diff options
author | Han-Wen Nienhuys <hanwen@google.com> | 2022-01-20 18:12:13 +0300 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2022-01-20 22:31:53 +0300 |
commit | 66c0dabab5e15f78d0505be36cac4a383e14cf88 (patch) | |
tree | db6fd2622162b3d16eceb899975472e16d14e2c3 /reftable/record.h | |
parent | 9391b88dab5145f01c9b8c3d79dba567058086e1 (diff) |
reftable: make reftable_record a tagged union
This reduces the amount of glue code, because we don't need a void
pointer or vtable within the structure.
The only snag is that reftable_index_record contain a strbuf, so it
cannot be zero-initialized. To address this, use reftable_new_record()
to return fresh instance, given a record type. Since
reftable_new_record() doesn't cause heap allocation anymore, it should
be balanced with reftable_record_release() rather than
reftable_record_destroy().
Thanks to Peff for the suggestion.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'reftable/record.h')
-rw-r--r-- | reftable/record.h | 42 |
1 files changed, 18 insertions, 24 deletions
diff --git a/reftable/record.h b/reftable/record.h index da75d7d1f1..010a322e90 100644 --- a/reftable/record.h +++ b/reftable/record.h @@ -63,16 +63,10 @@ struct reftable_record_vtable { int (*equal)(const void *a, const void *b, int hash_size); }; -/* record is a generic wrapper for different types of records. */ -struct reftable_record { - void *data; - struct reftable_record_vtable *ops; -}; - /* returns true for recognized block types. Block start with the block type. */ int reftable_is_block_type(uint8_t typ); -/* creates a malloced record of the given type. Dispose with record_destroy */ +/* return an initialized record for the given type */ struct reftable_record reftable_new_record(uint8_t typ); /* Encode `key` into `dest`. Sets `is_restart` to indicate a restart. Returns @@ -100,6 +94,22 @@ struct reftable_obj_record { int offset_len; }; +/* record is a generic wrapper for different types of records. It is normally + * created on the stack, or embedded within another struct. If the type is + * known, a fresh instance can be initialized explicitly. Otherwise, use + * reftable_new_record() to initialize generically (as the index_record is not + * valid as 0-initialized structure) + */ +struct reftable_record { + uint8_t type; + union { + struct reftable_ref_record ref; + struct reftable_log_record log; + struct reftable_obj_record obj; + struct reftable_index_record idx; + } u; +}; + /* see struct record_vtable */ int reftable_record_equal(struct reftable_record *a, struct reftable_record *b, int hash_size); void reftable_record_key(struct reftable_record *rec, struct strbuf *dest); @@ -114,25 +124,9 @@ int reftable_record_decode(struct reftable_record *rec, struct strbuf key, int hash_size); int reftable_record_is_deletion(struct reftable_record *rec); -/* zeroes out the embedded record */ +/* frees and zeroes out the embedded record */ void reftable_record_release(struct reftable_record *rec); -/* clear and deallocate embedded record, and zero `rec`. */ -void reftable_record_destroy(struct reftable_record *rec); - -/* initialize generic records from concrete records. The generic record should - * be zeroed out. */ -void reftable_record_from_obj(struct reftable_record *rec, - struct reftable_obj_record *objrec); -void reftable_record_from_index(struct reftable_record *rec, - struct reftable_index_record *idxrec); -void reftable_record_from_ref(struct reftable_record *rec, - struct reftable_ref_record *refrec); -void reftable_record_from_log(struct reftable_record *rec, - struct reftable_log_record *logrec); -struct reftable_ref_record *reftable_record_as_ref(struct reftable_record *ref); -struct reftable_log_record *reftable_record_as_log(struct reftable_record *ref); - /* for qsort. */ int reftable_ref_record_compare_name(const void *a, const void *b); |