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-rw-r--r--guix/config.scm.in4
-rw-r--r--guix/lzlib.scm633
-rw-r--r--guix/self.scm1
3 files changed, 638 insertions, 0 deletions
diff --git a/guix/config.scm.in b/guix/config.scm.in
index 247b15ed81..0ada0f3c38 100644
--- a/guix/config.scm.in
+++ b/guix/config.scm.in
@@ -34,6 +34,7 @@
%system
%libz
+ %liblz
%gzip
%bzip2
%xz))
@@ -90,6 +91,9 @@
(define %libz
"@LIBZ@")
+(define %liblz
+ "@LIBLZ@")
+
(define %gzip
"@GZIP@")
diff --git a/guix/lzlib.scm b/guix/lzlib.scm
new file mode 100644
index 0000000000..d596f0d95d
--- /dev/null
+++ b/guix/lzlib.scm
@@ -0,0 +1,633 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2019 Pierre Neidhardt <mail@ambrevar.xyz>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix 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.
+;;;
+;;; GNU Guix 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 GNU Guix. If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix lzlib)
+ #:use-module (rnrs bytevectors)
+ #:use-module (rnrs arithmetic bitwise)
+ #:use-module (ice-9 binary-ports)
+ #:use-module (ice-9 match)
+ #:use-module (system foreign)
+ #:use-module (guix config)
+ #:export (lzlib-available?
+ make-lzip-input-port
+ make-lzip-output-port
+ call-with-lzip-input-port
+ call-with-lzip-output-port
+ %default-member-length-limit
+ %default-compression-level))
+
+;;; Commentary:
+;;;
+;;; Bindings to the lzlib / liblz API. Some convenience functions are also
+;;; provided (see the export).
+;;;
+;;; While the bindings are complete, the convenience functions only support
+;;; single member archives. To decompress single member archives, we loop
+;;; until lz-decompress-read returns 0. This is simpler. To support multiple
+;;; members properly, we need (among others) to call lz-decompress-finish and
+;;; loop over lz-decompress-read until lz-decompress-finished? returns #t.
+;;; Otherwise a multi-member archive starting with an empty member would only
+;;; decompress the empty member and stop there, resulting in truncated output.
+
+;;; Code:
+
+(define %lzlib
+ ;; File name of lzlib's shared library. When updating via 'guix pull',
+ ;; '%liblz' might be undefined so protect against it.
+ (delay (dynamic-link (if (defined? '%liblz)
+ %liblz
+ "liblz"))))
+
+(define (lzlib-available?)
+ "Return true if lzlib is available, #f otherwise."
+ (false-if-exception (force %lzlib)))
+
+(define (lzlib-procedure ret name parameters)
+ "Return a procedure corresponding to C function NAME in liblz, or #f if
+either lzlib or the function could not be found."
+ (match (false-if-exception (dynamic-func name (force %lzlib)))
+ ((? pointer? ptr)
+ (pointer->procedure ret ptr parameters))
+ (#f
+ #f)))
+
+(define-wrapped-pointer-type <lz-decoder>
+ ;; Scheme counterpart of the 'LZ_Decoder' opaque type.
+ lz-decoder?
+ pointer->lz-decoder
+ lz-decoder->pointer
+ (lambda (obj port)
+ (format port "#<lz-decoder ~a>"
+ (number->string (object-address obj) 16))))
+
+(define-wrapped-pointer-type <lz-encoder>
+ ;; Scheme counterpart of the 'LZ_Encoder' opaque type.
+ lz-encoder?
+ pointer->lz-encoder
+ lz-encoder->pointer
+ (lambda (obj port)
+ (format port "#<lz-encoder ~a>"
+ (number->string (object-address obj) 16))))
+
+;; From lzlib.h
+(define %error-number-ok 0)
+(define %error-number-bad-argument 1)
+(define %error-number-mem-error 2)
+(define %error-number-sequence-error 3)
+(define %error-number-header-error 4)
+(define %error-number-unexpected-eof 5)
+(define %error-number-data-error 6)
+(define %error-number-library-error 7)
+
+
+;; Compression bindings.
+
+(define lz-compress-open
+ (let ((proc (lzlib-procedure '* "LZ_compress_open" (list int int uint64)))
+ ;; member-size is an "unsigned long long", and the C standard guarantees
+ ;; a minimum range of 0..2^64-1.
+ (unlimited-size (- (expt 2 64) 1)))
+ (lambda* (dictionary-size match-length-limit #:optional (member-size unlimited-size))
+ "Initialize the internal stream state for compression and returns a
+pointer that can only be used as the encoder argument for the other
+lz-compress functions, or a null pointer if the encoder could not be
+allocated.
+
+See the manual: (lzlib) Compression functions."
+ (let ((encoder-ptr (proc dictionary-size match-length-limit member-size)))
+ (if (not (= (lz-compress-error encoder-ptr) -1))
+ (pointer->lz-encoder encoder-ptr)
+ (throw 'lzlib-error 'lz-compress-open))))))
+
+(define lz-compress-close
+ (let ((proc (lzlib-procedure int "LZ_compress_close" '(*))))
+ (lambda (encoder)
+ "Close encoder. ENCODER can no longer be used as an argument to any
+lz-compress function. "
+ (let ((ret (proc (lz-encoder->pointer encoder))))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-compress-close ret)
+ ret)))))
+
+(define lz-compress-finish
+ (let ((proc (lzlib-procedure int "LZ_compress_finish" '(*))))
+ (lambda (encoder)
+ "Tell that all the data for this member have already been written (with
+the `lz-compress-write' function). It is safe to call `lz-compress-finish' as
+many times as needed. After all the produced compressed data have been read
+with `lz-compress-read' and `lz-compress-member-finished?' returns #t, a new
+member can be started with 'lz-compress-restart-member'."
+ (let ((ret (proc (lz-encoder->pointer encoder))))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-compress-finish (lz-compress-error encoder))
+ ret)))))
+
+(define lz-compress-restart-member
+ (let ((proc (lzlib-procedure int "LZ_compress_restart_member" (list '* uint64))))
+ (lambda (encoder member-size)
+ "Start a new member in a multimember data stream.
+Call this function only after `lz-compress-member-finished?' indicates that the
+current member has been fully read (with the `lz-compress-read' function)."
+ (let ((ret (proc (lz-encoder->pointer encoder) member-size)))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-compress-restart-member
+ (lz-compress-error encoder))
+ ret)))))
+
+(define lz-compress-sync-flush
+ (let ((proc (lzlib-procedure int "LZ_compress_sync_flush" (list '*))))
+ (lambda (encoder)
+ "Make available to `lz-compress-read' all the data already written with
+the `LZ-compress-write' function. First call `lz-compress-sync-flush'. Then
+call 'lz-compress-read' until it returns 0.
+
+Repeated use of `LZ-compress-sync-flush' may degrade compression ratio,
+so use it only when needed. "
+ (let ((ret (proc (lz-encoder->pointer encoder))))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-compress-sync-flush
+ (lz-compress-error encoder))
+ ret)))))
+
+(define lz-compress-read
+ (let ((proc (lzlib-procedure int "LZ_compress_read" (list '* '* int))))
+ (lambda* (encoder lzfile-bv #:optional (start 0) (count (bytevector-length lzfile-bv)))
+ "Read up to COUNT bytes from the encoder stream, storing the results in LZFILE-BV.
+Return the number of uncompressed bytes written, a strictly positive integer."
+ (let ((ret (proc (lz-encoder->pointer encoder)
+ (bytevector->pointer lzfile-bv start)
+ count)))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-compress-read (lz-compress-error encoder))
+ ret)))))
+
+(define lz-compress-write
+ (let ((proc (lzlib-procedure int "LZ_compress_write" (list '* '* int))))
+ (lambda* (encoder bv #:optional (start 0) (count (bytevector-length bv)))
+ "Write up to COUNT bytes from BV to the encoder stream. Return the
+number of uncompressed bytes written, a strictly positive integer."
+ (let ((ret (proc (lz-encoder->pointer encoder)
+ (bytevector->pointer bv start)
+ count)))
+ (if (< ret 0)
+ (throw 'lzlib-error 'lz-compress-write (lz-compress-error encoder))
+ ret)))))
+
+(define lz-compress-write-size
+ (let ((proc (lzlib-procedure int "LZ_compress_write_size" '(*))))
+ (lambda (encoder)
+ "The maximum number of bytes that can be immediately written through the
+`lz-compress-write' function.
+
+It is guaranteed that an immediate call to `lz-compress-write' will accept a
+SIZE up to the returned number of bytes. "
+ (let ((ret (proc (lz-encoder->pointer encoder))))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-compress-write-size (lz-compress-error encoder))
+ ret)))))
+
+(define lz-compress-error
+ (let ((proc (lzlib-procedure int "LZ_compress_errno" '(*))))
+ (lambda (encoder)
+ "ENCODER can be a Scheme object or a pointer."
+ (let* ((error-number (proc (if (lz-encoder? encoder)
+ (lz-encoder->pointer encoder)
+ encoder))))
+ error-number))))
+
+(define lz-compress-finished?
+ (let ((proc (lzlib-procedure int "LZ_compress_finished" '(*))))
+ (lambda (encoder)
+ "Return #t if all the data have been read and `lz-compress-close' can
+be safely called. Otherwise return #f."
+ (let ((ret (proc (lz-encoder->pointer encoder))))
+ (match ret
+ (1 #t)
+ (0 #f)
+ (_ (throw 'lzlib-error 'lz-compress-finished? (lz-compress-error encoder))))))))
+
+(define lz-compress-member-finished?
+ (let ((proc (lzlib-procedure int "LZ_compress_member_finished" '(*))))
+ (lambda (encoder)
+ "Return #t if the current member, in a multimember data stream, has
+been fully read and 'lz-compress-restart-member' can be safely called.
+Otherwise return #f."
+ (let ((ret (proc (lz-encoder->pointer encoder))))
+ (match ret
+ (1 #t)
+ (0 #f)
+ (_ (throw 'lzlib-error 'lz-compress-member-finished? (lz-compress-error encoder))))))))
+
+(define lz-compress-data-position
+ (let ((proc (lzlib-procedure uint64 "LZ_compress_data_position" '(*))))
+ (lambda (encoder)
+ "Return the number of input bytes already compressed in the current
+member."
+ (let ((ret (proc (lz-encoder->pointer encoder))))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-compress-data-position
+ (lz-compress-error encoder))
+ ret)))))
+
+(define lz-compress-member-position
+ (let ((proc (lzlib-procedure uint64 "LZ_compress_member_position" '(*))))
+ (lambda (encoder)
+ "Return the number of compressed bytes already produced, but perhaps
+not yet read, in the current member."
+ (let ((ret (proc (lz-encoder->pointer encoder))))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-compress-member-position
+ (lz-compress-error encoder))
+ ret)))))
+
+(define lz-compress-total-in-size
+ (let ((proc (lzlib-procedure uint64 "LZ_compress_total_in_size" '(*))))
+ (lambda (encoder)
+ "Return the total number of input bytes already compressed."
+ (let ((ret (proc (lz-encoder->pointer encoder))))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-compress-total-in-size
+ (lz-compress-error encoder))
+ ret)))))
+
+(define lz-compress-total-out-size
+ (let ((proc (lzlib-procedure uint64 "LZ_compress_total_out_size" '(*))))
+ (lambda (encoder)
+ "Return the total number of compressed bytes already produced, but
+perhaps not yet read."
+ (let ((ret (proc (lz-encoder->pointer encoder))))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-compress-total-out-size
+ (lz-compress-error encoder))
+ ret)))))
+
+
+;; Decompression bindings.
+
+(define lz-decompress-open
+ (let ((proc (lzlib-procedure '* "LZ_decompress_open" '())))
+ (lambda ()
+ "Initializes the internal stream state for decompression and returns a
+pointer that can only be used as the decoder argument for the other
+lz-decompress functions, or a null pointer if the decoder could not be
+allocated.
+
+See the manual: (lzlib) Decompression functions."
+ (let ((decoder-ptr (proc)))
+ (if (not (= (lz-decompress-error decoder-ptr) -1))
+ (pointer->lz-decoder decoder-ptr)
+ (throw 'lzlib-error 'lz-decompress-open))))))
+
+(define lz-decompress-close
+ (let ((proc (lzlib-procedure int "LZ_decompress_close" '(*))))
+ (lambda (decoder)
+ "Close decoder. DECODER can no longer be used as an argument to any
+lz-decompress function. "
+ (let ((ret (proc (lz-decoder->pointer decoder))))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-decompress-close ret)
+ ret)))))
+
+(define lz-decompress-finish
+ (let ((proc (lzlib-procedure int "LZ_decompress_finish" '(*))))
+ (lambda (decoder)
+ "Tell that all the data for this stream have already been written (with
+the `lz-decompress-write' function). It is safe to call
+`lz-decompress-finish' as many times as needed."
+ (let ((ret (proc (lz-decoder->pointer decoder))))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-decompress-finish (lz-decompress-error decoder))
+ ret)))))
+
+(define lz-decompress-reset
+ (let ((proc (lzlib-procedure int "LZ_decompress_reset" '(*))))
+ (lambda (decoder)
+ "Reset the internal state of DECODER as it was just after opening it
+with the `lz-decompress-open' function. Data stored in the internal buffers
+is discarded. Position counters are set to 0."
+ (let ((ret (proc (lz-decoder->pointer decoder))))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-decompress-reset
+ (lz-decompress-error decoder))
+ ret)))))
+
+(define lz-decompress-sync-to-member
+ (let ((proc (lzlib-procedure int "LZ_decompress_sync_to_member" '(*))))
+ (lambda (decoder)
+ "Reset the error state of DECODER and enters a search state that lasts
+until a new member header (or the end of the stream) is found. After a
+successful call to `lz-decompress-sync-to-member', data written with
+`lz-decompress-write' will be consumed and 'lz-decompress-read' will return 0
+until a header is found.
+
+This function is useful to discard any data preceding the first member, or to
+discard the rest of the current member, for example in case of a data
+error. If the decoder is already at the beginning of a member, this function
+does nothing."
+ (let ((ret (proc (lz-decoder->pointer decoder))))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-decompress-sync-to-member
+ (lz-decompress-error decoder))
+ ret)))))
+
+(define lz-decompress-read
+ (let ((proc (lzlib-procedure int "LZ_decompress_read" (list '* '* int))))
+ (lambda* (decoder file-bv #:optional (start 0) (count (bytevector-length file-bv)))
+ "Read up to COUNT bytes from the decoder stream, storing the results in FILE-BV.
+Return the number of uncompressed bytes written, a non-negative positive integer."
+ (let ((ret (proc (lz-decoder->pointer decoder)
+ (bytevector->pointer file-bv start)
+ count)))
+ (if (< ret 0)
+ (throw 'lzlib-error 'lz-decompress-read (lz-decompress-error decoder))
+ ret)))))
+
+(define lz-decompress-write
+ (let ((proc (lzlib-procedure int "LZ_decompress_write" (list '* '* int))))
+ (lambda* (decoder bv #:optional (start 0) (count (bytevector-length bv)))
+ "Write up to COUNT bytes from BV to the decoder stream. Return the
+number of uncompressed bytes written, a non-negative integer."
+ (let ((ret (proc (lz-decoder->pointer decoder)
+ (bytevector->pointer bv start)
+ count)))
+ (if (< ret 0)
+ (throw 'lzlib-error 'lz-decompress-write (lz-decompress-error decoder))
+ ret)))))
+
+(define lz-decompress-write-size
+ (let ((proc (lzlib-procedure int "LZ_decompress_write_size" '(*))))
+ (lambda (decoder)
+ "Return the maximum number of bytes that can be immediately written
+through the `lz-decompress-write' function.
+
+It is guaranteed that an immediate call to `lz-decompress-write' will accept a
+SIZE up to the returned number of bytes. "
+ (let ((ret (proc (lz-decoder->pointer decoder))))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-decompress-write-size (lz-decompress-error decoder))
+ ret)))))
+
+(define lz-decompress-error
+ (let ((proc (lzlib-procedure int "LZ_decompress_errno" '(*))))
+ (lambda (decoder)
+ "DECODER can be a Scheme object or a pointer."
+ (let* ((error-number (proc (if (lz-decoder? decoder)
+ (lz-decoder->pointer decoder)
+ decoder))))
+ error-number))))
+
+(define lz-decompress-finished?
+ (let ((proc (lzlib-procedure int "LZ_decompress_finished" '(*))))
+ (lambda (decoder)
+ "Return #t if all the data have been read and `lz-decompress-close' can
+be safely called. Otherwise return #f."
+ (let ((ret (proc (lz-decoder->pointer decoder))))
+ (match ret
+ (1 #t)
+ (0 #f)
+ (_ (throw 'lzlib-error 'lz-decompress-finished? (lz-decompress-error decoder))))))))
+
+(define lz-decompress-member-finished?
+ (let ((proc (lzlib-procedure int "LZ_decompress_member_finished" '(*))))
+ (lambda (decoder)
+ "Return #t if the current member, in a multimember data stream, has
+been fully read and `lz-decompress-restart-member' can be safely called.
+Otherwise return #f."
+ (let ((ret (proc (lz-decoder->pointer decoder))))
+ (match ret
+ (1 #t)
+ (0 #f)
+ (_ (throw 'lzlib-error 'lz-decompress-member-finished? (lz-decompress-error decoder))))))))
+
+(define lz-decompress-member-version
+ (let ((proc (lzlib-procedure int "LZ_decompress_member_version" '(*))))
+ (lambda (decoder)
+ (let ((ret (proc (lz-decoder->pointer decoder))))
+ "Return the version of current member from member header."
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-decompress-data-position
+ (lz-decompress-error decoder))
+ ret)))))
+
+(define lz-decompress-dictionary-size
+ (let ((proc (lzlib-procedure int "LZ_decompress_dictionary_size" '(*))))
+ (lambda (decoder)
+ (let ((ret (proc (lz-decoder->pointer decoder))))
+ "Return the dictionary size of current member from member header."
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-decompress-member-position
+ (lz-decompress-error decoder))
+ ret)))))
+
+(define lz-decompress-data-crc
+ (let ((proc (lzlib-procedure unsigned-int "LZ_decompress_data_crc" '(*))))
+ (lambda (decoder)
+ (let ((ret (proc (lz-decoder->pointer decoder))))
+ "Return the 32 bit Cyclic Redundancy Check of the data decompressed
+from the current member. The returned value is valid only when
+`lz-decompress-member-finished' returns #t. "
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-decompress-member-position
+ (lz-decompress-error decoder))
+ ret)))))
+
+(define lz-decompress-data-position
+ (let ((proc (lzlib-procedure uint64 "LZ_decompress_data_position" '(*))))
+ (lambda (decoder)
+ "Return the number of decompressed bytes already produced, but perhaps
+not yet read, in the current member."
+ (let ((ret (proc (lz-decoder->pointer decoder))))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-decompress-data-position
+ (lz-decompress-error decoder))
+ ret)))))
+
+(define lz-decompress-member-position
+ (let ((proc (lzlib-procedure uint64 "LZ_decompress_member_position" '(*))))
+ (lambda (decoder)
+ "Return the number of input bytes already decompressed in the current
+member."
+ (let ((ret (proc (lz-decoder->pointer decoder))))
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-decompress-member-position
+ (lz-decompress-error decoder))
+ ret)))))
+
+(define lz-decompress-total-in-size
+ (let ((proc (lzlib-procedure uint64 "LZ_decompress_total_in_size" '(*))))
+ (lambda (decoder)
+ (let ((ret (proc (lz-decoder->pointer decoder))))
+ "Return the total number of input bytes already compressed."
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-decompress-total-in-size
+ (lz-decompress-error decoder))
+ ret)))))
+
+(define lz-decompress-total-out-size
+ (let ((proc (lzlib-procedure uint64 "LZ_decompress_total_out_size" '(*))))
+ (lambda (decoder)
+ (let ((ret (proc (lz-decoder->pointer decoder))))
+ "Return the total number of compressed bytes already produced, but
+perhaps not yet read."
+ (if (= ret -1)
+ (throw 'lzlib-error 'lz-decompress-total-out-size
+ (lz-decompress-error decoder))
+ ret)))))
+
+
+;; High level functions.
+(define %lz-decompress-input-buffer-size (* 64 1024))
+
+(define* (lzread! decoder file-port bv
+ #:optional (start 0) (count (bytevector-length bv)))
+ "Read up to COUNT bytes from FILE-PORT into BV at offset START. Return the
+number of uncompressed bytes actually read; it is zero if COUNT is zero or if
+the end-of-stream has been reached."
+ ;; WARNING: Because we don't alternate between lz-reads and lz-writes, we can't
+ ;; process more than %lz-decompress-input-buffer-size from the file-port.
+ (when (> count %lz-decompress-input-buffer-size)
+ (set! count %lz-decompress-input-buffer-size))
+ (let* ((written 0)
+ (read 0)
+ (file-bv (get-bytevector-n file-port count)))
+ (unless (eof-object? file-bv)
+ (begin
+ (while (and (< 0 (lz-decompress-write-size decoder))
+ (< written (bytevector-length file-bv)))
+ (set! written (+ written
+ (lz-decompress-write decoder file-bv written
+ (- (bytevector-length file-bv) written)))))))
+ (let loop ((rd 0))
+ (if (< start (bytevector-length bv))
+ (begin
+ (set! rd (lz-decompress-read decoder bv start (- (bytevector-length bv) start)))
+ (set! start (+ start rd))
+ (set! read (+ read rd)))
+ (set! rd 0))
+ (unless (= rd 0)
+ (loop rd)))
+ read))
+
+(define* (lzwrite encoder bv lz-port
+ #:optional (start 0) (count (bytevector-length bv)))
+ "Write up to COUNT bytes from BV at offset START into LZ-PORT. Return
+the number of uncompressed bytes written, a non-negative integer."
+ (let ((written 0)
+ (read 0))
+ (while (and (< 0 (lz-compress-write-size encoder))
+ (< written count))
+ (set! written (+ written
+ (lz-compress-write encoder bv (+ start written) (- count written)))))
+ (when (= written 0)
+ (lz-compress-finish encoder))
+ (let ((lz-bv (make-bytevector written)))
+ (let loop ((rd 0))
+ (set! rd (lz-compress-read encoder lz-bv 0 (bytevector-length lz-bv)))
+ (put-bytevector lz-port lz-bv 0 rd)
+ (set! read (+ read rd))
+ (unless (= rd 0)
+ (loop rd))))
+ ;; `written' is the total byte count of uncompressed data.
+ written))
+
+
+;;;
+;;; Port interface.
+;;;
+
+;; Alist of (levels (dictionary-size match-length-limit)). 0 is the fastest.
+;; See bbexample.c in lzlib's source.
+(define %compression-levels
+ `((0 (65535 16))
+ (1 (,(bitwise-arithmetic-shift-left 1 20) 5))
+ (2 (,(bitwise-arithmetic-shift-left 3 19) 6))
+ (3 (,(bitwise-arithmetic-shift-left 1 21) 8))
+ (4 (,(bitwise-arithmetic-shift-left 3 20) 12))
+ (5 (,(bitwise-arithmetic-shift-left 1 22) 20))
+ (6 (,(bitwise-arithmetic-shift-left 1 23) 36))
+ (7 (,(bitwise-arithmetic-shift-left 1 24) 68))
+ (8 (,(bitwise-arithmetic-shift-left 3 23) 132))
+ (9 (,(bitwise-arithmetic-shift-left 1 25) 273))))
+
+(define %default-compression-level
+ 6)
+
+(define* (make-lzip-input-port port)
+ "Return an input port that decompresses data read from PORT, a file port.
+PORT is automatically closed when the resulting port is closed."
+ (define decoder (lz-decompress-open))
+
+ (define (read! bv start count)
+ (lzread! decoder port bv start count))
+
+ (make-custom-binary-input-port "lzip-input" read! #f #f
+ (lambda ()
+ (lz-decompress-close decoder)
+ (close-port port))))
+
+(define* (make-lzip-output-port port
+ #:key
+ (level %default-compression-level))
+ "Return an output port that compresses data at the given LEVEL, using PORT,
+a file port, as its sink. PORT is automatically closed when the resulting
+port is closed."
+ (define encoder (apply lz-compress-open
+ (car (assoc-ref %compression-levels level))))
+
+ (define (write! bv start count)
+ (lzwrite encoder bv port start count))
+
+ (make-custom-binary-output-port "lzip-output" write! #f #f
+ (lambda ()
+ (lz-compress-finish encoder)
+ ;; "lz-read" the trailing metadata added by `lz-compress-finish'.
+ (let ((lz-bv (make-bytevector (* 64 1024))))
+ (let loop ((rd 0))
+ (set! rd (lz-compress-read encoder lz-bv 0 (bytevector-length lz-bv)))
+ (put-bytevector port lz-bv 0 rd)
+ (unless (= rd 0)
+ (loop rd))))
+ (lz-compress-close encoder)
+ (close-port port))))
+
+(define* (call-with-lzip-input-port port proc)
+ "Call PROC with a port that wraps PORT and decompresses data read from it.
+PORT is closed upon completion."
+ (let ((lzip (make-lzip-input-port port)))
+ (dynamic-wind
+ (const #t)
+ (lambda ()
+ (proc lzip))
+ (lambda ()
+ (close-port lzip)))))
+
+(define* (call-with-lzip-output-port port proc
+ #:key
+ (level %default-compression-level))
+ "Call PROC with an output port that wraps PORT and compresses data. PORT is
+close upon completion."
+ (let ((lzip (make-lzip-output-port port
+ #:level level)))
+ (dynamic-wind
+ (const #t)
+ (lambda ()
+ (proc lzip))
+ (lambda ()
+ (close-port lzip)))))
+
+;;; lzlib.scm ends here
diff --git a/guix/self.scm b/guix/self.scm
index 7098e4ea29..74ea65240c 100644
--- a/guix/self.scm
+++ b/guix/self.scm
@@ -925,6 +925,7 @@ Info manual."
%store-database-directory
%config-directory
%libz
+ ;; TODO: %liblz
%gzip
%bzip2
%xz))