Move source files into folder

src/db-postgresql.cpp

@@ -0,0 +1,226 @@
+#include <stdexcept>
+#include <iostream>
+#include <fstream>
+#include <cstdlib>
+#include <arpa/inet.h>
+#include "db-postgresql.h"
+#include "util.h"
+#include "types.h"
+
+#define ARRLEN(x) (sizeof(x) / sizeof((x)[0]))
+
+DBPostgreSQL::DBPostgreSQL(const std::string &mapdir)
+{
+	std::ifstream ifs(mapdir + "world.mt");
+	if (!ifs.good())
+		throw std::runtime_error("Failed to read world.mt");
+	std::string connect_string = read_setting("pgsql_connection", ifs);
+	ifs.close();
+	db = PQconnectdb(connect_string.c_str());
+
+	if (PQstatus(db) != CONNECTION_OK) {
+		throw std::runtime_error(std::string(
+			"PostgreSQL database error: ") +
+			PQerrorMessage(db)
+		);
+	}
+
+	prepareStatement(
+		"get_block_pos",
+		"SELECT posX::int4, posY::int4, posZ::int4 FROM blocks WHERE"
+		" (posX BETWEEN $1::int4 AND $2::int4) AND"
+		" (posY BETWEEN $3::int4 AND $4::int4) AND"
+		" (posZ BETWEEN $5::int4 AND $6::int4)"
+	);
+	prepareStatement(
+		"get_blocks",
+		"SELECT posY::int4, data FROM blocks WHERE"
+		" posX = $1::int4 AND posZ = $2::int4"
+		" AND (posY BETWEEN $3::int4 AND $4::int4)"
+	);
+	prepareStatement(
+		"get_block_exact",
+		"SELECT data FROM blocks WHERE"
+		" posX = $1::int4 AND posY = $2::int4 AND posZ = $3::int4"
+	);
+
+	checkResults(PQexec(db, "START TRANSACTION;"));
+	checkResults(PQexec(db, "SET TRANSACTION ISOLATION LEVEL REPEATABLE READ;"));
+}
+
+
+DBPostgreSQL::~DBPostgreSQL()
+{
+	try {
+		checkResults(PQexec(db, "COMMIT;"));
+	} catch (const std::exception& caught) {
+		std::cerr << "could not finalize: " << caught.what() << std::endl;
+	}
+	PQfinish(db);
+}
+
+
+std::vector<BlockPos> DBPostgreSQL::getBlockPos(BlockPos min, BlockPos max)
+{
+	int32_t const x1 = htonl(min.x);
+	int32_t const x2 = htonl(max.x - 1);
+	int32_t const y1 = htonl(min.y);
+	int32_t const y2 = htonl(max.y - 1);
+	int32_t const z1 = htonl(min.z);
+	int32_t const z2 = htonl(max.z - 1);
+
+	const void *args[] = { &x1, &x2, &y1, &y2, &z1, &z2 };
+	const int argLen[] = { 4, 4, 4, 4, 4, 4 };
+	const int argFmt[] = { 1, 1, 1, 1, 1, 1 };
+
+	PGresult *results = execPrepared(
+		"get_block_pos", ARRLEN(args), args,
+		argLen, argFmt, false
+	);
+
+	int numrows = PQntuples(results);
+
+	std::vector<BlockPos> positions;
+	positions.reserve(numrows);
+
+	for (int row = 0; row < numrows; ++row)
+		positions.emplace_back(pg_to_blockpos(results, row, 0));
+
+	PQclear(results);
+
+	return positions;
+}
+
+
+void DBPostgreSQL::getBlocksOnXZ(BlockList &blocks, int16_t xPos, int16_t zPos,
+		int16_t min_y, int16_t max_y)
+{
+	int32_t const x = htonl(xPos);
+	int32_t const z = htonl(zPos);
+	int32_t const y1 = htonl(min_y);
+	int32_t const y2 = htonl(max_y - 1);
+
+	const void *args[] = { &x, &z, &y1, &y2 };
+	const int argLen[] = { 4, 4, 4, 4 };
+	const int argFmt[] = { 1, 1, 1, 1 };
+
+	PGresult *results = execPrepared(
+		"get_blocks", ARRLEN(args), args,
+		argLen, argFmt, false
+	);
+
+	int numrows = PQntuples(results);
+
+	for (int row = 0; row < numrows; ++row) {
+		BlockPos position;
+		position.x = xPos;
+		position.y = pg_binary_to_int(results, row, 0);
+		position.z = zPos;
+		blocks.emplace_back(
+			position,
+			ustring(
+				reinterpret_cast<unsigned char*>(
+					PQgetvalue(results, row, 1)
+				),
+				PQgetlength(results, row, 1)
+			)
+		);
+	}
+
+	PQclear(results);
+}
+
+
+void DBPostgreSQL::getBlocksByPos(BlockList &blocks,
+			const std::vector<BlockPos> &positions)
+{
+	int32_t x, y, z;
+
+	const void *args[] = { &x, &y, &z };
+	const int argLen[] = { 4, 4, 4 };
+	const int argFmt[] = { 1, 1, 1 };
+
+	for (auto pos : positions) {
+		x = htonl(pos.x);
+		y = htonl(pos.y);
+		z = htonl(pos.z);
+
+		PGresult *results = execPrepared(
+			"get_block_exact", ARRLEN(args), args,
+			argLen, argFmt, false
+		);
+
+		if (PQntuples(results) > 0) {
+			blocks.emplace_back(
+				pos,
+				ustring(
+					reinterpret_cast<unsigned char*>(
+						PQgetvalue(results, 0, 0)
+					),
+					PQgetlength(results, 0, 0)
+				)
+			);
+		}
+
+		PQclear(results);
+	}
+}
+
+
+PGresult *DBPostgreSQL::checkResults(PGresult *res, bool clear)
+{
+	ExecStatusType statusType = PQresultStatus(res);
+
+	switch (statusType) {
+	case PGRES_COMMAND_OK:
+	case PGRES_TUPLES_OK:
+		break;
+	case PGRES_FATAL_ERROR:
+		throw std::runtime_error(
+			std::string("PostgreSQL database error: ") +
+			PQresultErrorMessage(res)
+		);
+	default:
+		throw std::runtime_error(
+			"Unhandled PostgreSQL result code"
+		);
+	}
+
+	if (clear)
+		PQclear(res);
+
+	return res;
+}
+
+void DBPostgreSQL::prepareStatement(const std::string &name, const std::string &sql)
+{
+	checkResults(PQprepare(db, name.c_str(), sql.c_str(), 0, NULL));
+}
+
+PGresult *DBPostgreSQL::execPrepared(
+	const char *stmtName, const int paramsNumber,
+	const void **params,
+	const int *paramsLengths, const int *paramsFormats,
+	bool clear
+)
+{
+	return checkResults(PQexecPrepared(db, stmtName, paramsNumber,
+		(const char* const*) params, paramsLengths, paramsFormats,
+		1 /* binary output */), clear
+	);
+}
+
+int DBPostgreSQL::pg_binary_to_int(PGresult *res, int row, int col)
+{
+	int32_t* raw = reinterpret_cast<int32_t*>(PQgetvalue(res, row, col));
+	return ntohl(*raw);
+}
+
+BlockPos DBPostgreSQL::pg_to_blockpos(PGresult *res, int row, int col)
+{
+	BlockPos result;
+	result.x = pg_binary_to_int(res, row, col);
+	result.y = pg_binary_to_int(res, row, col + 1);
+	result.z = pg_binary_to_int(res, row, col + 2);
+	return result;
+}