From: Han-Wen Nienhuys <hanwen@xxxxxxxxxx> Signed-off-by: Han-Wen Nienhuys <hanwen@xxxxxxxxxx> --- Makefile | 1 + reftable/generic.h | 32 ++++++++++ reftable/reftable-generic.h | 41 +++++++++++++ reftable/reftable-iterator.h | 39 ++++++++++++ reftable/reftable.c | 115 +++++++++++++++++++++++++++++++++++ 5 files changed, 228 insertions(+) create mode 100644 reftable/generic.h create mode 100644 reftable/reftable-generic.h create mode 100644 reftable/reftable-iterator.h create mode 100644 reftable/reftable.c diff --git a/Makefile b/Makefile index 2653894d0308..1e94c2e0ac2c 100644 --- a/Makefile +++ b/Makefile @@ -2406,6 +2406,7 @@ REFTABLE_OBJS += reftable/block.o REFTABLE_OBJS += reftable/blocksource.o REFTABLE_OBJS += reftable/publicbasics.o REFTABLE_OBJS += reftable/record.o +REFTABLE_OBJS += reftable/reftable.o REFTABLE_OBJS += reftable/tree.o REFTABLE_OBJS += reftable/writer.o REFTABLE_OBJS += reftable/zlib-compat.o diff --git a/reftable/generic.h b/reftable/generic.h new file mode 100644 index 000000000000..98886a06402d --- /dev/null +++ b/reftable/generic.h @@ -0,0 +1,32 @@ +/* +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 GENERIC_H +#define GENERIC_H + +#include "record.h" +#include "reftable-generic.h" + +/* generic interface to reftables */ +struct reftable_table_vtable { + int (*seek_record)(void *tab, struct reftable_iterator *it, + struct reftable_record *); + uint32_t (*hash_id)(void *tab); + uint64_t (*min_update_index)(void *tab); + uint64_t (*max_update_index)(void *tab); +}; + +struct reftable_iterator_vtable { + int (*next)(void *iter_arg, struct reftable_record *rec); + void (*close)(void *iter_arg); +}; + +void iterator_set_empty(struct reftable_iterator *it); +int iterator_next(struct reftable_iterator *it, struct reftable_record *rec); + +#endif diff --git a/reftable/reftable-generic.h b/reftable/reftable-generic.h new file mode 100644 index 000000000000..d019dbbc19f1 --- /dev/null +++ b/reftable/reftable-generic.h @@ -0,0 +1,41 @@ +/* +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_GENERIC_H +#define REFTABLE_GENERIC_H + +#include "reftable-iterator.h" + +struct reftable_table_vtable; + +/* + * Provides a unified API for reading tables, either merged tables, or single + * readers. */ +struct reftable_table { + struct reftable_table_vtable *ops; + void *table_arg; +}; + +int reftable_table_seek_ref(struct reftable_table *tab, + struct reftable_iterator *it, const char *name); + +/* returns the hash ID from a generic reftable_table */ +uint32_t reftable_table_hash_id(struct reftable_table *tab); + +/* returns the max update_index covered by this table. */ +uint64_t reftable_table_max_update_index(struct reftable_table *tab); + +/* returns the min update_index covered by this table. */ +uint64_t reftable_table_min_update_index(struct reftable_table *tab); + +/* convenience function to read a single ref. Returns < 0 for error, 0 + for success, and 1 if ref not found. */ +int reftable_table_read_ref(struct reftable_table *tab, const char *name, + struct reftable_ref_record *ref); + +#endif diff --git a/reftable/reftable-iterator.h b/reftable/reftable-iterator.h new file mode 100644 index 000000000000..d3eee7af3571 --- /dev/null +++ b/reftable/reftable-iterator.h @@ -0,0 +1,39 @@ +/* +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_ITERATOR_H +#define REFTABLE_ITERATOR_H + +#include "reftable-record.h" + +struct reftable_iterator_vtable; + +/* iterator is the generic interface for walking over data stored in a + * reftable. + */ +struct reftable_iterator { + struct reftable_iterator_vtable *ops; + void *iter_arg; +}; + +/* reads the next reftable_ref_record. Returns < 0 for error, 0 for OK and > 0: + * end of iteration. + */ +int reftable_iterator_next_ref(struct reftable_iterator *it, + struct reftable_ref_record *ref); + +/* reads the next reftable_log_record. Returns < 0 for error, 0 for OK and > 0: + * end of iteration. + */ +int reftable_iterator_next_log(struct reftable_iterator *it, + struct reftable_log_record *log); + +/* releases resources associated with an iterator. */ +void reftable_iterator_destroy(struct reftable_iterator *it); + +#endif diff --git a/reftable/reftable.c b/reftable/reftable.c new file mode 100644 index 000000000000..85ab8ba9f963 --- /dev/null +++ b/reftable/reftable.c @@ -0,0 +1,115 @@ +/* +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 "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_ref_record ref = { + .refname = (char *)name, + }; + struct reftable_record rec = { NULL }; + reftable_record_from_ref(&rec, &ref); + 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; +} + +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 == NULL) { + 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 = { NULL }; + reftable_record_from_ref(&rec, ref); + return iterator_next(it, &rec); +} + +int reftable_iterator_next_log(struct reftable_iterator *it, + struct reftable_log_record *log) +{ + struct reftable_record rec = { NULL }; + reftable_record_from_log(&rec, log); + return iterator_next(it, &rec); +} + +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 == NULL); + it->iter_arg = NULL; + it->ops = &empty_vtable; +} -- gitgitgadget
