Add ProtocolBlockTypePalette (cuberite#4391)

.gitmodules

@@ -63,3 +63,6 @@
 	path = lib/fmt
 	url = https://github.com/fmtlib/fmt.git
 	ignore = dirty
+[submodule "Tools/BlockTypePaletteGenerator/lib/lunajson"]
+	path = Tools/BlockTypePaletteGenerator/lib/lunajson
+	url = https://github.com/grafi-tt/lunajson.git

Tools/BlockTypePaletteGenerator/Generator.lua

@@ -0,0 +1,91 @@
+-- lib/lunajson/src/ is not in default Lua package paths
+package.path = 'lib/lunajson/src/?.lua;' .. package.path;
+
+
+--- Prints usage instructions to stdout.
+-- If the optional `message` is passed, output is prepended by message _and_
+-- redirected to stderr.
+function usage(message)
+	if message then
+		io.output(io.stderr);
+		io.write(message, "\n\n");
+	end
+	io.write(
+		"Usage: lua Generator.lua INPUTFILE OUTPUTFILE\n"..
+		"Converts the Minecraft blocks.json report format to the cuberite "..
+		"block type palette format.\n"..
+		"\n"..
+		"INPUTFILE and OUTPUTFILE must point to a valid path. INPUTFILE must "..
+		"be readable and OUTPUTFILE must be writable. Either can be replaced "..
+		"with `-` (dash character) to point to standard-input or -output.\n");
+	os.exit(message and 1 or 0);
+end
+
+
+-- Test whether the script is run in a path where it can load it's libraries
+if not pcall(function() require("lunajson.decoder") end) then
+	usage("Could not load required libraries, please run `Generator.lua` "..
+		"within its directory and make sure to run `git submodule update`.");
+end
+
+
+-- Check/Prepare CLI arguments
+local inpath, outpath = ...;
+io.input(io.stdin);
+io.output(io.stdout);
+
+if select("#", ...) ~= 2 then
+	usage("Incorrect number of arguments.");
+end
+
+if inpath ~= "-" then
+	local handle, err = io.open(inpath, "r");
+	io.input(handle or usage(err));
+end
+
+if outpath ~= "-" then
+	local handle, err = io.open(outpath, "w");
+	io.output(handle or usage(err));
+end
+
+
+-- Main program starts here
+local decode = (require("lunajson.decoder"))();
+local encode = (require("lunajson.encoder"))();
+
+local input = decode(io.input():read("*a"));
+local registry = {};
+local max_id = -1;
+
+
+for blockname, blockdata in pairs(input) do
+	for i = 1, #(blockdata.states or {}) do
+		local state = blockdata.states[i];
+		assert(registry[state.id + 1] == nil, "Ensure no duplicate IDs");
+
+		-- needed in the end to verify we got no holes in the array:
+		max_id = math.max(max_id, state.id);
+
+		registry[state.id + 1] = {
+			id = assert(state.id, "id is required."),
+			name = assert(blockname, "Block type name is required."),
+			-- default = state.default or nil,  -- may need this later
+			props = state.properties,
+		};
+	end
+end
+
+
+-- The following assertion is not necessary by the current spec, but is required
+-- by how lunajson distinguishes objects from arrays. Also if this fails, it is
+-- _very_ likely that the input file is faulty.
+assert(#registry == max_id + 1, "Ensure that registry has contiguous keys");
+
+local out = {
+	Metadata = {
+		ProtocolBlockTypePaletteVersion = 1
+	},
+	Palette = registry
+};
+
+io.write(encode(out), "\n");

Tools/BlockTypePaletteGenerator/Readme.md

@@ -0,0 +1,63 @@
+This generator crafts an intermediate index format to be read by cuberite
+
+# Running
+
+Run `lua ./Generator.lua`, pass `blocks.json` as first argument to the script
+and the desired output location as 2nd argument.
+
+Make sure to run the Generator from within its directory (`cd` into the path
+where `Generator.lua` is.)
+
+## Examples
+
+```bash
+SERVER=/path/to/server.jar
+java -cp "$SERVER" net.minecraft.data.Main --reports &&
+lua Generator.lua \
+	generated/reports/blocks.json \
+	../../Server/Protocol/1.13/ProtocolBlockTypePalette.json 
+```
+
+```bash
+SERVER=/path/to/server.jar
+java -cp "$SERVER" net.minecraft.data.Main --reports &&
+lua Generator.lua - -\
+	< generated/reports/blocks.json \
+	> ../Server/Protocol/1.13/ProtocolBlockTypePalette.json
+```
+
+## Output format
+
+The Format is a `JSON` document containing an object with at least two keys at
+the top level: `Metadata` and `Palette`.
+
+`Metadata` contains document metadata, namely a key `"ProtocolBlockType": 1`.
+
+`Palette` contains an array of objects. Each of these objects has at least the
+keys `id`, `name` and an optional `props` key that contains the individual
+properties of the current state. These properties are a KV dict of pure strings.
+
+The order of the array or object elements is not significant. `id` is unique.
+
+```json
+{
+  "Metadata": {
+    "ProtocolBlockType": 1
+  },
+  "Palette": [{
+      "id": 0,
+      "name": "minecraft:air"
+    }, {
+      "id": 1,
+      "name": "minecraft:stone"
+    }, {
+      "id": 221,
+      "name": "minecraft:dark_oak_leaves",
+      "props": {
+        "persistent": "false",
+        "distance": "4"
+      }
+    }
+  ]
+}
+```

src/BlockState.cpp

@@ -83,6 +83,52 @@ BlockState::BlockState(const BlockState & aCopyFrom, const std::map<AString, ASt
 
 
 
+bool BlockState::operator <(const BlockState & aOther) const
+{
+	// Fast-return this using checksum
+	if (mChecksum != aOther.mChecksum)
+	{
+		return (mChecksum < aOther.mChecksum);
+	}
+
+	// Can fast-return this due to how comparison works
+	if (mState.size() != aOther.mState.size())
+	{
+		return (mState.size() < aOther.mState.size());
+	}
+
+	auto itA = mState.begin();
+	auto itOther = aOther.mState.begin();
+
+	// don't need to check itOther, size checks above ensure size(A) == size(O)
+	while (itA != mState.end())
+	{
+		{
+			const auto cmp = itA->first.compare(itOther->first);
+			if (cmp != 0)
+			{
+				return (cmp < 0);
+			}
+		}
+		{
+			const auto cmp = itA->second.compare(itOther->second);
+			if (cmp != 0)
+			{
+				return (cmp < 0);
+			}
+		}
+
+		++itA;
+		++itOther;
+	}
+
+	return false;
+}
+
+
+
+
+
 bool BlockState::operator ==(const BlockState & aOther) const
 {
 	// Fast-fail if the checksums differ or differrent counts:

src/BlockState.h

@@ -52,6 +52,9 @@ class BlockState
 	(it's possible to erase a key from aCopyFrom by setting it to empty string in aAdditionalKeysAndValues). */
 	BlockState(const BlockState & aCopyFrom, const std::map<AString, AString> & aAdditionalKeysAndValues);
 
+	/** Less-than comparison. */
+	bool operator <(const BlockState & aOther) const;
+
 	/** Fast equality check. */
 	bool operator ==(const BlockState & aOther) const;
 

src/Protocol/CMakeLists.txt

@@ -1,3 +1,4 @@
+include_directories (SYSTEM "../../lib/jsoncpp/include")
 
 SET (SRCS
 	Authenticator.cpp
@@ -12,6 +13,7 @@ SET (SRCS
 	Protocol_1_12.cpp
 	Protocol_1_13.cpp
 	ProtocolRecognizer.cpp
+	ProtocolBlockTypePalette.cpp
 )
 
 SET (HDRS
@@ -28,6 +30,7 @@ SET (HDRS
 	Protocol_1_12.h
 	Protocol_1_13.h
 	ProtocolRecognizer.h
+	ProtocolBlockTypePalette.h
 )
 
 if (NOT MSVC)

src/Protocol/ProtocolBlockTypePalette.cpp

@@ -0,0 +1,144 @@
+#include "Globals.h"
+#include "ProtocolBlockTypePalette.h"
+#include <cstdint>
+#include <sstream>
+#include "json/value.h"
+#include "json/reader.h"
+
+
+
+
+
+ProtocolBlockTypePalette::ProtocolBlockTypePalette()
+{
+	// empty
+}
+
+
+
+
+
+bool ProtocolBlockTypePalette::loadFromString(const AString & aMapping)
+{
+	std::stringstream stream;
+	stream << aMapping;
+
+	return loadFromStream(stream);
+}
+
+
+
+
+
+bool ProtocolBlockTypePalette::loadFromStream(std::istream & aInputStream)
+{
+	Json::Value root;
+
+	try
+	{
+		aInputStream >> root;
+	}
+	#if defined _DEBUG
+	catch (const std::exception & e)
+	{
+		LOGD(e.what());
+		return false;
+	}
+	#else
+	catch (const std::exception &)
+	{
+		return false;
+	}
+	#endif
+
+	if (!root.isObject() ||
+		!root.isMember("Metadata") ||
+		!root["Metadata"].isMember("ProtocolBlockTypePaletteVersion") ||
+		!root.isMember("Palette") ||
+		!root["Palette"].isArray())
+	{
+		LOGD("Incorrect palette format.");
+		return false;
+	}
+
+	if (root["Metadata"]["ProtocolBlockTypePaletteVersion"].asUInt() != 1)
+	{
+		LOGD("Palette format version not supported.");
+		return false;
+	}
+
+	auto len = root["Palette"].size();
+	for (decltype(len) i = 0; i < len; ++i)
+	{
+		const auto & record = root["Palette"][i];
+		if (!record.isObject())
+		{
+			LOGD("Record #%u must be a JSON object.", i);
+			return false;
+		}
+
+		auto blocktype = record["name"].asString();
+		auto id = std::stoul(record["id"].asString());
+		std::map<AString, AString> state;
+
+		if (id >= NOT_FOUND)
+		{
+			LOGD("`id` must be less than ProtocolBlockTypePalette::NOT_FOUND, but is %lu", id);
+			return false;
+		}
+
+		if (record.isMember("props"))
+		{
+			const auto & props = record["props"];
+			if (!props.isObject())
+			{
+				LOGD("`props` key must be a JSON object.");
+				return false;
+			}
+			for (const auto & key: props.getMemberNames())
+			{
+				state[key] = props[key].asString();
+			}
+		}
+
+		// Block type map entry already exists?
+		if (mIndex.count(blocktype) == 0)
+		{
+			mIndex.insert({blocktype, std::map<BlockState, UInt32>()});
+		}
+
+		const auto & result = mIndex[blocktype].insert({BlockState(state), id});
+		if (result.second == false)
+		{
+			LOGINFO("Duplicate block state encountered (Current ID: %lu, other: %lu)", result.first->second, id);
+		}
+	}
+	return true;
+}
+
+
+
+
+
+UInt32 ProtocolBlockTypePalette::index(const AString & aBlockTypeName, const BlockState & aBlockState) const
+{
+	auto a = mIndex.find(aBlockTypeName);
+	if (a != mIndex.end())
+	{
+		auto b = a->second.find(aBlockState);
+		if (b != a->second.end())
+		{
+			return b->second;
+		}
+	}
+	return NOT_FOUND;
+}
+
+
+
+
+
+void ProtocolBlockTypePalette::clear()
+{
+	return mIndex.clear();
+}