Improve header comment and strengthen type checking for entry #2794
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Signed-off-by: Jim Brunner <[email protected]>
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## unstable #2794 +/- ##
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+ Coverage 72.30% 72.46% +0.16%
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Files 128 128
Lines 70211 70224 +13
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+ Hits 50763 50888 +125
+ Misses 19448 19336 -112
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ranshid
approved these changes
Nov 3, 2025
| /* The entry pointer is the field sds. We encode the entry layout type | ||
| * in the field SDS header. Field type SDS_TYPE_5 doesn't have any spare bits to | ||
| * encode this so we use it only for the first layout type. | ||
| /* There are 3 different formats for the "entry". In all cases, the "entry" pointer points into the |
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there are 4 right? expiration existence only multiply the past 2 encoding types (embedded value and non-embedded value)
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In types 2 and 3, the expiration is optional. I didn't consider/document these as fundamentally different types. If we do that, there would be 5 types.
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O.K I understand it better now. LGTM
eifrah-aws
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Nov 6, 2025
…-io#2794) In `entry.c`, the `entry` is a block of memory with variable contents. The structure can be difficult to understand. A new header comment more clearly documents the contents/layout of the `entry`. Also, in `entry.h`, the `entry` was defined by `typedef void entry`. This allows blind casting to the `entry` type. It defeats compiler type checking. Even though the `entry` has a variable definition, we can define entry as a legitimate type which allows the compiler to perform type checking. By performing `typedef struct _entry entry`, now the `entry` is understood to be a pointer to some type of undefined structure. We can pass a pointer and the compiler can typecheck the pointer. (Of course we can't dereference it, because we haven't actually defined the struct.) Signed-off-by: Jim Brunner <[email protected]>
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In
entry.c, theentryis a block of memory with variable contents. The structure can be difficult to understand. A new header comment more clearly documents the contents/layout of theentry.Also, in
entry.h, theentrywas defined bytypedef void entry. This allows blind casting to theentrytype. It defeats compiler type checking.Even though the
entryhas a variable definition, we can define entry as a legitimate type which allows the compiler to perform type checking. By performingtypedef struct _entry entry, now theentryis understood to be a pointer to some type of undefined structure. We can pass a pointer and the compiler can typecheck the pointer. (Of course we can't dereference it, because we haven't actually defined the struct.)