Files
git/reftable/reftable-record.h
Patrick Steinhardt 87ff723018 reftable/record: convert old and new object IDs to arrays
In 7af607c58d (reftable/record: store "val1" hashes as static arrays,
2024-01-03) and b31e3cc620 (reftable/record: store "val2" hashes as
static arrays, 2024-01-03) we have converted ref records to store their
object IDs in a static array. Convert log records to do the same so that
their old and new object IDs are arrays, too.

This change results in two allocations less per log record that we're
iterating over. Before:

    HEAP SUMMARY:
        in use at exit: 13,473 bytes in 122 blocks
      total heap usage: 8,068,495 allocs, 8,068,373 frees, 401,011,862 bytes allocated

After:

    HEAP SUMMARY:
        in use at exit: 13,473 bytes in 122 blocks
      total heap usage: 6,068,489 allocs, 6,068,367 frees, 361,011,822 bytes allocated

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-03-05 09:10:06 -08:00

117 lines
3.4 KiB
C

/*
Copyright 2020 Google LLC
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file or at
https://developers.google.com/open-source/licenses/bsd
*/
#ifndef REFTABLE_RECORD_H
#define REFTABLE_RECORD_H
#include "hash-ll.h"
#include <stdint.h>
/*
* Basic data types
*
* Reftables store the state of each ref in struct reftable_ref_record, and they
* store a sequence of reflog updates in struct reftable_log_record.
*/
/* reftable_ref_record holds a ref database entry target_value */
struct reftable_ref_record {
char *refname; /* Name of the ref, malloced. */
size_t refname_cap;
uint64_t update_index; /* Logical timestamp at which this value is
* written */
enum {
/* tombstone to hide deletions from earlier tables */
REFTABLE_REF_DELETION = 0x0,
/* a simple ref */
REFTABLE_REF_VAL1 = 0x1,
/* a tag, plus its peeled hash */
REFTABLE_REF_VAL2 = 0x2,
/* a symbolic reference */
REFTABLE_REF_SYMREF = 0x3,
#define REFTABLE_NR_REF_VALUETYPES 4
} value_type;
union {
unsigned char val1[GIT_MAX_RAWSZ];
struct {
unsigned char value[GIT_MAX_RAWSZ]; /* first hash */
unsigned char target_value[GIT_MAX_RAWSZ]; /* second hash */
} val2;
char *symref; /* referent, malloced 0-terminated string */
} value;
};
/* Returns the first hash, or NULL if `rec` is not of type
* REFTABLE_REF_VAL1 or REFTABLE_REF_VAL2. */
const unsigned char *reftable_ref_record_val1(const struct reftable_ref_record *rec);
/* Returns the second hash, or NULL if `rec` is not of type
* REFTABLE_REF_VAL2. */
const unsigned char *reftable_ref_record_val2(const struct reftable_ref_record *rec);
/* returns whether 'ref' represents a deletion */
int reftable_ref_record_is_deletion(const struct reftable_ref_record *ref);
/* prints a reftable_ref_record onto stdout. Useful for debugging. */
void reftable_ref_record_print(const struct reftable_ref_record *ref,
uint32_t hash_id);
/* frees and nulls all pointer values inside `ref`. */
void reftable_ref_record_release(struct reftable_ref_record *ref);
/* returns whether two reftable_ref_records are the same. Useful for testing. */
int reftable_ref_record_equal(const struct reftable_ref_record *a,
const struct reftable_ref_record *b, int hash_size);
/* reftable_log_record holds a reflog entry */
struct reftable_log_record {
char *refname;
uint64_t update_index; /* logical timestamp of a transactional update.
*/
enum {
/* tombstone to hide deletions from earlier tables */
REFTABLE_LOG_DELETION = 0x0,
/* a simple update */
REFTABLE_LOG_UPDATE = 0x1,
#define REFTABLE_NR_LOG_VALUETYPES 2
} value_type;
union {
struct {
unsigned char new_hash[GIT_MAX_RAWSZ];
unsigned char old_hash[GIT_MAX_RAWSZ];
char *name;
char *email;
uint64_t time;
int16_t tz_offset;
char *message;
} update;
} value;
};
/* returns whether 'ref' represents the deletion of a log record. */
int reftable_log_record_is_deletion(const struct reftable_log_record *log);
/* frees and nulls all pointer values. */
void reftable_log_record_release(struct reftable_log_record *log);
/* returns whether two records are equal. Useful for testing. */
int reftable_log_record_equal(const struct reftable_log_record *a,
const struct reftable_log_record *b, int hash_size);
/* dumps a reftable_log_record on stdout, for debugging/testing. */
void reftable_log_record_print(struct reftable_log_record *log,
uint32_t hash_id);
#endif