| 1 | package net.spy.memcached.transcoders; |
| 2 | |
| 3 | import java.io.ByteArrayInputStream; |
| 4 | import java.io.ByteArrayOutputStream; |
| 5 | import java.io.IOException; |
| 6 | import java.io.ObjectInputStream; |
| 7 | import java.io.ObjectOutputStream; |
| 8 | import java.io.UnsupportedEncodingException; |
| 9 | import java.util.zip.GZIPInputStream; |
| 10 | import java.util.zip.GZIPOutputStream; |
| 11 | |
| 12 | import net.spy.memcached.CachedData; |
| 13 | import net.spy.memcached.compat.CloseUtil; |
| 14 | import net.spy.memcached.compat.SpyObject; |
| 15 | |
| 16 | /** |
| 17 | * Base class for any transcoders that may want to work with serialized or |
| 18 | * compressed data. |
| 19 | */ |
| 20 | public abstract class BaseSerializingTranscoder extends SpyObject { |
| 21 | |
| 22 | /** |
| 23 | * Default compression threshold value. |
| 24 | */ |
| 25 | public static final int DEFAULT_COMPRESSION_THRESHOLD = 16384; |
| 26 | |
| 27 | private static final String DEFAULT_CHARSET = "UTF-8"; |
| 28 | |
| 29 | protected int compressionThreshold=DEFAULT_COMPRESSION_THRESHOLD; |
| 30 | protected String charset=DEFAULT_CHARSET; |
| 31 | |
| 32 | private final int maxSize; |
| 33 | |
| 34 | /** |
| 35 | * Initialize a serializing transcoder with the given maximum data size. |
| 36 | */ |
| 37 | public BaseSerializingTranscoder(int max) { |
| 38 | super(); |
| 39 | maxSize = max; |
| 40 | } |
| 41 | |
| 42 | public boolean asyncDecode(CachedData d) { |
| 43 | return false; |
| 44 | } |
| 45 | |
| 46 | /** |
| 47 | * Set the compression threshold to the given number of bytes. This |
| 48 | * transcoder will attempt to compress any data being stored that's larger |
| 49 | * than this. |
| 50 | * |
| 51 | * @param to the number of bytes |
| 52 | */ |
| 53 | public void setCompressionThreshold(int to) { |
| 54 | compressionThreshold=to; |
| 55 | } |
| 56 | |
| 57 | /** |
| 58 | * Set the character set for string value transcoding (defaults to UTF-8). |
| 59 | */ |
| 60 | public void setCharset(String to) { |
| 61 | // Validate the character set. |
| 62 | try { |
| 63 | new String(new byte[97], to); |
| 64 | } catch (UnsupportedEncodingException e) { |
| 65 | throw new RuntimeException(e); |
| 66 | } |
| 67 | charset=to; |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * Get the bytes representing the given serialized object. |
| 72 | */ |
| 73 | protected byte[] serialize(Object o) { |
| 74 | if(o == null) { |
| 75 | throw new NullPointerException("Can't serialize null"); |
| 76 | } |
| 77 | byte[] rv=null; |
| 78 | try { |
| 79 | ByteArrayOutputStream bos=new ByteArrayOutputStream(); |
| 80 | ObjectOutputStream os=new ObjectOutputStream(bos); |
| 81 | os.writeObject(o); |
| 82 | os.close(); |
| 83 | bos.close(); |
| 84 | rv=bos.toByteArray(); |
| 85 | } catch(IOException e) { |
| 86 | throw new IllegalArgumentException("Non-serializable object", e); |
| 87 | } |
| 88 | return rv; |
| 89 | } |
| 90 | |
| 91 | /** |
| 92 | * Get the object represented by the given serialized bytes. |
| 93 | */ |
| 94 | protected Object deserialize(byte[] in) { |
| 95 | Object rv=null; |
| 96 | try { |
| 97 | if(in != null) { |
| 98 | ByteArrayInputStream bis=new ByteArrayInputStream(in); |
| 99 | ObjectInputStream is=new ObjectInputStream(bis); |
| 100 | rv=is.readObject(); |
| 101 | is.close(); |
| 102 | bis.close(); |
| 103 | } |
| 104 | } catch(IOException e) { |
| 105 | getLogger().warn("Caught IOException decoding %d bytes of data", |
| 106 | in.length, e); |
| 107 | } catch (ClassNotFoundException e) { |
| 108 | getLogger().warn("Caught CNFE decoding %d bytes of data", |
| 109 | in.length, e); |
| 110 | } |
| 111 | return rv; |
| 112 | } |
| 113 | |
| 114 | /** |
| 115 | * Compress the given array of bytes. |
| 116 | */ |
| 117 | protected byte[] compress(byte[] in) { |
| 118 | if(in == null) { |
| 119 | throw new NullPointerException("Can't compress null"); |
| 120 | } |
| 121 | ByteArrayOutputStream bos=new ByteArrayOutputStream(); |
| 122 | GZIPOutputStream gz=null; |
| 123 | try { |
| 124 | gz = new GZIPOutputStream(bos); |
| 125 | gz.write(in); |
| 126 | } catch (IOException e) { |
| 127 | throw new RuntimeException("IO exception compressing data", e); |
| 128 | } finally { |
| 129 | CloseUtil.close(gz); |
| 130 | CloseUtil.close(bos); |
| 131 | } |
| 132 | byte[] rv=bos.toByteArray(); |
| 133 | getLogger().debug("Compressed %d bytes to %d", in.length, rv.length); |
| 134 | return rv; |
| 135 | } |
| 136 | |
| 137 | /** |
| 138 | * Decompress the given array of bytes. |
| 139 | * |
| 140 | * @return null if the bytes cannot be decompressed |
| 141 | */ |
| 142 | protected byte[] decompress(byte[] in) { |
| 143 | ByteArrayOutputStream bos=null; |
| 144 | if(in != null) { |
| 145 | ByteArrayInputStream bis=new ByteArrayInputStream(in); |
| 146 | bos=new ByteArrayOutputStream(); |
| 147 | GZIPInputStream gis; |
| 148 | try { |
| 149 | gis = new GZIPInputStream(bis); |
| 150 | |
| 151 | byte[] buf=new byte[8192]; |
| 152 | int r=-1; |
| 153 | while((r=gis.read(buf)) > 0) { |
| 154 | bos.write(buf, 0, r); |
| 155 | } |
| 156 | } catch (IOException e) { |
| 157 | getLogger().warn("Failed to decompress data", e); |
| 158 | bos = null; |
| 159 | } |
| 160 | } |
| 161 | return bos == null ? null : bos.toByteArray(); |
| 162 | } |
| 163 | |
| 164 | /** |
| 165 | * Decode the string with the current character set. |
| 166 | */ |
| 167 | protected String decodeString(byte[] data) { |
| 168 | String rv=null; |
| 169 | try { |
| 170 | if(data != null) { |
| 171 | rv=new String(data, charset); |
| 172 | } |
| 173 | } catch (UnsupportedEncodingException e) { |
| 174 | throw new RuntimeException(e); |
| 175 | } |
| 176 | return rv; |
| 177 | } |
| 178 | |
| 179 | /** |
| 180 | * Encode a string into the current character set. |
| 181 | */ |
| 182 | protected byte[] encodeString(String in) { |
| 183 | byte[] rv=null; |
| 184 | try { |
| 185 | rv=in.getBytes(charset); |
| 186 | } catch (UnsupportedEncodingException e) { |
| 187 | throw new RuntimeException(e); |
| 188 | } |
| 189 | return rv; |
| 190 | } |
| 191 | |
| 192 | public int getMaxSize() { |
| 193 | return maxSize; |
| 194 | } |
| 195 | |
| 196 | } |