// the db first
lseek(fd, sizeof(struct rarchdb_header), SEEK_CUR);
while ((rv = value_provider(ctx, &item)) == 0)
{
if((rv = rmsgpack_dom_write(fd, &item)) < 0)
return rv;
rmsgpack_dom_value_free(&item);
item_count++;
}
if (rv < 0)
return rv;
if((rv = rmsgpack_dom_write(fd, &sentinal)) < 0)
return rv;
header.metadata_offset = httobe64(lseek(fd, 0, SEEK_CUR));
md.count = item_count;
rarchdb_write_metadata(fd, &md);
lseek(fd, root, SEEK_SET);
write(fd, &header, sizeof(header));
printf(
#ifdef _WIN32
"Created DB with %I64u entries\n"
#else
"Created DB with %llu entries\n"
#endif
,(unsigned long long)item_count);
return 0;
}
static int rarchdb_read_index_header(int fd, struct rarchdb_index *idx)
{
uint64_t name_len = 50;
return rmsgpack_dom_read_into(fd,
"name", idx->name, &name_len,
"key_size", &idx->key_size,
"next", &idx->next,
NULL);
}
static void rarchdb_write_index_header(int fd, struct rarchdb_index *idx)
{
rmsgpack_write_map_header(fd, 3);
rmsgpack_write_string(fd, "name", strlen("name"));
rmsgpack_write_string(fd, idx->name, strlen(idx->name));
rmsgpack_write_string(fd, "key_size", strlen("key_size"));
rmsgpack_write_uint(fd, idx->key_size);
rmsgpack_write_string(fd, "next", strlen("next"));
rmsgpack_write_uint(fd, idx->next);
}
void rarchdb_close(struct rarchdb *db)
{
close(db->fd);
db->fd = -1;
}
int rarchdb_open(const char *path, struct rarchdb *db)
{
struct rarchdb_header header;
struct rarchdb_metadata md;
int rv;
int fd = open(path, O_RDWR);
if (fd == -1)
return -errno;
db->root = lseek(fd, 0, SEEK_CUR);
if ((rv = read(fd, &header, sizeof(header))) == -1)
{
rv = -errno;
goto error;
}
if (strncmp(header.magic_number, MAGIC_NUMBER, sizeof(MAGIC_NUMBER)) != 0)
{
rv = -EINVAL;
goto error;
}
header.metadata_offset = betoht64(header.metadata_offset);
lseek(fd, header.metadata_offset, SEEK_SET);
if (rarchdb_read_metadata(fd, &md) < 0)
{
rv = -EINVAL;
goto error;
}
db->count = md.count;
db->first_index_offset = lseek(fd, 0, SEEK_CUR);
db->fd = fd;
rarchdb_read_reset(db);
return 0;
error:
close(fd);
return rv;
}
static int rarchdb_find_index(struct rarchdb *db, const char *index_name, struct rarchdb_index *idx)
{
off_t eof = lseek(db->fd, 0, SEEK_END);
off_t offset = lseek(db->fd, db->first_index_offset, SEEK_SET);
while (offset < eof)
{
rarchdb_read_index_header(db->fd, idx);
if (strncmp(index_name, idx->name, strlen(idx->name)) == 0)
return 0;
offset = lseek(db->fd, idx->next, SEEK_CUR);
}
return -1;
}
static int node_compare(const void *a, const void* b, void *ctx)
{
return memcmp(a, b, *(uint8_t*)ctx);
}
static int binsearch(const void *buff, const void *item, uint64_t count, uint8_t field_size, uint64_t *offset)
{
int mid = count / 2;
int item_size = field_size + sizeof(uint64_t);
uint64_t *current = (uint64_t*)buff + (mid * item_size);
int rv = node_compare(current, item, &field_size);
if (rv == 0)
{
*offset = *(uint64_t*)(current + field_size);
return 0;
}
else if (count == 0)
return -1;
else if (rv > 0)
return binsearch(buff, item, mid, field_size, offset);
return binsearch(current + item_size, item, count - mid, field_size, offset);
}
int rarchdb_find_entry(struct rarchdb *db, const char *index_name, const void *key)
{
struct rarchdb_index idx;
int rv;
void *buff;
uint64_t offset;
ssize_t bufflen, nread = 0;
if (rarchdb_find_index(db, index_name, &idx) < 0)
{
rarchdb_read_reset(db);
return -1;
}
bufflen = idx.next;
buff = malloc(bufflen);
if (!buff)
return -ENOMEM;
while (nread < bufflen)
{
void *buff_ = (uint64_t*)buff + nread;
rv = read(db->fd, buff_, bufflen - nread);
if (rv <= 0)
{
free(buff);
return -errno;
}
nread += rv;
}
rv = binsearch(buff, key, db->count, idx.key_size, &offset);
free(buff);
rarchdb_read_reset(db);
if (rv == 0)
lseek(db->fd, offset, SEEK_SET);
return rv;
}
int rarchdb_read_reset(struct rarchdb *db)
{
db->eof = 0;
return lseek(db->fd, db->root + sizeof(struct rarchdb_header), SEEK_SET);
}
int rarchdb_read_item(struct rarchdb *db, struct rmsgpack_dom_value *out)
{
int rv;
if (db->eof)
return EOF;
rv = rmsgpack_dom_read(db->fd, out);
if (rv < 0)
return rv;
if (out->type == RDT_NULL)
{
db->eof = 1;
return EOF;
}
return 0;
}
static int node_iter(void *value, void *ctx)
{
struct node_iter_ctx *nictx = (struct node_iter_ctx*)ctx;
if (write(nictx->db->fd, value, nictx->idx->key_size + sizeof(uint64_t)) > 0)
return 0;
return -1;
}
uint64_t rarchdb_tell(struct rarchdb *db)
{
return lseek(db->fd, 0, SEEK_CUR);
}
int rarchdb_create_index(struct rarchdb *db, const char* name, const char *field_name)
{
int rv;
struct node_iter_ctx nictx;
struct rmsgpack_dom_value key;
struct rarchdb_index idx;
struct rmsgpack_dom_value item;
struct rmsgpack_dom_value *field;
void* buff = NULL;
uint64_t *buff_u64 = NULL;
uint8_t field_size = 0;
struct bintree tree;
uint64_t item_loc = rarchdb_tell(db);
uint64_t idx_header_offset;
bintree_new(&tree, node_compare, &field_size);
rarchdb_read_reset(db);
key.type = RDT_STRING;
key.string.len = strlen(field_name);
// We know we aren't going to change it
key.string.buff = (char *) field_name;
while(rarchdb_read_item(db, &item) == 0)
{
if (item.type != RDT_MAP)
{
rv = -EINVAL;
printf("Only map keys are supported\n");
goto clean;
}
field = rmsgpack_dom_value_map_value(&item, &key);
if (!field)
{
rv = -EINVAL;
printf("field not found in item\n");
goto clean;
}
if (field->type != RDT_BINARY)
{
rv = -EINVAL;
printf("field is not binary\n");
goto clean;
}
if (field->binary.len == 0)
{
rv = -EINVAL;
printf("field is empty\n");
goto clean;
}
if (field_size == 0)
field_size = field->binary.len;
else if (field->binary.len != field_size)
{
rv = -EINVAL;
printf("field is not of correct size\n");
goto clean;
}
buff = malloc(field_size + sizeof(uint64_t));
if(!buff)
{
rv = -ENOMEM;
goto clean;
}
memcpy(buff, field->binary.buff, field_size);
buff_u64 = (uint64_t*)buff + field_size;
memcpy(buff_u64, &item_loc, sizeof(uint64_t));
if (bintree_insert(&tree, buff) != 0)
{
printf("Value is not unique: ");
rmsgpack_dom_value_print(field);
printf("\n");
rv = -EINVAL;
goto clean;
}
buff = NULL;
rmsgpack_dom_value_free(&item);
item_loc = rarchdb_tell(db);
}
(void)rv;
(void)idx_header_offset;
idx_header_offset = lseek(db->fd, 0, SEEK_END);
strncpy(idx.name, name, 50);
idx.name[49] = '\0';
idx.key_size = field_size;
idx.next = db->count * (field_size + sizeof(uint64_t));
rarchdb_write_index_header(db->fd, &idx);
nictx.db = db;
nictx.idx = &idx;
bintree_iterate(&tree, node_iter, &nictx);
bintree_free(&tree);
clean:
rmsgpack_dom_value_free(&item);
if (buff)
free(buff);
rarchdb_read_reset(db);
return 0;
}