add Lib::PDF support for packing

pdf-raku · Apr 19, 2017 · 1399a04 · 1399a04
1 parent 9fcb95c
commit 1399a04
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Showing 3 changed files with 26 additions and 16 deletions.
diff --git a/Changes b/Changes
@@ -1,6 +1,7 @@
     Release 0.2.2
     - Experimental use of Lib::PDF
-      Speed up the slowest test xt/filter-predictos_bulk.t
+      -- Speed up the slowest test xt/filter-predictors_bulk.t
+      -- Fast packing alternative for PDF::IO::Util
       For regression purposes, at this stage. Probably wont
       persue seriously until Rakudo has better JIT.
 

diff --git a/lib/PDF/IO/Util.pm b/lib/PDF/IO/Util.pm
@@ -14,19 +14,27 @@ module PDF::IO::Util {
         $haveit;
     }
 
+    #| loads a faster alternative
+    our sub xs(Str $module-name, Str $sub-name) {
+        (require ::($module-name)).so;
+        ::($module-name)::('&'~$sub-name);
+    }
     #= network ordered byte packing and unpacking
-    proto sub unpack( $, $ --> Buf) is export(:pack) {*};
-    proto sub pack( $, $ --> Buf) is export(:pack) {*};
-    proto sub pack-le( $, $ --> Buf) is export(:pack) {*};
-    multi sub unpack( $nums!, 4)  { buf8.new: flat $nums.list.map: { ($_ +> 4, $_ +& 15) } }
-    multi sub unpack( $nums!, 16) { buf16.new: flat $nums.list.map: -> \hi, \lo { hi +< 8  +  lo } }
-    multi sub unpack( $nums!, 32) { buf32.new: flat $nums.list.map: -> \b1, \b2, \b3, \b4 { b1 +< 24  +  b2 +< 16  +  b3 +< 8  +  b4 } }
-    multi sub unpack( $nums!, $n) { resample( $nums, 8, $n); }
-    multi sub pack( $nums!, 4)  { buf8.new: flat $nums.list.map: -> \hi, \lo { hi +< 4  +  lo } }
-    multi sub pack( $nums!, 16) { buf8.new: flat $nums.list.map: { ($_ +> 8, $_) } }
-    multi sub pack( $nums!, 32) { buf8.new: flat $nums.list.map: { ($_ +> 24, $_ +> 16, $_ +> 8, $_) } }
+    proto sub unpack-pp( $, $ --> Buf) is export(:pack-pp) {*};
+    proto sub pack-pp( $, $ --> Buf) is export(:pack-pp) {*};
+    proto sub pack-le( $, $ --> Buf) is export(:pack,:pack-pp) {*};
+    my constant Packer = 'Lib::PDF::Buf';
+    our &pack is export(:pack) = libpdf-available() ?? xs(Packer, 'pack') !! &pack-pp;
+    our &unpack is export(:pack) = libpdf-available() ?? xs(Packer, 'unpack') !! &unpack-pp;
+    multi sub unpack-pp( $nums!, 4)  { buf8.new: flat $nums.list.map: { ($_ +> 4, $_ +& 15) } }
+    multi sub unpack-pp( $nums!, 16) { buf16.new: flat $nums.list.map: -> \hi, \lo { hi +< 8  +  lo } }
+    multi sub unpack-pp( $nums!, 32) { buf32.new: flat $nums.list.map: -> \b1, \b2, \b3, \b4 { b1 +< 24  +  b2 +< 16  +  b3 +< 8  +  b4 } }
+    multi sub unpack-pp( $nums!, $n) { resample( $nums, 8, $n); }
+    multi sub pack-pp( $nums!, 4)  { buf8.new: flat $nums.list.map: -> \hi, \lo { hi +< 4  +  lo } }
+    multi sub pack-pp( $nums!, 16) { buf8.new: flat $nums.list.map: { ($_ +> 8, $_) } }
+    multi sub pack-pp( $nums!, 32) { buf8.new: flat $nums.list.map: { ($_ +> 24, $_ +> 16, $_ +> 8, $_) } }
     multi sub pack-le( $nums!, 32) { buf8.new: flat $nums.list.map: { ($_, $_ +> 8, $_ +> 16, $_ +> 24) } }
-    multi sub pack( $nums!, $n) { resample( $nums, $n, 8); }
+    multi sub pack-pp( $nums!, $n) { resample( $nums, $n, 8); }
     sub container(UInt $bits) {
         $bits <= 8 ?? uint8 !! ($bits > 16 ?? uint32 !! uint16)
     }
@@ -63,7 +71,7 @@ module PDF::IO::Util {
     }
     #| variable resampling, e.g. to decode/encode:
     #|   obj 123 0 << /Type /XRef /W [1, 3, 1]
-    multi sub unpack( $nums!, Array $W!)  {
+    multi sub unpack-pp( $nums!, Array $W!)  {
         my uint $i = 0;
         my uint $j = 0;
         my uint32 @out;
@@ -86,7 +94,7 @@ module PDF::IO::Util {
         @shaped;
     }
 
-    multi sub pack($shaped, Array $W!)  {
+    multi sub pack-pp($shaped, Array $W!)  {
         my uint8 @out;
         @out[$W.sum * +$shaped - 1] = 0
             if +$shaped;

diff --git a/t/io-util.t b/t/io-util.t
@@ -21,8 +21,9 @@ is-deeply ($buf = pack([1415192289,], 32)), buf8.new(84, 90, 30, 225), '32 bit p
 is-deeply ($buf = pack([2 ** 32 - 1415192289 - 1,], 32)), buf8.new(255-84, 255-90, 255-30, 255-225), '32 bit packing (twos comp)';
 
 quietly {
-    is-deeply ($buf = unpack(@bytes, 6)), buf8.new(2, 33, 16, 30, 10, 3, 8, 60), '6 bit unpack';
-    is-deeply pack($buf, 6), $bytes, 'resample round-trip: 8 => 6 => 8';
+    use PDF::IO::Util :pack-pp;
+    is-deeply ($buf = unpack-pp(@bytes, 6)), buf8.new(2, 33, 16, 30, 10, 3, 8, 60), '6 bit unpack';
+    is-deeply pack-pp($buf, 6), $bytes, 'resample round-trip: 8 => 6 => 8';
 
     is-deeply ($buf = unpack([109], 1)), buf8.new(0, 1, 1, 0, 1, 1, 0, 1), '1 bit unpack';
     is-deeply ($buf = pack($buf, 1)), buf8.new(109), '8 => 1 => 8 round trip';