1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
#include "clickhouse_config.h"
#if USE_YAML_CPP
#include "YAMLParser.h"
#include <vector>
#include <Poco/DOM/Document.h>
#include <Poco/DOM/NodeList.h>
#include <Poco/DOM/Element.h>
#include <Poco/DOM/AutoPtr.h>
#include <Poco/DOM/NamedNodeMap.h>
#include <Poco/DOM/Text.h>
#include <Common/Exception.h>
#error #include <yaml-cpp/yaml.h>
using namespace Poco::XML;
namespace DB
{
namespace ErrorCodes
{
extern const int CANNOT_OPEN_FILE;
extern const int CANNOT_PARSE_YAML;
}
namespace
{
/// A prefix symbol in yaml key
/// We add attributes to nodes by using a prefix symbol in the key part.
/// Currently we use @ as a prefix symbol. Note, that @ is reserved
/// by YAML standard, so we need to write a key-value pair like this: "@attribute": attr_value
const char YAML_ATTRIBUTE_PREFIX = '@';
Poco::AutoPtr<Poco::XML::Element> cloneXMLNode(const Poco::XML::Element & original_node)
{
Poco::AutoPtr<Poco::XML::Element> clone_node = original_node.ownerDocument()->createElement(original_node.nodeName());
original_node.parentNode()->appendChild(clone_node);
return clone_node;
}
void processNode(const YAML::Node & node, Poco::XML::Element & parent_xml_node)
{
auto * xml_document = parent_xml_node.ownerDocument();
switch (node.Type())
{
case YAML::NodeType::Scalar:
{
std::string value = node.as<std::string>();
Poco::AutoPtr<Poco::XML::Text> xml_value = xml_document->createTextNode(value);
parent_xml_node.appendChild(xml_value);
break;
}
/// For sequences we repeat the parent xml node. For example,
/// seq:
/// - val1
/// - val2
/// is converted into the following xml:
/// <seq>val1</seq>
/// <seq>val2</seq>
///
/// A sequence of mappings is converted in the same way:
/// seq:
/// - k1: val1
/// k2: val2
/// - k3: val3
/// is converted into the following xml:
/// <seq><k1>val1</k1><k2>val2</k2></seq>
/// <seq><k3>val3</k3></seq>
case YAML::NodeType::Sequence:
{
size_t i = 0;
for (auto it = node.begin(); it != node.end(); ++it, ++i)
{
const auto & child_node = *it;
bool need_clone_parent_xml_node = (i > 0);
if (need_clone_parent_xml_node)
{
/// Create a new parent node with same tag for each child node
processNode(child_node, *cloneXMLNode(parent_xml_node));
}
else
{
/// Map, so don't recreate the parent node but add directly
processNode(child_node, parent_xml_node);
}
}
break;
}
case YAML::NodeType::Map:
{
for (const auto & key_value_pair : node)
{
const auto & key_node = key_value_pair.first;
const auto & value_node = key_value_pair.second;
std::string key = key_node.as<std::string>();
bool is_attribute = (key.starts_with(YAML_ATTRIBUTE_PREFIX) && value_node.IsScalar());
if (is_attribute)
{
/// we use substr(1) here to remove YAML_ATTRIBUTE_PREFIX from key
auto attribute_name = key.substr(1);
std::string value = value_node.as<std::string>();
parent_xml_node.setAttribute(attribute_name, value);
}
else
{
if (key == "#text" && value_node.IsScalar())
{
for (Node * child_node = parent_xml_node.firstChild(); child_node; child_node = child_node->nextSibling())
if (child_node->nodeType() == Node::TEXT_NODE)
throw Exception(ErrorCodes::CANNOT_PARSE_YAML,
"YAMLParser has encountered node with several text nodes "
"and cannot continue parsing of the file");
std::string value = value_node.as<std::string>();
Poco::AutoPtr<Poco::XML::Text> xml_value = xml_document->createTextNode(value);
parent_xml_node.appendChild(xml_value);
}
else
{
Poco::AutoPtr<Poco::XML::Element> xml_key = xml_document->createElement(key);
parent_xml_node.appendChild(xml_key);
processNode(value_node, *xml_key);
}
}
}
break;
}
case YAML::NodeType::Null: break;
case YAML::NodeType::Undefined:
{
throw Exception(ErrorCodes::CANNOT_PARSE_YAML,
"YAMLParser has encountered node with undefined type and cannot continue parsing "
"of the file");
}
}
}
}
Poco::AutoPtr<Poco::XML::Document> YAMLParser::parse(const String& path)
{
YAML::Node node_yml;
try
{
node_yml = YAML::LoadFile(path);
}
catch (const YAML::ParserException& e)
{
/// yaml-cpp cannot parse the file because its contents are incorrect
throw Exception(ErrorCodes::CANNOT_PARSE_YAML, "Unable to parse YAML configuration file {}, {}", path, e.what());
}
catch (const YAML::BadFile&)
{
/// yaml-cpp cannot open the file even though it exists
throw Exception(ErrorCodes::CANNOT_OPEN_FILE, "Unable to open YAML configuration file {}", path);
}
Poco::AutoPtr<Poco::XML::Document> xml = new Document;
Poco::AutoPtr<Poco::XML::Element> root_node = xml->createElement("clickhouse");
xml->appendChild(root_node);
try
{
processNode(node_yml, *root_node);
}
catch (const YAML::TypedBadConversion<std::string>&)
{
throw Exception(ErrorCodes::CANNOT_PARSE_YAML,
"YAMLParser has encountered node with key "
"or value which cannot be represented as string and cannot continue parsing of the file");
}
return xml;
}
}
#endif
|
