[PATCH v3 11/19] reftable: generic interface to tables
From: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
---
Makefile | 3 +
reftable/generic.c | 169 +++++++++++++++++++++++++++++++++++
reftable/generic.h | 32 +++++++
reftable/reftable-generic.h | 47 ++++++++++
reftable/reftable-iterator.h | 39 ++++++++
reftable/reftable.c | 115 ++++++++++++++++++++++++
6 files changed, 405 insertions(+)
create mode 100644 reftable/generic.c
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 38aa8d5400f..c6bbf4d4a2f 100644
--- a/Makefile
+++ b/Makefile
@@ -2440,6 +2440,9 @@ REFTABLE_OBJS += reftable/block.o
REFTABLE_OBJS += reftable/blocksource.o
REFTABLE_OBJS += reftable/publicbasics.o
REFTABLE_OBJS += reftable/record.o
+REFTABLE_OBJS += reftable/refname.o
+REFTABLE_OBJS += reftable/generic.o
+REFTABLE_OBJS += reftable/stack.o
REFTABLE_OBJS += reftable/tree.o
REFTABLE_OBJS += reftable/writer.o
diff --git a/reftable/generic.c b/reftable/generic.c
new file mode 100644
index 00000000000..7a8a738d860
--- /dev/null
+++ b/reftable/generic.c
@@ -0,0 +1,169 @@
+/*
+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_seek_log(struct reftable_table *tab,
+ struct reftable_iterator *it, const char *name)
+{
+ struct reftable_log_record log = {
+ .refname = (char *)name,
+ .update_index = ~((uint64_t)0),
+ };
+ struct reftable_record rec = { NULL };
+ reftable_record_from_log(&rec, &log);
+ 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 = { 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);
+ it->iter_arg = NULL;
+ it->ops = &empty_vtable;
+}
diff --git a/reftable/generic.h b/reftable/generic.h
new file mode 100644
index 00000000000..98886a06402
--- /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 00000000000..d239751a778
--- /dev/null
+++ b/reftable/reftable-generic.h
@@ -0,0 +1,47 @@
+/*
+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_log(struct reftable_table *tab,
+ struct reftable_iterator *it, const char *name);
+
+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);
+
+/* dump table contents onto stdout for debugging */
+int reftable_table_print(struct reftable_table *tab);
+
+#endif
diff --git a/reftable/reftable-iterator.h b/reftable/reftable-iterator.h
new file mode 100644
index 00000000000..d3eee7af357
--- /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 00000000000..0e4607a7cd6
--- /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) {
+ 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);
+ it->iter_arg = NULL;
+ it->ops = &empty_vtable;
+}
--
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Han-Wen Nienhuys via GitGitGadget <gitgitgadget@gmail.com>