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Diffstat (limited to 'src/ranch_crc32c.erl')
| -rw-r--r-- | src/ranch_crc32c.erl | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/src/ranch_crc32c.erl b/src/ranch_crc32c.erl new file mode 100644 index 0000000..fc9be35 --- /dev/null +++ b/src/ranch_crc32c.erl @@ -0,0 +1,115 @@ +%% Copyright (c) 2018, Loïc Hoguin <[email protected]> +%% +%% Permission to use, copy, modify, and/or distribute this software for any +%% purpose with or without fee is hereby granted, provided that the above +%% copyright notice and this permission notice appear in all copies. +%% +%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + +-module(ranch_crc32c). + +-export([crc32c/1]). +-export([crc32c/2]). + +-define(CRC32C_TABLE, { + 16#00000000, 16#F26B8303, 16#E13B70F7, 16#1350F3F4, + 16#C79A971F, 16#35F1141C, 16#26A1E7E8, 16#D4CA64EB, + 16#8AD958CF, 16#78B2DBCC, 16#6BE22838, 16#9989AB3B, + 16#4D43CFD0, 16#BF284CD3, 16#AC78BF27, 16#5E133C24, + 16#105EC76F, 16#E235446C, 16#F165B798, 16#030E349B, + 16#D7C45070, 16#25AFD373, 16#36FF2087, 16#C494A384, + 16#9A879FA0, 16#68EC1CA3, 16#7BBCEF57, 16#89D76C54, + 16#5D1D08BF, 16#AF768BBC, 16#BC267848, 16#4E4DFB4B, + 16#20BD8EDE, 16#D2D60DDD, 16#C186FE29, 16#33ED7D2A, + 16#E72719C1, 16#154C9AC2, 16#061C6936, 16#F477EA35, + 16#AA64D611, 16#580F5512, 16#4B5FA6E6, 16#B93425E5, + 16#6DFE410E, 16#9F95C20D, 16#8CC531F9, 16#7EAEB2FA, + 16#30E349B1, 16#C288CAB2, 16#D1D83946, 16#23B3BA45, + 16#F779DEAE, 16#05125DAD, 16#1642AE59, 16#E4292D5A, + 16#BA3A117E, 16#4851927D, 16#5B016189, 16#A96AE28A, + 16#7DA08661, 16#8FCB0562, 16#9C9BF696, 16#6EF07595, + 16#417B1DBC, 16#B3109EBF, 16#A0406D4B, 16#522BEE48, + 16#86E18AA3, 16#748A09A0, 16#67DAFA54, 16#95B17957, + 16#CBA24573, 16#39C9C670, 16#2A993584, 16#D8F2B687, + 16#0C38D26C, 16#FE53516F, 16#ED03A29B, 16#1F682198, + 16#5125DAD3, 16#A34E59D0, 16#B01EAA24, 16#42752927, + 16#96BF4DCC, 16#64D4CECF, 16#77843D3B, 16#85EFBE38, + 16#DBFC821C, 16#2997011F, 16#3AC7F2EB, 16#C8AC71E8, + 16#1C661503, 16#EE0D9600, 16#FD5D65F4, 16#0F36E6F7, + 16#61C69362, 16#93AD1061, 16#80FDE395, 16#72966096, + 16#A65C047D, 16#5437877E, 16#4767748A, 16#B50CF789, + 16#EB1FCBAD, 16#197448AE, 16#0A24BB5A, 16#F84F3859, + 16#2C855CB2, 16#DEEEDFB1, 16#CDBE2C45, 16#3FD5AF46, + 16#7198540D, 16#83F3D70E, 16#90A324FA, 16#62C8A7F9, + 16#B602C312, 16#44694011, 16#5739B3E5, 16#A55230E6, + 16#FB410CC2, 16#092A8FC1, 16#1A7A7C35, 16#E811FF36, + 16#3CDB9BDD, 16#CEB018DE, 16#DDE0EB2A, 16#2F8B6829, + 16#82F63B78, 16#709DB87B, 16#63CD4B8F, 16#91A6C88C, + 16#456CAC67, 16#B7072F64, 16#A457DC90, 16#563C5F93, + 16#082F63B7, 16#FA44E0B4, 16#E9141340, 16#1B7F9043, + 16#CFB5F4A8, 16#3DDE77AB, 16#2E8E845F, 16#DCE5075C, + 16#92A8FC17, 16#60C37F14, 16#73938CE0, 16#81F80FE3, + 16#55326B08, 16#A759E80B, 16#B4091BFF, 16#466298FC, + 16#1871A4D8, 16#EA1A27DB, 16#F94AD42F, 16#0B21572C, + 16#DFEB33C7, 16#2D80B0C4, 16#3ED04330, 16#CCBBC033, + 16#A24BB5A6, 16#502036A5, 16#4370C551, 16#B11B4652, + 16#65D122B9, 16#97BAA1BA, 16#84EA524E, 16#7681D14D, + 16#2892ED69, 16#DAF96E6A, 16#C9A99D9E, 16#3BC21E9D, + 16#EF087A76, 16#1D63F975, 16#0E330A81, 16#FC588982, + 16#B21572C9, 16#407EF1CA, 16#532E023E, 16#A145813D, + 16#758FE5D6, 16#87E466D5, 16#94B49521, 16#66DF1622, + 16#38CC2A06, 16#CAA7A905, 16#D9F75AF1, 16#2B9CD9F2, + 16#FF56BD19, 16#0D3D3E1A, 16#1E6DCDEE, 16#EC064EED, + 16#C38D26C4, 16#31E6A5C7, 16#22B65633, 16#D0DDD530, + 16#0417B1DB, 16#F67C32D8, 16#E52CC12C, 16#1747422F, + 16#49547E0B, 16#BB3FFD08, 16#A86F0EFC, 16#5A048DFF, + 16#8ECEE914, 16#7CA56A17, 16#6FF599E3, 16#9D9E1AE0, + 16#D3D3E1AB, 16#21B862A8, 16#32E8915C, 16#C083125F, + 16#144976B4, 16#E622F5B7, 16#F5720643, 16#07198540, + 16#590AB964, 16#AB613A67, 16#B831C993, 16#4A5A4A90, + 16#9E902E7B, 16#6CFBAD78, 16#7FAB5E8C, 16#8DC0DD8F, + 16#E330A81A, 16#115B2B19, 16#020BD8ED, 16#F0605BEE, + 16#24AA3F05, 16#D6C1BC06, 16#C5914FF2, 16#37FACCF1, + 16#69E9F0D5, 16#9B8273D6, 16#88D28022, 16#7AB90321, + 16#AE7367CA, 16#5C18E4C9, 16#4F48173D, 16#BD23943E, + 16#F36E6F75, 16#0105EC76, 16#12551F82, 16#E03E9C81, + 16#34F4F86A, 16#C69F7B69, 16#D5CF889D, 16#27A40B9E, + 16#79B737BA, 16#8BDCB4B9, 16#988C474D, 16#6AE7C44E, + 16#BE2DA0A5, 16#4C4623A6, 16#5F16D052, 16#AD7D5351 +}). + +%% The interface mirrors erlang:crc32/1,2. +-spec crc32c(iodata()) -> non_neg_integer(). +crc32c(Data) -> + do_crc32c(16#ffffffff, iolist_to_binary(Data)). + +-spec crc32c(CRC, iodata()) -> CRC when CRC::non_neg_integer(). +crc32c(OldCrc, Data) -> + do_crc32c(OldCrc bxor 16#ffffffff, iolist_to_binary(Data)). + +do_crc32c(OldCrc, <<C, Rest/bits>>) -> + do_crc32c((OldCrc bsr 8) bxor element(1 + ((OldCrc bxor C) band 16#ff), ?CRC32C_TABLE), + Rest); +do_crc32c(OldCrc, <<>>) -> + OldCrc bxor 16#ffffffff. + +-ifdef(TEST). +crc32c_test_() -> + Tests = [ + %% Tests from RFC3720 B.4. + {<<0:32/unit:8>>, 16#8a9136aa}, + {iolist_to_binary([16#ff || _ <- lists:seq(1, 32)]), 16#62a8ab43}, + {iolist_to_binary([N || N <- lists:seq(0, 16#1f)]), 16#46dd794e}, + {iolist_to_binary([N || N <- lists:seq(16#1f, 0, -1)]), 16#113fdb5c}, + {<<16#01c00000:32, 0:32, 0:32, 0:32, 16#14000000:32, 16#00000400:32, 16#00000014:32, + 16#00000018:32, 16#28000000:32, 0:32, 16#02000000:32, 0:32>>, 16#d9963a56} + ], + [{iolist_to_binary(io_lib:format("16#~8.16.0b", [R])), + fun() -> R = crc32c(V) end} || {V, R} <- Tests]. +-endif. |