diff options
| -rw-r--r-- | pict.scm | 62 | ||||
| -rw-r--r-- | pict/base64.scm | 256 |
2 files changed, 306 insertions, 12 deletions
@@ -19,10 +19,13 @@ (define-module (pict) #:use-module (pict sxml) + #:use-module (pict base64) #:use-module ((sxml simple) #:hide (xml->sxml)) #:use-module (sxml transform) #:use-module (sxml fold) #:use-module ((sxml xpath) #:hide (filter)) + #:use-module (ice-9 binary-ports) + #:use-module (rnrs bytevectors) #:use-module (srfi srfi-1) #:use-module (srfi srfi-9) #:use-module (srfi srfi-9 gnu) @@ -148,21 +151,56 @@ list VALS." '(0 . ()) (cons 0 vals)))) +(define (png-size file-name) + "Return two values: width and height of the PNG file at FILE-NAME." + (define (bv->size bv) + (car (bytevector->uint-list bv (endianness big) 4))) + (call-with-input-file file-name + (lambda (port) + (get-bytevector-n port 8) ; throw away header + (get-bytevector-n port 4) ; throw away first chunk length + (if (bytevector=? (get-bytevector-n port 4) + #vu8(73 72 68 82)) ; IHDR + (values + (bv->size (get-bytevector-n port 4)) ; width + (bv->size (get-bytevector-n port 4))) ; height + (values #f #f))))) + (define (pict-from-file file-name) "Attempt to read FILE-NAME, convert its contents to SXML and wrap it in a <PICT> record. If this fails return #F." - (catch 'parser-error - (lambda () - (make-pict - (match (call-with-input-file file-name xml->sxml) - (('*TOP* ('*PI* . rest) svg) svg) - (('*TOP* svg) svg)))) - (lambda _ - (format (current-error-port) - "Failed to parse picture from file `~a'.~%\ -Is this really an SVG file?~%" - file-name) - #f))) + (let ((header (call-with-input-file file-name + (lambda (port) (get-bytevector-n port 8))))) + (make-pict + (match header + (#vu8(137 80 78 71 13 10 26 10) ; PNG + (call-with-values + (lambda () (png-size file-name)) + (lambda (width height) + `(svg (@ (width ,width) + (height ,height) + (xmlns "http://www.w3.org/2000/svg") + (xmlns:xlink "http://www.w3.org/1999/xlink")) + (image (@ (width ,width) + (height ,height) + (xlink:href + ,(string-append + "data:image/png;base64," + (call-with-input-file file-name + (lambda (port) + (base64-encode (get-bytevector-all port))) + #:binary #t))))))))) + (_ ; Assume SVG + (catch 'parser-error + (lambda () + (match (call-with-input-file file-name xml->sxml) + (('*TOP* ('*PI* . rest) svg) svg) + (('*TOP* svg) svg))) + (lambda args + (format (current-error-port) + "Failed to load picture from file `~a'.~%Only PNG or SVG are supported.~%~a~%" + file-name args) + #f))))))) ;;; SXML utilities diff --git a/pict/base64.scm b/pict/base64.scm new file mode 100644 index 0000000..21c0d26 --- /dev/null +++ b/pict/base64.scm @@ -0,0 +1,256 @@ +;; -*- mode: scheme; coding: utf-8 -*- +;; +;; This module was taken from the Guix sources and renamed to +;; (pict base64) on February 9, 2019. +;; +;; This module was renamed from (weinholt text base64 (1 0 20100612)) to +;; (guix base64) by Nikita Karetnikov <nikita@karetnikov.org> on +;; February 12, 2014. +;; +;; Some optimizations made by Ludovic Courtès <ludo@gnu.org>, 2015. +;; Turned into a Guile module (instead of R6RS). +;; +;; This program 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. +;; +;; This program 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 this program. If not, see <http://www.gnu.org/licenses/>. +;; +;; This file incorporates work covered by the following copyright and +;; permission notice: +;; +;; Copyright © 2009, 2010 Göran Weinholt <goran@weinholt.se> +;; +;; Permission is hereby granted, free of charge, to any person obtaining a +;; copy of this software and associated documentation files (the "Software"), +;; to deal in the Software without restriction, including without limitation +;; the rights to use, copy, modify, merge, publish, distribute, sublicense, +;; and/or sell copies of the Software, and to permit persons to whom the +;; Software is furnished to do so, subject to the following conditions: +;; +;; The above copyright notice and this permission notice shall be included in +;; all copies or substantial portions of the Software. +;; +;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +;; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +;; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL +;; THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +;; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING +;; FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER +;; DEALINGS IN THE SOFTWARE. + +;; RFC 4648 Base-N Encodings + +(define-module (pict base64) + #:export (base64-encode + base64-decode + base64-alphabet + base64url-alphabet + get-delimited-base64 + put-delimited-base64) + #:use-module (rnrs) + #:use-module ((srfi srfi-13) + #:select (string-index + string-prefix? string-suffix? + string-concatenate string-trim-both))) + + +(define-syntax define-alias + (syntax-rules () + ((_ new old) + (define-syntax new (identifier-syntax old))))) + +;; Force the use of Guile's own primitives to avoid the overhead of its 'fx' +;; procedures. + +(define-alias fxbit-field bitwise-bit-field) +(define-alias fxarithmetic-shift ash) +(define-alias fxarithmetic-shift-left ash) +(define-alias fxand logand) +(define-alias fxior logior) +(define-alias fxxor logxor) + +(define base64-alphabet + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/") + +(define base64url-alphabet + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_") + +(define base64-encode + (case-lambda + ;; Simple interface. Returns a string containing the canonical + ;; base64 representation of the given bytevector. + ((bv) + (base64-encode bv 0 (bytevector-length bv) #f #f base64-alphabet #f)) + ((bv start) + (base64-encode bv start (bytevector-length bv) #f #f base64-alphabet #f)) + ((bv start end) + (base64-encode bv start end #f #f base64-alphabet #f)) + ((bv start end line-length) + (base64-encode bv start end line-length #f base64-alphabet #f)) + ((bv start end line-length no-padding) + (base64-encode bv start end line-length no-padding base64-alphabet #f)) + ((bv start end line-length no-padding alphabet) + (base64-encode bv start end line-length no-padding alphabet #f)) + ;; Base64 encodes the bytes [start,end[ in the given bytevector. + ;; Lines are limited to line-length characters (unless #f), + ;; which must be a multiple of four. To omit the padding + ;; characters (#\=) set no-padding to a true value. If port is + ;; #f, returns a string. + ((bv start end line-length no-padding alphabet port) + (assert (or (not line-length) (zero? (mod line-length 4)))) + (let-values (((p extract) (if port + (values port (lambda () (values))) + (open-string-output-port)))) + (letrec ((put (if line-length + (let ((chars 0)) + (lambda (p c) + (when (fx=? chars line-length) + (set! chars 0) + (put-char p #\linefeed)) + (set! chars (fx+ chars 1)) + (put-char p c))) + put-char))) + (let lp ((i start)) + (cond ((= i end)) + ((<= (+ i 3) end) + (let ((x (bytevector-uint-ref bv i (endianness big) 3))) + (put p (string-ref alphabet (fxbit-field x 18 24))) + (put p (string-ref alphabet (fxbit-field x 12 18))) + (put p (string-ref alphabet (fxbit-field x 6 12))) + (put p (string-ref alphabet (fxbit-field x 0 6))) + (lp (+ i 3)))) + ((<= (+ i 2) end) + (let ((x (fxarithmetic-shift-left (bytevector-u16-ref bv i (endianness big)) 8))) + (put p (string-ref alphabet (fxbit-field x 18 24))) + (put p (string-ref alphabet (fxbit-field x 12 18))) + (put p (string-ref alphabet (fxbit-field x 6 12))) + (unless no-padding + (put p #\=)))) + (else + (let ((x (fxarithmetic-shift-left (bytevector-u8-ref bv i) 16))) + (put p (string-ref alphabet (fxbit-field x 18 24))) + (put p (string-ref alphabet (fxbit-field x 12 18))) + (unless no-padding + (put p #\=) + (put p #\=))))))) + (extract))))) + + ;; Decodes a base64 string. The string must contain only pure + ;; unpadded base64 data. + +(define base64-decode + (case-lambda + ((str) + (base64-decode str base64-alphabet #f)) + ((str alphabet) + (base64-decode str alphabet #f)) + ((str alphabet port) + (unless (zero? (mod (string-length str) 4)) + (error 'base64-decode + "input string must be a multiple of four characters")) + (let-values (((p extract) (if port + (values port (lambda () (values))) + (open-bytevector-output-port)))) + (do ((i 0 (+ i 4))) + ((= i (string-length str)) + (extract)) + (let ((c1 (string-ref str i)) + (c2 (string-ref str (+ i 1))) + (c3 (string-ref str (+ i 2))) + (c4 (string-ref str (+ i 3)))) + ;; TODO: be more clever than string-index + (let ((i1 (string-index alphabet c1)) + (i2 (string-index alphabet c2)) + (i3 (string-index alphabet c3)) + (i4 (string-index alphabet c4))) + (cond ((and i1 i2 i3 i4) + (let ((x (fxior (fxarithmetic-shift-left i1 18) + (fxarithmetic-shift-left i2 12) + (fxarithmetic-shift-left i3 6) + i4))) + (put-u8 p (fxbit-field x 16 24)) + (put-u8 p (fxbit-field x 8 16)) + (put-u8 p (fxbit-field x 0 8)))) + ((and i1 i2 i3 (char=? c4 #\=) + (= i (- (string-length str) 4))) + (let ((x (fxior (fxarithmetic-shift-left i1 18) + (fxarithmetic-shift-left i2 12) + (fxarithmetic-shift-left i3 6)))) + (put-u8 p (fxbit-field x 16 24)) + (put-u8 p (fxbit-field x 8 16)))) + ((and i1 i2 (char=? c3 #\=) (char=? c4 #\=) + (= i (- (string-length str) 4))) + (let ((x (fxior (fxarithmetic-shift-left i1 18) + (fxarithmetic-shift-left i2 12)))) + (put-u8 p (fxbit-field x 16 24)))) + (else + (error 'base64-decode "invalid input" + (list c1 c2 c3 c4))))))))))) + +(define (get-line-comp f port) + (if (port-eof? port) + (eof-object) + (f (get-line port)))) + + ;; Reads the common -----BEGIN/END type----- delimited format from + ;; the given port. Returns two values: a string with the type and a + ;; bytevector containing the base64 decoded data. The second value + ;; is the eof object if there is an eof before the BEGIN delimiter. + +(define (get-delimited-base64 port) + (define (get-first-data-line port) + ;; Some MIME data has header fields in the same format as mail + ;; or http. These are ignored. + (let ((line (get-line-comp string-trim-both port))) + (cond ((eof-object? line) line) + ((string-index line #\:) + (let lp () ;read until empty line + (let ((line (get-line-comp string-trim-both port))) + (if (string=? line "") + (get-line-comp string-trim-both port) + (lp))))) + (else line)))) + (let ((line (get-line-comp string-trim-both port))) + (cond ((eof-object? line) + (values "" (eof-object))) + ((string=? line "") + (get-delimited-base64 port)) + ((and (string-prefix? "-----BEGIN " line) + (string-suffix? "-----" line)) + (let* ((type (substring line 11 (- (string-length line) 5))) + (endline (string-append "-----END " type "-----"))) + (let-values (((outp extract) (open-bytevector-output-port))) + (let lp ((line (get-first-data-line port))) + (cond ((eof-object? line) + (error 'get-delimited-base64 + "unexpected end of file")) + ((string-prefix? "-" line) + (unless (string=? line endline) + (error 'get-delimited-base64 + "bad end delimiter" type line)) + (values type (extract))) + (else + (unless (and (= (string-length line) 5) + (string-prefix? "=" line)) ;Skip Radix-64 checksum + (base64-decode line base64-alphabet outp)) + (lp (get-line-comp string-trim-both port)))))))) + (else ;skip garbage (like in openssl x509 -in foo -text output). + (get-delimited-base64 port))))) + +(define put-delimited-base64 + (case-lambda + ((port type bv line-length) + (display (string-append "-----BEGIN " type "-----\n") port) + (base64-encode bv 0 (bytevector-length bv) + line-length #f base64-alphabet port) + (display (string-append "\n-----END " type "-----\n") port)) + ((port type bv) + (put-delimited-base64 port type bv 76)))) |