Initial commit of prepstmt, selects, record sets

This is full of holes, but all the basics are covered.

1 files changed, 54 insertions, 0 deletions

diff --git a/lib/output/pq/pqStmt.cpp b/lib/output/pq/pqStmt.cpp
new file mode 100644
index 0000000..04b48c6
--- /dev/null
+++ b/lib/output/pq/pqStmt.cpp
@@ -0,0 +1,54 @@
+#include "pqStmt.h"
+#include "libpq-fe.h"
+#include "pqBindings.h"
+#include "pqConn.h"
+#include "pqRecordSet.h"
+#include <compileTimeFormatter.h>
+#include <cstdlib>
+#include <functional>
+#include <helpers.h>
+#include <map>
+#include <stdexcept>
+#include <utility>
+#include <vector>
+
+namespace MyGrate::Output::Pq {
+	PqPrepStmt::PqPrepStmt(const char * const q, std::size_t n, PqConn * c) :
+		conn {c->conn.get()}, name {prepareAsNeeded(q, n, c)}, res {nullptr, nullptr}
+	{
+	}
+
+	void
+	PqPrepStmt::execute(const std::initializer_list<DbValue> & vs)
+	{
+		Bindings b {vs};
+		res = {PQexecPrepared(conn, name.c_str(), (int)vs.size(), b.values.data(), b.lengths.data(), nullptr, 0),
+				&PQclear};
+		verify<std::runtime_error>(
+				PQresultStatus(res.get()) == PGRES_COMMAND_OK || PQresultStatus(res.get()) == PGRES_TUPLES_OK, name);
+	}
+
+	std::size_t
+	PqPrepStmt::rows() const
+	{
+		return std::strtoul(PQcmdTuples(res.get()), nullptr, 10);
+	}
+
+	RecordSetPtr
+	PqPrepStmt::recordSet()
+	{
+		return std::make_unique<PqRecordSet>(std::move(res));
+	}
+
+	std::string
+	PqPrepStmt::prepareAsNeeded(const char * const q, std::size_t n, PqConn * c)
+	{
+		if (const auto i = c->stmts.find(q); i != c->stmts.end()) {
+			return i->second;
+		}
+		auto nam {AdHoc::scprintf<"pst%0x">(c->stmts.size())};
+		ResPtr res {PQprepare(c->conn.get(), nam.c_str(), q, (int)n, nullptr), PQclear};
+		verify<std::runtime_error>(PQresultStatus(res.get()) == PGRES_COMMAND_OK, q);
+		return c->stmts.emplace(q, std::move(nam)).first->second;
+	}
+}