From 58841ef12f6cba1bb622353c1fcaa0e3c6fb46c9 Mon Sep 17 00:00:00 2001
From: Ilya Zhuravlev <zhuravlevilya@ya.ru>
Date: Tue, 23 Oct 2012 01:18:44 +0400
Subject: Add dummy and LevelDB database backends

---
 src/database-sqlite3.cpp | 319 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 319 insertions(+)
 create mode 100644 src/database-sqlite3.cpp

(limited to 'src/database-sqlite3.cpp')

diff --git a/src/database-sqlite3.cpp b/src/database-sqlite3.cpp
new file mode 100644
index 000000000..e15aa0c1c
--- /dev/null
+++ b/src/database-sqlite3.cpp
@@ -0,0 +1,319 @@
+/*
+	SQLite format specification:
+	- Initially only replaces sectors/ and sectors2/
+	
+	If map.sqlite does not exist in the save dir
+	or the block was not found in the database
+	the map will try to load from sectors folder.
+	In either case, map.sqlite will be created
+	and all future saves will save there.
+	
+	Structure of map.sqlite:
+	Tables:
+		blocks
+			(PK) INT pos
+			BLOB data
+*/
+
+#include "map.h"
+#include "mapsector.h"
+#include "mapblock.h"
+#include "main.h"
+#include "filesys.h"
+#include "voxel.h"
+#include "porting.h"
+#include "mapgen.h"
+#include "nodemetadata.h"
+#include "settings.h"
+#include "log.h"
+#include "profiler.h"
+#include "nodedef.h"
+#include "gamedef.h"
+#include "util/directiontables.h"
+#include "rollback_interface.h"
+
+#include "database-sqlite3.h"
+
+Database_SQLite3::Database_SQLite3(ServerMap *map, std::string savedir)
+{
+	m_database = NULL;
+	m_database_read = NULL;
+	m_database_write = NULL;
+	m_database_list = NULL;
+	m_savedir = savedir;
+	srvmap = map;
+}
+
+int Database_SQLite3::Initialized(void)
+{
+	return m_database ? 1 : 0;
+}
+
+void Database_SQLite3::beginSave() {
+	verifyDatabase();
+	if(sqlite3_exec(m_database, "BEGIN;", NULL, NULL, NULL) != SQLITE_OK)
+		infostream<<"WARNING: beginSave() failed, saving might be slow.";
+}
+
+void Database_SQLite3::endSave() {
+	verifyDatabase();
+	if(sqlite3_exec(m_database, "COMMIT;", NULL, NULL, NULL) != SQLITE_OK)
+		infostream<<"WARNING: endSave() failed, map might not have saved.";
+}
+
+void Database_SQLite3::createDirs(std::string path)
+{
+	if(fs::CreateAllDirs(path) == false)
+	{
+		infostream<<DTIME<<"Database_SQLite3: Failed to create directory "
+				<<"\""<<path<<"\""<<std::endl;
+		throw BaseException("Database_SQLite3 failed to create directory");
+	}
+}
+
+void Database_SQLite3::verifyDatabase() {
+	if(m_database)
+		return;
+	
+	{
+		std::string dbp = m_savedir + DIR_DELIM + "map.sqlite";
+		bool needs_create = false;
+		int d;
+		
+		/*
+			Open the database connection
+		*/
+	
+		createDirs(m_savedir); // ?
+	
+		if(!fs::PathExists(dbp))
+			needs_create = true;
+	
+		d = sqlite3_open_v2(dbp.c_str(), &m_database, SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, NULL);
+		if(d != SQLITE_OK) {
+			infostream<<"WARNING: SQLite3 database failed to open: "<<sqlite3_errmsg(m_database)<<std::endl;
+			throw FileNotGoodException("Cannot open database file");
+		}
+		
+		if(needs_create)
+			createDatabase();
+	
+		d = sqlite3_prepare(m_database, "SELECT `data` FROM `blocks` WHERE `pos`=? LIMIT 1", -1, &m_database_read, NULL);
+		if(d != SQLITE_OK) {
+			infostream<<"WARNING: SQLite3 database read statment failed to prepare: "<<sqlite3_errmsg(m_database)<<std::endl;
+			throw FileNotGoodException("Cannot prepare read statement");
+		}
+		
+		d = sqlite3_prepare(m_database, "REPLACE INTO `blocks` VALUES(?, ?)", -1, &m_database_write, NULL);
+		if(d != SQLITE_OK) {
+			infostream<<"WARNING: SQLite3 database write statment failed to prepare: "<<sqlite3_errmsg(m_database)<<std::endl;
+			throw FileNotGoodException("Cannot prepare write statement");
+		}
+		
+		d = sqlite3_prepare(m_database, "SELECT `pos` FROM `blocks`", -1, &m_database_list, NULL);
+		if(d != SQLITE_OK) {
+			infostream<<"WARNING: SQLite3 database list statment failed to prepare: "<<sqlite3_errmsg(m_database)<<std::endl;
+			throw FileNotGoodException("Cannot prepare read statement");
+		}
+		
+		infostream<<"ServerMap: SQLite3 database opened"<<std::endl;
+	}
+}
+
+void Database_SQLite3::saveBlock(MapBlock *block)
+{
+	DSTACK(__FUNCTION_NAME);
+	/*
+		Dummy blocks are not written
+	*/
+	if(block->isDummy())
+	{
+		/*v3s16 p = block->getPos();
+		infostream<<"Database_SQLite3::saveBlock(): WARNING: Not writing dummy block "
+				<<"("<<p.X<<","<<p.Y<<","<<p.Z<<")"<<std::endl;*/
+		return;
+	}
+
+	// Format used for writing
+	u8 version = SER_FMT_VER_HIGHEST;
+	// Get destination
+	v3s16 p3d = block->getPos();
+	
+	
+#if 0
+	v2s16 p2d(p3d.X, p3d.Z);
+	std::string sectordir = getSectorDir(p2d);
+
+	createDirs(sectordir);
+
+	std::string fullpath = sectordir+DIR_DELIM+getBlockFilename(p3d);
+	std::ofstream o(fullpath.c_str(), std::ios_base::binary);
+	if(o.good() == false)
+		throw FileNotGoodException("Cannot open block data");
+#endif
+	/*
+		[0] u8 serialization version
+		[1] data
+	*/
+	
+	verifyDatabase();
+	
+	std::ostringstream o(std::ios_base::binary);
+	
+	o.write((char*)&version, 1);
+	
+	// Write basic data
+	block->serialize(o, version, true);
+	
+	// Write block to database
+	
+	std::string tmp = o.str();
+	const char *bytes = tmp.c_str();
+	
+	if(sqlite3_bind_int64(m_database_write, 1, getBlockAsInteger(p3d)) != SQLITE_OK)
+		infostream<<"WARNING: Block position failed to bind: "<<sqlite3_errmsg(m_database)<<std::endl;
+	if(sqlite3_bind_blob(m_database_write, 2, (void *)bytes, o.tellp(), NULL) != SQLITE_OK) // TODO this mught not be the right length
+		infostream<<"WARNING: Block data failed to bind: "<<sqlite3_errmsg(m_database)<<std::endl;
+	int written = sqlite3_step(m_database_write);
+	if(written != SQLITE_DONE)
+		infostream<<"WARNING: Block failed to save ("<<p3d.X<<", "<<p3d.Y<<", "<<p3d.Z<<") "
+		<<sqlite3_errmsg(m_database)<<std::endl;
+	// Make ready for later reuse
+	sqlite3_reset(m_database_write);
+	
+	// We just wrote it to the disk so clear modified flag
+	block->resetModified();
+}
+
+MapBlock* Database_SQLite3::loadBlock(v3s16 blockpos)
+{
+	v2s16 p2d(blockpos.X, blockpos.Z);
+        verifyDatabase();
+        
+        if(sqlite3_bind_int64(m_database_read, 1, getBlockAsInteger(blockpos)) != SQLITE_OK)
+                infostream<<"WARNING: Could not bind block position for load: "
+                        <<sqlite3_errmsg(m_database)<<std::endl;
+        if(sqlite3_step(m_database_read) == SQLITE_ROW) {
+                /*
+                        Make sure sector is loaded
+                */
+                MapSector *sector = srvmap->createSector(p2d);
+                
+                /*
+                        Load block
+                */
+                const char * data = (const char *)sqlite3_column_blob(m_database_read, 0);
+                size_t len = sqlite3_column_bytes(m_database_read, 0);
+                
+                std::string datastr(data, len);
+                
+//                srvmap->loadBlock(&datastr, blockpos, sector, false);
+
+		try {
+                	std::istringstream is(datastr, std::ios_base::binary);
+                     
+                   	u8 version = SER_FMT_VER_INVALID;
+                     	is.read((char*)&version, 1);
+
+                     	if(is.fail())
+                             	throw SerializationError("ServerMap::loadBlock(): Failed"
+                                	             " to read MapBlock version");
+
+                     	MapBlock *block = NULL;
+                     	bool created_new = false;
+                     	block = sector->getBlockNoCreateNoEx(blockpos.Y);
+                     	if(block == NULL)
+                     	{
+                             	block = sector->createBlankBlockNoInsert(blockpos.Y);
+                             	created_new = true;
+                     	}
+                     
+                     	// Read basic data
+                     	block->deSerialize(is, version, true);
+                     
+                     	// If it's a new block, insert it to the map
+                     	if(created_new)
+                             	sector->insertBlock(block);
+                     
+                     	/*
+                             	Save blocks loaded in old format in new format
+                     	*/
+
+                     	//if(version < SER_FMT_VER_HIGHEST || save_after_load)
+                     	// Only save if asked to; no need to update version
+                     	//if(save_after_load)
+                        //     	saveBlock(block);
+                     
+                     	// We just loaded it from, so it's up-to-date.
+                     	block->resetModified();
+
+             	}
+             	catch(SerializationError &e)
+             	{
+                     	errorstream<<"Invalid block data in database"
+                                     <<" ("<<blockpos.X<<","<<blockpos.Y<<","<<blockpos.Z<<")"
+                                     <<" (SerializationError): "<<e.what()<<std::endl;
+                     
+                     // TODO: Block should be marked as invalid in memory so that it is
+                     // not touched but the game can run
+
+                     	if(g_settings->getBool("ignore_world_load_errors")){
+                             errorstream<<"Ignoring block load error. Duck and cover! "
+                                             <<"(ignore_world_load_errors)"<<std::endl;
+                     	} else {
+                             throw SerializationError("Invalid block data in database");
+                             //assert(0);
+                     	}
+             	}
+
+
+                sqlite3_step(m_database_read);
+                // We should never get more than 1 row, so ok to reset
+                sqlite3_reset(m_database_read);
+
+                return srvmap->getBlockNoCreateNoEx(blockpos);  // should not be using this here
+        }
+        sqlite3_reset(m_database_read);
+	return(NULL);
+}
+
+void Database_SQLite3::createDatabase()
+{
+	int e;
+	assert(m_database);
+	e = sqlite3_exec(m_database,
+		"CREATE TABLE IF NOT EXISTS `blocks` ("
+			"`pos` INT NOT NULL PRIMARY KEY,"
+			"`data` BLOB"
+		");"
+	, NULL, NULL, NULL);
+	if(e == SQLITE_ABORT)
+		throw FileNotGoodException("Could not create sqlite3 database structure");
+	else
+		infostream<<"ServerMap: SQLite3 database structure was created";
+	
+}
+
+void Database_SQLite3::listAllLoadableBlocks(core::list<v3s16> &dst)
+{
+	verifyDatabase();
+	
+	while(sqlite3_step(m_database_list) == SQLITE_ROW)
+	{
+		sqlite3_int64 block_i = sqlite3_column_int64(m_database_list, 0);
+		v3s16 p = getIntegerAsBlock(block_i);
+		//dstream<<"block_i="<<block_i<<" p="<<PP(p)<<std::endl;
+		dst.push_back(p);
+	}
+}
+
+Database_SQLite3::~Database_SQLite3()
+{
+	if(m_database_read)
+		sqlite3_finalize(m_database_read);
+	if(m_database_write)
+		sqlite3_finalize(m_database_write);
+	if(m_database)
+		sqlite3_close(m_database);
+}
+
-- 
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