Fix BloomFilterPolicy changes for unsigned char (ARM) (#6024)

pdillinger · facebook-github-bot · commit 42b5494ec81f · 2019-11-12T15:29:15.000-08:00
Summary: Bug in PR #5941 when char is unsigned that should only affect assertion on unused/invalid filter metadata. Pull Request resolved: #6024 Test Plan: on ARM: ./bloom_test && ./db_bloom_filter_test && ./block_based_filter_block_test && ./full_filter_block_test && ./partitioned_filter_block_test Differential Revision: D18461206 Pulled By: pdillinger fbshipit-source-id: 68a7c813a0b5791c05265edc03cdf52c78880e9a
diff --git a/table/block_based/filter_policy.cc b/table/block_based/filter_policy.cc
@@ -338,7 +338,8 @@ FilterBitsReader* BloomFilterPolicy::GetFilterBitsReader(
     return new AlwaysFalseFilter();
   }
 
-  char raw_num_probes = contents.data()[len_with_meta - 5];
+  int8_t raw_num_probes =
+      static_cast<int8_t>(contents.data()[len_with_meta - 5]);
   // NB: *num_probes > 30 and < 128 probably have not been used, because of
   // BloomFilterPolicy::initialize, unless directly calling
   // FullFilterBitsBuilder as an API, but we are leaving those cases in

Original file line number	Diff line number	Diff line change
`@@ -338,7 +338,8 @@ FilterBitsReader* BloomFilterPolicy::GetFilterBitsReader(`
`338`	`338`	`return new AlwaysFalseFilter();`
`339`	`339`	`}`
`340`	`340`
`341`		`- char raw_num_probes = contents.data()[len_with_meta - 5];`
	`341`	`+ int8_t raw_num_probes =`
	`342`	`+ static_cast<int8_t>(contents.data()[len_with_meta - 5]);`
`342`	`343`	`// NB: *num_probes > 30 and < 128 probably have not been used, because of`
`343`	`344`	`// BloomFilterPolicy::initialize, unless directly calling`
`344`	`345`	`// FullFilterBitsBuilder as an API, but we are leaving those cases in`