Coverage Report

Coverage Report - org.jscsi.target.storage.IStorageModule

Classes in this File

 /**
  * 
  */
 package org.jscsi.target.storage;
 
 
 import java.io.IOException;
 
 import org.jscsi.target.scsi.cdb.CommandDescriptorBlock;
 
 
 /**
  * This is an abstract super class offering methods for storage and retrieval of data, as well as emulating some
  * properties of block storage devices.
  * <p>
  * All index and length parameters used by the read and write methods are referring to bytes, unlike the values sent in
  * {@link CommandDescriptorBlock} s.
  * 
  * @author Andreas Ergenzinger
  */
 public interface IStorageModule {
 
     /**
      * A fictitious block size.
      */
     public static final int VIRTUAL_BLOCK_SIZE = 512;
 
     /**
      * This method can be used for checking if a (series of) I/O operations will result in an {@link IOException} due to
      * trying to access blocks outside the medium's boundaries.
      * <p>
      * The SCSI standard requires checking for these boundary violations right after receiving a read or write command,
      * so that an appropriate error message can be returned to the initiator. Therefore this method must be called prior
      * to each read or write sequence.
      * <p>
      * The values returned by this method and their meaning with regard to the interval [0, {@link #getSizeInBlocks()} -
      * 1] are shown in the following table:
      * <p>
      * <table border="1">
      * <tr>
      * <th>Return Value</th>
      * <th>Meaning</th>
      * </tr>
      * <tr>
      * <td>0</td>
      * <td>no boundaries are violated</td>
      * </tr>
      * <tr>
      * <td>1</td>
      * <td>the <i>logicalBlockAddress</i> parameter lies outside of the interval</td>
      * </tr>
      * <tr>
      * <td>2</td>
      * <td>the interval [<i>logicalBlockAddress</i>, <i>logicalBlockAddress</i> + <i>transferLengthInBlocks</i>]<br/>
      * lies outside of the interval, or <i>transferLengthInBlocks</i> is negative</td>
      * </tr>
      * </table>
      * <p>
      * Note that the parameters of this method are referring to blocks, not to byte indices.
      * 
      * @param logicalBlockAddress the index of the first block of data to be read or written
      * @param transferLengthInBlocks the total number of consecutive blocks about to be read or written
      * @return see table in description
      */
     int checkBounds (final long logicalBlockAddress, final int transferLengthInBlocks);
 
     /**
      * Returns the storage space size in bytes divided by the block size in bytes (rounded down).
      * 
      * @return the virtual amount of storage blocks available
      */
     long getSizeInBlocks ();
 
     /**
      * Copies bytes from storage to the passed byte array.
      * 
      * @param bytes the array into which the data will be copied will be filled with data from storage
      * @param storageIndex the position of the first byte to be copied
      * @throws IOException
      */
     void read (byte[] bytes, long storageIndex) throws IOException;
 
     /**
      * Saves part of the passed byte array's content.
      * 
      * @param bytes the source of the data to be stored
      * @param storageIndex byte offset in the storage area
      * @throws IOException
      */
     void write (byte[] bytes, long storageIndex) throws IOException;
 
     /**
      * Closing the storage.
      * 
      * @throws IOException to be closed
      */
     void close () throws IOException;
 
 }

1		/**
2		*
3		*/
4		package org.jscsi.target.storage;
5
6
7		import java.io.IOException;
8
9		import org.jscsi.target.scsi.cdb.CommandDescriptorBlock;
10
11
12		/**
13		* This is an abstract super class offering methods for storage and retrieval of data, as well as emulating some
14		* properties of block storage devices.
15		* <p>
16		* All index and length parameters used by the read and write methods are referring to bytes, unlike the values sent in
17		* {@link CommandDescriptorBlock} s.
18		*
19		* @author Andreas Ergenzinger
20		*/
21		public interface IStorageModule {
22
23		/**
24		* A fictitious block size.
25		*/
26		public static final int VIRTUAL_BLOCK_SIZE = 512;
27
28		/**
29		* This method can be used for checking if a (series of) I/O operations will result in an {@link IOException} due to
30		* trying to access blocks outside the medium's boundaries.
31		* <p>
32		* The SCSI standard requires checking for these boundary violations right after receiving a read or write command,
33		* so that an appropriate error message can be returned to the initiator. Therefore this method must be called prior
34		* to each read or write sequence.
35		* <p>
36		* The values returned by this method and their meaning with regard to the interval [0, {@link #getSizeInBlocks()} -
37		* 1] are shown in the following table:
38		* <p>
39		* <table border="1">
40		* <tr>
41		* <th>Return Value</th>
42		* <th>Meaning</th>
43		* </tr>
44		* <tr>
45		* <td>0</td>
46		* <td>no boundaries are violated</td>
47		* </tr>
48		* <tr>
49		* <td>1</td>
50		* <td>the <i>logicalBlockAddress</i> parameter lies outside of the interval</td>
51		* </tr>
52		* <tr>
53		* <td>2</td>
54		* <td>the interval [<i>logicalBlockAddress</i>, <i>logicalBlockAddress</i> + <i>transferLengthInBlocks</i>]<br/>
55		* lies outside of the interval, or <i>transferLengthInBlocks</i> is negative</td>
56		* </tr>
57		* </table>
58		* <p>
59		* Note that the parameters of this method are referring to blocks, not to byte indices.
60		*
61		* @param logicalBlockAddress the index of the first block of data to be read or written
62		* @param transferLengthInBlocks the total number of consecutive blocks about to be read or written
63		* @return see table in description
64		*/
65		int checkBounds (final long logicalBlockAddress, final int transferLengthInBlocks);
66
67		/**
68		* Returns the storage space size in bytes divided by the block size in bytes (rounded down).
69		*
70		* @return the virtual amount of storage blocks available
71		*/
72		long getSizeInBlocks ();
73
74		/**
75		* Copies bytes from storage to the passed byte array.
76		*
77		* @param bytes the array into which the data will be copied will be filled with data from storage
78		* @param storageIndex the position of the first byte to be copied
79		* @throws IOException
80		*/
81		void read (byte[] bytes, long storageIndex) throws IOException;
82
83		/**
84		* Saves part of the passed byte array's content.
85		*
86		* @param bytes the source of the data to be stored
87		* @param storageIndex byte offset in the storage area
88		* @throws IOException
89		*/
90		void write (byte[] bytes, long storageIndex) throws IOException;
91
92		/**
93		* Closing the storage.
94		*
95		* @throws IOException to be closed
96		*/
97		void close () throws IOException;
98
99		}