refactor: Change config section and key string literals into constants (#7095)

Co-authored-by: Bart <11445373+bthomee@users.noreply.github.com>

src/libxrpl/config/BasicConfig.cpp

@@ -0,0 +1,183 @@
+#include <xrpl/config/BasicConfig.h>
+
+#include <xrpl/basics/StringUtilities.h>
+
+#include <boost/regex/v5/regbase.hpp>
+#include <boost/regex/v5/regex.hpp>
+#include <boost/regex/v5/regex_match.hpp>
+
+#include <ostream>
+#include <string>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+namespace xrpl {
+
+Section::Section(std::string name) : name_(std::move(name))
+{
+}
+
+void
+Section::set(std::string const& key, std::string const& value)
+{
+    lookup_.insert_or_assign(key, value);
+}
+
+void
+Section::append(std::vector<std::string> const& lines)
+{
+    // <key> '=' <value>
+    static boost::regex const kRe1(
+        "^"                        // start of line
+        "(?:\\s*)"                 // whitespace (optional)
+        "([a-zA-Z][_a-zA-Z0-9]*)"  // <key>
+        "(?:\\s*)"                 // whitespace (optional)
+        "(?:=)"                    // '='
+        "(?:\\s*)"                 // whitespace (optional)
+        "(.*\\S+)"                 // <value>
+        "(?:\\s*)"                 // whitespace (optional)
+        ,
+        boost::regex_constants::optimize);
+
+    lines_.reserve(lines_.size() + lines.size());
+    for (auto line : lines)
+    {
+        auto removeComment = [](std::string& val) -> bool {
+            bool removedTrailing = false;
+            auto comment = val.find('#');
+            while (comment != std::string::npos)
+            {
+                if (comment == 0)
+                {
+                    // entire value is a comment. In most cases, this
+                    // would have already been handled by the file reader
+                    val = "";
+                    break;
+                }
+                if (val.at(comment - 1) == '\\')
+                {
+                    // we have an escaped comment char. Erase the escape char
+                    // and keep looking
+                    val.erase(comment - 1, 1);
+                }
+                else
+                {
+                    // this must be a real comment. Extract the value
+                    // as a substring and stop looking.
+                    val = trimWhitespace(val.substr(0, comment));
+                    removedTrailing = true;
+                    break;
+                }
+
+                comment = val.find('#', comment);
+            }
+            return removedTrailing;
+        };
+
+        if (removeComment(line) && !line.empty())
+            hadTrailingComments_ = true;
+
+        if (line.empty())
+            continue;
+
+        boost::smatch match;
+        if (boost::regex_match(line, match, kRe1))
+        {
+            set(match[1], match[2]);
+        }
+        else
+        {
+            values_.push_back(line);
+        }
+
+        lines_.push_back(std::move(line));
+    }
+}
+
+bool
+Section::exists(std::string const& name) const
+{
+    return lookup_.contains(name);
+}
+
+std::ostream&
+operator<<(std::ostream& os, Section const& section)
+{
+    for (auto const& [k, v] : section.lookup_)
+        os << k << "=" << v << "\n";
+    return os;
+}
+
+//------------------------------------------------------------------------------
+
+bool
+BasicConfig::exists(std::string const& name) const
+{
+    return map_.contains(name);
+}
+
+Section&
+BasicConfig::section(std::string const& name)
+{
+    return map_.emplace(name, name).first->second;
+}
+
+Section const&
+BasicConfig::section(std::string const& name) const
+{
+    static Section const kNone("");
+    auto const iter = map_.find(name);
+    if (iter == map_.end())
+        return kNone;
+    return iter->second;
+}
+
+void
+BasicConfig::overwrite(std::string const& section, std::string const& key, std::string const& value)
+{
+    auto const result =
+        map_.emplace(std::piecewise_construct, std::make_tuple(section), std::make_tuple(section));
+    result.first->second.set(key, value);
+}
+
+void
+BasicConfig::deprecatedClearSection(std::string const& section)
+{
+    auto i = map_.find(section);
+    if (i != map_.end())
+        i->second = Section(section);
+}
+
+void
+BasicConfig::legacy(std::string const& section, std::string value)
+{
+    map_.emplace(section, section).first->second.legacy(std::move(value));
+}
+
+std::string
+BasicConfig::legacy(std::string const& sectionName) const
+{
+    return section(sectionName).legacy();
+}
+
+void
+BasicConfig::build(IniFileSections const& ifs)
+{
+    for (auto const& entry : ifs)
+    {
+        auto const result = map_.emplace(
+            std::piecewise_construct, std::make_tuple(entry.first), std::make_tuple(entry.first));
+        result.first->second.append(entry.second);
+    }
+}
+
+std::ostream&
+operator<<(std::ostream& ss, BasicConfig const& c)
+{
+    for (auto const& [k, v] : c.map_)
+        ss << "[" << k << "]\n" << v;
+    return ss;
+}
+
+}  // namespace xrpl