git-commit-vandalism/reftable/reftable-record.h
Han-Wen Nienhuys e303bf22f9 reftable: (de)serialization for the polymorphic record type.
The reftable format is structured as a sequence of blocks, and each block
contains a sequence of prefix-compressed key-value records. There are 4 types of
records, and they have similarities in how they must be handled. This is
achieved by introducing a polymorphic 'record' type that encapsulates ref, log,
index and object records.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00

115 lines
3.3 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 <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. */
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 {
uint8_t *val1; /* malloced hash. */
struct {
uint8_t *value; /* first value, malloced hash */
uint8_t *target_value; /* second value, malloced 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. */
uint8_t *reftable_ref_record_val1(struct reftable_ref_record *rec);
/* Returns the second hash, or NULL if `rec` is not of type
* REFTABLE_REF_VAL2. */
uint8_t *reftable_ref_record_val2(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(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(struct reftable_ref_record *a,
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 {
uint8_t *new_hash;
uint8_t *old_hash;
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(struct reftable_log_record *a,
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