GH-1047 parse world files and integrate MCEdit with world page

depends/libnbtplusplus/src/io/stream_reader.cpp

@@ -0,0 +1,110 @@
+/*
+ * libnbt++ - A library for the Minecraft Named Binary Tag format.
+ * Copyright (C) 2013, 2015  ljfa-ag
+ *
+ * This file is part of libnbt++.
+ *
+ * libnbt++ is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libnbt++ is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libnbt++.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "io/stream_reader.h"
+#include "make_unique.h"
+#include "tag_compound.h"
+#include <istream>
+
+namespace nbt
+{
+namespace io
+{
+
+std::pair<std::string, std::unique_ptr<tag_compound>> read_compound(std::istream& is, endian::endian e)
+{
+    return stream_reader(is, e).read_compound();
+}
+
+std::pair<std::string, std::unique_ptr<tag>> read_tag(std::istream& is, endian::endian e)
+{
+    return stream_reader(is, e).read_tag();
+}
+
+stream_reader::stream_reader(std::istream& is, endian::endian e) noexcept:
+    is(is), endian(e)
+{}
+
+std::istream& stream_reader::get_istr() const
+{
+    return is;
+}
+
+endian::endian stream_reader::get_endian() const
+{
+    return endian;
+}
+
+std::pair<std::string, std::unique_ptr<tag_compound>> stream_reader::read_compound()
+{
+    if(read_type() != tag_type::Compound)
+    {
+        is.setstate(std::ios::failbit);
+        throw input_error("Tag is not a compound");
+    }
+    std::string key = read_string();
+    auto comp = make_unique<tag_compound>();
+    comp->read_payload(*this);
+    return {std::move(key), std::move(comp)};
+}
+
+std::pair<std::string, std::unique_ptr<tag>> stream_reader::read_tag()
+{
+    tag_type type = read_type();
+    std::string key = read_string();
+    std::unique_ptr<tag> t = read_payload(type);
+    return {std::move(key), std::move(t)};
+}
+
+std::unique_ptr<tag> stream_reader::read_payload(tag_type type)
+{
+    std::unique_ptr<tag> t = tag::create(type);
+    t->read_payload(*this);
+    return t;
+}
+
+tag_type stream_reader::read_type(bool allow_end)
+{
+    int type = is.get();
+    if(!is)
+        throw input_error("Error reading tag type");
+    if(!is_valid_type(type, allow_end))
+    {
+        is.setstate(std::ios::failbit);
+        throw input_error("Invalid tag type: " + std::to_string(type));
+    }
+    return static_cast<tag_type>(type);
+}
+
+std::string stream_reader::read_string()
+{
+    uint16_t len;
+    read_num(len);
+    if(!is)
+        throw input_error("Error reading string");
+
+    std::string ret(len, '\0');
+    is.read(&ret[0], len); //C++11 allows us to do this
+    if(!is)
+        throw input_error("Error reading string");
+    return ret;
+}
+
+}
+}