Lot of code for generating code. Working on unit tests.

2018-09-09 18:52:32 +02:00 · 2018-09-09 18:52:32 +02:00 · 8f4845d4d2
commit 8f4845d4d2
parent da45929b12
42 changed files with 1089 additions and 267 deletions
--- a/pglablib/codebuilder/CodeBuilder.cpp
+++ b/pglablib/codebuilder/CodeBuilder.cpp
@ -0,0 +1,119 @@
+#include "CodeBuilder.h"
+#include "Pgsql_Result.h"
+#include "IndentationConfig.h"
+#include "LanguageConfig.h"
+#include "StructureTemplate.h"
+#include "util.h"
+#include <QTextStream>
+
+void FormatToStream(QTextStream &stream, QString format, std::function<void(QTextStream &, QString)> field_callback)
+{
+	// Use static to optimize only once
+	static QRegularExpression cached_find_var_re("(?:[^\\\\]|^)(\\/%([a-zA-Z0-9_-]+)%\\/)", QRegularExpression::OptimizeOnFirstUsageOption);
+
+	int from = 0;
+	QRegularExpressionMatch match;
+	while (format.indexOf(cached_find_var_re, from, &match) >= 0) {
+		if (from > 0) {
+			// Because the regex has to check for backslash in front we have the from position
+			// one position before where we actually should continue for the second match and later ie when from > 0
+			// Therefor increase from by 1 to make the substring (midRef) calculation work
+			++from;
+		}
+		// copy code before the var to the stream
+		stream << format.midRef(from, match.capturedStart(1) - from);
+		field_callback(stream, match.captured(2));
+		from = match.capturedEnd()-1; // -1 because it wants to match one character before or start of line to make sure there is no backslash
+	}
+	if (from > 0) {
+		// same reason as at the start of the loop
+		++from;
+	}
+	stream << format.midRef(from);
+}
+
+void CodeBuilder::GenCodeForExecutingQuery(QTextStream &q, const QString &query, const Pgsql::Result &result)
+{
+// %1 query string
+// %2 struct_name
+// %3 list of field assignments
+	QString exec_query_template = "Pgsql::Result result = conn.query(%1);";
+
+	QString loop_start_template =
+		"Pgsql::Result result = conn.query(/%query_literal%/);"
+		"for (auto row: result) {\n"
+		"	 Pgsql::Col col(row);\n"
+		"    /%struct_type%/ v;\n"
+		"/%assign_fields%/"
+		"}";
+
+	// %field_name%
+	// %column_name%
+	// %column_index%
+	QString assign_result_field_template = "col >> v./%field_name%/";
+	QString query_string_literal = ConvertToMultiLineCString(query);
+
+	// [optional] Gen declaration of result structure
+	GenReturnStructDefinition(q, result);
+
+	// assume we have connection? What name???
+
+	// gen code for creating and executing statement
+	// - bind parameters
+
+	// Gen code for iterating through result and filling the result struct/or local variables
+
+
+}
+
+void CodeBuilder::GenReturnStructDefinition(QTextStream &q, const Pgsql::Result &result) const
+{
+	std::shared_ptr<const StructureTemplate> templ = m_configuration->structureTemplate();
+
+	QString struct_name = "TODO";
+	QString field_format = templ->m_fieldTemplate;
+	int field_indent_levels = templ->m_fieldIndentation;
+	QString field_indent_string = m_configuration->indentationConfig()->getIndentString(field_indent_levels);
+	// Make struct start
+	q << QString(templ->m_startTemplate).arg(struct_name);
+	// Process fields
+	for (int column = 0; column < result.cols(); ++column) {
+		QString res_col_name = result.getColName(column);
+		Oid type_oid = result.type(column);
+
+		q << field_indent_string;
+		genFieldDeclaration(q, field_format, res_col_name, type_oid);
+		q << "\n";
+		// Unfortunatly there is no easy reliable way to determine if a column can contain null values
+		// For simple result columns we can have a look at the original column and if that has a NOT NULL constraint
+		// then we can assume NOT NULL for the result if there are no LEFT/RIGHT JOINS or other constructs that can introduce NULL
+		// values
+
+		// Any way at generation time we might want to be able to specify the null handle
+		// - exception/error return
+		// - magic value
+		// - boost::optional
+		// - boolean flags
+		// - null pointer (useful for languages where this has no cost, other cases boolean flags will be more performant)
+	}
+	// Finish struct
+	q << QString(templ->m_endTemplate).arg(struct_name);
+}
+
+QString CodeBuilder::columnNameToVariableName(QString column_name) const
+{
+	return m_configuration->columnNameToFieldName(column_name);
+}
+
+QString CodeBuilder::getTypeName(Oid dbtype) const
+{
+	return m_configuration->getTypeName(dbtype);
+}
+
+void CodeBuilder::genFieldDeclaration(QTextStream &q, const QString &format, const QString &column_name, Oid column_type) const
+{
+	QString field_name = columnNameToVariableName(column_name);
+	QString type_name = getTypeName(column_type);
+	q << QString(format).arg(field_name).arg(type_name);
+}
+