From: Stephan Bosch <stephan.bosch@open-xchange.com>
Date: Thu, 7 May 2020 12:56:17 +0000 (+0200)
Subject: lib-json: json-ostream - Add support for writing directly to the underlying stream
X-Git-Tag: 2.4.0~2377
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=60381661f762ad9d2203f8df43d7ba0a8cd96e2d;p=thirdparty%2Fdovecot%2Fcore.git

lib-json: json-ostream - Add support for writing directly to the underlying stream
---

diff --git a/src/lib-json/json-ostream.c b/src/lib-json/json-ostream.c
index 9f7176fb98..777073c39b 100644
--- a/src/lib-json/json-ostream.c
+++ b/src/lib-json/json-ostream.c
@@ -38,6 +38,8 @@ struct json_ostream {
 	bool value_opened:1;
 	bool value_persists:1;
 	bool string_opened:1;
+	bool space_opening:1;
+	bool space_opened:1;
 	bool last_errors_not_checked:1;
 	bool error_handling_disabled:1;
 	bool nfailed:1;
@@ -261,6 +263,15 @@ static int json_ostream_do_write_more(struct json_ostream *stream)
 
 	if (stream->closed)
 		return -1;
+	if (stream->space_opened) {
+		if (stream->space_opening) {
+			ret = json_generate_space_open(stream->generator);
+			if (ret <= 0)
+				return ret;
+			stream->space_opening = FALSE;
+		}
+		return 1;
+	}
 
 	switch (stream->node.value.content_type) {
 	case JSON_CONTENT_TYPE_STRING:
@@ -406,6 +417,7 @@ json_ostream_write_init(struct json_ostream *stream, const char *name,
 {
 	int ret;
 
+	i_assert(!stream->space_opened);
 	i_assert(name == NULL || !stream->string_opened);
 	i_assert(!stream->string_opened || type == JSON_TYPE_STRING);
 
@@ -426,6 +438,30 @@ json_ostream_write_init(struct json_ostream *stream, const char *name,
 	return 1;
 }
 
+static int
+json_ostream_write_space_init(struct json_ostream *stream, const char *name)
+{
+	int ret;
+
+	i_assert(!stream->string_opened);
+
+	ret = json_ostream_flush(stream);
+	if (ret <= 0)
+		return ret;
+
+	if (stream->space_opened)
+		return 1;
+
+	if (name != NULL) {
+		i_assert(!stream->member_name_written);
+		ret = json_generate_object_member(stream->generator, name);
+		if (ret <= 0)
+			return ret;
+	}
+	stream->member_name_written = FALSE;
+	return 1;
+}
+
 /*
  * Values
  */
@@ -1198,6 +1234,8 @@ json_ostream_do_write_node(struct json_ostream *stream,
 int json_ostream_write_node(struct json_ostream *stream,
 			    const struct json_node *node, bool copy)
 {
+	i_assert(!stream->space_opened);
+
 	return json_ostream_do_write_node(stream, node, TRUE, copy);
 }
 
@@ -1272,3 +1310,41 @@ json_ostream_nopen_string_stream(struct json_ostream *stream, const char *name)
 	json_ostream_nwrite_post(stream, ret);
 	return ostream;
 }
+
+/*
+ * <space>
+ */
+
+int json_ostream_open_space(struct json_ostream *stream, const char *name)
+{
+	int ret;
+
+	ret = json_ostream_write_space_init(stream, name);
+	if (ret <= 0)
+		return ret;
+
+	i_zero(&stream->node);
+	stream->space_opened = TRUE;
+	stream->space_opening = TRUE;
+
+	return json_ostream_write_more(stream);
+}
+
+void json_ostream_nopen_space(struct json_ostream *stream, const char *name)
+{
+	int ret;
+
+	if (!json_ostream_nwrite_pre(stream))
+		return;
+	ret = json_ostream_open_space(stream, name);
+	json_ostream_nwrite_post(stream, ret);
+}
+
+void json_ostream_close_space(struct json_ostream *stream)
+{
+	i_assert(stream->space_opened);
+	i_assert(!stream->space_opening);
+
+	json_generate_space_close(stream->generator);
+	stream->space_opened = FALSE;
+}
diff --git a/src/lib-json/json-ostream.h b/src/lib-json/json-ostream.h
index 3d0356f63a..bc0d5baf4b 100644
--- a/src/lib-json/json-ostream.h
+++ b/src/lib-json/json-ostream.h
@@ -293,4 +293,17 @@ int json_ostream_open_string_stream(struct json_ostream *stream,
 struct ostream *
 json_ostream_nopen_string_stream(struct json_ostream *stream, const char *name);
 
+/*
+ * <space>
+ */
+
+/* Try to prepare the stream for writing raw JSON text to the underlying output
+   stream directly. Returns 1 if ready, 0 if the json output stream needs to be
+   flushed more (tried implicitly) before the stream can be opened, -1 if error.
+ */
+int json_ostream_open_space(struct json_ostream *stream, const char *name);
+void json_ostream_nopen_space(struct json_ostream *stream, const char *name);
+/* Continue after writing raw JSON to the underlying output stream directly. */
+void json_ostream_close_space(struct json_ostream *stream);
+
 #endif
diff --git a/src/lib-json/test-json-ostream.c b/src/lib-json/test-json-ostream.c
index 14e95f3553..d5eee45f10 100644
--- a/src/lib-json/test-json-ostream.c
+++ b/src/lib-json/test-json-ostream.c
@@ -2415,6 +2415,253 @@ static void test_json_ostream_nwrite_tree(void)
 	str_free(&buffer);
 }
 
+static void test_json_ostream_nwrite_space(void)
+{
+	string_t *buffer;
+	struct ostream *output;
+	struct json_ostream *joutput;
+
+	buffer = str_new(default_pool, 256);
+	output = o_stream_create_buffer(buffer);
+	o_stream_set_no_error_handling(output, TRUE);
+
+	/* <space> */
+	test_begin("json ostream nwrite space - <space>");
+	joutput = json_ostream_create(output, 0);
+	json_ostream_nopen_space(joutput, NULL);
+	o_stream_nsend_str(output, "212345");
+	json_ostream_close_space(joutput);
+	json_ostream_nfinish_destroy(&joutput);
+	test_assert_strcmp("212345", str_c(buffer));
+	test_end();
+	str_truncate(buffer, 0);
+	output->offset = 0;
+
+	/* [ <space> ] */
+	test_begin("json ostream nwrite space - [ <space> ]");
+	joutput = json_ostream_create(output, 0);
+	json_ostream_ndescend_array(joutput, NULL);
+	json_ostream_nopen_space(joutput, NULL);
+	o_stream_nsend_str(output, "\"frop\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nascend_array(joutput);
+	json_ostream_nfinish_destroy(&joutput);
+	test_assert_strcmp("[\"frop\"]", str_c(buffer));
+	test_end();
+	str_truncate(buffer, 0);
+	output->offset = 0;
+
+	/* [ <space>, string ] */
+	test_begin("json ostream nwrite space - [ <space>, string ]");
+	joutput = json_ostream_create(output, 0);
+	json_ostream_ndescend_array(joutput, NULL);
+	json_ostream_nopen_space(joutput, NULL);
+	o_stream_nsend_str(output, "\"frop\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nwrite_string(joutput, NULL, "friep");
+	json_ostream_nascend_array(joutput);
+	json_ostream_nfinish_destroy(&joutput);
+	test_assert_strcmp("[\"frop\",\"friep\"]", str_c(buffer));
+	test_end();
+	str_truncate(buffer, 0);
+	output->offset = 0;
+
+	/* [ string, <space> ] */
+	test_begin("json ostream nwrite space - [ string, <space> ]");
+	joutput = json_ostream_create(output, 0);
+	json_ostream_ndescend_array(joutput, NULL);
+	json_ostream_nwrite_string(joutput, NULL, "frop");
+	json_ostream_nopen_space(joutput, NULL);
+	o_stream_nsend_str(output, "[13234]");
+	json_ostream_close_space(joutput);
+	json_ostream_nascend_array(joutput);
+	json_ostream_nfinish_destroy(&joutput);
+	test_assert_strcmp("[\"frop\",[13234]]", str_c(buffer));
+	test_end();
+	str_truncate(buffer, 0);
+	output->offset = 0;
+
+	/* [ <space>, <space> ] */
+	test_begin("json ostream nwrite space - [ <space>, <space> ]");
+	joutput = json_ostream_create(output, 0);
+	json_ostream_ndescend_array(joutput, NULL);
+	json_ostream_nopen_space(joutput, NULL);
+	o_stream_nsend_str(output, "\"frop\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nopen_space(joutput, NULL);
+	o_stream_nsend_str(output, "\"friep\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nascend_array(joutput);
+	json_ostream_nfinish_destroy(&joutput);
+	test_assert_strcmp("[\"frop\",\"friep\"]", str_c(buffer));
+	test_end();
+	str_truncate(buffer, 0);
+	output->offset = 0;
+
+	/* { "a": <space> } */
+	test_begin("json ostream nwrite space - { \"a\": <space> }");
+	joutput = json_ostream_create(output, 0);
+	json_ostream_ndescend_object(joutput, NULL);
+	json_ostream_nopen_space(joutput, "a");
+	o_stream_nsend_str(output, "\"frop\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nascend_object(joutput);
+	json_ostream_nfinish_destroy(&joutput);
+	test_assert_strcmp("{\"a\":\"frop\"}", str_c(buffer));
+	test_end();
+	str_truncate(buffer, 0);
+	output->offset = 0;
+
+	/* { "a": <space>, "b": string } */
+	test_begin("json ostream nwrite space - "
+		   "{ \"a\": <space>, \"b\": string }");
+	joutput = json_ostream_create(output, 0);
+	json_ostream_ndescend_object(joutput, NULL);
+	json_ostream_nopen_space(joutput, "a");
+	o_stream_nsend_str(output, "\"frop\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nwrite_string(joutput, "b", "friep");
+	json_ostream_nascend_object(joutput);
+	json_ostream_nfinish_destroy(&joutput);
+	test_assert_strcmp("{\"a\":\"frop\",\"b\":\"friep\"}", str_c(buffer));
+	test_end();
+	str_truncate(buffer, 0);
+	output->offset = 0;
+
+	/* { "a": string, "b": <space> } */
+	test_begin("json ostream nwrite space - "
+		   "{ \"a\": string, \"b\": <space> }");
+	joutput = json_ostream_create(output, 0);
+	json_ostream_ndescend_object(joutput, NULL);
+	json_ostream_nwrite_string(joutput, "a", "frop");
+	json_ostream_nopen_space(joutput, "b");
+	o_stream_nsend_str(output, "[13234]");
+	json_ostream_close_space(joutput);
+	json_ostream_nascend_object(joutput);
+	json_ostream_nfinish_destroy(&joutput);
+	test_assert_strcmp("{\"a\":\"frop\",\"b\":[13234]}", str_c(buffer));
+	test_end();
+	str_truncate(buffer, 0);
+	output->offset = 0;
+
+	/* { "a": <space>, "b": <space> } */
+	test_begin("json ostream nwrite space - "
+		   "{ \"a\": <space>, \"b\": <space> }");
+	joutput = json_ostream_create(output, 0);
+	json_ostream_ndescend_object(joutput, NULL);
+	json_ostream_nopen_space(joutput, "a");
+	o_stream_nsend_str(output, "\"frop\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nopen_space(joutput, "b");
+	o_stream_nsend_str(output, "\"friep\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nascend_object(joutput);
+	json_ostream_nfinish_destroy(&joutput);
+	test_assert_strcmp("{\"a\":\"frop\",\"b\":\"friep\"}", str_c(buffer));
+	test_end();
+	str_truncate(buffer, 0);
+	output->offset = 0;
+
+	/* { <space> } */
+	test_begin("json ostream nwrite space - { <space> }");
+	joutput = json_ostream_create(output, 0);
+	json_ostream_ndescend_object(joutput, NULL);
+	json_ostream_nopen_space(joutput, NULL);
+	o_stream_nsend_str(output, "\"a\":\"frop\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nascend_object(joutput);
+	json_ostream_nfinish_destroy(&joutput);
+	test_assert_strcmp("{\"a\":\"frop\"}", str_c(buffer));
+	test_end();
+	str_truncate(buffer, 0);
+	output->offset = 0;
+
+	/* { <space>, "b": string } */
+	test_begin("json ostream nwrite space - { <space>, \"b\": string }");
+	joutput = json_ostream_create(output, 0);
+	json_ostream_ndescend_object(joutput, NULL);
+	json_ostream_nopen_space(joutput, NULL);
+	o_stream_nsend_str(output, "\"a\":\"frop\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nwrite_string(joutput, "b", "friep");
+	json_ostream_nascend_object(joutput);
+	json_ostream_nfinish_destroy(&joutput);
+	test_assert_strcmp("{\"a\":\"frop\",\"b\":\"friep\"}", str_c(buffer));
+	test_end();
+	str_truncate(buffer, 0);
+	output->offset = 0;
+
+	/* { "a": string, <space> } */
+	test_begin("json ostream nwrite space - "
+		   "{ \"a\": string, <space> }");
+	joutput = json_ostream_create(output, 0);
+	json_ostream_ndescend_object(joutput, NULL);
+	json_ostream_nwrite_string(joutput, "a", "frop");
+	json_ostream_nopen_space(joutput, NULL);
+	o_stream_nsend_str(output, "\"b\":[13234]");
+	json_ostream_close_space(joutput);
+	json_ostream_nascend_object(joutput);
+	json_ostream_nfinish_destroy(&joutput);
+	test_assert_strcmp("{\"a\":\"frop\",\"b\":[13234]}", str_c(buffer));
+	test_end();
+	str_truncate(buffer, 0);
+	output->offset = 0;
+
+	/* { <space>, <space> } */
+	test_begin("json ostream nwrite space - { <space>, <space> }");
+	joutput = json_ostream_create(output, 0);
+	json_ostream_ndescend_object(joutput, NULL);
+	json_ostream_nopen_space(joutput, NULL);
+	o_stream_nsend_str(output, "\"a\":\"frop\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nopen_space(joutput, NULL);
+	o_stream_nsend_str(output, "\"b\":\"friep\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nascend_object(joutput);
+	json_ostream_nfinish_destroy(&joutput);
+	test_assert_strcmp("{\"a\":\"frop\",\"b\":\"friep\"}", str_c(buffer));
+	test_end();
+	str_truncate(buffer, 0);
+	output->offset = 0;
+
+	/* { "a": <space>, <space> } */
+	test_begin("json ostream nwrite space - { \"a\": <space>, <space> }");
+	joutput = json_ostream_create(output, 0);
+	json_ostream_ndescend_object(joutput, NULL);
+	json_ostream_nopen_space(joutput, "a");
+	o_stream_nsend_str(output, "\"frop\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nopen_space(joutput, NULL);
+	o_stream_nsend_str(output, "\"b\":\"friep\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nascend_object(joutput);
+	json_ostream_nfinish_destroy(&joutput);
+	test_assert_strcmp("{\"a\":\"frop\",\"b\":\"friep\"}", str_c(buffer));
+	test_end();
+	str_truncate(buffer, 0);
+	output->offset = 0;
+
+	/* { <space>, "b": <space> } */
+	test_begin("json ostream nwrite space - { <space>, \"b\": <space> }");
+	joutput = json_ostream_create(output, 0);
+	json_ostream_ndescend_object(joutput, NULL);
+	json_ostream_nopen_space(joutput, NULL);
+	o_stream_nsend_str(output, "\"a\":\"frop\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nopen_space(joutput, "b");
+	o_stream_nsend_str(output, "\"friep\"");
+	json_ostream_close_space(joutput);
+	json_ostream_nascend_object(joutput);
+	json_ostream_nfinish_destroy(&joutput);
+	test_assert_strcmp("{\"a\":\"frop\",\"b\":\"friep\"}", str_c(buffer));
+	test_end();
+	str_truncate(buffer, 0);
+	output->offset = 0;
+
+	o_stream_destroy(&output);
+	str_free(&buffer);
+}
+
 int main(int argc, char *argv[])
 {
 	int c;
@@ -2424,6 +2671,7 @@ int main(int argc, char *argv[])
 		test_json_ostream_nwrite,
 		test_json_ostream_write_tree,
 		test_json_ostream_nwrite_tree,
+		test_json_ostream_nwrite_space,
 		NULL
 	};