/*
* Config Tree
* -----------
*
* A hierarchical data structure supporting arbitrary nesting. Each node
* (Config::Node) has a key and either a value or children (in fact, it may
* have both, but this does not make semantic sense and so the config tree
* builders take care not to allow it).
*
* All values are simply strings for now. They may have defaults, which are
* actually supplied by the caller and returned when a queried node cannot be
* found.
*
* Nodes at the same nesting level (siblings) are strung together in a
* linked list. Parents also maintain pointers to the first and last of their
* children (for order-preserving iteration) as well as a map for direct
* lookup by key.
*
* Keys may be reused at a given level. Key-value pairs will have their order
* preserved when iterated but only the most recent key is returned in direct
* map lookups.
*
* Example:
*
* <game name="scud">
* <roms>
* <crom name="foo.bin" offset=0/>
* <crom name="bar.bin" offset=2/>
* </roms>
*
* config["game/roms"].Value() <-- should return nothing
* config["game/roms/crom/offset"].Value() <-- "2", the second <crom> tag
* config["game/roms"].begin() <-- iterate over two <crom> tags
*
* INI Semantics
* -------------
*
* INI files are linear in nature and divided into sections. Config trees built
* to represent INI files must adhere to the following rules:
*
* - Section nodes have their key set to the section name and value empty.
* They are the only nodes that can have children (i.e., IsLeaf() == false,
* HasChildren() == true).
* - Top-level node in the tree is the global section, and its key is
* "Global".
* - Only the global section (top-level section) may have child nodes that are
* sections. The config tree can therefore only be up to 2 levels deep: the
* first, top-most level consists of global parameters, and section nodes
* provide one more level of nesting.
*
* INI files contain zero or more sections followed by zero or more settings
* each.
*
* Setting0 = 100
* [ Global ]
* Setting1 = 200
* [ Section1 ]
* SettingA = 1 ; this is a comment
* SettingB = foo
* [ Section2 ]
* SettingX = bar
* SettingZ = "baz" ; quotes are optional and are stripped off during parsing
*
* Any setting not explicitly part of a section is assigned to the "Global"
* section. For example, Setting0 and Setting1 above are both part of "Global".
*/
#include "Util/NewConfig.h"
#include "OSD/Logger.h"
#include "Pkgs/tinyxml2.h"
#include <algorithm>
#include <fstream>
#include <queue>
#include <cstdlib>
#include <iostream>
namespace Util
{
namespace Config
{
Node Node::s_empty_node;
bool Node::ValueAsBool() const
{
const char *value = m_value.c_str();
if (!value || !stricmp(value, "false") || !stricmp(value, "off") || !stricmp(value, "no"))
return false;
else if (!stricmp(value, "true") || !stricmp(value, "on") || !stricmp(value, "yes"))
return true;
return bool(ValueAsUnsigned());
}
bool Node::ValueAsBoolWithDefault(bool default_value) const
{
if (this == &s_empty_node)
return default_value;
return ValueAsBool();
}
uint64_t Node::ValueAsUnsigned() const
{
if (m_value.find("0x") == 0 || m_value.find("0X") == 0)
return strtoull(m_value.c_str() + 2, 0, 16);
return strtoull(m_value.c_str(), 0, 10);
}
uint64_t Node::ValueAsUnsignedWithDefault(uint64_t default_value) const
{
if (this == &s_empty_node)
return default_value;
return ValueAsUnsigned();
}
const Node &Node::operator[](const std::string &path) const
{
const Node *e = this;
std::vector<std::string> keys = Util::Format(path).Split('/');
for (auto &key: keys)
{
auto it = e->m_children.find(key);
if (it == e->m_children.end())
return s_empty_node;
e = it->second.get();
}
return *e;
}
Node &Node::Get(const std::string &path)
{
// This is probably dangerous and we should just have a non-const []
return const_cast<Node &>(operator[](path));
}
const Node &Node::Get(const std::string &path) const
{
return operator[](path);
}
std::string Node::ToString(size_t indent_level) const
{
std::ostringstream os;
std::fill_n(std::ostream_iterator<char>(os), 2 * indent_level, ' ');
os << m_key;
if (m_value.length())
os << '=' << m_value;
os << " children={";
for (auto v: m_children)
os << ' ' << v.first;
os << " }" << std::endl;
for (Ptr_t child = m_first_child; child; child = child->m_next_sibling)
os << child->ToString(indent_level + 1);
return os.str();
}
void Node::Print(size_t indent_level) const
{
std::cout << ToString(indent_level);
}
Node &Node::Add(const std::string &path, const std::string &value)
{
std::vector<std::string> keys = Util::Format(path).Split('/');
Node *parent = this;
Ptr_t node;
for (size_t i = 0; i < keys.size(); i++)
{
// Create node at this level
node = std::make_shared<Node>(keys[i]);
// The leaf node gets the value
if (i == keys.size() - 1)
node->SetValue(value);
// Attach node to parent and move down to next nesting level: last
// created node is new parent
AddChild(*parent, node);
parent = node.get();
}
return *node;
}
void Node::Set(const std::string &key, const std::string &value)
{
Node &node = Get(key);
if (node.Empty())
Add(key, value);
else
node.SetValue(value);
}
// Adds a newly-created node (which, among other things, implies no
// children) as a child
void Node::AddChild(Node &parent, Ptr_t &node)
{
if (!parent.m_last_child)
{
parent.m_first_child = node;
parent.m_last_child = node;
}
else
{
parent.m_last_child->m_next_sibling = node;
parent.m_last_child = node;
}
parent.m_children[node->m_key] = node;
}
void Node::DeepCopy(const Node &that)
{
if (this == &that)
return;
Destroy();
*const_cast<std::string *>(&m_key) = that.m_key;
m_value = that.m_value;
for (Ptr_t child = that.m_first_child; child; child = child->m_next_sibling)
{
Ptr_t copied_child = std::make_shared<Node>(*child);
AddChild(*this, copied_child);
}
}
Node &Node::operator=(const Node &rhs)
{
DeepCopy(rhs);
return *this;
}
Node::Node()
{
//std::cout << "<<< Created " << "<null>" << " (" << this << ")" << std::endl;
}
Node::Node(const std::string &key)
: m_key(key)
{
//std::cout << "<<< Created " << key << " (" << this << ")" << std::endl;
}
Node::Node(const std::string &key, const std::string &value)
: m_key(key),
m_value(value)
{
//std::cout << "<<< Created " << key << '=' << value << " (" << this << ")" << std::endl;
}
Node::Node(const Node &that)
: m_key(that.m_key),
m_value(that.m_value)
{
DeepCopy(that);
}
Node::~Node()
{
//std::cout << ">>> Destroyed " << m_key << " (" << this << ")" << std::endl;
}
Node::Ptr_t CreateEmpty()
{
return std::shared_ptr<Node>(new Node());
}
static void PopulateFromXML(Util::Config::Node::Ptr_t &config, const tinyxml2::XMLDocument &xml)
{
using namespace tinyxml2;
std::queue<std::pair<const XMLElement *, Util::Config::Node *>> q;
// Push the top level of the XML tree
for (const XMLElement *e = xml.RootElement(); e != 0; e = e->NextSiblingElement())
q.push( { e, config.get() } );
// Process the elements in order, pushing subsequent levels along with the
// config nodes to add them to
while (!q.empty())
{
const XMLElement *element = q.front().first;
Util::Config::Node *parent_node = q.front().second;
q.pop();
// Create a config entry for this XML element
Util::Config::Node *node = &parent_node->Add(element->Name(), element->GetText() ? std::string(element->GetText()) : std::string());
// Create entries for each attribute
for (const XMLAttribute *a = element->FirstAttribute(); a != 0; a = a->Next())
node->Add(a->Name(), a->Value());
// Push all child elements
for (const XMLElement *e = element->FirstChildElement(); e != 0; e = e->NextSiblingElement())
q.push( { e, node } );
}
}
Node::Ptr_t FromXML(const std::string &text)
{
Node::Ptr_t config = std::make_shared<Util::Config::Node>("xml");
using namespace tinyxml2;
XMLDocument xml;
auto ret = xml.Parse(text.c_str());
if (ret != XML_SUCCESS)
{
ErrorLog("Failed to parse XML (%s).", xml.ErrorName());
return CreateEmpty();
}
PopulateFromXML(config, xml);
return config;
}
Node::Ptr_t FromXMLFile(const std::string &filename)
{
Node::Ptr_t config = std::make_shared<Util::Config::Node>("xml");
using namespace tinyxml2;
XMLDocument xml;
auto ret = xml.LoadFile(filename.c_str());
if (ret != XML_SUCCESS)
{
ErrorLog("Failed to parse %s (%s).", filename.c_str(), xml.ErrorName());
return CreateEmpty();
}
PopulateFromXML(config, xml);
return config;
}
static std::string StripComment(const std::string &line)
{
// Find first semicolon not enclosed in ""
bool inside_quotes = false;
for (auto it = line.begin(); it != line.end(); ++it)
{
inside_quotes ^= (*it == '\"');
if (!inside_quotes && *it == ';')
return std::string(line.begin(), it);
}
return line;
}
static void ParseAssignment(Node ¤t_section, const std::string &filename, size_t line_num, const std::string &line)
{
size_t idx_equals = line.find_first_of('=');
if (idx_equals == std::string::npos)
{
ErrorLog("%s:%d: Syntax error. No '=' found.", filename.c_str(), line_num);
return;
}
std::string lvalue(TrimWhiteSpace(std::string(line.begin(), line.begin() + idx_equals)));
if (lvalue.empty())
{
ErrorLog("%s:%d: Syntax error. Setting name missing before '='.", filename.c_str(), line_num);
return;
}
// Get rvalue, which is allowed to be empty and strip off quotes if they
// exist. Only a single pair of quotes encasing the rvalue are permitted.
std::string rvalue(TrimWhiteSpace(std::string(line.begin() + idx_equals + 1, line.end())));
size_t idx_first_quote = rvalue.find_first_of('\"');
size_t idx_last_quote = rvalue.find_last_of('\"');
if (idx_first_quote == 0 && idx_last_quote == (rvalue.length() - 1) && idx_first_quote != idx_last_quote)
rvalue = std::string(rvalue.begin() + idx_first_quote + 1, rvalue.begin() + idx_last_quote);
if (std::count(rvalue.begin(), rvalue.end(), '\"') != 0)
{
ErrorLog("%s:%d: Warning: Extraneous quotes present on line.", filename.c_str(), line_num);
}
// In INI files, we do not allow multiple settings with the same key. If
// a setting is specified multiple times, previous ones are overwritten.
if (current_section[lvalue].Empty())
current_section.Add(lvalue, rvalue);
else
current_section.Get(lvalue).SetValue(rvalue);
}
Node::Ptr_t FromINIFile(const std::string &filename)
{
std::ifstream file;
file.open(filename);
if (file.fail())
{
ErrorLog("Unable to open '%s'. Configuration will not be loaded.", filename.c_str());
return CreateEmpty();
}
Node::Ptr_t global_ptr = std::make_shared<Node>("Global"); // the root is also the "Global" section
Node &global = *global_ptr;
Node *current_section = &global;
size_t line_num = 1;
while (!file.eof())
{
if (file.fail())
{
ErrorLog("%s:%d: File read error. Configuration will be incomplete.");
return CreateEmpty();
}
std::string line;
std::getline(file, line);
line = StripComment(line);
line = TrimWhiteSpace(line);
if (!line.empty())
{
if (*line.begin() == '[' && *line.rbegin() == ']')
{
// Check if section exists else create a new one
std::string section(TrimWhiteSpace(std::string(line.begin() + 1, line.begin() + line.length() - 1)));
if (section.empty() || section == "Global") // empty section names (e.g., "[]") assigned to "[ Global ]"
current_section = &global;
else if (global[section].Empty())
{
Node &new_section = global.Add(section);
current_section = &new_section;
}
else
current_section = &global.Get(section);
}
else
{
ParseAssignment(*current_section, filename, line_num, line);
}
}
line_num++;
}
return global_ptr;
}
/*
* Produces a new INI section by merging two existing sections.
*
* - Nodes from x and y with children are ignored as per INI semantics.
* The presence of children indicates a section, not a setting.
* - Settings from y override settings in x if already present.
* - If multiple settings with the same key are present in either of the
* source configs (which technically violates INI semantics), the last
* ends up being used.
* - x's key is retained.
*/
Node::Ptr_t MergeINISections(const Node &x, const Node &y)
{
Node::Ptr_t merged_ptr = std::make_shared<Node>(x.Key()); // result has same key as x
Node &merged = *merged_ptr;
// First copy settings from section x
for (auto it = x.begin(); it != x.end(); ++it)
{
auto &key = it->Key();
auto &value = it->Value();
if (it->IsLeaf())
{
// INI semantics: take care to only create a single setting per key
merged.Set(key, value);
}
}
// Merge in settings from section y
for (auto it = y.begin(); it != y.end(); ++it)
{
auto &key = it->Key();
auto &value = it->Value();
if (it->IsLeaf())
{
merged.Set(key, value);
}
}
return merged_ptr;
}
static void WriteSection(std::ofstream &file, const Node §ion)
{
file << "[ " << section.Key() << " ]" << std::endl;
file << std::endl;
for (auto it = section.begin(); it != section.end(); ++it)
{
if (it->IsLeaf())
file << it->Key() << " = \"" << it->Value() << "\"" << std::endl;
}
file << std::endl << std::endl;
}
void WriteINIFile(const std::string &filename, const Node &config, const std::string &header_comment)
{
std::ofstream file;
file.open(filename);
if (file.fail())
{
ErrorLog("Unable to write to '%s'. Configuration will not be saved.");
return;
}
if (!header_comment.empty())
file << header_comment << std::endl << std::endl;
WriteSection(file, config);
for (auto it = config.begin(); it != config.end(); ++it)
{
if (it->HasChildren())
WriteSection(file, *it);
}
}
} // Config
} // Util