[PATCH v2 06/15] reftable/generic: move generic iterator code into iterator interface

[Patrick Steinhardt <ps@pks.im>]

Move functions relating to the reftable iterator from "generic.c" into
"iter.c". This prepares for the removal of the former subsystem.

While at it, remove some unneeded braces to conform to our coding style.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 reftable/generic.c | 107 +--------------------------------------------
 reftable/generic.h |  10 -----
 reftable/iter.c    | 105 ++++++++++++++++++++++++++++++++++++++++++++
 reftable/iter.h    |  27 ++++++++++++
 4 files changed, 133 insertions(+), 116 deletions(-)

diff --git a/reftable/generic.c b/reftable/generic.c
index 28ae26145e..6ecf9b880f 100644
--- a/reftable/generic.c
+++ b/reftable/generic.c
@@ -9,6 +9,7 @@ license that can be found in the LICENSE file or at
 #include "constants.h"
 #include "record.h"
 #include "generic.h"
+#include "iter.h"
 #include "reftable-iterator.h"
 #include "reftable-generic.h"
 
@@ -32,37 +33,6 @@ void reftable_table_init_log_iter(struct reftable_table *tab,
 	table_init_iter(tab, it, BLOCK_TYPE_LOG);
 }
 
-int reftable_iterator_seek_ref(struct reftable_iterator *it,
-			       const char *name)
-{
-	struct reftable_record want = {
-		.type = BLOCK_TYPE_REF,
-		.u.ref = {
-			.refname = (char *)name,
-		},
-	};
-	return it->ops->seek(it->iter_arg, &want);
-}
-
-int reftable_iterator_seek_log_at(struct reftable_iterator *it,
-				  const char *name, uint64_t update_index)
-{
-	struct reftable_record want = {
-		.type = BLOCK_TYPE_LOG,
-		.u.log = {
-			.refname = (char *)name,
-			.update_index = update_index,
-		},
-	};
-	return it->ops->seek(it->iter_arg, &want);
-}
-
-int reftable_iterator_seek_log(struct reftable_iterator *it,
-			       const char *name)
-{
-	return reftable_iterator_seek_log_at(it, name, ~((uint64_t) 0));
-}
-
 int reftable_table_read_ref(struct reftable_table *tab, const char *name,
 			    struct reftable_ref_record *ref)
 {
@@ -152,78 +122,3 @@ 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_seek(struct reftable_iterator *it, struct reftable_record *want)
-{
-	return it->ops->seek(it->iter_arg, want);
-}
-
-int iterator_next(struct reftable_iterator *it, struct reftable_record *rec)
-{
-	return it->ops->next(it->iter_arg, rec);
-}
-
-static int empty_iterator_seek(void *arg, struct reftable_record *want)
-{
-	return 0;
-}
-
-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 = {
-	.seek = &empty_iterator_seek,
-	.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
index 8341fa570e..837fbb8df2 100644
--- a/reftable/generic.h
+++ b/reftable/generic.h
@@ -24,14 +24,4 @@ void table_init_iter(struct reftable_table *tab,
 		     struct reftable_iterator *it,
 		     uint8_t typ);
 
-struct reftable_iterator_vtable {
-	int (*seek)(void *iter_arg, struct reftable_record *want);
-	int (*next)(void *iter_arg, struct reftable_record *rec);
-	void (*close)(void *iter_arg);
-};
-
-void iterator_set_empty(struct reftable_iterator *it);
-int iterator_seek(struct reftable_iterator *it, struct reftable_record *want);
-int iterator_next(struct reftable_iterator *it, struct reftable_record *rec);
-
 #endif
diff --git a/reftable/iter.c b/reftable/iter.c
index a7484aba60..225feb7871 100644
--- a/reftable/iter.c
+++ b/reftable/iter.c
@@ -16,6 +16,43 @@ license that can be found in the LICENSE file or at
 #include "reader.h"
 #include "reftable-error.h"
 
+int iterator_seek(struct reftable_iterator *it, struct reftable_record *want)
+{
+	return it->ops->seek(it->iter_arg, want);
+}
+
+int iterator_next(struct reftable_iterator *it, struct reftable_record *rec)
+{
+	return it->ops->next(it->iter_arg, rec);
+}
+
+static int empty_iterator_seek(void *arg, struct reftable_record *want)
+{
+	return 0;
+}
+
+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 = {
+	.seek = &empty_iterator_seek,
+	.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;
+}
+
 static void filtering_ref_iterator_close(void *iter_arg)
 {
 	struct filtering_ref_iterator *fri = iter_arg;
@@ -181,3 +218,71 @@ void iterator_from_indexed_table_ref_iter(struct reftable_iterator *it,
 	it->iter_arg = itr;
 	it->ops = &indexed_table_ref_iter_vtable;
 }
+
+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_seek_ref(struct reftable_iterator *it,
+			       const char *name)
+{
+	struct reftable_record want = {
+		.type = BLOCK_TYPE_REF,
+		.u.ref = {
+			.refname = (char *)name,
+		},
+	};
+	return it->ops->seek(it->iter_arg, &want);
+}
+
+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_seek_log_at(struct reftable_iterator *it,
+				  const char *name, uint64_t update_index)
+{
+	struct reftable_record want = {
+		.type = BLOCK_TYPE_LOG,
+		.u.log = {
+			.refname = (char *)name,
+			.update_index = update_index,
+		},
+	};
+	return it->ops->seek(it->iter_arg, &want);
+}
+
+int reftable_iterator_seek_log(struct reftable_iterator *it,
+			       const char *name)
+{
+	return reftable_iterator_seek_log_at(it, name, ~((uint64_t) 0));
+}
+
+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;
+}
diff --git a/reftable/iter.h b/reftable/iter.h
index b75d7ac2ac..3b401f1259 100644
--- a/reftable/iter.h
+++ b/reftable/iter.h
@@ -16,6 +16,33 @@ license that can be found in the LICENSE file or at
 #include "reftable-iterator.h"
 #include "reftable-generic.h"
 
+/*
+ * The virtual function table for implementing generic reftable iterators.
+ */
+struct reftable_iterator_vtable {
+	int (*seek)(void *iter_arg, struct reftable_record *want);
+	int (*next)(void *iter_arg, struct reftable_record *rec);
+	void (*close)(void *iter_arg);
+};
+
+/*
+ * Position the iterator at the wanted record such that a call to
+ * `iterator_next()` would return that record, if it exists.
+ */
+int iterator_seek(struct reftable_iterator *it, struct reftable_record *want);
+
+/*
+ * Yield the next record and advance the iterator. Returns <0 on error, 0 when
+ * a record was yielded, and >0 when the iterator hit an error.
+ */
+int iterator_next(struct reftable_iterator *it, struct reftable_record *rec);
+
+/*
+ * Set up the iterator such that it behaves the same as an iterator with no
+ * entries.
+ */
+void iterator_set_empty(struct reftable_iterator *it);
+
 /* iterator that produces only ref records that point to `oid` */
 struct filtering_ref_iterator {
 	struct strbuf oid;
-- 
2.46.0.46.g406f326d27.dirty