fix(encoding/ghash): PJW64 should use 64-bit width#4728
fix(encoding/ghash): PJW64 should use 64-bit width#4728guoxing-li wants to merge 1 commit intogogf:masterfrom
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@guoxing-li 老哥，感谢贡献，但是CI失败了哦。 |
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Pull request overview
This PR fixes a bug in the PJW64 hash function in encoding/ghash/ghash_pjw.go, where the BitsInUnsignedInt variable was incorrectly set to 32 instead of 64. This caused the 64-bit variant of the PJW hash algorithm to compute the wrong shift amounts (ThreeQuarters, OneEighth) and HighBits mask, effectively running as a 32-bit-wide algorithm in a 64-bit context.
Changes:
- Corrects
BitsInUnsignedIntinPJW64from32to64, making the algorithm genuinely 64-bit.
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| func PJW64(str []byte) uint64 { | ||
| var ( | ||
| BitsInUnsignedInt uint64 = 32 // 4 * 8 | ||
| BitsInUnsignedInt uint64 = 64 // 4 * 8 |
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This fix changes the hash algorithm's computation, which means PJW64 will now produce a different output for the same input compared to before. The existing unit test in ghash_z_unit_test.go (line 79) still asserts the old expected value of uint64(31150), which was computed using the incorrect 32-bit-wide parameters. The test expected value must be updated to the new correct output produced by the 64-bit algorithm, otherwise the test suite will fail.
| func PJW64(str []byte) uint64 { | ||
| var ( | ||
| BitsInUnsignedInt uint64 = 32 // 4 * 8 | ||
| BitsInUnsignedInt uint64 = 64 // 4 * 8 |
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The inline comment // 4 * 8 on the BitsInUnsignedInt line is now stale. The value was changed to 64 to correctly represent a 64-bit integer (8 bytes × 8 bits), so the comment should be updated to // 8 * 8 to remain accurate.
| BitsInUnsignedInt uint64 = 64 // 4 * 8 | |
| BitsInUnsignedInt uint64 = 64 // 8 * 8 |
Please ensure you adhere to every item in this list.
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提交前请遵守每个事项，感谢！
<类型>[可选 范围]: <描述>例如fix(os/gtime): fix time zone issue<类型>是必须的，可以是fix、feat、build、ci、docs、style、refactor、perf、test、chore中的一个<类型>后在括号中填写受影响的包名或范围，例如(os/gtime)Fixes #1234，如果不是完全修复则添加Updates #1234