authorgravatar for michael.larouche@gmail.comMichaël Larouche <michael.larouche@gmail.com> 2020-03-31 16:52:16-04:00
committergravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2020-03-31 20:08:42-04:00
loga5af78c376fc41424b81ea83766b38a0a1d17870
tree0df644dd190b25bdf7692e8e2a917682248ecbc8
parente3d12471a2554154b507ed675e35530b55259984

Fix porting of zlib alder32 with large input

1 files changed, 29 insertions(+), 8 deletions(-)

lib/std/hash/adler.zig+29-8
......@@ -42,18 +42,23 @@ pub const Adler32 = struct {
4242
4343 s2 %= base;
4444 } else {
45 const n = nmax / 16; // note: 16 | nmax
46
4547 var i: usize = 0;
46 while (i + nmax <= input.len) : (i += nmax) {
47 const n = nmax / 16; // note: 16 | nmax
4848
49 while (i + nmax <= input.len) {
4950 var rounds: usize = 0;
5051 while (rounds < n) : (rounds += 1) {
5152 comptime var j: usize = 0;
5253 inline while (j < 16) : (j += 1) {
53 s1 +%= input[i + n * j];
54 s1 +%= input[i + j];
5455 s2 +%= s1;
5556 }
57 i += 16;
5658 }
59
60 s1 %= base;
61 s2 %= base;
5762 }
5863
5964 if (i < input.len) {
......@@ -89,19 +94,35 @@ pub const Adler32 = struct {
8994};
9095
9196test "adler32 sanity" {
92 testing.expect(Adler32.hash("a") == 0x620062);
93 testing.expect(Adler32.hash("example") == 0xbc002ed);
97 testing.expectEqual(@as(u32, 0x620062), Adler32.hash("a"));
98 testing.expectEqual(@as(u32, 0xbc002ed), Adler32.hash("example"));
9499}
95100
96101test "adler32 long" {
97102 const long1 = [_]u8{1} ** 1024;
98 testing.expect(Adler32.hash(long1[0..]) == 0x06780401);
103 testing.expectEqual(@as(u32, 0x06780401), Adler32.hash(long1[0..]));
99104
100105 const long2 = [_]u8{1} ** 1025;
101 testing.expect(Adler32.hash(long2[0..]) == 0x0a7a0402);
106 testing.expectEqual(@as(u32, 0x0a7a0402), Adler32.hash(long2[0..]));
102107}
103108
104109test "adler32 very long" {
105110 const long = [_]u8{1} ** 5553;
106 testing.expect(Adler32.hash(long[0..]) == 0x707f15b2);
111 testing.expectEqual(@as(u32, 0x707f15b2), Adler32.hash(long[0..]));
112}
113
114test "adler32 very long with variation" {
115 const long = comptime blk: {
116 @setEvalBranchQuota(7000);
117 var result: [6000]u8 = undefined;
118
119 var i: usize = 0;
120 while (i < result.len) : (i += 1) {
121 result[i] = @truncate(u8, i);
122 }
123
124 break :blk result;
125 };
126
127 testing.expectEqual(@as(u32, 0x5af38d6e), std.hash.Adler32.hash(long[0..]));
107128}