RetroArch/libretro-db/libretrodb.c
2015-11-14 16:03:49 -03:00

594 lines
12 KiB
C

#include <stdio.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 <retro_file.h>
#include <retro_endianness.h>
#include <compat/strl.h>
#include "libretrodb.h"
#include "rmsgpack_dom.h"
#include "rmsgpack.h"
#include "bintree.h"
#include "query.h"
#include "libretrodb.h"
#define MAGIC_NUMBER "RARCHDB"
struct node_iter_ctx
{
libretrodb_t *db;
libretrodb_index_t *idx;
};
struct libretrodb
{
RFILE *fd;
uint64_t root;
uint64_t count;
uint64_t first_index_offset;
char path[1024];
};
struct libretrodb_index
{
char name[50];
uint64_t key_size;
uint64_t next;
};
typedef struct libretrodb_metadata
{
uint64_t count;
} libretrodb_metadata_t;
typedef struct libretrodb_header
{
char magic_number[sizeof(MAGIC_NUMBER)-1];
uint64_t metadata_offset;
} libretrodb_header_t;
struct libretrodb_cursor
{
int is_valid;
RFILE *fd;
int eof;
libretrodb_query_t *query;
libretrodb_t *db;
};
static struct rmsgpack_dom_value sentinal;
static int libretrodb_read_metadata(RFILE *fd, libretrodb_metadata_t *md)
{
return rmsgpack_dom_read_into(fd, "count", &md->count, NULL);
}
static int libretrodb_write_metadata(RFILE *fd, libretrodb_metadata_t *md)
{
rmsgpack_write_map_header(fd, 1);
rmsgpack_write_string(fd, "count", strlen("count"));
return rmsgpack_write_uint(fd, md->count);
}
static int validate_document(const struct rmsgpack_dom_value *doc)
{
unsigned i;
struct rmsgpack_dom_value key, value;
int rv = 0;
if (doc->type != RDT_MAP)
return -EINVAL;
for (i = 0; i < doc->val.map.len; i++)
{
key = doc->val.map.items[i].key;
value = doc->val.map.items[i].value;
if (key.type != RDT_STRING)
return -EINVAL;
if (key.val.string.len <= 0)
return -EINVAL;
if (key.val.string.buff[0] == '$')
return -EINVAL;
if (value.type != RDT_MAP)
continue;
if ((rv == validate_document(&value)) != 0)
return rv;
}
return rv;
}
int libretrodb_create(RFILE *fd, libretrodb_value_provider value_provider,
void *ctx)
{
int rv;
libretrodb_metadata_t md;
struct rmsgpack_dom_value item;
uint64_t item_count = 0;
libretrodb_header_t header = {{0}};
ssize_t root = retro_fseek(fd, 0, SEEK_CUR);
memcpy(header.magic_number, MAGIC_NUMBER, sizeof(MAGIC_NUMBER)-1);
/* We write the header in the end because we need to know the size of
* the db first */
retro_fseek(fd, sizeof(libretrodb_header_t), SEEK_CUR);
while ((rv = value_provider(ctx, &item)) == 0)
{
if ((rv = validate_document(&item)) < 0)
goto clean;
if ((rv = rmsgpack_dom_write(fd, &item)) < 0)
goto clean;
item_count++;
}
if (rv < 0)
goto clean;
if ((rv = rmsgpack_dom_write(fd, &sentinal)) < 0)
goto clean;
header.metadata_offset = swap_if_little64(retro_fseek(fd, 0, SEEK_CUR));
md.count = item_count;
libretrodb_write_metadata(fd, &md);
retro_fseek(fd, root, SEEK_SET);
retro_fwrite(fd, &header, sizeof(header));
clean:
rmsgpack_dom_value_free(&item);
return rv;
}
static int libretrodb_read_index_header(RFILE *fd, libretrodb_index_t *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 libretrodb_write_index_header(RFILE *fd, libretrodb_index_t *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 libretrodb_close(libretrodb_t *db)
{
if (db->fd)
retro_fclose(db->fd);
db->fd = NULL;
}
int libretrodb_open(const char *path, libretrodb_t *db)
{
libretrodb_header_t header;
libretrodb_metadata_t md;
int rv;
RFILE *fd = retro_fopen(path, RFILE_MODE_READ, -1);
if (!fd)
return -errno;
strlcpy(db->path, path, sizeof(db->path));
db->root = retro_fseek(fd, 0, SEEK_CUR);
if ((rv = retro_fread(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 = swap_if_little64(header.metadata_offset);
retro_fseek(fd, (ssize_t)header.metadata_offset, SEEK_SET);
if (libretrodb_read_metadata(fd, &md) < 0)
{
rv = -EINVAL;
goto error;
}
db->count = md.count;
db->first_index_offset = retro_fseek(fd, 0, SEEK_CUR);
db->fd = fd;
return 0;
error:
if (fd)
retro_fclose(fd);
return rv;
}
static int libretrodb_find_index(libretrodb_t *db, const char *index_name,
libretrodb_index_t *idx)
{
ssize_t eof = retro_fseek(db->fd, 0, SEEK_END);
ssize_t offset = retro_fseek(db->fd, (ssize_t)db->first_index_offset, SEEK_SET);
while (offset < eof)
{
libretrodb_read_index_header(db->fd, idx);
if (strncmp(index_name, idx->name, strlen(idx->name)) == 0)
return 0;
offset = retro_fseek(db->fd, (ssize_t)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;
}
if (count == 0)
return -1;
if (rv > 0)
return binsearch(buff, item, mid, field_size, offset);
return binsearch(current + item_size, item,
count - mid, field_size, offset);
}
int libretrodb_find_entry(libretrodb_t *db, const char *index_name,
const void *key, struct rmsgpack_dom_value *out)
{
libretrodb_index_t idx;
int rv;
void *buff;
uint64_t offset;
ssize_t bufflen, nread = 0;
if (libretrodb_find_index(db, index_name, &idx) < 0)
return -1;
bufflen = idx.next;
buff = malloc(bufflen);
if (!buff)
return -ENOMEM;
while (nread < bufflen)
{
void *buff_ = (uint64_t *)buff + nread;
rv = retro_fread(db->fd, buff_, bufflen - nread);
if (rv <= 0)
{
free(buff);
return -errno;
}
nread += rv;
}
rv = binsearch(buff, key, db->count, (ssize_t)idx.key_size, &offset);
free(buff);
if (rv == 0)
retro_fseek(db->fd, (ssize_t)offset, SEEK_SET);
return rmsgpack_dom_read(db->fd, out);
}
/**
* libretrodb_cursor_reset:
* @cursor : Handle to database cursor.
*
* Resets cursor.
*
* Returns: ???.
**/
int libretrodb_cursor_reset(libretrodb_cursor_t *cursor)
{
cursor->eof = 0;
return retro_fseek(cursor->fd,
(ssize_t)(cursor->db->root + sizeof(libretrodb_header_t)),
SEEK_SET);
}
int libretrodb_cursor_read_item(libretrodb_cursor_t *cursor,
struct rmsgpack_dom_value *out)
{
int rv;
if (cursor->eof)
return EOF;
retry:
rv = rmsgpack_dom_read(cursor->fd, out);
if (rv < 0)
return rv;
if (out->type == RDT_NULL)
{
cursor->eof = 1;
return EOF;
}
if (cursor->query)
{
if (!libretrodb_query_filter(cursor->query, out))
{
rmsgpack_dom_value_free(out);
goto retry;
}
}
return 0;
}
/**
* libretrodb_cursor_close:
* @cursor : Handle to database cursor.
*
* Closes cursor and frees up allocated memory.
**/
void libretrodb_cursor_close(libretrodb_cursor_t *cursor)
{
if (!cursor)
return;
if (cursor->fd)
retro_fclose(cursor->fd);
if (cursor->query)
libretrodb_query_free(cursor->query);
cursor->is_valid = 0;
cursor->eof = 1;
cursor->fd = NULL;
cursor->db = NULL;
cursor->query = NULL;
}
/**
* libretrodb_cursor_open:
* @db : Handle to database.
* @cursor : Handle to database cursor.
* @q : Query to execute.
*
* Opens cursor to database based on query @q.
*
* Returns: 0 if successful, otherwise negative.
**/
int libretrodb_cursor_open(libretrodb_t *db, libretrodb_cursor_t *cursor,
libretrodb_query_t *q)
{
cursor->fd = retro_fopen(db->path, RFILE_MODE_READ | RFILE_HINT_MMAP, -1);
if (!cursor->fd)
return -errno;
cursor->db = db;
cursor->is_valid = 1;
libretrodb_cursor_reset(cursor);
cursor->query = q;
if (q)
libretrodb_query_inc_ref(q);
return 0;
}
static int node_iter(void *value, void *ctx)
{
struct node_iter_ctx *nictx = (struct node_iter_ctx*)ctx;
if (retro_fwrite(nictx->db->fd, value,
(ssize_t)(nictx->idx->key_size + sizeof(uint64_t))) > 0)
return 0;
return -1;
}
static uint64_t libretrodb_tell(libretrodb_t *db)
{
return retro_fseek(db->fd, 0, SEEK_CUR);
}
int libretrodb_create_index(libretrodb_t *db,
const char *name, const char *field_name)
{
int rv;
struct node_iter_ctx nictx;
struct rmsgpack_dom_value key;
libretrodb_index_t idx;
struct rmsgpack_dom_value item;
struct rmsgpack_dom_value *field;
uint64_t idx_header_offset;
libretrodb_cursor_t cur = {0};
void *buff = NULL;
uint64_t *buff_u64 = NULL;
uint8_t field_size = 0;
uint64_t item_loc = libretrodb_tell(db);
bintree_t *tree = bintree_new(node_compare, &field_size);
if (!tree || (libretrodb_cursor_open(db, &cur, NULL) != 0))
{
rv = -1;
goto clean;
}
key.type = RDT_STRING;
key.val.string.len = strlen(field_name);
/* We know we aren't going to change it */
key.val.string.buff = (char *) field_name;
while (libretrodb_cursor_read_item(&cur, &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->val.binary.len == 0)
{
rv = -EINVAL;
printf("field is empty\n");
goto clean;
}
if (field_size == 0)
field_size = field->val.binary.len;
else if (field->val.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->val.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 = libretrodb_tell(db);
}
idx_header_offset = retro_fseek(db->fd, 0, SEEK_END);
(void)idx_header_offset;
(void)rv;
strncpy(idx.name, name, 50);
idx.name[49] = '\0';
idx.key_size = field_size;
idx.next = db->count * (field_size + sizeof(uint64_t));
libretrodb_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);
if (cur.is_valid)
libretrodb_cursor_close(&cur);
return 0;
}
libretrodb_cursor_t *libretrodb_cursor_new(void)
{
libretrodb_cursor_t *dbc = (libretrodb_cursor_t*)
calloc(1, sizeof(*dbc));
if (!dbc)
return NULL;
return dbc;
}
void libretrodb_cursor_free(libretrodb_cursor_t *dbc)
{
if (!dbc)
return;
free(dbc);
}
libretrodb_t *libretrodb_new(void)
{
libretrodb_t *db = (libretrodb_t*)calloc(1, sizeof(*db));
if (!db)
return NULL;
return db;
}
void libretrodb_free(libretrodb_t *db)
{
if (!db)
return;
free(db);
}