racket/collects/setup/xref.rkt
Matthew Flatt cd257fe65b setup/xref: simplify db interaction
Relies on improvements to SQLite retry support.
2012-12-03 18:57:53 -07:00

137 lines
4.9 KiB
Racket

#lang scheme/base
(require scribble/xref
scheme/fasl
scheme/path
racket/promise
setup/dirs
"getinfo.rkt"
"private/path-utils.rkt"
"doc-db.rkt")
(provide load-collections-xref
make-collections-xref)
(define cached-xref #f)
(define (get-dests no-user?)
(define main-dirs
(parameterize ([current-library-collection-paths
(let ([d (find-collects-dir)])
(if d (list d) null))])
(for/hash ([k (in-list (find-relevant-directories '(scribblings) 'no-planet))])
(values k #t))))
(apply
append
(for*/list ([dir (find-relevant-directories '(scribblings) 'all-available)]
[d (let ([info-proc (get-info/full dir)])
(if info-proc
(info-proc 'scribblings)
'()))])
(unless (and (list? d) (pair? d))
(error 'xref "bad scribblings entry: ~e" d))
(let* ([len (length d)]
[flags (if (len . >= . 2) (cadr d) '())]
[name (if (len . >= . 4)
(cadddr d)
(path->string
(path-replace-suffix (file-name-from-path (car d))
#"")))]
[out-count (if (len . >= . 5)
(list-ref d 4)
1)])
(if (not (and (len . >= . 3) (memq 'omit (caddr d))))
(let ([d (doc-path dir name flags (hash-ref main-dirs dir #f)
(if no-user? 'never 'false-if-missing))])
(if d
(for*/list ([i (in-range (add1 out-count))]
[p (in-value (build-path d (format "out~a.sxref" i)))]
#:when (file-exists? p))
p)
null))
null)))))
(define ((dest->source done-ht) dest)
(if (hash-ref done-ht dest #f)
(lambda () #f)
(lambda ()
(hash-set! done-ht dest #t)
(with-handlers ([exn:fail? (lambda (exn)
(log-warning
"warning: ~a"
(if (exn? exn)
(exn-message exn)
(format "~e" exn)))
#f)])
(cadr (call-with-input-file* dest fasl->s-exp))))))
(define (make-key->source db-path no-user?)
(define main-db (cons (or db-path
(build-path (find-doc-dir) "docindex.sqlite"))
;; cache for a connection:
(box #f)))
(define user-db (and (not no-user?)
(cons (build-path (find-user-doc-dir) "docindex.sqlite")
;; cache for a connection:
(box #f))))
(define done-ht (make-hash)) ; tracks already-loaded documents
(define forced-all? #f)
(define (force-all)
;; force all documents
(define thunks (get-reader-thunks no-user? done-ht))
(set! forced-all? #t)
(lambda ()
;; return a procedure so we can produce a list of results:
(lambda ()
(for/list ([thunk (in-list thunks)])
(thunk)))))
(lambda (key)
(cond
[forced-all? #f]
[key
(define (try p)
(and p
(let* ([maybe-db (unbox (cdr p))]
[db
;; Use a cached connection, or...
(or (and (box-cas! (cdr p) maybe-db #f)
maybe-db)
;; ... create a new one
(and (file-exists? (car p))
(doc-db-file->connection (car p))))])
(and
db
(let ()
;; The db query:
(begin0
(doc-db-key->path db key)
;; cache the connection, if none is already cached:
(or (box-cas! (cdr p) #f db)
(doc-db-disconnect db))))))))
(define dest (or (try main-db) (try user-db)))
(and dest
(if (eq? dest #t)
(force-all)
((dest->source done-ht) dest)))]
[else
(unless forced-all?
(force-all))])))
(define (get-reader-thunks no-user? done-ht)
(map (dest->source done-ht)
(filter values (get-dests no-user?))))
(define (load-collections-xref [report-loading void])
(or cached-xref
(begin (report-loading)
(set! cached-xref
(make-collections-xref))
cached-xref)))
(define (make-collections-xref #:no-user? [no-user? #f]
#:doc-db [db-path #f])
(if (doc-db-available?)
(load-xref null
#:demand-source (make-key->source db-path no-user?))
(load-xref (get-reader-thunks no-user? (make-hash)))))