Java tutorial
/* * Copyright (C) 2012-2015 DataStax Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.datastax.driver.core; import com.datastax.driver.core.exceptions.DriverInternalError; import com.google.common.collect.ImmutableMap; import io.netty.buffer.ByteBuf; import io.netty.util.CharsetUtil; import java.net.InetAddress; import java.net.InetSocketAddress; import java.net.UnknownHostException; import java.nio.ByteBuffer; import java.nio.charset.CharacterCodingException; import java.util.*; /** * ByteBuf utility methods. */ abstract class CBUtil { // TODO rename private CBUtil() { } private static String readString(ByteBuf cb, int length) { try { String str = cb.toString(cb.readerIndex(), length, CharsetUtil.UTF_8); cb.readerIndex(cb.readerIndex() + length); return str; } catch (IllegalStateException e) { // That's the way netty encapsulate a CCE if (e.getCause() instanceof CharacterCodingException) throw new DriverInternalError("Cannot decode string as UTF8"); else throw e; } } public static String readString(ByteBuf cb) { try { int length = cb.readUnsignedShort(); return readString(cb, length); } catch (IndexOutOfBoundsException e) { throw new DriverInternalError( "Not enough bytes to read an UTF8 serialized string preceded by it's 2 bytes length"); } } public static void writeString(String str, ByteBuf cb) { byte[] bytes = str.getBytes(CharsetUtil.UTF_8); cb.writeShort(bytes.length); cb.writeBytes(bytes); } public static int sizeOfString(String str) { return 2 + encodedUTF8Length(str); } private static int encodedUTF8Length(String st) { int strlen = st.length(); int utflen = 0; for (int i = 0; i < strlen; i++) { int c = st.charAt(i); if ((c >= 0x0001) && (c <= 0x007F)) utflen++; else if (c > 0x07FF) utflen += 3; else utflen += 2; } return utflen; } public static String readLongString(ByteBuf cb) { try { int length = cb.readInt(); return readString(cb, length); } catch (IndexOutOfBoundsException e) { throw new DriverInternalError( "Not enough bytes to read an UTF8 serialized string preceded by it's 4 bytes length"); } } public static void writeLongString(String str, ByteBuf cb) { byte[] bytes = str.getBytes(CharsetUtil.UTF_8); cb.writeInt(bytes.length); cb.writeBytes(bytes); } public static int sizeOfLongString(String str) { return 4 + str.getBytes(CharsetUtil.UTF_8).length; } public static byte[] readBytes(ByteBuf cb) { try { int length = cb.readUnsignedShort(); byte[] bytes = new byte[length]; cb.readBytes(bytes); return bytes; } catch (IndexOutOfBoundsException e) { throw new DriverInternalError("Not enough bytes to read a byte array preceded by it's 2 bytes length"); } } public static void writeBytes(byte[] bytes, ByteBuf cb) { cb.writeShort(bytes.length); cb.writeBytes(bytes); } public static void writeBytes(ByteBuffer bytes, ByteBuf cb) { cb.writeShort(bytes.remaining()); cb.writeBytes(bytes.duplicate()); } public static int sizeOfBytes(byte[] bytes) { return 2 + bytes.length; } public static int sizeOfBytes(ByteBuffer bytes) { return 2 + bytes.remaining(); } public static Map<String, ByteBuffer> readBytesMap(ByteBuf cb) { int length = cb.readUnsignedShort(); ImmutableMap.Builder<String, ByteBuffer> builder = ImmutableMap.builder(); for (int i = 0; i < length; i++) { String key = readString(cb); ByteBuffer value = readValue(cb); if (value == null) value = Statement.NULL_PAYLOAD_VALUE; builder.put(key, value); } return builder.build(); } public static void writeBytesMap(Map<String, ByteBuffer> m, ByteBuf cb) { cb.writeShort(m.size()); for (Map.Entry<String, ByteBuffer> entry : m.entrySet()) { writeString(entry.getKey(), cb); ByteBuffer value = entry.getValue(); if (value == Statement.NULL_PAYLOAD_VALUE) value = null; writeValue(value, cb); } } public static int sizeOfBytesMap(Map<String, ByteBuffer> m) { int size = 2; for (Map.Entry<String, ByteBuffer> entry : m.entrySet()) { size += sizeOfString(entry.getKey()); size += sizeOfBytes(entry.getValue()); } return size; } public static ConsistencyLevel readConsistencyLevel(ByteBuf cb) { return ConsistencyLevel.fromCode(cb.readUnsignedShort()); } public static void writeConsistencyLevel(ConsistencyLevel consistency, ByteBuf cb) { cb.writeShort(consistency.code); } public static int sizeOfConsistencyLevel(ConsistencyLevel consistency) { return 2; } public static <T extends Enum<T>> T readEnumValue(Class<T> enumType, ByteBuf cb) { String value = CBUtil.readString(cb); try { return Enum.valueOf(enumType, value.toUpperCase()); } catch (IllegalArgumentException e) { throw new DriverInternalError( String.format("Invalid value '%s' for %s", value, enumType.getSimpleName())); } } public static <T extends Enum<T>> void writeEnumValue(T enumValue, ByteBuf cb) { writeString(enumValue.toString(), cb); } public static <T extends Enum<T>> int sizeOfEnumValue(T enumValue) { return sizeOfString(enumValue.toString()); } public static UUID readUUID(ByteBuf cb) { long msb = cb.readLong(); long lsb = cb.readLong(); return new UUID(msb, lsb); } public static void writeUUID(UUID uuid, ByteBuf cb) { cb.writeLong(uuid.getMostSignificantBits()); cb.writeLong(uuid.getLeastSignificantBits()); } public static int sizeOfUUID(UUID uuid) { return 16; } public static List<String> readStringList(ByteBuf cb) { int length = cb.readUnsignedShort(); List<String> l = new ArrayList<String>(length); for (int i = 0; i < length; i++) l.add(readString(cb)); return l; } public static void writeStringList(List<String> l, ByteBuf cb) { cb.writeShort(l.size()); for (String str : l) writeString(str, cb); } public static int sizeOfStringList(List<String> l) { int size = 2; for (String str : l) size += sizeOfString(str); return size; } public static Map<String, String> readStringMap(ByteBuf cb) { int length = cb.readUnsignedShort(); Map<String, String> m = new HashMap<String, String>(length); for (int i = 0; i < length; i++) { String k = readString(cb).toUpperCase(); String v = readString(cb); m.put(k, v); } return m; } public static void writeStringMap(Map<String, String> m, ByteBuf cb) { cb.writeShort(m.size()); for (Map.Entry<String, String> entry : m.entrySet()) { writeString(entry.getKey(), cb); writeString(entry.getValue(), cb); } } public static int sizeOfStringMap(Map<String, String> m) { int size = 2; for (Map.Entry<String, String> entry : m.entrySet()) { size += sizeOfString(entry.getKey()); size += sizeOfString(entry.getValue()); } return size; } public static Map<String, List<String>> readStringToStringListMap(ByteBuf cb) { int length = cb.readUnsignedShort(); Map<String, List<String>> m = new HashMap<String, List<String>>(length); for (int i = 0; i < length; i++) { String k = readString(cb).toUpperCase(); List<String> v = readStringList(cb); m.put(k, v); } return m; } public static void writeStringToStringListMap(Map<String, List<String>> m, ByteBuf cb) { cb.writeShort(m.size()); for (Map.Entry<String, List<String>> entry : m.entrySet()) { writeString(entry.getKey(), cb); writeStringList(entry.getValue(), cb); } } public static int sizeOfStringToStringListMap(Map<String, List<String>> m) { int size = 2; for (Map.Entry<String, List<String>> entry : m.entrySet()) { size += sizeOfString(entry.getKey()); size += sizeOfStringList(entry.getValue()); } return size; } public static ByteBuffer readValue(ByteBuf cb) { int length = cb.readInt(); if (length < 0) return null; ByteBuf slice = cb.readSlice(length); return ByteBuffer.wrap(readRawBytes(slice)); } public static void writeValue(byte[] bytes, ByteBuf cb) { if (bytes == null) { cb.writeInt(-1); return; } cb.writeInt(bytes.length); cb.writeBytes(bytes); } public static void writeValue(ByteBuffer bytes, ByteBuf cb) { if (bytes == null) { cb.writeInt(-1); return; } if (bytes == BoundStatement.UNSET) { cb.writeInt(-2); return; } cb.writeInt(bytes.remaining()); cb.writeBytes(bytes.duplicate()); } public static int sizeOfValue(byte[] bytes) { return 4 + (bytes == null ? 0 : bytes.length); } public static int sizeOfValue(ByteBuffer bytes) { return 4 + (bytes == null ? 0 : bytes.remaining()); } public static List<ByteBuffer> readValueList(ByteBuf cb) { int size = cb.readUnsignedShort(); if (size == 0) return Collections.<ByteBuffer>emptyList(); List<ByteBuffer> l = new ArrayList<ByteBuffer>(size); for (int i = 0; i < size; i++) l.add(readValue(cb)); return l; } public static void writeValueList(List<ByteBuffer> values, ByteBuf cb) { cb.writeShort(values.size()); for (ByteBuffer value : values) CBUtil.writeValue(value, cb); } public static int sizeOfValueList(List<ByteBuffer> values) { int size = 2; for (ByteBuffer value : values) size += CBUtil.sizeOfValue(value); return size; } public static void writeNamedValueList(Map<String, ByteBuffer> namedValues, ByteBuf cb) { cb.writeShort(namedValues.size()); for (Map.Entry<String, ByteBuffer> entry : namedValues.entrySet()) { CBUtil.writeString(entry.getKey(), cb); CBUtil.writeValue(entry.getValue(), cb); } } public static int sizeOfNamedValueList(Map<String, ByteBuffer> namedValues) { int size = 2; for (Map.Entry<String, ByteBuffer> entry : namedValues.entrySet()) { size += CBUtil.sizeOfString(entry.getKey()); size += CBUtil.sizeOfValue(entry.getValue()); } return size; } public static InetSocketAddress readInet(ByteBuf cb) { int addrSize = cb.readByte(); byte[] address = new byte[addrSize]; cb.readBytes(address); int port = cb.readInt(); try { return new InetSocketAddress(InetAddress.getByAddress(address), port); } catch (UnknownHostException e) { throw new DriverInternalError( String.format("Invalid IP address (%d.%d.%d.%d) while deserializing inet address", address[0], address[1], address[2], address[3])); } } public static void writeInet(InetSocketAddress inet, ByteBuf cb) { byte[] address = inet.getAddress().getAddress(); cb.writeByte(address.length); cb.writeBytes(address); cb.writeInt(inet.getPort()); } public static int sizeOfInet(InetSocketAddress inet) { byte[] address = inet.getAddress().getAddress(); return 1 + address.length + 4; } /* * Reads *all* readable bytes from {@code cb} and return them. * If {@code cb} is backed by an array, this will return the underlying array directly, without copy. */ public static byte[] readRawBytes(ByteBuf cb) { if (cb.hasArray() && cb.readableBytes() == cb.array().length) { // Move the readerIndex just so we consistently consume the input cb.readerIndex(cb.writerIndex()); return cb.array(); } // Otherwise, just read the bytes in a new array byte[] bytes = new byte[cb.readableBytes()]; cb.readBytes(bytes); return bytes; } }