git/reftable/generic.c
Han-Wen Nienhuys 66c0dabab5 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>
2022-01-20 11:31:53 -08:00

177 lines
3.9 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
*/
#include "basics.h"
#include "constants.h"
#include "record.h"
#include "generic.h"
#include "reftable-iterator.h"
#include "reftable-generic.h"
int reftable_table_seek_ref(struct reftable_table *tab,
struct reftable_iterator *it, const char *name)
{
struct reftable_record rec = { .type = BLOCK_TYPE_REF,
.u.ref = {
.refname = (char *)name,
} };
return tab->ops->seek_record(tab->table_arg, it, &rec);
}
int reftable_table_seek_log(struct reftable_table *tab,
struct reftable_iterator *it, const char *name)
{
struct reftable_record rec = { .type = BLOCK_TYPE_LOG,
.u.log = {
.refname = (char *)name,
.update_index = ~((uint64_t)0),
} };
return tab->ops->seek_record(tab->table_arg, it, &rec);
}
int reftable_table_read_ref(struct reftable_table *tab, const char *name,
struct reftable_ref_record *ref)
{
struct reftable_iterator it = { NULL };
int err = reftable_table_seek_ref(tab, &it, name);
if (err)
goto done;
err = reftable_iterator_next_ref(&it, ref);
if (err)
goto done;
if (strcmp(ref->refname, name) ||
reftable_ref_record_is_deletion(ref)) {
reftable_ref_record_release(ref);
err = 1;
goto done;
}
done:
reftable_iterator_destroy(&it);
return err;
}
int reftable_table_print(struct reftable_table *tab) {
struct reftable_iterator it = { NULL };
struct reftable_ref_record ref = { NULL };
struct reftable_log_record log = { NULL };
uint32_t hash_id = reftable_table_hash_id(tab);
int err = reftable_table_seek_ref(tab, &it, "");
if (err < 0) {
return err;
}
while (1) {
err = reftable_iterator_next_ref(&it, &ref);
if (err > 0) {
break;
}
if (err < 0) {
return err;
}
reftable_ref_record_print(&ref, hash_id);
}
reftable_iterator_destroy(&it);
reftable_ref_record_release(&ref);
err = reftable_table_seek_log(tab, &it, "");
if (err < 0) {
return err;
}
while (1) {
err = reftable_iterator_next_log(&it, &log);
if (err > 0) {
break;
}
if (err < 0) {
return err;
}
reftable_log_record_print(&log, hash_id);
}
reftable_iterator_destroy(&it);
reftable_log_record_release(&log);
return 0;
}
uint64_t reftable_table_max_update_index(struct reftable_table *tab)
{
return tab->ops->max_update_index(tab->table_arg);
}
uint64_t reftable_table_min_update_index(struct reftable_table *tab)
{
return tab->ops->min_update_index(tab->table_arg);
}
uint32_t reftable_table_hash_id(struct reftable_table *tab)
{
return tab->ops->hash_id(tab->table_arg);
}
void reftable_iterator_destroy(struct reftable_iterator *it)
{
if (!it->ops) {
return;
}
it->ops->close(it->iter_arg);
it->ops = NULL;
FREE_AND_NULL(it->iter_arg);
}
int reftable_iterator_next_ref(struct reftable_iterator *it,
struct reftable_ref_record *ref)
{
struct reftable_record rec = {
.type = BLOCK_TYPE_REF,
.u.ref = *ref,
};
int err = iterator_next(it, &rec);
*ref = rec.u.ref;
return err;
}
int reftable_iterator_next_log(struct reftable_iterator *it,
struct reftable_log_record *log)
{
struct reftable_record rec = {
.type = BLOCK_TYPE_LOG,
.u.log = *log,
};
int err = iterator_next(it, &rec);
*log = rec.u.log;
return err;
}
int iterator_next(struct reftable_iterator *it, struct reftable_record *rec)
{
return it->ops->next(it->iter_arg, rec);
}
static int empty_iterator_next(void *arg, struct reftable_record *rec)
{
return 1;
}
static void empty_iterator_close(void *arg)
{
}
static struct reftable_iterator_vtable empty_vtable = {
.next = &empty_iterator_next,
.close = &empty_iterator_close,
};
void iterator_set_empty(struct reftable_iterator *it)
{
assert(!it->ops);
it->iter_arg = NULL;
it->ops = &empty_vtable;
}