#ifndef DBFS_DBFS_H
#define DBFS_DBFS_H
#include <sys/stat.h>
#include <errno.h>
#include <event2/event.h>
#include "ops.h"
#include "../evfuse.h"
#include "../evsql.h"
#include "../lib/error.h"
/*
* Structs and functions shared between all dbfs components
*/
struct dbfs {
struct event_base *ev_base;
const char *db_conninfo;
struct evsql *db;
struct evfuse *ev_fuse;
};
// XXX: not sure how this should work
#define CACHE_TIMEOUT 1.0
/*
* Convert the CHAR(4) inodes.type from SQL into a mode_t.
*
* Returns zero for unknown types.
*/
mode_t _dbfs_mode (const char *type);
/*
* Check that the number of rows and columns in the result set matches what we expect.
*
* If rows is nonzero, there must be exactly that many rows (mostly useful for rows=1).
* The number of columns must always be given, and match.
*
* Returns;
* -1 if the query failed, the columns/rows do not match
* 0 the results match
* 1 there were no results (zero rows)
*/
int _dbfs_check_res (struct evsql_result *res, size_t rows, size_t cols);
/*
* Same as _dbfs_check_res, but returns ENOENT/EIO directly
*/
err_t dbfs_check_result (struct evsql_result *res, size_t rows, size_t cols);
/*
* Stat fields
*/
// columns used for stat_info
#define DBFS_STAT_COLS " inodes.type, inodes.mode, dbfs_size(inodes.type, inodes.data, inodes.link_path), (SELECT COUNT(*) FROM inodes i LEFT JOIN file_tree ft ON (i.ino = ft.ino) WHERE i.ino = inodes.ino) AS nlink"
#define DBFS_STAT_RESULT_INFO \
{ EVSQL_FMT_BINARY, EVSQL_TYPE_STRING }, \
{ EVSQL_FMT_BINARY, EVSQL_TYPE_UINT16 }, \
{ EVSQL_FMT_BINARY, EVSQL_TYPE_UINT32 }, \
{ EVSQL_FMT_BINARY, EVSQL_TYPE_UINT64 }
struct dbfs_stat_values {
const char *type;
uint16_t mode;
uint32_t size;
uint64_t nlink;
};
#define DBFS_STAT_RESULT_VALUES(ptr) \
&(ptr)->type, &(ptr)->mode, &(ptr)->size, &(ptr)->nlink
/*
* Fill a `struct state` with info retrieved from a SQL query.
*
* The result must contain four columns, starting at the given offset:
* inodes.type, inodes.mode, inodes.size, count(*) AS nlink
*
* Note that this does not fill the st_ino field
*/
int _dbfs_stat_info (struct stat *st, struct dbfs_stat_values *values);
/** interrupt.c
*
* Fuse interrupts are handled using fuse_req_interrupt_func. Calling this registers a callback function with the req,
* which may or may not be called either by fuse_req_interrupt_func, or later on via evfuse's event handler. It is
* assumed that this will never be called after a call to fuse_reply_*.
*
* Hence, to handle an interrupt, we must first ensure that fuse_reply_* will not be called afterwards (it'll return
* an error), and then we must call fuse_reply_err(req, EINTR).
*
* In the simplest case, we can simply submit a query, and then abort it once the req is interrupted (now or later).
* In the more complicated case, we can check if the request was interrupted, if not, do the query and handle
* interrupts.
*/
/*
* Useable as a callback to fuse_req_interrupt_func, will abort the given query and err the req.
*
* Due to a locking bug in libfuse 2.7.4, this will actually delay the fuse_req_err until the next event-loop iteration.
*/
void dbfs_interrupt_query (struct fuse_req *req, void *query_ptr);
/*
* XXX: More complicated state, is this actually needed?
*/
struct dbfs_interrupt_ctx {
struct fuse_req *req;
struct evsql_query *query;
int interrupted : 1;
};
/*
* Register as a fuse interrupt function for simple requests that only run one query without allocating any resources.
*
* This will abort the query if the interrupt is run, causing it's callback to not be called.
*
* Returns nonzero if the request was already interrupted, zero otherwise. Be careful that the interrupt does not get
* fired between you checking for it and setting query.
*/
int dbfs_interrupt_register (struct fuse_req *req, struct dbfs_interrupt_ctx *ctx);
#endif /* DBFS_DBFS_H */