diff --git a/builtin/unpack-objects.c b/builtin/unpack-objects.c
index 7439ec53be..05a2d48011 100644
--- a/builtin/unpack-objects.c
+++ b/builtin/unpack-objects.c
@@ -359,20 +359,21 @@ static void unpack_non_delta_entry(enum object_type type, unsigned long size,
 }
 
 struct input_zstream_data {
+	struct odb_stream base;
 	git_zstream *zstream;
 	int status;
 };
 
-static ssize_t feed_input_zstream(struct odb_write_stream *in_stream,
-				  unsigned char *buf, size_t buf_len)
+static ssize_t feed_input_zstream(struct odb_stream *in_stream,
+				  char *buf, size_t buf_len)
 {
-	struct input_zstream_data *data = in_stream->data;
+	struct input_zstream_data *data = container_of(in_stream, struct input_zstream_data, base);
 	git_zstream *zstream = data->zstream;
 
 	if (data->status != Z_OK)
 		return 0;
 
-	zstream->next_out = buf;
+	zstream->next_out = (unsigned char *) buf;
 	zstream->avail_out = buf_len;
 
 	while (data->status == Z_OK && zstream->avail_out == buf_len) {
@@ -388,24 +389,24 @@ static ssize_t feed_input_zstream(struct odb_write_stream *in_stream,
 static void stream_blob(unsigned long size, unsigned nr)
 {
 	git_zstream zstream = { 0 };
-	struct input_zstream_data data = { 0 };
-	struct odb_write_stream in_stream = {
-		.read = feed_input_zstream,
-		.data = &data,
-		.size = size,
-		.type = OBJ_BLOB,
+	struct input_zstream_data in_stream = {
+		.base = {
+			.read = feed_input_zstream,
+			.size = size,
+			.type = OBJ_BLOB,
+		},
+		.zstream = &zstream,
+		.status = Z_OK,
 	};
 	struct obj_info *info = &obj_list[nr];
 
-	data.zstream = &zstream;
-	data.status = Z_OK;
 	git_inflate_init(&zstream);
 
-	if (odb_write_object_stream(the_repository->objects, &in_stream, &info->oid))
+	if (odb_write_object_stream(the_repository->objects, &in_stream.base, &info->oid))
 		die(_("failed to write object in stream"));
 
-	if (data.status != Z_STREAM_END)
-		die(_("inflate returned (%d)"), data.status);
+	if (in_stream.status != Z_STREAM_END)
+		die(_("inflate returned (%d)"), in_stream.status);
 	git_inflate_end(&zstream);
 
 	if (strict) {
diff --git a/object-file.c b/object-file.c
index 5f6d584c35..068c6e5672 100644
--- a/object-file.c
+++ b/object-file.c
@@ -702,7 +702,7 @@ static void prepare_packfile_transaction(struct odb_transaction_files *transacti
 		die_errno("unable to write pack header");
 }
 
-static int hash_stream(struct odb_write_stream *stream,
+static int hash_stream(struct odb_stream *stream,
 		       const struct git_hash_algo *hash_algo,
 		       struct object_id *result_oid)
 {
@@ -717,8 +717,8 @@ static int hash_stream(struct odb_write_stream *stream,
 	git_hash_update(&ctx, buf, header_len);
 
 	while (1) {
-		ssize_t read_result = odb_write_stream_read(stream, buf,
-							    sizeof(buf));
+		ssize_t read_result = odb_stream_read(stream, buf,
+						      sizeof(buf));
 		if (read_result < 0)
 			return -1;
 		if (!read_result)
@@ -742,7 +742,7 @@ static int hash_stream(struct odb_write_stream *stream,
  */
 static void stream_to_pack(struct transaction_packfile *state,
 			   struct git_hash_ctx *ctx,
-			   struct odb_write_stream *stream)
+			   struct odb_stream *stream)
 {
 	git_zstream s;
 	unsigned char ibuf[16384];
@@ -761,8 +761,8 @@ static void stream_to_pack(struct transaction_packfile *state,
 
 	while (status != Z_STREAM_END) {
 		if (!is_finished && !s.avail_in) {
-			ssize_t rsize = odb_write_stream_read(stream, ibuf,
-							      sizeof(ibuf));
+			ssize_t rsize = odb_stream_read(stream, ibuf,
+							sizeof(ibuf));
 			if (rsize < 0)
 				die("failed to read object data");
 			if (!rsize)
@@ -872,7 +872,7 @@ clear_exit:
  * callers should avoid this code path when filters are requested.
  */
 static int odb_transaction_files_write_object_stream(struct odb_transaction *base,
-						     struct odb_write_stream *stream,
+						     struct odb_stream *stream,
 						     struct object_id *result_oid)
 {
 	struct odb_transaction_files *transaction = container_of(base,
@@ -952,8 +952,8 @@ int index_fd(struct index_state *istate, struct object_id *oid,
 		ret = index_core(istate, oid, fd, xsize_t(st->st_size),
 				 type, path, flags);
 	} else {
-		struct odb_write_stream stream;
-		odb_write_stream_from_fd(&stream, fd, xsize_t(st->st_size), OBJ_BLOB);
+		struct odb_stream *stream = odb_write_stream_from_fd(fd, xsize_t(st->st_size),
+								     OBJ_BLOB);
 
 		if (flags & INDEX_WRITE_OBJECT) {
 			struct object_database *odb = the_repository->objects;
@@ -963,15 +963,14 @@ int index_fd(struct index_state *istate, struct object_id *oid,
 			if (!inflight)
 				odb_transaction_begin_or_die(odb, &transaction, 0);
 			ret = odb_transaction_write_object_stream(transaction,
-								  &stream,
-								  oid);
+								  stream, oid);
 			if (!inflight)
 				odb_transaction_commit(transaction);
 		} else {
-			ret = hash_stream(&stream, the_repository->hash_algo, oid);
+			ret = hash_stream(stream, the_repository->hash_algo, oid);
 		}
 
-		odb_write_stream_release(&stream);
+		odb_stream_close(stream);
 	}
 
 	close(fd);
diff --git a/odb.c b/odb.c
index 585b2b2965..eec4cc5302 100644
--- a/odb.c
+++ b/odb.c
@@ -1028,7 +1028,7 @@ int odb_write_object_ext(struct object_database *odb,
 }
 
 int odb_write_object_stream(struct object_database *odb,
-			    struct odb_write_stream *stream,
+			    struct odb_stream *stream,
 			    struct object_id *oid)
 {
 	return odb_source_write_object_stream(odb->sources, stream, oid);
diff --git a/odb.h b/odb.h
index 019d3af3e8..fbe75c5a81 100644
--- a/odb.h
+++ b/odb.h
@@ -626,10 +626,10 @@ static inline int odb_write_object(struct object_database *odb,
 	return odb_write_object_ext(odb, buf, len, type, oid, NULL, 0);
 }
 
-struct odb_write_stream;
+struct odb_stream;
 
 int odb_write_object_stream(struct object_database *odb,
-			    struct odb_write_stream *stream,
+			    struct odb_stream *stream,
 			    struct object_id *oid);
 
 void parse_alternates(const char *string,
diff --git a/odb/source-files.c b/odb/source-files.c
index f7b8c76549..6defe5ac4f 100644
--- a/odb/source-files.c
+++ b/odb/source-files.c
@@ -174,7 +174,7 @@ static int odb_source_files_write_object(struct odb_source *source,
 }
 
 static int odb_source_files_write_object_stream(struct odb_source *source,
-						struct odb_write_stream *stream,
+						struct odb_stream *stream,
 						struct object_id *oid)
 {
 	struct odb_source_files *files = odb_source_files_downcast(source);
diff --git a/odb/source-inmemory.c b/odb/source-inmemory.c
index 485d587036..795672adf2 100644
--- a/odb/source-inmemory.c
+++ b/odb/source-inmemory.c
@@ -256,7 +256,7 @@ static int odb_source_inmemory_write_object(struct odb_source *source,
 }
 
 static int odb_source_inmemory_write_object_stream(struct odb_source *source,
-						   struct odb_write_stream *stream,
+						   struct odb_stream *stream,
 						   struct object_id *oid)
 {
 	char buf[16384];
@@ -268,7 +268,7 @@ static int odb_source_inmemory_write_object_stream(struct odb_source *source,
 	while (1) {
 		ssize_t bytes_read;
 
-		bytes_read = odb_write_stream_read(stream, buf, sizeof(buf));
+		bytes_read = odb_stream_read(stream, buf, sizeof(buf));
 		if (bytes_read < 0) {
 			ret = error("failed to read object stream");
 			goto out;
diff --git a/odb/source-loose.c b/odb/source-loose.c
index 038defd905..ff1bede7fe 100644
--- a/odb/source-loose.c
+++ b/odb/source-loose.c
@@ -845,7 +845,7 @@ static int odb_source_loose_write_object(struct odb_source *source,
 }
 
 static int odb_source_loose_write_object_stream(struct odb_source *source,
-						struct odb_write_stream *in_stream,
+						struct odb_stream *in_stream,
 						struct object_id *oid)
 {
 	struct odb_source_loose *loose = odb_source_loose_downcast(source);
@@ -891,8 +891,8 @@ static int odb_source_loose_write_object_stream(struct odb_source *source,
 		unsigned char *in0 = stream.next_in;
 
 		if (!stream.avail_in && !is_finished) {
-			ssize_t read_len = odb_write_stream_read(in_stream, buf,
-								 sizeof(buf));
+			ssize_t read_len = odb_stream_read(in_stream, buf,
+							   sizeof(buf));
 			if (read_len < 0) {
 				close(fd);
 				err = -1;
diff --git a/odb/source-packed.c b/odb/source-packed.c
index b3186ca593..630d955585 100644
--- a/odb/source-packed.c
+++ b/odb/source-packed.c
@@ -609,7 +609,7 @@ static int odb_source_packed_write_object(struct odb_source *source UNUSED,
 }
 
 static int odb_source_packed_write_object_stream(struct odb_source *source UNUSED,
-						 struct odb_write_stream *stream UNUSED,
+						 struct odb_stream *stream UNUSED,
 						 struct object_id *oid UNUSED)
 {
 	return error("packed backend cannot write object streams");
diff --git a/odb/source.h b/odb/source.h
index 89b0c39682..0b99c698b5 100644
--- a/odb/source.h
+++ b/odb/source.h
@@ -221,7 +221,7 @@ struct odb_source {
 	 * otherwise.
 	 */
 	int (*write_object_stream)(struct odb_source *source,
-				   struct odb_write_stream *stream,
+				   struct odb_stream *stream,
 				   struct object_id *oid);
 
 	/*
@@ -436,7 +436,7 @@ static inline int odb_source_write_object(struct odb_source *source,
  * out pointer for the object ID.
  */
 static inline int odb_source_write_object_stream(struct odb_source *source,
-						 struct odb_write_stream *stream,
+						 struct odb_stream *stream,
 						 struct object_id *oid)
 {
 	return source->write_object_stream(source, stream, oid);
diff --git a/odb/streaming.c b/odb/streaming.c
index 98e2152e36..1a267e6b90 100644
--- a/odb/streaming.c
+++ b/odb/streaming.c
@@ -232,16 +232,6 @@ struct odb_stream *odb_read_stream_open(struct object_database *odb,
 	return st;
 }
 
-ssize_t odb_write_stream_read(struct odb_write_stream *st, void *buf, size_t sz)
-{
-	return st->read(st, buf, sz);
-}
-
-void odb_write_stream_release(struct odb_write_stream *st)
-{
-	free(st->data);
-}
-
 int odb_stream_blob_to_fd(struct object_database *odb,
 			  int fd,
 			  const struct object_id *oid,
@@ -299,14 +289,15 @@ int odb_stream_blob_to_fd(struct object_database *odb,
 }
 
 struct read_object_fd_data {
+	struct odb_stream base;
 	int fd;
 	size_t remaining;
 };
 
-static ssize_t read_object_fd(struct odb_write_stream *stream,
-			      unsigned char *buf, size_t len)
+static ssize_t read_object_fd(struct odb_stream *stream,
+			      char *buf, size_t len)
 {
-	struct read_object_fd_data *data = stream->data;
+	struct read_object_fd_data *data = container_of(stream, struct read_object_fd_data, base);
 	ssize_t read_result;
 	size_t count;
 
@@ -323,17 +314,23 @@ static ssize_t read_object_fd(struct odb_write_stream *stream,
 	return read_result;
 }
 
-void odb_write_stream_from_fd(struct odb_write_stream *stream, int fd,
-			      size_t size, enum object_type type)
+static int close_object_fd(struct odb_stream *stream UNUSED)
+{
+	/* The file descriptor is owned by the caller for now. */
+	return 0;
+}
+
+struct odb_stream *odb_write_stream_from_fd(int fd, size_t size, enum object_type type)
 {
 	struct read_object_fd_data *data;
 
 	CALLOC_ARRAY(data, 1);
+	data->base.read = read_object_fd;
+	data->base.close = close_object_fd;
+	data->base.size = size;
+	data->base.type = type;
 	data->fd = fd;
 	data->remaining = size;
 
-	stream->data = data;
-	stream->read = read_object_fd;
-	stream->size = size;
-	stream->type = type;
+	return &data->base;
 }
diff --git a/odb/streaming.h b/odb/streaming.h
index 037954c231..60b9803190 100644
--- a/odb/streaming.h
+++ b/odb/streaming.h
@@ -15,8 +15,8 @@ typedef int (*odb_stream_close_fn)(struct odb_stream *);
 typedef ssize_t (*odb_stream_read_fn)(struct odb_stream *, char *, size_t);
 
 /*
- * A stream that can be used to read an object from the object database without
- * loading all of it into memory.
+ * A stream that can be used to read an object from or write an object into the
+ * object database without loading all of it into memory.
  */
 struct odb_stream {
 	odb_stream_close_fn close;
@@ -48,30 +48,6 @@ int odb_stream_close(struct odb_stream *stream);
  */
 ssize_t odb_stream_read(struct odb_stream *stream, void *buf, size_t len);
 
-/*
- * A stream that provides an object to be written to the object database without
- * loading all of it into memory.
- */
-struct odb_write_stream {
-	ssize_t (*read)(struct odb_write_stream *, unsigned char *, size_t);
-	void *data;
-	size_t size;
-	enum object_type type;
-};
-
-/*
- * Read data from the stream into the buffer. Returns 0 when finished and the
- * number of bytes read on success. Returns a negative error code in case
- * reading from the stream fails.
- */
-ssize_t odb_write_stream_read(struct odb_write_stream *stream, void *buf,
-			      size_t len);
-
-/*
- * Releases memory allocated for underlying stream data.
- */
-void odb_write_stream_release(struct odb_write_stream *stream);
-
 /*
  * Look up the object by its ID and write the full contents to the file
  * descriptor. The object must be a blob, or the function will fail. When
@@ -92,7 +68,6 @@ int odb_stream_blob_to_fd(struct object_database *odb,
 /*
  * Sets up an ODB write stream that reads from an fd.
  */
-void odb_write_stream_from_fd(struct odb_write_stream *stream, int fd,
-			      size_t size, enum object_type type);
+struct odb_stream *odb_write_stream_from_fd(int fd, size_t size, enum object_type type);
 
 #endif /* STREAMING_H */
diff --git a/odb/transaction.c b/odb/transaction.c
index 6aaf133812..69d71b9e97 100644
--- a/odb/transaction.c
+++ b/odb/transaction.c
@@ -39,7 +39,7 @@ int odb_transaction_commit(struct odb_transaction *transaction)
 }
 
 int odb_transaction_write_object_stream(struct odb_transaction *transaction,
-					struct odb_write_stream *stream,
+					struct odb_stream *stream,
 					struct object_id *oid)
 {
 	return transaction->write_object_stream(transaction, stream, oid);
diff --git a/odb/transaction.h b/odb/transaction.h
index 1eb74664c6..65248a409c 100644
--- a/odb/transaction.h
+++ b/odb/transaction.h
@@ -31,7 +31,7 @@ struct odb_transaction {
 	 * otherwise.
 	 */
 	int (*write_object_stream)(struct odb_transaction *transaction,
-				   struct odb_write_stream *stream,
+				   struct odb_stream *stream,
 				   struct object_id *oid);
 
 	/*
@@ -81,7 +81,7 @@ int odb_transaction_commit(struct odb_transaction *transaction);
  * error code otherwise.
  */
 int odb_transaction_write_object_stream(struct odb_transaction *transaction,
-					struct odb_write_stream *stream,
+					struct odb_stream *stream,
 					struct object_id *oid);
 
 /*
diff --git a/t/unit-tests/u-odb-inmemory.c b/t/unit-tests/u-odb-inmemory.c
index 839a0fd3b7..b8b331b37d 100644
--- a/t/unit-tests/u-odb-inmemory.c
+++ b/t/unit-tests/u-odb-inmemory.c
@@ -266,13 +266,13 @@ void test_odb_inmemory__freshen_object(void)
 }
 
 struct membuf_write_stream {
-	struct odb_write_stream base;
+	struct odb_stream base;
 	const char *buf;
 	size_t offset;
 };
 
-static ssize_t membuf_write_stream_read(struct odb_write_stream *stream,
-					unsigned char *buf, size_t len)
+static ssize_t membuf_write_stream_read(struct odb_stream *stream,
+					char *buf, size_t len)
 {
 	struct membuf_write_stream *s = container_of(stream, struct membuf_write_stream, base);
 	size_t chunk_size = 2;