[PATCH 06/10] reftable/generic: move generic iterator code into iterator interface

From

Patrick Steinhardt <ps@pks.im>

Date

Aug 13, 2024, 06:24 UTC

Message-ID

<14924604cebe20ac30d291399b0200016fa8b4e3.1723528765.git.ps@pks.im>

In-Reply-To

<cover.1723528765.git.ps@pks.im>

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 reftable/generic.c | 107 +--------------------------------------------
 reftable/generic.h |  10 -----
 reftable/iter.c    | 106 ++++++++++++++++++++++++++++++++++++++++++++
 reftable/iter.h    |  27 ++++++++++++
 4 files changed, 134 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..844853fad2 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 +218,72 @@ 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