bundles/org.simantics.acorn/src/org/simantics/acorn/FileIO.java

   1 package org.simantics.acorn;
   2
   3 import java.io.BufferedOutputStream;
   4 import java.io.IOException;
   5 import java.io.OutputStream;
   6 import java.io.RandomAccessFile;
   7 import java.nio.ByteBuffer;
   8 import java.nio.channels.FileChannel;
   9 import java.nio.channels.SeekableByteChannel;
  10 import java.nio.file.Files;
  11 import java.nio.file.OpenOption;
  12 import java.nio.file.Path;
  13 import java.nio.file.Paths;
  14 import java.nio.file.StandardOpenOption;
  15 import java.nio.file.attribute.FileAttribute;
  16 import java.util.HashMap;
  17 import java.util.HashSet;
  18 import java.util.Map;
  19 import java.util.Set;
  20
  21 import org.simantics.databoard.file.RuntimeIOException;
  22 import org.slf4j.Logger;
  23 import org.slf4j.LoggerFactory;
  24
  25 public class FileIO {
  26
  27     private static final Logger LOGGER = LoggerFactory.getLogger(FileIO.class);
  28
  29     private static final FileAttribute<?>[] NO_ATTRIBUTES = {};
  30
  31     private static final Set<OpenOption> CREATE_OPTIONS = new HashSet<>(2);
  32     private static final Set<OpenOption> APPEND_OPTIONS = new HashSet<>(1);
  33
  34     static {
  35         CREATE_OPTIONS.add(StandardOpenOption.WRITE);
  36         CREATE_OPTIONS.add(StandardOpenOption.CREATE);
  37
  38         APPEND_OPTIONS.add(StandardOpenOption.APPEND);
  39     }
  40
  41         private Path path;
  42         private int writePosition = 0;
  43
  44         public FileIO(Path path) {
  45                 this.path = path;
  46         }
  47
  48         //private static final boolean TRACE_SWAP = false;
  49         private static final boolean TRACE_PERF = false;
  50
  51         public synchronized int saveBytes(byte[] bytes, int length, boolean overwrite) throws IOException {
  52                 if(overwrite) writePosition = 0;
  53                 int result = writePosition;
  54                 long start = System.nanoTime();
  55                 Set<OpenOption> options = writePosition == 0 ? CREATE_OPTIONS : APPEND_OPTIONS;
  56
  57                 ByteBuffer bb = ByteBuffer.wrap(bytes, 0, length);
  58                 try (FileChannel fc = FileChannel.open(path, options, NO_ATTRIBUTES)) {
  59             fc.write(bb);
  60
  61             writePosition += length;
  62             if(TRACE_PERF) {
  63                 long duration = System.nanoTime()-start;
  64                 double ds = 1e-9*duration;
  65                 LOGGER.info("Wrote " + bytes.length + " bytes @ " + 1e-6*bytes.length / ds + "MB/s");
  66             }
  67             return result;
  68                 } catch (Throwable t) {
  69                     throw new IOException("An error occured file saving bytes for file " + path.toAbsolutePath().toString(), t);
  70                 }
  71         }
  72
  73     public synchronized byte[] readBytes(int offset, int length) throws IOException {
  74         long start = System.nanoTime();
  75         try (SeekableByteChannel channel = Files.newByteChannel(path)) {
  76             channel.position(offset);
  77             ByteBuffer buf = ByteBuffer.allocate(length);
  78             int read = 0;
  79             while (read < length) {
  80                 read += channel.read(buf);
  81             }
  82             byte[] result = buf.array();
  83             if (result.length != length)
  84                 LOGGER.info("result length does not match expected {} {} {}", this, result.length, length);
  85             if (TRACE_PERF) {
  86                 long duration = System.nanoTime() - start;
  87                 double ds = 1e-9 * duration;
  88                 LOGGER.info("Read " + result.length + " bytes @ " + 1e-6 * result.length / ds + "MB/s");
  89             }
  90             return result;
  91         }
  92     }
  93
  94         public static void syncPath(Path f) throws IOException {
  95                 // Does not seem to need 's' according to unit test in Windows
  96                 try (RandomAccessFile raf = new RandomAccessFile(f.toFile(), "rw")) {
  97                         raf.getFD().sync();
  98                 }
  99         }
 100
 101         static void uncheckedSyncPath(Path f) {
 102                 try {
 103                         syncPath(f);
 104                 } catch (IOException e) {
 105                         throw new RuntimeIOException(e);
 106                 }
 107         }
 108
 109         public static void main(String[] args) throws Exception {
 110
 111                 byte[] buf = new byte[1024*1024];
 112
 113                 long s = System.nanoTime();
 114
 115                 Path test = Paths.get("e:/work/test.dat");
 116                 OutputStream fs = Files.newOutputStream(test);
 117                 OutputStream os = new BufferedOutputStream(fs, 128*1024);
 118
 119                 for(int i=0;i<40;i++) {
 120                         os.write(buf);
 121                 }
 122
 123                 os.flush();
 124                 //fs.getFD().sync();
 125                 os.close();
 126
 127                 syncPath(test);
 128
 129                 if (LOGGER.isDebugEnabled()) {
 130                 long duration = System.nanoTime()-s;
 131                 LOGGER.info("Took " + 1e-6*duration + "ms.");
 132                 }
 133         }
 134
 135 }