reftable: convert from strbuf to reftable_buf

Convert the reftable library to use the `reftable_buf` interface instead
of the `strbuf` interface. This is mostly a mechanical change via sed(1)
with some manual fixes where functions for `strbuf` and `reftable_buf`
differ. The converted code does not yet handle allocation failures. This
will be handled in subsequent commits.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Taylor Blau <[email protected]>

reftable/basics.c

@@ -260,7 +260,7 @@ int names_equal(const char **a, const char **b)
 	return a[i] == b[i];
 }
 
-int common_prefix_size(struct strbuf *a, struct strbuf *b)
+int common_prefix_size(struct reftable_buf *a, struct reftable_buf *b)
 {
 	int p = 0;
 	for (; p < a->len && p < b->len; p++) {

reftable/basics.h

@@ -57,7 +57,9 @@ int reftable_buf_setlen(struct reftable_buf *buf, size_t len);
 int reftable_buf_cmp(const struct reftable_buf *a, const struct reftable_buf *b);
 
 /*
- * Add the given bytes to the buffer. Returns 0 on success,
+ * Append `len` bytes from `data` to the buffer. This function works with
+ * arbitrary byte sequences, including ones that contain embedded NUL
+ * characters. As such, we use `void *` as input type. Returns 0 on success,
  * REFTABLE_OUT_OF_MEMORY_ERROR on allocation failure.
  */
 int reftable_buf_add(struct reftable_buf *buf, const void *data, size_t len);
@@ -144,8 +146,7 @@ char *reftable_strdup(const char *str);
 #endif
 
 /* Find the longest shared prefix size of `a` and `b` */
-struct strbuf;
-int common_prefix_size(struct strbuf *a, struct strbuf *b);
+int common_prefix_size(struct reftable_buf *a, struct reftable_buf *b);
 
 int hash_size(uint32_t id);
 

reftable/block.c

@@ -38,7 +38,7 @@ int footer_size(int version)
 }
 
 static int block_writer_register_restart(struct block_writer *w, int n,
-					 int is_restart, struct strbuf *key)
+					 int is_restart, struct reftable_buf *key)
 {
 	int rlen = w->restart_len;
 	if (rlen >= MAX_RESTARTS) {
@@ -59,8 +59,8 @@ static int block_writer_register_restart(struct block_writer *w, int n,
 
 	w->next += n;
 
-	strbuf_reset(&w->last_key);
-	strbuf_add(&w->last_key, key->buf, key->len);
+	reftable_buf_reset(&w->last_key);
+	reftable_buf_add(&w->last_key, key->buf, key->len);
 	w->entries++;
 	return 0;
 }
@@ -98,8 +98,8 @@ uint8_t block_writer_type(struct block_writer *bw)
    empty key. */
 int block_writer_add(struct block_writer *w, struct reftable_record *rec)
 {
-	struct strbuf empty = STRBUF_INIT;
-	struct strbuf last =
+	struct reftable_buf empty = REFTABLE_BUF_INIT;
+	struct reftable_buf last =
 		w->entries % w->restart_interval == 0 ? empty : w->last_key;
 	struct string_view out = {
 		.buf = w->buf + w->next,
@@ -109,7 +109,7 @@ int block_writer_add(struct block_writer *w, struct reftable_record *rec)
 	struct string_view start = out;
 
 	int is_restart = 0;
-	struct strbuf key = STRBUF_INIT;
+	struct reftable_buf key = REFTABLE_BUF_INIT;
 	int n = 0;
 	int err = -1;
 
@@ -133,7 +133,7 @@ int block_writer_add(struct block_writer *w, struct reftable_record *rec)
 	err = block_writer_register_restart(w, start.len - out.len, is_restart,
 					    &key);
 done:
-	strbuf_release(&key);
+	reftable_buf_release(&key);
 	return err;
 }
 
@@ -325,7 +325,7 @@ uint8_t block_reader_type(const struct block_reader *r)
 	return r->block.data[r->header_off];
 }
 
-int block_reader_first_key(const struct block_reader *br, struct strbuf *key)
+int block_reader_first_key(const struct block_reader *br, struct reftable_buf *key)
 {
 	int off = br->header_off + 4, n;
 	struct string_view in = {
@@ -334,7 +334,7 @@ int block_reader_first_key(const struct block_reader *br, struct strbuf *key)
 	};
 	uint8_t extra = 0;
 
-	strbuf_reset(key);
+	reftable_buf_reset(key);
 
 	n = reftable_decode_key(key, &extra, in);
 	if (n < 0)
@@ -355,13 +355,13 @@ void block_iter_seek_start(struct block_iter *it, const struct block_reader *br)
 	it->block = br->block.data;
 	it->block_len = br->block_len;
 	it->hash_size = br->hash_size;
-	strbuf_reset(&it->last_key);
+	reftable_buf_reset(&it->last_key);
 	it->next_off = br->header_off + 4;
 }
 
 struct restart_needle_less_args {
 	int error;
-	struct strbuf needle;
+	struct reftable_buf needle;
 	const struct block_reader *reader;
 };
 
@@ -433,7 +433,7 @@ int block_iter_next(struct block_iter *it, struct reftable_record *rec)
 
 void block_iter_reset(struct block_iter *it)
 {
-	strbuf_reset(&it->last_key);
+	reftable_buf_reset(&it->last_key);
 	it->next_off = 0;
 	it->block = NULL;
 	it->block_len = 0;
@@ -442,12 +442,12 @@ void block_iter_reset(struct block_iter *it)
 
 void block_iter_close(struct block_iter *it)
 {
-	strbuf_release(&it->last_key);
-	strbuf_release(&it->scratch);
+	reftable_buf_release(&it->last_key);
+	reftable_buf_release(&it->scratch);
 }
 
 int block_iter_seek_key(struct block_iter *it, const struct block_reader *br,
-			struct strbuf *want)
+			struct reftable_buf *want)
 {
 	struct restart_needle_less_args args = {
 		.needle = *want,
@@ -537,7 +537,7 @@ int block_iter_seek_key(struct block_iter *it, const struct block_reader *br,
 		 * with themselves.
 		 */
 		reftable_record_key(&rec, &it->last_key);
-		if (strbuf_cmp(&it->last_key, want) >= 0) {
+		if (reftable_buf_cmp(&it->last_key, want) >= 0) {
 			it->next_off = prev_off;
 			goto done;
 		}
@@ -554,7 +554,7 @@ void block_writer_release(struct block_writer *bw)
 	REFTABLE_FREE_AND_NULL(bw->zstream);
 	REFTABLE_FREE_AND_NULL(bw->restarts);
 	REFTABLE_FREE_AND_NULL(bw->compressed);
-	strbuf_release(&bw->last_key);
+	reftable_buf_release(&bw->last_key);
 	/* the block is not owned. */
 }
 

reftable/block.h

@@ -38,7 +38,7 @@ struct block_writer {
 	uint32_t restart_len;
 	uint32_t restart_cap;
 
-	struct strbuf last_key;
+	struct reftable_buf last_key;
 	int entries;
 };
 
@@ -98,7 +98,7 @@ void block_reader_release(struct block_reader *br);
 uint8_t block_reader_type(const struct block_reader *r);
 
 /* Decodes the first key in the block */
-int block_reader_first_key(const struct block_reader *br, struct strbuf *key);
+int block_reader_first_key(const struct block_reader *br, struct reftable_buf *key);
 
 /* Iterate over entries in a block */
 struct block_iter {
@@ -109,21 +109,21 @@ struct block_iter {
 	int hash_size;
 
 	/* key for last entry we read. */
-	struct strbuf last_key;
-	struct strbuf scratch;
+	struct reftable_buf last_key;
+	struct reftable_buf scratch;
 };
 
 #define BLOCK_ITER_INIT { \
-	.last_key = STRBUF_INIT, \
-	.scratch = STRBUF_INIT, \
+	.last_key = REFTABLE_BUF_INIT, \
+	.scratch = REFTABLE_BUF_INIT, \
 }
 
 /* Position `it` at start of the block */
 void block_iter_seek_start(struct block_iter *it, const struct block_reader *br);
 
 /* Position `it` to the `want` key in the block */
 int block_iter_seek_key(struct block_iter *it, const struct block_reader *br,
-			struct strbuf *want);
+			struct reftable_buf *want);
 
 /* return < 0 for error, 0 for OK, > 0 for EOF. */
 int block_iter_next(struct block_iter *it, struct reftable_record *rec);

reftable/blocksource.c

@@ -27,7 +27,7 @@ static void strbuf_close(void *b UNUSED)
 static int strbuf_read_block(void *v, struct reftable_block *dest, uint64_t off,
 			     uint32_t size)
 {
-	struct strbuf *b = v;
+	struct reftable_buf *b = v;
 	assert(off + size <= b->len);
 	REFTABLE_CALLOC_ARRAY(dest->data, size);
 	if (!dest->data)
@@ -39,7 +39,7 @@ static int strbuf_read_block(void *v, struct reftable_block *dest, uint64_t off,
 
 static uint64_t strbuf_size(void *b)
 {
-	return ((struct strbuf *)b)->len;
+	return ((struct reftable_buf *)b)->len;
 }
 
 static struct reftable_block_source_vtable strbuf_vtable = {
@@ -50,7 +50,7 @@ static struct reftable_block_source_vtable strbuf_vtable = {
 };
 
 void block_source_from_strbuf(struct reftable_block_source *bs,
-			      struct strbuf *buf)
+			      struct reftable_buf *buf)
 {
 	assert(!bs->ops);
 	bs->ops = &strbuf_vtable;

reftable/blocksource.h

@@ -12,9 +12,10 @@ license that can be found in the LICENSE file or at
 #include "system.h"
 
 struct reftable_block_source;
+struct reftable_buf;
 
 /* Create an in-memory block source for reading reftables */
 void block_source_from_strbuf(struct reftable_block_source *bs,
-			      struct strbuf *buf);
+			      struct reftable_buf *buf);
 
 #endif

reftable/iter.c

@@ -55,7 +55,7 @@ void iterator_set_empty(struct reftable_iterator *it)
 static void filtering_ref_iterator_close(void *iter_arg)
 {
 	struct filtering_ref_iterator *fri = iter_arg;
-	strbuf_release(&fri->oid);
+	reftable_buf_release(&fri->oid);
 	reftable_iterator_destroy(&fri->it);
 }
 
@@ -115,7 +115,7 @@ static void indexed_table_ref_iter_close(void *p)
 	block_iter_close(&it->cur);
 	reftable_block_done(&it->block_reader.block);
 	reftable_free(it->offsets);
-	strbuf_release(&it->oid);
+	reftable_buf_release(&it->oid);
 }
 
 static int indexed_table_ref_iter_next_block(struct indexed_table_ref_iter *it)
@@ -197,7 +197,7 @@ int indexed_table_ref_iter_new(struct indexed_table_ref_iter **dest,
 
 	*itr = empty;
 	itr->r = r;
-	strbuf_add(&itr->oid, oid, oid_len);
+	reftable_buf_add(&itr->oid, oid, oid_len);
 
 	itr->offsets = offsets;
 	itr->offset_len = offset_len;

reftable/iter.h

@@ -44,12 +44,12 @@ 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;
+	struct reftable_buf oid;
 	struct reftable_iterator it;
 };
 #define FILTERING_REF_ITERATOR_INIT \
 	{                           \
-		.oid = STRBUF_INIT  \
+		.oid = REFTABLE_BUF_INIT  \
 	}
 
 void iterator_from_filtering_ref_iterator(struct reftable_iterator *,
@@ -60,7 +60,7 @@ void iterator_from_filtering_ref_iterator(struct reftable_iterator *,
  */
 struct indexed_table_ref_iter {
 	struct reftable_reader *r;
-	struct strbuf oid;
+	struct reftable_buf oid;
 
 	/* mutable */
 	uint64_t *offsets;
@@ -75,7 +75,7 @@ struct indexed_table_ref_iter {
 
 #define INDEXED_TABLE_REF_ITER_INIT { \
 	.cur = BLOCK_ITER_INIT, \
-	.oid = STRBUF_INIT, \
+	.oid = REFTABLE_BUF_INIT, \
 }
 
 void iterator_from_indexed_table_ref_iter(struct reftable_iterator *it,

reftable/reader.c

@@ -350,8 +350,8 @@ static int table_iter_seek_start(struct table_iter *ti, uint8_t typ, int index)
 static int table_iter_seek_linear(struct table_iter *ti,
 				  struct reftable_record *want)
 {
-	struct strbuf want_key = STRBUF_INIT;
-	struct strbuf got_key = STRBUF_INIT;
+	struct reftable_buf want_key = REFTABLE_BUF_INIT;
+	struct reftable_buf got_key = REFTABLE_BUF_INIT;
 	struct reftable_record rec;
 	int err;
 
@@ -401,7 +401,7 @@ static int table_iter_seek_linear(struct table_iter *ti,
 		if (err < 0)
 			goto done;
 
-		if (strbuf_cmp(&got_key, &want_key) > 0) {
+		if (reftable_buf_cmp(&got_key, &want_key) > 0) {
 			table_iter_block_done(&next);
 			break;
 		}
@@ -422,20 +422,20 @@ static int table_iter_seek_linear(struct table_iter *ti,
 
 done:
 	reftable_record_release(&rec);
-	strbuf_release(&want_key);
-	strbuf_release(&got_key);
+	reftable_buf_release(&want_key);
+	reftable_buf_release(&got_key);
 	return err;
 }
 
 static int table_iter_seek_indexed(struct table_iter *ti,
 				   struct reftable_record *rec)
 {
 	struct reftable_record want_index = {
-		.type = BLOCK_TYPE_INDEX, .u.idx = { .last_key = STRBUF_INIT }
+		.type = BLOCK_TYPE_INDEX, .u.idx = { .last_key = REFTABLE_BUF_INIT }
 	};
 	struct reftable_record index_result = {
 		.type = BLOCK_TYPE_INDEX,
-		.u.idx = { .last_key = STRBUF_INIT },
+		.u.idx = { .last_key = REFTABLE_BUF_INIT },
 	};
 	int err;
 
@@ -765,7 +765,7 @@ static int reftable_reader_refs_for_unindexed(struct reftable_reader *r,
 	}
 	*filter = empty;
 
-	strbuf_add(&filter->oid, oid, oid_len);
+	reftable_buf_add(&filter->oid, oid, oid_len);
 	iterator_from_table_iter(&filter->it, ti);
 
 	iterator_from_filtering_ref_iterator(it, filter);