forked from proxyee-down-org/proxyee-down
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Showing
7 changed files
with
250 additions
and
81 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,124 @@ | ||
| package lee.study.down.io; | ||
|
|
||
| import java.io.Closeable; | ||
| import java.io.IOException; | ||
| import java.io.RandomAccessFile; | ||
| import java.lang.reflect.Field; | ||
| import java.lang.reflect.Method; | ||
| import java.nio.channels.FileChannel; | ||
| import sun.misc.Unsafe; | ||
| import sun.nio.ch.FileChannelImpl; | ||
|
|
||
| public class Mmap implements Closeable { | ||
|
|
||
| private static final Unsafe unsafe; | ||
| private static final Method mmap; | ||
| private static final Method unmmap; | ||
| private static final int BYTE_ARRAY_OFFSET; | ||
|
|
||
| private long addr, size; | ||
| private final String loc; | ||
|
|
||
| static { | ||
| try { | ||
| Field singleoneInstanceField = Unsafe.class.getDeclaredField("theUnsafe"); | ||
| singleoneInstanceField.setAccessible(true); | ||
| unsafe = (Unsafe) singleoneInstanceField.get(null); | ||
|
|
||
| mmap = getMethod(FileChannelImpl.class, "map0", int.class, long.class, long.class); | ||
| unmmap = getMethod(FileChannelImpl.class, "unmap0", long.class, long.class); | ||
|
|
||
| BYTE_ARRAY_OFFSET = unsafe.arrayBaseOffset(byte[].class); | ||
| } catch (Exception e) { | ||
| throw new RuntimeException(e); | ||
| } | ||
| } | ||
|
|
||
| //Bundle reflection calls to get access to the given method | ||
| private static Method getMethod(Class<?> cls, String name, Class<?>... params) throws Exception { | ||
| Method m = cls.getDeclaredMethod(name, params); | ||
| m.setAccessible(true); | ||
| return m; | ||
| } | ||
|
|
||
| //Round to next 4096 bytes | ||
| private static long roundTo4096(long i) { | ||
| return (i + 0xfffL) & ~0xfffL; | ||
| } | ||
|
|
||
| //Given that the location and size have been set, map that location | ||
| //for the given length and set this.addr to the returned offset | ||
| private void mapAndSetOffset() throws IOException { | ||
| RandomAccessFile backingFile = null; | ||
| FileChannel ch = null; | ||
| try { | ||
| backingFile = new RandomAccessFile(this.loc, "rw"); | ||
| ch = backingFile.getChannel(); | ||
| this.addr = (long) mmap.invoke(ch, 1, 0L, this.size); | ||
| } catch (Exception e) { | ||
| throw new IOException("mmap mapAndSetOffset", e); | ||
| } finally { | ||
| if (ch != null) { | ||
| ch.close(); | ||
| } | ||
| if (backingFile != null) { | ||
| backingFile.close(); | ||
| } | ||
| } | ||
| } | ||
|
|
||
| public Mmap(final String loc, long len) throws IOException { | ||
| this.loc = loc; | ||
| this.size = roundTo4096(len); | ||
| mapAndSetOffset(); | ||
| } | ||
|
|
||
| public Mmap(final String loc, long pos, long len) throws Exception { | ||
| this.loc = loc; | ||
| this.size = roundTo4096(len); | ||
| mapAndSetOffset(); | ||
| } | ||
|
|
||
| //Callers should synchronize to avoid calls in the middle of this, but | ||
| //it is undesirable to synchronize w/ all access methods. | ||
| public void remap(long nLen) throws Exception { | ||
| unmmap.invoke(null, addr, this.size); | ||
| this.size = roundTo4096(nLen); | ||
| mapAndSetOffset(); | ||
| } | ||
|
|
||
| public int getInt(long pos) { | ||
| return unsafe.getInt(pos + addr); | ||
| } | ||
|
|
||
| public long getLong(long pos) { | ||
| return unsafe.getLong(pos + addr); | ||
| } | ||
|
|
||
| public void putInt(long pos, int val) { | ||
| unsafe.putInt(pos + addr, val); | ||
| } | ||
|
|
||
| public void putLong(long pos, long val) { | ||
| unsafe.putLong(pos + addr, val); | ||
| } | ||
|
|
||
| //May want to have offset & length within data as well, for both of these | ||
| public void getBytes(long pos, byte[] data) { | ||
| unsafe.copyMemory(null, pos + addr, data, BYTE_ARRAY_OFFSET, data.length); | ||
| } | ||
|
|
||
| public void putBytes(long pos, byte[] data) { | ||
| unsafe.copyMemory(data, BYTE_ARRAY_OFFSET, null, pos + addr, data.length); | ||
| } | ||
|
|
||
| @Override | ||
| public void close() throws IOException { | ||
| try { | ||
| unmmap.invoke(null, addr, this.size); | ||
| } catch (Exception e) { | ||
| throw new IOException("unmap error", e); | ||
| } | ||
| } | ||
|
|
||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.