[GR-37755] Implement Zlib.crc_table by using Java code and not using libz

PullRequest: truffleruby/3282

Author: eregon

src/main/c/zlib/zlib.c

@@ -518,6 +518,11 @@ rb_zlib_crc32_combine(VALUE klass, VALUE crc1, VALUE crc2, VALUE len2)
  *
  * Returns the table for calculating CRC checksum as an array.
  */
+#ifdef TRUFFLERUBY
+static VALUE rb_zlib_crc_table(VALUE obj) {
+    return RUBY_CEXT_INVOKE("zlib_get_crc_table");
+}
+#else
 static VALUE
 rb_zlib_crc_table(VALUE obj)
 {
@@ -537,6 +542,7 @@ rb_zlib_crc_table(VALUE obj)
     }
     return dst;
 }
+#endif
 
 
 

src/main/java/org/truffleruby/cext/CExtNodes.java

@@ -1954,4 +1954,12 @@ protected boolean isRubyThread(VirtualFrame frame) {
                     threadManager.isRubyManagedThread(Thread.currentThread());
         }
     }
+
+    @CoreMethod(names = "zlib_get_crc_table", onSingleton = true)
+    public abstract static class ZLibGetCRCTable extends CoreMethodArrayArgumentsNode {
+        @Specialization
+        protected RubyArray zlibGetCRCTable() {
+            return createArray(ZLibCRCTable.TABLE.clone());
+        }
+    }
 }

src/main/java/org/truffleruby/cext/ZLibCRCTable.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2022 Oracle and/or its affiliates. All rights reserved. This
+ * code is released under a tri EPL/GPL/LGPL license. You can use it,
+ * redistribute it and/or modify it under the terms of the:
+ *
+ * Eclipse Public License version 2.0, or
+ * GNU General Public License version 2, or
+ * GNU Lesser General Public License version 2.1.
+ */
+package org.truffleruby.cext;
+
+public final class ZLibCRCTable {
+
+    // @formatter:off
+    public static final long[] TABLE = {
+            0L, 1996959894L, 3993919788L, 2567524794L,
+            124634137L, 1886057615L, 3915621685L, 2657392035L,
+            249268274L, 2044508324L, 3772115230L, 2547177864L,
+            162941995L, 2125561021L, 3887607047L, 2428444049L,
+            498536548L, 1789927666L, 4089016648L, 2227061214L,
+            450548861L, 1843258603L, 4107580753L, 2211677639L,
+            325883990L, 1684777152L, 4251122042L, 2321926636L,
+            335633487L, 1661365465L, 4195302755L, 2366115317L,
+            997073096L, 1281953886L, 3579855332L, 2724688242L,
+            1006888145L, 1258607687L, 3524101629L, 2768942443L,
+            901097722L, 1119000684L, 3686517206L, 2898065728L,
+            853044451L, 1172266101L, 3705015759L, 2882616665L,
+            651767980L, 1373503546L, 3369554304L, 3218104598L,
+            565507253L, 1454621731L, 3485111705L, 3099436303L,
+            671266974L, 1594198024L, 3322730930L, 2970347812L,
+            795835527L, 1483230225L, 3244367275L, 3060149565L,
+            1994146192L, 31158534L, 2563907772L, 4023717930L,
+            1907459465L, 112637215L, 2680153253L, 3904427059L,
+            2013776290L, 251722036L, 2517215374L, 3775830040L,
+            2137656763L, 141376813L, 2439277719L, 3865271297L,
+            1802195444L, 476864866L, 2238001368L, 4066508878L,
+            1812370925L, 453092731L, 2181625025L, 4111451223L,
+            1706088902L, 314042704L, 2344532202L, 4240017532L,
+            1658658271L, 366619977L, 2362670323L, 4224994405L,
+            1303535960L, 984961486L, 2747007092L, 3569037538L,
+            1256170817L, 1037604311L, 2765210733L, 3554079995L,
+            1131014506L, 879679996L, 2909243462L, 3663771856L,
+            1141124467L, 855842277L, 2852801631L, 3708648649L,
+            1342533948L, 654459306L, 3188396048L, 3373015174L,
+            1466479909L, 544179635L, 3110523913L, 3462522015L,
+            1591671054L, 702138776L, 2966460450L, 3352799412L,
+            1504918807L, 783551873L, 3082640443L, 3233442989L,
+            3988292384L, 2596254646L, 62317068L, 1957810842L,
+            3939845945L, 2647816111L, 81470997L, 1943803523L,
+            3814918930L, 2489596804L, 225274430L, 2053790376L,
+            3826175755L, 2466906013L, 167816743L, 2097651377L,
+            4027552580L, 2265490386L, 503444072L, 1762050814L,
+            4150417245L, 2154129355L, 426522225L, 1852507879L,
+            4275313526L, 2312317920L, 282753626L, 1742555852L,
+            4189708143L, 2394877945L, 397917763L, 1622183637L,
+            3604390888L, 2714866558L, 953729732L, 1340076626L,
+            3518719985L, 2797360999L, 1068828381L, 1219638859L,
+            3624741850L, 2936675148L, 906185462L, 1090812512L,
+            3747672003L, 2825379669L, 829329135L, 1181335161L,
+            3412177804L, 3160834842L, 628085408L, 1382605366L,
+            3423369109L, 3138078467L, 570562233L, 1426400815L,
+            3317316542L, 2998733608L, 733239954L, 1555261956L,
+            3268935591L, 3050360625L, 752459403L, 1541320221L,
+            2607071920L, 3965973030L, 1969922972L, 40735498L,
+            2617837225L, 3943577151L, 1913087877L, 83908371L,
+            2512341634L, 3803740692L, 2075208622L, 213261112L,
+            2463272603L, 3855990285L, 2094854071L, 198958881L,
+            2262029012L, 4057260610L, 1759359992L, 534414190L,
+            2176718541L, 4139329115L, 1873836001L, 414664567L,
+            2282248934L, 4279200368L, 1711684554L, 285281116L,
+            2405801727L, 4167216745L, 1634467795L, 376229701L,
+            2685067896L, 3608007406L, 1308918612L, 956543938L,
+            2808555105L, 3495958263L, 1231636301L, 1047427035L,
+            2932959818L, 3654703836L, 1088359270L, 936918000L,
+            2847714899L, 3736837829L, 1202900863L, 817233897L,
+            3183342108L, 3401237130L, 1404277552L, 615818150L,
+            3134207493L, 3453421203L, 1423857449L, 601450431L,
+            3009837614L, 3294710456L, 1567103746L, 711928724L,
+            3020668471L, 3272380065L, 1510334235L, 755167117L,
+    };
+    // @formatter:on
+
+}