not so fast

fontland/fontland/db.rkt

@@ -0,0 +1,35 @@
+#lang debug racket
+(require sugar/debug sugar/cache racket/class racket/match
+         db racket/logging racket/draw openssl/sha1 racket/runtime-path)
+(provide (all-defined-out))
+
+(define-runtime-path db-file "fontland.sqlite")
+(define current-query-debug (make-parameter #f))
+(define current-dbc (make-parameter (sqlite3-connect #:database db-file #:mode 'create)))
+
+(define-logger db)
+
+(define (log-query q) (when (current-query-debug) (log-db-info q)))
+
+(define-syntax-rule (query-exec-logging q arg ...)
+  (begin (log-query q) (query-exec (current-dbc) q arg ...)))
+
+(define-syntax-rule (query-rows-logging q arg ...)
+  (begin (log-query q) (query-rows (current-dbc) q arg ...)))
+
+(define (add-record! rec)
+  (define recstring (format "(~a, '~a')" (car rec) (bytes->hex-string (cdr rec))))
+  (query-exec-logging (format "insert or replace into layouts (crc, layout) values ~a" recstring)))
+
+(define/caching (get-layout-from-db which)
+  (match (query-rows-logging (format "select layout from layouts where crc==~a" which))
+    [(list (vector val)) (hex-string->bytes val)]
+    [_ #false]))
+
+(define (init-db)
+  (query-exec-logging "create table if not exists layouts (crc INTEGER, layout TEXT, PRIMARY KEY (crc))"))
+
+(module+ main
+  (init-db)
+  (add-record! (cons 42 #"01234"))
+  (get-layout-from-db 42))

fontland/fontland/font.rkt

@@ -1,12 +1,13 @@
 #lang debug racket/base
 (require (for-syntax racket/base)
          "helper.rkt"
-         "ffi/freetype.rkt"
+         "unsafe/freetype.rkt"
          "subset.rkt"
          "glyph.rkt"
          "bbox.rkt"
          "glyphrun.rkt"
          "directory.rkt"
+         "db.rkt"
          xenomorph
          "tables.rkt"
          racket/contract
@@ -18,7 +19,7 @@
          sugar/unstable/dict
          sugar/unstable/js
          racket/port
-         "ffi/harfbuzz.rkt"
+         "unsafe/harfbuzz.rkt"
          "glyph-position.rkt"
          sugar/list
          racket/promise
@@ -266,8 +267,8 @@ https://github.com/mbutterick/fontkit/blob/master/src/TTFFont.js
 (define (hb-layout->glyphrun this hbr)
   (match hbr
     [(hash-table ('hb-gids gidxs)
-       ('hb-clusters clusters)
-       ('hb-positions posns))
+                 ('hb-clusters clusters)
+                 ('hb-positions posns))
      (define glyphs (for/list ([gidx (in-list gidxs)]
                                [cluster (in-list clusters)])
                               (send this getGlyph gidx cluster)))
@@ -311,8 +312,15 @@ https://github.com/mbutterick/fontkit/blob/master/src/TTFFont.js
   (define (get-layout string)
     (define codepoints (map char->integer (string->list string)))
     (define args (list codepoints (if userFeatures (sort userFeatures symbol<?) null) script language))
-    (define res (hash-ref! layout-cache (apply layout-cache-key (· this _crc) args) (λ () (encode hb-output (apply harfbuzz-layout this args) #f))))
-    (dump (decode hb-output res))) ;; `dump` converts to hash
+    (define key (apply layout-cache-key (· this _crc) args))
+    (hash-ref! layout-cache key
+               (λ ()
+                 #;(encode hb-output (apply harfbuzz-layout this args) #f)
+                 (match (get-layout-from-db key)
+                   [(? bytes? res) (dump (decode hb-output res))]
+                   [_  (define new-layout (apply harfbuzz-layout this args))
+                       (add-record! (cons key (encode hb-output new-layout #f)))
+                       (make-hasheq new-layout)])))) ;; `dump` converts to hash
   ;; work on substrs to reuse cached pieces
   ;; caveat: no shaping / positioning that involve word spaces
   ;; todo: why does caching produce slightly different results in test files
@@ -322,7 +330,7 @@ https://github.com/mbutterick/fontkit/blob/master/src/TTFFont.js
      (define substrs (for/list ([substr (in-list (regexp-match* " " string #:gap-select? #t))]
                                 #:when (positive? (string-length substr)))
                                substr))
-     (apply append-glyphruns (map get-layout substrs))]
+     (apply append-glyphruns (map (λ (lo) (hb-layout->glyphrun this lo)) (map get-layout substrs)))]
     [else (if debug
               (get-layout string)
               (hb-layout->glyphrun this (get-layout string)))]))
@@ -410,4 +418,3 @@ https://github.com/mbutterick/fontkit/blob/master/src/base.js
     (and (equal? (hash-ref h 'hb-gids) '(227 480 732 412))
          (equal? (hash-ref h 'hb-clusters) '((82) (105) (102 108) (101)))
          (equal? (hash-ref h 'hb-positions) '((601 0 0 0 0) (279 0 0 0 0) (580 0 0 0 0) (547 0 0 0 0)))))))
- 

fontland/fontland/glyph.rkt

@@ -9,7 +9,7 @@
          sugar/unstable/dict
          sugar/unstable/js
          sugar/unstable/stub
-         "ffi/freetype.rkt"
+         "unsafe/freetype.rkt"
          "helper.rkt")
 (provide (all-defined-out))
 (module+ test (require rackunit))