/* * Copyright 2010, 2011, 2012 mapsforge.org * * This program 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. * * This program 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 * this program. If not, see <http://www.gnu.org/licenses/>. */ package org.mapsforge.map.reader.header; import java.io.IOException; import org.mapsforge.core.model.BoundingBox; import org.mapsforge.core.model.CoordinatesUtil; import org.mapsforge.core.model.Tag; import org.mapsforge.core.model.Tile; import org.mapsforge.map.reader.ReadBuffer; final class RequiredFields { /** * Magic byte at the beginning of a valid binary map file. */ private static final String BINARY_OSM_MAGIC_BYTE = "mapsforge binary OSM"; /** * Maximum size of the file header in bytes. */ private static final int HEADER_SIZE_MAX = 1000000; /** * Minimum size of the file header in bytes. */ private static final int HEADER_SIZE_MIN = 70; /** * The name of the Mercator projection as stored in the file header. */ private static final String MERCATOR = "Mercator"; /** * Version of the map file format which is supported by this implementation. */ private static final int SUPPORTED_FILE_VERSION = 3; static FileOpenResult readBoundingBox(ReadBuffer readBuffer, MapFileInfoBuilder mapFileInfoBuilder) { double minLatitude = CoordinatesUtil.microdegreesToDegrees(readBuffer.readInt()); double minLongitude = CoordinatesUtil.microdegreesToDegrees(readBuffer.readInt()); double maxLatitude = CoordinatesUtil.microdegreesToDegrees(readBuffer.readInt()); double maxLongitude = CoordinatesUtil.microdegreesToDegrees(readBuffer.readInt()); try { mapFileInfoBuilder.boundingBox = new BoundingBox(minLatitude, minLongitude, maxLatitude, maxLongitude); } catch (IllegalArgumentException e) { return new FileOpenResult(e.getMessage()); } return FileOpenResult.SUCCESS; } static FileOpenResult readFileSize(ReadBuffer readBuffer, long fileSize, MapFileInfoBuilder mapFileInfoBuilder) { // get and check the file size (8 bytes) long headerFileSize = readBuffer.readLong(); if (headerFileSize != fileSize) { return new FileOpenResult("invalid file size: " + headerFileSize); } mapFileInfoBuilder.fileSize = fileSize; return FileOpenResult.SUCCESS; } static FileOpenResult readFileVersion(ReadBuffer readBuffer, MapFileInfoBuilder mapFileInfoBuilder) { // get and check the file version (4 bytes) int fileVersion = readBuffer.readInt(); if (fileVersion != SUPPORTED_FILE_VERSION) { return new FileOpenResult("unsupported file version: " + fileVersion); } mapFileInfoBuilder.fileVersion = fileVersion; return FileOpenResult.SUCCESS; } static FileOpenResult readMagicByte(ReadBuffer readBuffer) throws IOException { // read the the magic byte and the file header size into the buffer int magicByteLength = BINARY_OSM_MAGIC_BYTE.length(); if (!readBuffer.readFromFile(magicByteLength + 4)) { return new FileOpenResult("reading magic byte has failed"); } // get and check the magic byte String magicByte = readBuffer.readUTF8EncodedString(magicByteLength); if (!BINARY_OSM_MAGIC_BYTE.equals(magicByte)) { return new FileOpenResult("invalid magic byte: " + magicByte); } return FileOpenResult.SUCCESS; } static FileOpenResult readMapDate(ReadBuffer readBuffer, MapFileInfoBuilder mapFileInfoBuilder) { // get and check the the map date (8 bytes) long mapDate = readBuffer.readLong(); // is the map date before 2010-01-10 ? if (mapDate < 1200000000000L) { return new FileOpenResult("invalid map date: " + mapDate); } mapFileInfoBuilder.mapDate = mapDate; return FileOpenResult.SUCCESS; } static FileOpenResult readPoiTags(ReadBuffer readBuffer, MapFileInfoBuilder mapFileInfoBuilder) { // get and check the number of POI tags (2 bytes) int numberOfPoiTags = readBuffer.readShort(); if (numberOfPoiTags < 0) { return new FileOpenResult("invalid number of POI tags: " + numberOfPoiTags); } Tag[] poiTags = new Tag[numberOfPoiTags]; for (int currentTagId = 0; currentTagId < numberOfPoiTags; ++currentTagId) { // get and check the POI tag String tag = readBuffer.readUTF8EncodedString(); if (tag == null) { return new FileOpenResult("POI tag must not be null: " + currentTagId); } poiTags[currentTagId] = new Tag(tag); } mapFileInfoBuilder.poiTags = poiTags; return FileOpenResult.SUCCESS; } static FileOpenResult readProjectionName(ReadBuffer readBuffer, MapFileInfoBuilder mapFileInfoBuilder) { // get and check the projection name String projectionName = readBuffer.readUTF8EncodedString(); if (!MERCATOR.equals(projectionName)) { return new FileOpenResult("unsupported projection: " + projectionName); } mapFileInfoBuilder.projectionName = projectionName; return FileOpenResult.SUCCESS; } static FileOpenResult readRemainingHeader(ReadBuffer readBuffer) throws IOException { // get and check the size of the remaining file header (4 bytes) int remainingHeaderSize = readBuffer.readInt(); if (remainingHeaderSize < HEADER_SIZE_MIN || remainingHeaderSize > HEADER_SIZE_MAX) { return new FileOpenResult("invalid remaining header size: " + remainingHeaderSize); } // read the header data into the buffer if (!readBuffer.readFromFile(remainingHeaderSize)) { return new FileOpenResult("reading header data has failed: " + remainingHeaderSize); } return FileOpenResult.SUCCESS; } static FileOpenResult readTilePixelSize(ReadBuffer readBuffer, MapFileInfoBuilder mapFileInfoBuilder) { // get and check the tile pixel size (2 bytes) int tilePixelSize = readBuffer.readShort(); if (tilePixelSize != Tile.TILE_SIZE) { return new FileOpenResult("unsupported tile pixel size: " + tilePixelSize); } mapFileInfoBuilder.tilePixelSize = tilePixelSize; return FileOpenResult.SUCCESS; } static FileOpenResult readWayTags(ReadBuffer readBuffer, MapFileInfoBuilder mapFileInfoBuilder) { // get and check the number of way tags (2 bytes) int numberOfWayTags = readBuffer.readShort(); if (numberOfWayTags < 0) { return new FileOpenResult("invalid number of way tags: " + numberOfWayTags); } Tag[] wayTags = new Tag[numberOfWayTags]; for (int currentTagId = 0; currentTagId < numberOfWayTags; ++currentTagId) { // get and check the way tag String tag = readBuffer.readUTF8EncodedString(); if (tag == null) { return new FileOpenResult("way tag must not be null: " + currentTagId); } wayTags[currentTagId] = new Tag(tag); } mapFileInfoBuilder.wayTags = wayTags; return FileOpenResult.SUCCESS; } private RequiredFields() { throw new IllegalStateException(); } }