;;======================================================================
;; Copyright 2017, Matthew Welland.
;;
;; This file is part of Megatest.
;;
;; Megatest is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;;
;; Megatest is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with Megatest. If not, see <http://www.gnu.org/licenses/>.
;;======================================================================
(declare (unit dbfile))
;; (declare (uses debugprint))
(declare (uses commonmod))
(module dbfile
*
(import scheme
chicken
data-structures
extras
matchable)
(import (prefix sqlite3 sqlite3:)
posix typed-records srfi-18 srfi-1
srfi-69
stack
files
ports
commonmod
)
;; (import debugprint)
;;======================================================================
;; R E C O R D S
;;======================================================================
;; a single Megatest area with it's multiple dbs is
;; managed in a dbstruct
;;
(defstruct dbr:dbstruct
(areapath #f)
(homehost #f)
(tmppath #f)
(read-only #f)
(subdbs (make-hash-table))
)
;; NOTE: Need one dbr:subdb per main.db, 1.db ...
;;
(defstruct dbr:subdb
(dbname #f) ;; .megatest/1.db
(mtdbfile #f) ;; mtrah/.megatest/1.db
(mtdbdat #f) ;; only need one of these for syncing
;; (dbdats (make-hash-table)) ;; id => dbdat
(tmpdbfile #f) ;; /tmp/.../.megatest/1.db
;; (refndbfile #f) ;; /tmp/.../.megatest/1.db_ref
(dbstack (make-stack)) ;; stack for tmp dbr:dbdat,
(homehost #f) ;; not used yet
(on-homehost #f) ;; not used yet
(read-only #f)
(last-sync 0)
(last-write (current-seconds))
) ;; goal is to converge on one struct for an area but for now it is too confusing
;; need to keep dbhandles and cached statements together
(defstruct dbr:dbdat
(dbfile #f)
(dbh #f)
(stmt-cache (make-hash-table))
(read-only #f)
(birth-sec (current-seconds)))
(define *dbstruct-dbs* #f)
(define *db-open-mutex* (make-mutex))
(define *db-access-mutex* (make-mutex)) ;; used in common.scm
(define *no-sync-db* #f)
(define *db-sync-in-progress* #f)
(define *db-with-db-mutex* (make-mutex))
(define *max-api-process-requests* 0)
(define *api-process-request-count* 0)
(define *db-write-access* #t)
(define *db-last-sync* 0) ;; last time the sync to megatest.db happened
(define *db-multi-sync-mutex* (make-mutex)) ;; protect access to *db-sync-in-progress*, *db-last-sync*
(define (db:generic-error-printout exn . message)
(print-call-chain (current-error-port))
(apply dbfile:print-err message)
(dbfile:print-err
", error: " ((condition-property-accessor 'exn 'message) exn)
", arguments: " ((condition-property-accessor 'exn 'arguments) exn)
", location: " ((condition-property-accessor 'exn 'location) exn)
))
(define (dbfile:run-id->key run-id)
(or run-id 'main))
(define (db:safely-close-sqlite3-db db stmt-cache #!key (try-num 3))
(if (<= try-num 0)
#f
(handle-exceptions
exn
(begin
(print "Attempt to safely close sqlite3 db failed. Trying again. exn=" exn)
(thread-sleep! 3)
(sqlite3:interrupt! db)
(db:safely-close-sqlite3-db db stmt-cache try-num: (- try-num 1)))
(if (sqlite3:database? db)
(let* ((stmts (and stmt-cache (hash-table-ref/default stmt-cache db #f))))
(if stmts (map sqlite3:finalize! (hash-table-values stmts)))
(sqlite3:finalize! db)
#t)
(begin
(dbfile:print-err "db:safely-close-sqlite3-db: " db " is not an sqlite3 db")
#f
)
))))
;; close all opened run-id dbs
(define (db:close-all dbstruct)
(if (dbr:dbstruct? dbstruct)
;; (handle-exceptions
;; exn
;; (begin
;; (debug:print 0 *default-log-port* "WARNING: Finalizing failed, " ((condition-property-accessor 'exn 'message) exn) ", note - exn=" exn)
;; (print-call-chain *default-log-port*))
;; (db:sync-touched dbstruct 0 force-sync: #t) ;; NO. Do not do this here. Instead we rely on a server to be started when there are writes, even if the server itself is not going to be used as a server.
(let* ((subdbs (hash-table-values (dbr:dbstruct-subdbs dbstruct))))
(for-each
(lambda (subdb)
(let* ((tdbs (stack->list (dbr:subdb-dbstack subdb)))
(mtdbdat (dbr:dbdat-dbh (dbr:subdb-mtdbdat subdb)))
#;(rdb (dbr:dbdat-dbh (dbr:subdb-refndb subdb))))
(map (lambda (dbdat)
(let* ((stmt-cache (dbr:dbdat-stmt-cache dbdat))
(dbh (dbr:dbdat-dbh dbdat)))
(db:safely-close-sqlite3-db dbh stmt-cache)))
tdbs)
(db:safely-close-sqlite3-db mtdbdat (dbr:dbdat-stmt-cache (dbr:subdb-mtdbdat subdb)))
;; (if (sqlite3:database? mdb) (sqlite3:finalize! mdb))
#;(db:safely-close-sqlite3-db rdb #f))) ;; stmt-cache))))) ;; (if (sqlite3:database? rdb) (sqlite3:finalize! rdb))))))
subdbs)
#t
)
#f
)
)
;; ;; set up a single db (e.g. main.db, 1.db ... etc.)
;; ;;
;; (define (db:setup-db dbstruct areapath run-id)
;; (let* ((dbname (db:run-id->dbname run-id))
;; (dbstruct (hash-table-ref/default dbstructs dbname #f)))
;; (if dbstruct
;; dbstruct
;; (let* ((dbstruct-new (make-dbr:dbstruct)))
;; (db:open-db dbstruct-new run-id areapath: areapath do-sync: #t)
;; (hash-table-set! dbstructs dbname dbstruct-new)
;; dbstruct-new))))
;; ; Returns the dbdat for a particular dbfile inside the area
;; ;;
;; (define (dbr:dbstruct-get-dbdat dbstruct dbfile)
;; (hash-table-ref/default (dbr:dbstruct-dbdats dbstruct) dbfile #f))
;;
;; (define (dbr:dbstruct-dbdat-put! dbstruct dbfile db)
;; (hash-table-set! (dbr:dbstruct-dbdats dbstruct) dbfile db))
;;
;; (define (db:run-id->first-num run-id)
;; (let* ((s (number->string run-id))
;; (l (string-length s)))
;; (substring s (- l 1) l)))
;; 1234 => 4/1234.db
;; #f => 0/main.db
;; (abandoned the idea of num/db)
;;
(define (dbfile:run-id->path apath run-id)
(conc apath"/"(dbfile:run-id->dbname run-id)))
(define (db:dbname->path apath dbname)
(conc apath"/"dbname))
;; POTENTIAL BUG: this implementation could produce a db file if run-id is neither #f or a number
(define (dbfile:run-id->dbname run-id)
(cond
((number? run-id) (conc ".megatest/" (modulo run-id 100) ".db"))
((not run-id) (conc ".megatest/main.db"))
(else run-id)))
;; Make the dbstruct, setup up auxillary db's and call for main db at least once
;;
;; called in http-transport and replicated in rmt.scm for *local* access.
;;
(define (dbfile:setup do-sync areapath tmppath)
(cond
(*dbstruct-dbs*
(dbfile:print-err "WARNING: dbfile:setup called when *dbstruct-dbs* is already initialized")
*dbstruct-dbs*) ;; TODO: when multiple areas are supported, this optimization will be a hazard
(else
(let* ((dbstruct (make-dbr:dbstruct)))
(set! *dbstruct-dbs* dbstruct)
(dbr:dbstruct-areapath-set! dbstruct areapath)
(dbr:dbstruct-tmppath-set! dbstruct tmppath)
dbstruct))))
(define (dbfile:get-subdb dbstruct run-id)
(let* ((dbfname (dbfile:run-id->dbname run-id)))
(hash-table-ref/default (dbr:dbstruct-subdbs dbstruct) dbfname #f)))
(define (dbfile:set-subdb dbstruct run-id subdb)
(hash-table-set! (dbr:dbstruct-subdbs dbstruct) (dbfile:run-id->dbname run-id) subdb))
(define *dbfile:num-handles-in-use* 0)
;; Get/open a database
;; if run-id => get run specific db
;; if #f => get main db
;; if run-id is a string treat it as a filename
;; if db already open - return inmem
;; if db not open, open inmem, rundb and sync then return inmem
;; inuse gets set automatically for rundb's
;;
(define (dbfile:get-dbdat dbstruct run-id)
(let* ((subdb (dbfile:get-subdb dbstruct run-id)))
(if (stack-empty? (dbr:subdb-dbstack subdb))
#f
(begin
(set! *dbfile:num-handles-in-use* (+ *dbfile:num-handles-in-use* 1))
(stack-pop! (dbr:subdb-dbstack subdb))))))
;; return a previously opened db handle to the stack of available handles
(define (dbfile:add-dbdat dbstruct run-id dbdat)
(let* ((subdb (dbfile:get-subdb dbstruct run-id)))
(set! *dbfile:num-handles-in-use* (- *dbfile:num-handles-in-use* 1))
(stack-push! (dbr:subdb-dbstack subdb) dbdat)))
;; set up a subdb
;;
(define (dbfile:init-subdb dbstruct run-id init-proc)
(let* ((dbname (dbfile:run-id->dbname run-id))
(areapath (dbr:dbstruct-areapath dbstruct))
(tmppath (dbr:dbstruct-tmppath dbstruct))
(mtdbpath (dbfile:run-id->path areapath run-id))
(tmpdbpath (dbfile:run-id->path tmppath run-id))
(mtdbdat (dbfile:open-sqlite3-db mtdbpath init-proc))
(newsubdb (make-dbr:subdb dbname: dbname
mtdbfile: mtdbpath
tmpdbfile: tmpdbpath
mtdbdat: mtdbdat)))
(dbfile:set-subdb dbstruct run-id newsubdb)
newsubdb)) ;; return the new subdb - but shouldn't really use it
;; returns dbdat with dbh and dbfilepath
;;
;; NOTE: the handle is on /tmp db file!
;;
;; 1. if needed setup the subdb for the given run-id
;; 2. if there is no existing db handle in the stack
;; create a new handle and return it (do NOT add
;; it to the stack).
;;
(define (dbfile:open-db dbstruct run-id init-proc)
(if (> *dbfile:num-handles-in-use* 10)
(let* ((wait-delay (- *dbfile:num-handles-in-use* 9)))
(dbfile:print-err "INFO: over ten dbfile handle threads in use ("*dbfile:num-handles-in-use*") delaying "wait-delay" second")
(thread-sleep! wait-delay)))
(let* ((subdb (dbfile:get-subdb dbstruct run-id)))
(if (not subdb) ;; not yet defined
(begin
(dbfile:init-subdb dbstruct run-id init-proc)
(dbfile:open-db dbstruct run-id init-proc))
(let* ((dbdat (dbfile:get-dbdat dbstruct run-id)))
(if dbdat
dbdat
(let* ((tmppath (dbr:dbstruct-tmppath dbstruct))
(tmpdbpath (dbfile:run-id->path tmppath run-id)))
(dbfile:open-sqlite3-db tmpdbpath init-proc)))))))
;; COMBINE dbfile:open-sqlite-db and dbfile:lock-create-open
;;
;; this stuff is for initial debugging, please remove it when
;; this code stabilizes
(define *dbopens* (make-hash-table))
(define (dbfile:inc-db-open dbfile)
(let* ((curr-opens-count (+ (hash-table-ref/default *dbopens* dbfile 0) 1)))
;; (if (> curr-opens-count 1) ;; this should NOT be happening
;; (dbfile:print-err "INFO: db "dbfile" has been opened "curr-opens-count" times!"))
(hash-table-set! *dbopens* dbfile curr-opens-count)
curr-opens-count))
;; Open the classic megatest.db file (defaults to open in toppath)
;;
;; NOTE: returns a dbdat not a dbstruct!
;;
(define (dbfile:open-sqlite3-db dbpath init-proc)
(let* ((dbexists (file-exists? dbpath))
(write-access (file-write-access? dbpath))
(db (dbfile:cautious-open-database dbpath init-proc))) #;(sqlite3:open-database dbpath)
(dbfile:inc-db-open dbpath)
;; (init-proc db)
(make-dbr:dbdat dbfile: dbpath dbh: db read-only: (not write-access))))
(define (dbfile:print-and-exit . params)
(with-output-to-port
(current-error-port)
(lambda ()
(apply print params)))
(exit 1))
(define (dbfile:print-err . params)
(with-output-to-port
(current-error-port)
(lambda ()
(apply print params))))
;; open an sql database inside a file lock
;; returns: db existed-prior-to-opening
;; RA => Returns a db handler; sets the lock if opened in writable mode
;;
;; (define *db-open-mutex* (make-mutex))
;;
#;(define (dbfile:lock-create-open fname initproc)
(let* ((parent-dir (or (pathname-directory fname)(current-directory))) ;; no parent? go local
(raw-fname (pathname-file fname))
(dir-writable (file-write-access? parent-dir))
(file-exists (file-exists? fname))
(file-write (if file-exists
(file-write-access? fname)
dir-writable )))
;; (mutex-lock! *db-open-mutex*) ;; tried this mutex, not clear it helped.
(if file-write ;; dir-writable
(condition-case
(let* ((lockfname (conc fname ".lock"))
(readyfname (conc parent-dir "/.ready-" raw-fname))
(readyexists (common:file-exists? readyfname)))
(if (not readyexists)
(common:simple-file-lock-and-wait lockfname))
(let ((db (sqlite3:open-database fname)))
(sqlite3:set-busy-handler! db (sqlite3:make-busy-timeout 136000))
(sqlite3:execute db "PRAGMA synchronous = 0;")
(if (not file-exists)
(initproc db))
(if (not readyexists)
(begin
(common:simple-file-release-lock lockfname)
(with-output-to-file
readyfname
(lambda ()
(print "Ready at "
(seconds->year-work-week/day-time
(current-seconds)))))))
db))
(exn (io-error) (dbfile:print-and-exit "ERROR: i/o error with " fname ". Check permissions, disk space etc. and try again."))
(exn (corrupt) (dbfile:print-and-exit "ERROR: database " fname " is corrupt. Repair it to proceed."))
(exn (busy) (dbfile:print-and-exit "ERROR: database " fname " is locked. Try copying to another location, remove original and copy back."))
(exn (permission)(dbfile:print-and-exit "ERROR: database " fname " has some permissions problem."))
(exn () (dbfile:print-and-exit "ERROR: Unknown error with database " fname " message: " ((condition-property-accessor 'exn 'message) exn))))
(condition-case
(begin
(dbfile:print-err "WARNING: opening db in non-writable dir " fname)
(let ((db (sqlite3:open-database fname)))
(sqlite3:set-busy-handler! db (sqlite3:make-busy-timeout 136000))
(sqlite3:execute db "PRAGMA synchronous = 0;")
;; (mutex-unlock! *db-open-mutex*)
db))
(exn (io-error)
(dbfile:print-and-exit
"ERROR: i/o error with " fname ". Check permissions, disk space etc. and try again."))
(exn (corrupt)
(dbfile:print-and-exit
"ERROR: database " fname " is corrupt. Repair it to proceed."))
(exn (busy)
(dbfile:print-and-exit
"ERROR: database " fname " is locked. Try copying to another location, remove original and copy back."))
(exn (permission)
(dbfile:print-and-exit
"ERROR: database " fname " has some permissions problem."))
(exn ()
(dbfile:print-and-exit
"ERROR: Unknown error with database " fname " message: " ((condition-property-accessor 'exn 'message) exn))))
)))
;; This routine creates the db if not already present. It is only called if the db is not already opened
;;
#;(define (db:init-dbstruct dbstruct run-id init-proc #!key (do-sync #t))
(let* ((subdb (dbfile:get-subdb dbstruct run-id))
(tmpdb-stack (dbr:subdb-dbstack subdb))
(max-stale-tmp (dbr:dbstruct-max-stale-secs dbstruct));; (configf:lookup-number *configdat* "server" "filling-db-max-stale-seconds" default: 10))
(dbpath (dbr:dbstruct-tmppath dbstruct)) ;; (db:dbfile-path)) ;; path to tmp db area
(dbname (dbfile:run-id->dbname run-id))
(dbexists (file-exists? dbpath))
(areapath (dbr:dbstruct-areapath dbstruct))
(mtdbfname (conc areapath "/"dbname))
(mtdbexists (file-exists? mtdbfname))
(mtdbmodtime (if mtdbexists (dbfile:lazy-sqlite-db-modification-time mtdbfname) #f))
(mtdb (db:open-sqlite-db mtdbfname init-proc))
;; the reference db for syncing
(refdbfname (conc dbpath "/"dbname"_ref"))
(refndb (db:open-megatest-db refdbfname))
;; (mtdbpath (dbr:dbdat-dbfile mtdb))
;; the tmpdb
(tmpdbfname (conc dbpath"/"dbname)) ;; /tmp/<stuff>/.megatest/[main|1,2...].db
(tmpdb (db:open-megatest-db tmpdbfname)) ;; lock-create-open dbpath db:initialize-main-db))
(dbfexists (common:file-exists? tmpdbfname)) ;; (conc dbpath "/megatest.db")))
(tmpdbmodtime (if dbfexists (common:lazy-sqlite-db-modification-time tmpdbfname) #f))
(write-access (file-write-access? mtdbfname))
;; (mtdbmodtime (if mtdbexists
;; (common:lazy-sqlite-db-modification-time mtdbpath)
;; #f)) ; moving this before db:open-megatest-db is
;; called. if wal mode is on -WAL and -shm file get
;; created with causing the tmpdbmodtime timestamp
;; always greater than mtdbmodtime (tmpdbmodtime (if
;; dbfexists (common:lazy-sqlite-db-modification-time
;; tmpdbfname) #f)) if wal mode is on -WAL and -shm
;; file get created when db:open-megatest-db is
;; called. modtimedelta will always be < 10 so db in
;; tmp not get synced (tmpdbmodtime (if dbfexists
;; (db:get-last-update-time (car tmpdb)) #f)) (fmt
;; (file-modification-time tmpdbfname))
(modtimedelta (and mtdbmodtime tmpdbmodtime (- mtdbmodtime tmpdbmodtime))))
(when write-access
(sqlite3:execute (dbr:dbdat-dbh mtdb) "drop trigger if exists update_tests_trigger")
(sqlite3:execute (dbr:dbdat-dbh mtdb) "drop trigger if exists update_runs_trigger"))
;; (print "mtdbmodtime " mtdbmodtime " tmpdbmodtime " tmpdbmodtime " mtdbpath " mtdbpath " " (conc *toppath* "/megatest.db"))
;; (debug:print-info 13 *default-log-port* "db:open-db>> mtdbpath="mtdbpath" mtdbexists="mtdbexists" and write-access="write-access)
(if (and dbexists (not write-access))
(begin
(set! *db-write-access* #f)
(dbr:subdb-read-only-set! subdb #t)))
(dbr:subdb-mtdb-set! subdb mtdb)
(dbr:subdb-tmpdb-set! subdb tmpdb)
(dbr:subdb-dbstack-set! subdb (make-stack)) ;; BB: why a stack? Why would the number of db's be indeterminate? Is this a legacy of 1.db 2.db .. ?
(stack-push! (dbr:subdb-dbstack subdb) tmpdb) ;; olddb is already a (cons db path)
(dbr:subdb-refndb-set! subdb refndb)
(if (and (or (not dbfexists)
(and modtimedelta
(> modtimedelta max-stale-tmp))) ;; if db in tmp is over ten seconds older than the file in MTRA then do a sync back
do-sync)
(begin
(dbfile:print-err "filling db " (dbr:dbdat-dbfile tmpdb) " with data \n from " (dbr:dbdat-dbfile mtdb) " mod time delta: " modtimedelta)
(db:sync-tables (db:sync-all-tables-list subdb) #f mtdb refndb tmpdb)
;; touch tmp db to avoid wal mode wierdness
(set! (file-modification-time tmpdbfname) (current-seconds))
(dbfile:print-err "INFO: db:sync-all-tables-list done.")
)
(dbfile:print-err " db, " (dbr:dbdat-dbfile tmpdb) " already exists or fresh enough, not propogating data from\n " (dbr:dbdat-dbfile mtdb) " mod time delta: " modtimedelta) )
;; (db:multi-db-sync subdb 'old2new)) ;; migrate data from megatest.db automatically
tmpdb))
(define (dbfile:cautious-open-database fname init-proc #!optional (tries-left 50))
(let* ((busy-file (conc fname"-journal"))
(delay-time (* (- 51 tries-left) 1.1))
(write-access (file-write-access? fname))
(dir-access (file-write-access? (pathname-directory fname)))
(retry (lambda ()
(thread-sleep! delay-time)
(if (> tries-left 0)
(dbfile:cautious-open-database fname init-proc (- tries-left 1))))))
(let* ((result (condition-case
(if dir-access
(dbfile:with-simple-file-lock
(conc fname ".lock")
(lambda ()
(let* ((db-exists (file-exists? fname))
(db (sqlite3:open-database fname))) ;; creates an empty db if it did not already exist.
(sqlite3:set-busy-handler! db (sqlite3:make-busy-timeout 30000))
(sqlite3:execute db (conc "PRAGMA synchronous = 0;"))
(if (and init-proc (not db-exists))
(init-proc db))
db)))
(begin
(if (file-exists? fname )
(begin
(sqlite3:open-database fname)
)
(print "file doesn't exist: " fname)
)
)
)
(exn (io-error)
(dbfile:print-err exn "ERROR: i/o error with " fname ". Check permissions, disk space etc. and try again.")
(retry))
(exn (corrupt)
(dbfile:print-err exn "ERROR: database " fname " is corrupt. Repair it to proceed.")
(retry))
(exn (busy)
(dbfile:print-err exn "ERROR: database " fname
" is locked. Try copying to another location, remove original and copy back.")
(retry))
(exn (permission)(dbfile:print-err exn "ERROR: database " fname " has some permissions problem.")
(retry))
(exn ()
(dbfile:print-err exn "ERROR: Unknown error with database " fname " message: "
((condition-property-accessor 'exn 'message) exn))
(retry)))))
result)))
(define (dbfile:brute-force-salvage-db fname)
(let* ((backupfname (conc fname"-"(current-process-id)".bak"))
(cmd (conc "cp "fname" "backupfname";mv "fname" "(conc fname ".delme;")
"cp "backupfname" "fname)))
(dbfile:print-err "WARNING: attempting recovery of file "fname" by running commands:\n"
" "cmd)
(system cmd)))
#;(define (dbfile:cautious-open-database-orig fname init-proc #!optional (tries-left 50))
(let* ((lock-file (conc fname".lock"))
(delay-time (* (- 51 tries-left) 1.1))
(retry (lambda ()
(thread-sleep! delay-time)
(if (> tries-left 0)
(dbfile:cautious-open-database fname init-proc (- tries-left 1))))))
(assert (>= tries-left 0) (conc "FATAL: too many attempts in dbfile:cautious-open-database of "fname", giving up."))
(if (and (file-write-access? fname) (not (dbfile:simple-file-lock lock-file expire-time: 3)))
(begin
(dbfile:print-err "INFO: dbfile:cautious-open-database: lock file " lock-file " exists, trying again in few seconds.")
(thread-sleep! 1)
(if (eq? tries-left 2)
(begin
(dbfile:print-err "INFO: stealing the lock "lock-file)
(delete-file* lock-file)))
(dbfile:cautious-open-database fname init-proc (- tries-left 1)))
(let* ((db-exists (file-exists? fname))
(result (condition-case
(let* ((db (sqlite3:open-database fname)))
(if (and init-proc (not db-exists))
(init-proc db))
db)
(exn (io-error)
(dbfile:print-err exn "ERROR: i/o error with " fname ". Check permissions, disk space etc. and try again.")
(retry))
(exn (corrupt)
(dbfile:print-err exn "ERROR: database " fname " is corrupt. Repair it to proceed.")
(retry))
(exn (busy)
(dbfile:print-err exn "ERROR: database " fname
" is locked. Try copying to another location, remove original and copy back.")
(retry))
(exn (permission)(dbfile:print-err exn "ERROR: database " fname " has some permissions problem.")
(retry))
(exn ()
(dbfile:print-err exn "ERROR: Unknown error with database " fname " message: "
((condition-property-accessor 'exn 'message) exn))
(retry)))))
(if (file-write-access? fname)
(dbfile:simple-file-release-lock lock-file)
)
result))))
(define (dbfile:open-no-sync-db dbpath)
(if *no-sync-db*
*no-sync-db*
(begin
(if (not (file-exists? dbpath))
(create-directory dbpath #t))
(let* ((dbname (conc dbpath "/no-sync.db"))
(db-exists (file-exists? dbname))
(init-proc (lambda (db)
(if (not db-exists)
(begin
(sqlite3:execute db "CREATE TABLE IF NOT EXISTS no_sync_metadat (var TEXT,val TEXT, CONSTRAINT no_sync_metadat_constraint UNIQUE (var));"))
)))
(db (dbfile:cautious-open-database dbname init-proc))) ;; (sqlite3:open-database dbname)))
(sqlite3:execute db "PRAGMA synchronous = 0;")
(sqlite3:set-busy-handler! db (sqlite3:make-busy-timeout 136000))
(set! *no-sync-db* db)
db))))
(define (db:no-sync-set db var val)
(sqlite3:execute db "INSERT OR REPLACE INTO no_sync_metadat (var,val) VALUES (?,?);" var val))
(define (db:no-sync-del! db var)
(sqlite3:execute db "DELETE FROM no_sync_metadat WHERE var=?;" var))
(define (db:no-sync-get/default db var default)
(let ((res default))
(sqlite3:for-each-row
(lambda (val)
(set! res val))
db
"SELECT val FROM no_sync_metadat WHERE var=?;"
var)
(if res
(let ((newres (if (string? res)
(string->number res)
#f)))
(if newres
newres
res))
res)))
;; transaction protected lock aquisition
;; either:
;; fails returns (#f . lock-creation-time)
;; succeeds (returns (#t . lock-creation-time)
;; use (db:no-sync-del! db keyname) to release the lock
;;
(define (db:no-sync-get-lock db keyname)
(sqlite3:with-transaction
db
(lambda ()
(condition-case
(let* ((curr-val (db:no-sync-get/default db keyname #f)))
(if curr-val
`(#f . ,curr-val) ;; (sqlite3:first-result db "SELECT val FROM no_sync_metadat WHERE var=?;" keyname))
(let ((lock-time (current-seconds)))
(sqlite3:execute db "INSERT OR REPLACE INTO no_sync_metadat (var,val) VALUES(?,?);" keyname lock-time)
`(#t . ,lock-time))))
(exn (io-error) (dbfile:print-err "ERROR: i/o error with no-sync db. Check permissions, disk space etc. and try again."))
(exn (corrupt) (dbfile:print-err "ERROR: database no-sync db is corrupt. Repair it to proceed."))
(exn (busy) (dbfile:print-err "ERROR: database no-sync db is locked. Try copying to another location, remove original and copy back."))
(exn (permission)(dbfile:print-err "ERROR: database no-sync db has some permissions problem."))
(exn () ;; (status done) ;; I don't know how to detect status done but no data!
(dbfile:print-err "ERROR: Unknown error with database no-sync db message: exn="(condition->list exn)", \n"
((condition-property-accessor 'exn 'message) exn))
`(#f . ,(current-seconds)))))))
(define (db:no-sync-get-lock-timeout db keyname timeout)
(let* ((lockdat (db:no-sync-get-lock db keyname)))
(match lockdat
((#f . lock-time)
(if (> (- (current-seconds) (if (string? lock-time)(string->number lock-time)lock-time)) timeout)
(let ((lock-time (current-seconds)))
;; (debug:print-info 2 *default-log-port* "db:no-sync-get-lock keyname=" keyname ", lock-time=" lock-time ", exn=" exn)
(sqlite3:execute db "INSERT OR REPLACE INTO no_sync_metadat (var,val) VALUES(?,?);" keyname lock-time)
`(#t . ,lock-time))
lockdat))
(else lockdat))))
;; NOTE: This will steal the lock after timeout of waiting.
;;
(define (db:with-no-sync-lock db keyname timeout proc)
(let* ((lockdat (db:no-sync-get-lock-timeout db keyname))
(gotlock (car lockdat))
(locktime (cdr lockdat)))
(if gotlock
(let ((res (proc)))
(db:no-sync-del! db keyname)
res))))
;;======================================================================
;; sync back functions pulled from db.scm
;;======================================================================
;; Get a lock from the no-sync-db for the from-db, then delta sync the from-db to the to-db, otherwise return #f
;;
(define (db:lock-and-delta-sync no-sync-db dbstruct from-db-file runid keys dbinit)
(assert (not *db-sync-in-progress*) "FATAL: db:lock-and-sync called while a sync is in progress.")
;; (dbfile:print-err *default-log-port* "db:lock-and-delta-sync")
(let* ((lock-file (conc from-db-file ".lock")))
(if (common:simple-file-lock lock-file)
(begin
(dbfile:print-err "INFO: db:lock-and-delta-sync copying db "runid" at "(current-seconds))
(set! *db-sync-in-progress* #t)
(db:sync-touched dbstruct runid keys dbinit)
(set! *db-sync-in-progress* #f)
(delete-file* lock-file)
#t)
(begin
(dbfile:print-err "INFO: could not get lock for " from-db-file ", sync likely in progress.")
#f
))))
;; ;; Get a lock from the no-sync-db for the from-db, then delta sync the from-db to the to-db, otherwise return #f
;; ;;
;; (define (db:lock-and-delta-sync-orig no-sync-db dbstruct from-db-file runid keys dbinit)
;; (assert (not *db-sync-in-progress*) "FATAL: db:lock-and-sync called while a sync is in progress.")
;; ;; (dbfile:print-err *default-log-port* "db:lock-and-delta-sync")
;; (let* ((lockdat (db:no-sync-get-lock-timeout no-sync-db from-db-file 60))
;; (gotlock (car lockdat))
;; (locktime (cdr lockdat)))
;; ;; (debug:print-info 3 *default-log-port* "db:lock-and-delta-sync: got lock?")
;;
;; (if gotlock
;; (begin
;; (dbfile:print-err "INFO: db:lock-and-delta-sync copying db "runid" at "(current-seconds))
;; (set! *db-sync-in-progress* #t)
;; (db:sync-touched dbstruct runid keys dbinit)
;; (set! *db-sync-in-progress* #f)
;; (db:no-sync-del! no-sync-db from-db-file)
;; #t)
;; (begin
;; (dbfile:print-err "ERROR: could not get lock for " from-db-file " from no-sync-db")
;; #f
;; ))))
;; sync run from tmp disk to nfs disk if touched
;;
;; call with dbinit=db:initialize-main-db
;;
(define (db:sync-touched dbstruct run-id keys #!key dbinit (force-sync #f))
(dbfile:print-err "db:sync-touched Syncing: " (conc (if run-id run-id "main") ".db"))
(let* (;; the subdb is needed to access the mtdbdat
(subdb (or (dbfile:get-subdb dbstruct run-id)
(dbfile:init-subdb dbstruct run-id dbinit)))
(tmpdbfile (dbr:subdb-tmpdbfile subdb))
(mtdb (dbr:subdb-mtdbdat subdb))
(tmpdb (db:open-db dbstruct run-id dbinit)) ;; sqlite3-db tmpdbfile #f))
(start-t (current-seconds)))
(mutex-lock! *db-multi-sync-mutex*)
(let ((update_info (cons "last_update" (if force-sync 0 *db-last-sync*) )))
(mutex-unlock! *db-multi-sync-mutex*)
(db:sync-tables (db:sync-all-tables-list dbstruct keys) update_info tmpdb mtdb))
(mutex-lock! *db-multi-sync-mutex*)
(set! *db-last-sync* start-t)
(set! *db-last-access* start-t)
(mutex-unlock! *db-multi-sync-mutex*)
(dbfile:add-dbdat dbstruct run-id tmpdb)
#t))
;; just tests, test_steps and test_data tables
(define db:sync-tests-only
(list
;; (list "strs"
;; '("id" #f)
;; '("str" #f))
(list "tests"
'("id" #f)
'("run_id" #f)
'("testname" #f)
'("host" #f)
'("cpuload" #f)
'("diskfree" #f)
'("uname" #f)
'("rundir" #f)
'("shortdir" #f)
'("item_path" #f)
'("state" #f)
'("status" #f)
'("attemptnum" #f)
'("final_logf" #f)
'("logdat" #f)
'("run_duration" #f)
'("comment" #f)
'("event_time" #f)
'("fail_count" #f)
'("pass_count" #f)
'("archived" #f)
'("last_update" #f))
(list "test_steps"
'("id" #f)
'("test_id" #f)
'("stepname" #f)
'("state" #f)
'("status" #f)
'("event_time" #f)
'("comment" #f)
'("logfile" #f)
'("last_update" #f))
(list "test_data"
'("id" #f)
'("test_id" #f)
'("category" #f)
'("variable" #f)
'("value" #f)
'("expected" #f)
'("tol" #f)
'("units" #f)
'("comment" #f)
'("status" #f)
'("type" #f)
'("last_update" #f))))
;; needs db to get keys, this is for syncing all tables
;;
(define (db:sync-main-list dbstruct keys)
(let ((keys keys)) ;; (db:get-keys dbstruct)))
(list
(list "keys"
'("id" #f)
'("fieldname" #f)
'("fieldtype" #f))
(list "metadat" '("var" #f) '("val" #f))
(append (list "runs"
'("id" #f))
(map (lambda (k)(list k #f))
(append keys
(list "runname" "state" "status" "owner" "event_time" "comment" "fail_count" "pass_count" "contour" "last_update"))))
(list "archive_disks"
'("id" #f)
'("archive_area_name" #f)
'("disk_path" #f)
'("last_df" #f)
'("last_df_time" #f)
'("creation_time" #f))
(list "archive_blocks"
'("id" #f)
'("archive_disk_id" #f)
'("disk_path" #f)
'("last_du" #f)
'("last_du_time" #f)
'("creation_time" #f))
(list "test_meta"
'("id" #f)
'("testname" #f)
'("owner" #f)
'("description" #f)
'("reviewed" #f)
'("iterated" #f)
'("avg_runtime" #f)
'("avg_disk" #f)
'("tags" #f)
'("jobgroup" #f)))))
(define (db:sync-all-tables-list dbstruct keys)
(append (db:sync-main-list dbstruct keys)
db:sync-tests-only))
;; tbls is ( ("tablename" ( "field1" [#f|proc1] ) ( "field2" [#f|proc2] ) .... ) )
;; db's are dbdat's
;;
;; if last-update specified ("field-name" . time-in-seconds)
;; then sync only records where field-name >= time-in-seconds
;; IFF field-name exists
;;
(define (db:sync-tables tbls last-update fromdb todb . slave-dbs)
(handle-exceptions
exn
(begin
(dbfile:print-err "EXCEPTION: database probably overloaded or unreadable in db:sync-tables.")
(print-call-chain (current-error-port))
(dbfile:print-err " message: " ((condition-property-accessor 'exn 'message) exn))
(dbfile:print-err "exn=" (condition->list exn))
(dbfile:print-err " status: " ((condition-property-accessor 'sqlite3 'status) exn))
(dbfile:print-err " src db: " (dbr:dbdat-dbfile fromdb))
(for-each (lambda (dbdat)
(let ((dbpath (dbr:dbdat-dbfile dbdat)))
(dbfile:print-err " dbpath: " dbpath)
(if #t ;; (not (db:repair-db dbdat))
(begin
(dbfile:print-err "Failed to rebuild (repair is turned off) " dbpath ", exiting now.")
(exit)))))
(cons todb slave-dbs))
0)
;; this is the work to be done")
(cond
((not fromdb) (dbfile:print-err "WARNING: db:sync-tables called with fromdb missing")
-1)
((not todb) (dbfile:print-err "WARNING: db:sync-tables called with todb missing")
-2)
((not (sqlite3:database? (dbr:dbdat-dbh fromdb)))
(dbfile:print-err "db:sync-tables called with fromdb not a database " fromdb)
-3)
((not (sqlite3:database? (dbr:dbdat-dbh todb)))
(dbfile:print-err "db:sync-tables called with todb not a database " todb)
-4)
((not (file-write-access? (dbr:dbdat-dbfile todb)))
(dbfile:print-err "db:sync-tables called with todb not a read-only database " todb)
-5)
((not (null? (let ((readonly-slave-dbs
(filter
(lambda (dbdat)
(not (file-write-access? (dbr:dbdat-dbfile todb))))
slave-dbs)))
(for-each
(lambda (bad-dbdat)
(dbfile:print-err "db:sync-tables called with todb not a read-only database " bad-dbdat))
readonly-slave-dbs)
readonly-slave-dbs))) -6)
(else
;; (dbfile:print-err "db:sync-tables: args are good")
(let ((stmts (make-hash-table)) ;; table-field => stmt
(all-stmts '()) ;; ( ( stmt1 value1 ) ( stml2 value2 ))
(numrecs (make-hash-table))
(start-time (current-milliseconds))
(tot-count 0))
(for-each ;; table
(lambda (tabledat)
(let* ((tablename (car tabledat))
(fields (cdr tabledat))
(has-last-update (member "last_update" fields))
(use-last-update (cond
((and has-last-update
(member "last_update" fields))
#t) ;; if given a number, just use it for all fields
((number? last-update) #f) ;; if not matched first entry then ignore last-update for this table
((and (pair? last-update)
(member (car last-update) ;; last-update field name
(map car fields)))
#t)
((and last-update (not (pair? last-update)) (not (number? last-update)))
(dbfile:print-err "ERROR: parameter last-update for db:sync-tables must be a pair or a number, received: " last-update);; found in fields
#f)
(else
#f)))
(last-update-value (if use-last-update ;; no need to check for has-last-update - it is already accounted for
(if (number? last-update)
last-update
(cdr last-update))
#f))
(last-update-field (if use-last-update
(if (number? last-update)
"last_update"
(car last-update))
#f))
(num-fields (length fields))
(field->num (make-hash-table))
(num->field (apply vector (map car fields))) ;; BBHERE
(full-sel (conc "SELECT " (string-intersperse (map car fields) ",")
" FROM " tablename (if use-last-update ;; apply last-update criteria
(conc " WHERE " last-update-field " >= " last-update-value)
"")
";"))
(full-ins (conc "INSERT OR REPLACE INTO " tablename " ( " (string-intersperse (map car fields) ",") " ) "
" VALUES ( " (string-intersperse (make-list num-fields "?") ",") " );"))
(fromdat '())
(fromdats '())
(totrecords 0)
(batch-len 100) ;; (string->number (or (configf:lookup *configdat* "sync" "batchsize") "100")))
(todat (make-hash-table))
(count 0)
(field-names (map car fields))
(delay-handicap 0) ;; (string->number (or (configf:lookup *configdat* "sync" "delay-handicap") "0")))
)
;; set up the field->num table
(for-each
(lambda (field)
(hash-table-set! field->num field count)
(set! count (+ count 1)))
fields)
;; read the source table
;; store a list of all rows in the table in fromdat, up to batch-len.
;; Then add fromdat to the fromdats list, clear fromdat and repeat.
(sqlite3:for-each-row
(lambda (a . b)
(set! fromdat (cons (apply vector a b) fromdat))
(if (> (length fromdat) batch-len)
(begin
(set! fromdats (cons fromdat fromdats))
(set! fromdat '())
(set! totrecords (+ totrecords 1)))
)
)
(dbr:dbdat-dbh fromdb)
full-sel)
;; Count less than batch-len as a record
(if (> (length fromdat) 0)
(set! totrecords (+ totrecords 1)))
;; tack on remaining records in fromdat
(if (not (null? fromdat))
(set! fromdats (cons fromdat fromdats)))
(sqlite3:for-each-row
(lambda (a . b)
(hash-table-set! todat a (apply vector a b)))
(dbr:dbdat-dbh todb)
full-sel)
(when (and delay-handicap (> delay-handicap 0))
(dbfile:print-err "imposing synthetic sync delay of "delay-handicap" seconds since sync/delay-handicap is configured")
(thread-sleep! delay-handicap)
(dbfile:print-err "synthetic sync delay of "delay-handicap" seconds completed")
)
;; first pass implementation, just insert all changed rows
(for-each
(lambda (targdb)
(let* ((db (dbr:dbdat-dbh targdb))
(drp-trigger (if (member "last_update" field-names)
(db:drop-trigger db tablename)
#f))
(has-last-update (member "last_update" field-names))
(is-trigger-dropped (if has-last-update
(db:is-trigger-dropped db tablename)
#f))
(stmth (sqlite3:prepare db full-ins))
(changed-rows 0))
(for-each
(lambda (fromdat-lst)
(sqlite3:with-transaction
db
(lambda ()
(for-each ;;
(lambda (fromrow)
(let* ((a (vector-ref fromrow 0))
(curr (hash-table-ref/default todat a #f))
(same #t))
(let loop ((i 0))
(if (or (not curr)
(not (equal? (vector-ref fromrow i)(vector-ref curr i))))
(set! same #f))
(if (and same
(< i (- num-fields 1)))
(loop (+ i 1))))
(if (not same)
(begin
(apply sqlite3:execute stmth (vector->list fromrow))
(hash-table-set! numrecs tablename (+ 1 (hash-table-ref/default numrecs tablename 0)))
(set! changed-rows (+ changed-rows 1))
)
)
))
fromdat-lst))))
fromdats)
(sqlite3:finalize! stmth)
(if (member "last_update" field-names)
(db:create-trigger db tablename))))
(append (list todb) slave-dbs)
)
)
)
tbls)
(let* ((runtime (- (current-milliseconds) start-time))
(should-print (or ;; (debug:debug-mode 12)
(common:low-noise-print 120 "db sync" (> runtime 500))))) ;; low and high sync times treated as separate.
(for-each
(lambda (dat)
(let ((tblname (car dat))
(count (cdr dat)))
(set! tot-count (+ tot-count count))
))
(sort (hash-table->alist numrecs)(lambda (a b)(> (cdr a)(cdr b))))))
tot-count)))))
;;======================================================================
;; trigger setup/takedown
;;======================================================================
(define db:trigger-list
(list (list "update_runs_trigger" "CREATE TRIGGER IF NOT EXISTS update_runs_trigger AFTER UPDATE ON runs
FOR EACH ROW
BEGIN
UPDATE runs SET last_update=(strftime('%s','now'))
WHERE id=old.id;
END;" )
(list "update_run_stats_trigger" "CREATE TRIGGER IF NOT EXISTS update_run_stats_trigger AFTER UPDATE ON run_stats
FOR EACH ROW
BEGIN
UPDATE run_stats SET last_update=(strftime('%s','now'))
WHERE id=old.id;
END;" )
(list "update_tests_trigger" "CREATE TRIGGER IF NOT EXISTS update_tests_trigger AFTER UPDATE ON tests
FOR EACH ROW
BEGIN
UPDATE tests SET last_update=(strftime('%s','now'))
WHERE id=old.id;
END;" )
(list "update_teststeps_trigger" "CREATE TRIGGER IF NOT EXISTS update_teststeps_trigger AFTER UPDATE ON test_steps
FOR EACH ROW
BEGIN
UPDATE test_steps SET last_update=(strftime('%s','now'))
WHERE id=old.id;
END;" )
(list "update_test_data_trigger" "CREATE TRIGGER IF NOT EXISTS update_test_data_trigger AFTER UPDATE ON test_data
FOR EACH ROW
BEGIN
UPDATE test_data SET last_update=(strftime('%s','now'))
WHERE id=old.id;
END;" )))
;;
;; ADD run-id SUPPORT
;;
(define (db:create-all-triggers dbstruct)
(db:with-db
dbstruct #f #f
(lambda (dbdat db)
(db:create-triggers db))))
(define (db:create-triggers db)
(for-each (lambda (key)
(sqlite3:execute db (cadr key)))
db:trigger-list))
(define (db:drop-all-triggers dbstruct)
(db:with-db
dbstruct #f #f
(lambda (dbdat db)
(db:drop-triggers db))))
(define (db:is-trigger-dropped db tbl-name)
(let* ((trigger-name (if (equal? tbl-name "test_steps")
"update_teststeps_trigger"
(conc "update_" tbl-name "_trigger")))
(res #f))
(sqlite3:for-each-row
(lambda (name)
(if (equal? name trigger-name)
(set! res #t)))
db
"SELECT name FROM sqlite_master WHERE type = 'trigger' ;")
res))
(define (db:drop-triggers db)
(for-each
(lambda (key)
(sqlite3:execute db (conc "drop trigger if exists " (car key))))
db:trigger-list))
(define (db:drop-trigger db tbl-name)
(let* ((trigger-name (if (equal? tbl-name "test_steps")
"update_teststeps_trigger"
(conc "update_" tbl-name "_trigger"))))
(for-each
(lambda (key)
(if (equal? (car key) trigger-name)
(sqlite3:execute db (conc "drop trigger if exists " trigger-name))))
db:trigger-list)))
(define (db:create-trigger db tbl-name)
(let* ((trigger-name (if (equal? tbl-name "test_steps")
"update_teststeps_trigger"
(conc "update_" tbl-name "_trigger"))))
(for-each (lambda (key)
(if (equal? (car key) trigger-name)
(sqlite3:execute db (cadr key))))
db:trigger-list)))
;;======================================================================
;; db access stuff
;;======================================================================
;; call with dbinit=db:initialize-main-db
;;
(define (db:open-db dbstruct run-id dbinit)
(mutex-lock! *db-open-mutex*)
(let* ((dbdat (dbfile:open-db dbstruct run-id dbinit)))
(set! *db-write-access* (not (dbr:dbdat-read-only dbdat)))
(mutex-unlock! *db-open-mutex*)
dbdat))
(define dbfile:db-init-proc (make-parameter #f))
;; (db:with-db dbstruct run-id sqlite3:exec "select blah fgrom blaz;")
;; r/w is a flag to indicate if the db is modified by this query #t = yes, #f = no
;;
(define (db:with-db dbstruct run-id r/w proc . params)
(let* ((have-struct (dbr:dbstruct? dbstruct))
(dbdat (if have-struct ;; this stuff just allows us to call with a db handle directly
(db:open-db dbstruct run-id (dbfile:db-init-proc)) ;; (dbfile:get-subdb dbstruct run-id)
#f))
(db (if have-struct ;; this stuff just allows us to call with a db handle directly
(dbr:dbdat-dbh dbdat)
dbstruct))
(fname (if dbdat
(dbr:dbdat-dbfile dbdat)
"nofilenameavailable"))
#;(subdb (if have-struct
(dbfile:get-subdb dbstruct run-id)
#f))
(use-mutex (> *api-process-request-count* 25))) ;; was 25
(if (and use-mutex
(common:low-noise-print 120 "over-50-parallel-api-requests"))
(dbfile:print-err *api-process-request-count* " parallel api requests being processed in process " (current-process-id) ", throttling access"))
(condition-case
(begin
(if use-mutex (mutex-lock! *db-with-db-mutex*))
(let ((res (apply proc dbdat db params)))
(if use-mutex (mutex-unlock! *db-with-db-mutex*))
;; (if (vector? dbstruct)(db:done-with dbstruct run-id r/w))
(if dbdat
(dbfile:add-dbdat dbstruct run-id dbdat))
res))
(exn (io-error)
(db:generic-error-printout exn "ERROR: i/o error with " fname ". Check permissions, disk space etc. and try again."))
(exn (corrupt)
(db:generic-error-printout exn "ERROR: database " fname " is corrupt. Repair it to proceed."))
(exn (busy)
(db:generic-error-printout exn "ERROR: database " fname
" is locked. Try copying to another location, remove original and copy back."))
(exn (permission)(db:generic-error-printout exn "ERROR: database " fname " has some permissions problem."))
(exn ()
(db:generic-error-printout exn "ERROR: Unknown error with database " fname " message: "
((condition-property-accessor 'exn 'message) exn))))))
;;======================================================================
;; file utils
;;======================================================================
;;======================================================================
;; lazy-safe get file mod time. on any error (file not existing etc.) return 0
;;
(define (dbfile:lazy-modification-time fpath)
(handle-exceptions
exn
(begin
(dbfile:print-err "Failed to get modification time for " fpath ", treating it as zero. exn=" exn)
0)
(if (file-exists? fpath)
(file-modification-time fpath)
0)))
;;======================================================================
;; find timestamp of newest file associated with a sqlite db file
(define (dbfile:lazy-sqlite-db-modification-time fpath)
(let* ((glob-list (handle-exceptions
exn
(begin
(dbfile:print-err "Failed to glob " fpath "*, exn=" exn)
`(,(conc "/no/such/file, message: " ((condition-property-accessor 'exn 'message) exn))))
(glob (conc fpath "*"))))
(file-list (if (eq? 0 (length glob-list))
'("/no/such/file")
glob-list)))
(apply max
(map
dbfile:lazy-modification-time
file-list))))
;; dot-locking egg seems not to work, using this for now
;; if lock is older than expire-time then remove it and try again
;; to get the lock
;;
(define (dbfile:simple-file-lock fname #!key (expire-time 300))
(let ((fmod-time (handle-exceptions
ext
(current-seconds)
(file-modification-time fname))))
(if (file-exists? fname)
(if (> (- (current-seconds) fmod-time) expire-time)
(begin
(handle-exceptions exn #f (delete-file* fname))
(dbfile:simple-file-lock fname expire-time: expire-time))
#f)
(let ((key-string (conc (get-host-name) "-" (current-process-id)))
(oup (open-output-file fname)))
(with-output-to-port
oup
(lambda ()
(print key-string)))
(close-output-port oup)
#;(with-output-to-file fname ;; bizarre. with-output-to-file does not seem to be cleaning up after itself.
(lambda ()
(print key-string)))
(thread-sleep! 0.25)
(if (file-exists? fname)
(handle-exceptions exn
#f
(with-input-from-file fname
(lambda ()
(equal? key-string (read-line)))))
#f)
)
)
)
)
(define (dbfile:simple-file-lock-and-wait fname #!key (expire-time 300))
(let ((end-time (+ expire-time (current-seconds))))
(let loop ((got-lock (dbfile:simple-file-lock fname expire-time: expire-time)))
(if got-lock
#t
(if (> end-time (current-seconds))
(begin
(thread-sleep! 3)
(loop (dbfile:simple-file-lock fname expire-time: expire-time)))
#f)))))
(define (dbfile:simple-file-release-lock fname)
(handle-exceptions
exn
#f ;; I don't really care why this failed (at least for now)
(delete-file* fname)))
(define (dbfile:with-simple-file-lock fname proc #!key (expire-time 300))
(let ((gotlock (dbfile:simple-file-lock-and-wait fname expire-time: expire-time)))
(if gotlock
(let ((res (proc)))
(dbfile:simple-file-release-lock fname)
res)
(assert #t "FATAL: simple file lock never got a lock."))))
)