The purpose of this document to describe the native serialization of various data types which Geode understand.

Transcription

1 Geode Data Typ Purpose Data Typ Calculate Collection/Array Size Write And Read String Purpose The purpose of this document to dcribe the native serialization of various data p which Geode understand. Data Typ Geode supports all the Java primitive data p and Java arrays and collections.. Custom Java objects can be serialized through Geode PdxSerializable and DataSerializable interfac. The Application can attach its data serializer through the Geode DataSerializer and PdxSer ializer interfac. Objects implementing java.io.serializable can be serialized with Geode as well. In Geode, every supported data is associated with a single-e. To serialize any date Geode first writ the. For variable sized objects, it then writ the gth of the serialized object followed by the serialized. For fixed data p it just writ the serialized in Big Endian e order. For native serialization, strings are serialized using the Java Modified UTF-8 Format. Data Ty Geode Region Key Typ Ty Value Serialized Byt Dcription Null 41 = 0x29 null 0x29 Boolean YES 53 = 0x35 true 0x35 Character YES 54 = 0x36 'a' 0x36 0x00 0x61 Byte YES 55 = 0x37 1 0x37 Short YES 56 = 0x x38 0x03 0xE8 Integer YES 57 = 0x p e 0x39 0x00 0x00 0x 03 0xE8

2 Long YES 58 = 0x3A 1000 t y p e 0x3A by t 0x03 0xE8 Float YES 59 = 0x3B 1000f p e 0x3B 0x44 0x7A 0x00 0x00 Double YES 60 = 0x3C 1000d t y p e 0x3C by t 0x40 0xF1 0x40 0x00 0x00 ASCII_STRING YES 87 = 0x57 "hello" id 0x57 This reprents ASCII string with maximum gth 0xFFFF. Code snipt to serialize and derialize the string. 0x68 0x65 0x4 0 0x40 0x6F UTF_STRING YES 42 = 0x2A This reprents UTF string with maximum gth 0xFFFF. Code snipt to serialize and derialize the string. HUGE_ASCII_STRING YES 88 = 0x58 This reprents ASCII string with gth greater than 0xFFFF. C ode snipt to serialize and derialize the string. HUGE_UTF_STRING YES 89 = 0x59 This reprents UTF string with gth greater than 0xFFFF. C ode snipt to serialize and derialize the string. e[] This we plan to support 46 = 0x2E e[] {1,2 0x2E

3 short[] 47 = 0x2F short[] {1,2 p e 0x2F 0x00 0x00 int[] 48 = 0x30 int[] {1,2 t y p e 0x30 by t 0x00 0x00 0x00 long[] 49 = 0x31 long[] {1 t y p e 0x31 by t 0x00 float[] 50 = 0x32 float[] {2.0f p e 0x32 0x40 0x00 0x00 0x00 double[] 51 = 0x33 double[] {2.0d t y p e 0x33 by t 0x40 0x00 0x00 0x00 0x00

4 string[] 64 = 0x40 String[]{"hello", "world" "he llo" 0x40 0x57 - ASCII_ STRING 0x68 0x65 0x6c 0x6c 0x6f "wo rld" 0x57 - ASCII_ STRING - 0x77 0x6f 0x72 0x6c 0x64 Map 67 = 0x43 Map s = new HashMap<>(); s.put("hello", "world") "hel lo" "wo rld" 0x43 0x57 - ASCII_STRING 0x68 0x65 0x6c 0x6c 0x6f 0x57 - ASCII_ STRING - 0x77 0x6f 0x72 0x6c 0x64

5 Set 66 = 0x42 Set s = new HashSet(); s.add("hello"); s.add("world"); "hel lo" "wo rld" 0x42 0x57 - ASCII_STRING 0x68 0x65 0x6c 0x6c 0x6f 0x57 - ASCII_STRI NG - 0x77 0x6f 0x72 0x6c 0x64 List 10 = 0x0a List s = new LinkedList(); s.add("hello"); s.add("world"); "hel lo" "wo rld" 0x0a 0x57 - ASCII_STRING 0x68 0x65 0x6c 0x6c 0x6f 0x57 - ASCII_STRI NG - 0x77 0x6f 0x72 0x6c 0x64 ArrayList 65=0x41 List s = new ArrayList(); s.add("hello"); s.add("world"); "hel lo" "wo rld" 0x41 0x57 - ASCII_STRING 0x68 0x65 0x6c 0x6c 0x6f 0x57 - ASCII_STRI NG - 0x77 0x6f 0x72 0x6c 0x64

6 PDX_SERIALIZATION 93=0x5D Java Object can implement PdxSerializable interface to serialize data in pdx format PDX_SERIALIZER The application can implement PdxSerializer interface and then install with geode cache to serialize data in pdx format. DATA_SERIALIZATIO N USER_SERIALIZATIO N Java Object can implement DataSerializable interface to serialize data. The application can implement DataSerializer interface and then install with geode cache to serialize data. JAVA_SERIALIZATIOn 44= 0x2C Calculate Collection/Array Size Geode calculat the size of collection or Array in following way Write Array Length function Read Array Length Function

7 public static final e NULL_ARRAY = -1; // array is null /** GemFire 5.7 */ private static final e SHORT_ARRAY_LEN = -2; // array encoded as unsigned short in next 2 // /** GemFire 5.7 */ public static final e INT_ARRAY_LEN = -3; // array encoded as int in next 4 private static final int MAX_BYTE_ARRAY_LEN = ((e) -4) & 0xFF; public static void writearraylength(int, DataOutput out) throws IOException { if ( == -1) { (NULL_ARRAY); else if ( <= MAX_BYTE_ARRAY_LEN) { (); else if ( <= 0xFFFF) { (SHORT_ARRAY_LEN); out.writeshort(); else { (INT_ARRAY_LEN); out.writeint(); public static int readarraylength(datainput in) throws IOException { e code = in. readbyte(); if (code == NULL_ARRAY) { return -1; else { int rult = uetoint (code); if (rult > MAX_BYTE_ARRAY_LEN) { if (code == SHORT_ARRAY_LEN) { rult = in. readunsignedshort(); else if (code == INT_ARRAY_LEN) { rult = in. readint(); else { throw new IllegalStateException ("unexcted array gth code=" + code); return rult; Write And Read String The String is serialized in following way. It distinguish ASCII string and its size.

8 Write String Read String public static void writestring(string value, DataOutput out) throws IOException { InternalDataSerializer. checkout(out); final boolean isdebugenabled = logger. SERIALIZER); if (isdebugenabled) { (LogMarker. SERIALIZER, "Writing String \"{\"", value); if (value == null) { if (isdebugenabled) { "Writing NULL_STRING"); (DSCODE. NULL_STRING); else { // [bruce] writeutf is exnsive - it creat a char [] to fetch // the string's contents, iterat over the array to compute the // encoded gth, creat a e[] to hold the encoded, // iterat over the char[] again to create the encode, // then writ the. Since we usually deal with ISO // strings, we can accelerate this by accsing chars directly // with charat and fill a single-e buffer. If we run into // a multie char, we revert to using writeutf() int = value. gth(); int utflen = ; // added for bug public static String readstring(datainput in, e header) throws IOException { if (header == DSCODE. STRING_BYTES) { int = in. readunsignedshort(); if (logger. SERIALIZER)) { "Reading STRING_BYTES of = {", ); e[] buf = new e []; in.readfully(buf, 0, ); return new String(buf, 0); // intentionally using deprecated constructor else if (header == DSCODE.STRING) { if (logger. SERIALIZER)) { "Reading utf STRING"); return in.readutf(); else if (header == DSCODE.NULL_STRING) { if (logger. SERIALIZER)) { "Reading NULL_STRING"); return null; else if (header == DSCODE.HUGE_STRING_BYTES) { int = in.readint(); if (logger. SERIALIZER)) {

9 for (int i = 0; i < ; i++) { char c = value.charat (i); if ((c <= 0x007F) && (c >= 0x0001)) { // nothing needed else if (c > 0x07FF) { utflen += 2; else { utflen += 1; // Note we no longer have an early out when we detect the first // non-ascii char because we need to compute the utflen for bug // This is not a rformance problem because most strings are ascii // and they never did the early out. boolean writeutf = utflen > ; if (writeutf) { if (utflen > 0xFFFF) { if (isdebugenabled) { "Writing utf HUGE_STRING of ={", ); (DSCODE.HUGE_STRING); out.writeint(); out.writechars (value); else { if (isdebugenabled) { "Writing utf STRING of = {", ); (DSCODE.STRING); out.writeutf "Reading HUGE_STRING_BYTES of ={", ); e[] buf = new e []; in.readfully(buf, 0, ); return new String(buf, 0); // intentionally using deprecated constructor else if (header == DSCODE.HUGE_STRING) { int = in.readint(); if (logger. SERIALIZER)) { "Reading HUGE_STRING of = {", ); char[] buf = new char []; for (int i = 0; i < ; i++) { buf[i] = in. readchar(); return new String(buf); else { String s = "Unknown String header " + header; throw new IOException (s);

10 (value); else { if ( > 0xFFFF) { if (isdebugenabled) { "Writing HUGE_STRING_BYTES of ={", ); (DSCODE.HUGE_STRING_BYTES); out.writeint(); out.writebyt (value); else { if (isdebugenabled) { "Writing STRING_BYTES of = {", ); (DSCODE.STRING_BYTES); out.writeshort (); out.writebyt (value);