terom@29: #ifndef DBFS_DBFS_H
terom@29: #define DBFS_DBFS_H
terom@29: 
terom@29: #include <sys/stat.h>
terom@29: #include <errno.h>
terom@29: 
terom@29: #include <event2/event.h>
terom@29: 
terom@29: #include "ops.h"
terom@29: #include "../evfuse.h"
terom@29: #include "../evsql.h"
terom@41: #include "../lib/error.h"
terom@29: 
terom@29: /*
terom@29:  * Structs and functions shared between all dbfs components
terom@29:  */
terom@29: 
terom@29: struct dbfs {
terom@29:     struct event_base *ev_base;
terom@29:     
terom@29:     const char *db_conninfo;
terom@29:     struct evsql *db;
terom@29: 
terom@29:     struct evfuse *ev_fuse;
terom@29: };
terom@29: 
terom@29: // XXX: not sure how this should work
terom@29: #define CACHE_TIMEOUT 1.0
terom@29: 
terom@31: // columns used for stat_info
terom@33: #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"
terom@31: 
terom@29: /*
terom@29:  * Convert the CHAR(4) inodes.type from SQL into a mode_t.
terom@29:  *
terom@29:  * Returns zero for unknown types.
terom@29:  */
terom@29: mode_t _dbfs_mode (const char *type);
terom@29: 
terom@29: /*
terom@29:  * Check that the number of rows and columns in the result set matches what we expect.
terom@29:  *
terom@29:  * If rows is nonzero, there must be exactly that many rows (mostly useful for rows=1).
terom@29:  * The number of columns must always be given, and match.
terom@29:  *
terom@29:  * Returns;
terom@29:  *  -1  if the query failed, the columns/rows do not match
terom@29:  *  0   the results match
terom@29:  *  1   there were no results (zero rows)
terom@29:  */
terom@29: int _dbfs_check_res (const struct evsql_result_info *res, size_t rows, size_t cols);
terom@29: 
terom@29: /*
terom@36:  * Same as _dbfs_check_res, but returns ENOENT/EIO directly
terom@36:  */
terom@36: err_t dbfs_check_result (const struct evsql_result_info *res, size_t rows, size_t cols);
terom@36: 
terom@36: /*
terom@29:  * Fill a `struct state` with info retrieved from a SQL query.
terom@29:  *
terom@29:  * The result must contain four columns, starting at the given offset:
terom@29:  *  inodes.type, inodes.mode, inodes.size, count(*) AS nlink
terom@29:  *
terom@29:  * Note that this does not fill the st_ino field
terom@29:  */
terom@29: int _dbfs_stat_info (struct stat *st, const struct evsql_result_info *res, size_t row, size_t col_offset);
terom@29: 
terom@41: /** interrupt.c 
terom@41:  *  
terom@41:  * Fuse interrupts are handled using fuse_req_interrupt_func. Calling this registers a callback function with the req,
terom@41:  * which may or may not be called either by fuse_req_interrupt_func, or later on via evfuse's event handler. It is
terom@41:  * assumed that this will never be called after a call to fuse_reply_*.
terom@41:  *
terom@41:  * Hence, to handle an interrupt, we must first ensure that fuse_reply_* will not be called afterwards (it'll return
terom@41:  * an error), and then we must call fuse_reply_err(req, EINTR).
terom@41:  *
terom@41:  * In the simplest case, we can simply submit a query, and then abort it once the req is interrupted (now or later).
terom@41:  * In the more complicated case, we can check if the request was interrupted, if not, do the query and handle
terom@41:  * interrupts.
terom@41:  */
terom@41: 
terom@41: /*
terom@41:  * Useable as a callback to fuse_req_interrupt_func, will abort the given query and err the req.
terom@42:  *
terom@42:  * Due to a locking bug in libfuse 2.7.4, this will actually delay the fuse_req_err until the next event-loop iteration.
terom@41:  */
terom@41: void dbfs_interrupt_query (struct fuse_req *req, void *query_ptr);
terom@41: 
terom@41: /*
terom@41:  * XXX: More complicated state, is this actually needed?
terom@41:  */
terom@41: struct dbfs_interrupt_ctx {
terom@41:     struct fuse_req *req;
terom@41:     struct evsql_query *query;
terom@41: 
terom@41:     int interrupted : 1;
terom@41: };
terom@41: 
terom@41: /*
terom@41:  * Register as a fuse interrupt function for simple requests that only run one query without allocating any resources.
terom@41:  *
terom@41:  * This will abort the query if the interrupt is run, causing it's callback to not be called.
terom@41:  *
terom@41:  * Returns nonzero if the request was already interrupted, zero otherwise. Be careful that the interrupt does not get
terom@41:  * fired between you checking for it and setting query.
terom@41:  */
terom@41: int dbfs_interrupt_register (struct fuse_req *req, struct dbfs_interrupt_ctx *ctx);
terom@41: 
terom@29: #endif /* DBFS_DBFS_H */