George McIntyre
111 lines
3.6 KiB
C++
111 lines
3.6 KiB
C++
/*
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* Copyright - See the COPYRIGHT that is included with this distribution.
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* pvxs is distributed subject to a Software License Agreement found
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* in file LICENSE that is included with this distribution.
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*
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* Author George S. McIntyre <george@level-n.com>, 2023
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*
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*/
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#include <string>
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#include <sstream>
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#include <stdexcept>
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#include <cstdlib>
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#include "fieldname.h"
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namespace pvxs {
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namespace ioc {
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static void pad(std::string& stringToPad, size_t padLength);
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/**
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* Construct a Group field name from a field name string. The string is a sequence of components separated by
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* periods each of which may be optionally followed by an array specifier. e.g. a.b[1].c.
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*
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* This constructor breaks the string on periods and stores each component in the fieldNameComponents member,
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* while extracting the array reference where specified.
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* @param fieldName
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*/
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FieldName::FieldName(const std::string& fieldName) {
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if (!fieldName.empty()) {
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// Split field name on periods
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std::stringstream splitter(fieldName);
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std::string fieldNamePart;
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while (std::getline(splitter, fieldNamePart, '.')) {
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if (fieldNamePart.empty()) {
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throw std::runtime_error("Empty field component in: " + fieldName);
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}
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// If this is an array reference then extract the index
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auto endArraySpecifier = fieldNamePart.size();
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if (fieldNamePart[endArraySpecifier - 1] == ']') {
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const size_t startArraySpecifier = fieldNamePart.find_last_of('[');
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if (startArraySpecifier == std::string::npos) {
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throw std::runtime_error("Invalid field array sub-script in : " + fieldName);
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}
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auto arrayIndex = fieldNamePart.substr(startArraySpecifier + 1);
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long index = 0;
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char* endScan;
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index = strtol(arrayIndex.c_str(), &endScan, 10);
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if (*endScan != ']') {
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throw std::runtime_error("Invalid field array sub-script in : " + fieldName);
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}
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fieldNameComponents.emplace_back(fieldNamePart.substr(0, startArraySpecifier), index);
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} else {
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// Otherwise this is a regular field part
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fieldNameComponents.emplace_back(fieldNamePart);
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}
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}
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// If empty then throw an error
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if (fieldNameComponents.empty()) {
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throw std::runtime_error("Empty field name");
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}
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}
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}
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/**
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* Convert this group field name to a string.
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*
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* @param padLength the amount of padding to add, defaults to none
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*/
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std::string FieldName::to_string(size_t padLength) const {
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std::string fieldName;
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if (fieldNameComponents.empty()) {
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fieldName = "/";
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} else {
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bool first = true;
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for (const auto& fieldNameComponent: fieldNameComponents) {
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if (!first) {
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fieldName += ".";
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} else {
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first = false;
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}
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fieldName += fieldNameComponent.name;
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if (fieldNameComponent.isArray()) {
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fieldName += "[" + std::to_string((unsigned)fieldNameComponent.index) + "]";
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}
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}
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}
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pad(fieldName, padLength);
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return fieldName;
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}
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/**
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* Utility function to pad given string with spaces
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*
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* @param stringToPad the string to be padded
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* @param padLength the amount of spaces to pad with
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*/
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static void pad(std::string& stringToPad, const size_t padLength) {
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if (padLength > stringToPad.size()) {
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stringToPad.insert(stringToPad.size(), padLength - stringToPad.size(), PADDING_CHARACTER);
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}
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}
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} // pvxs
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} // ioc
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