Author: desruisseaux
Date: Sun Jun 2 19:35:55 2013
New Revision: 1488774
URL: http://svn.apache.org/r1488774
Log:
More systematic creation of ByteBuffer, and leave the "rewind" operation to
callers.
Modified:
sis/branches/JDK7/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStoreConnection.java
sis/branches/JDK7/storage/sis-storage/src/test/java/org/apache/sis/storage/DataStoreConnectionTest.java
Modified:
sis/branches/JDK7/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStoreConnection.java
URL:
http://svn.apache.org/viewvc/sis/branches/JDK7/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStoreConnection.java?rev=1488774&r1=1488773&r2=1488774&view=diff
==============================================================================
---
sis/branches/JDK7/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStoreConnection.java
[UTF-8] (original)
+++
sis/branches/JDK7/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStoreConnection.java
[UTF-8] Sun Jun 2 19:35:55 2013
@@ -30,6 +30,7 @@ import javax.imageio.stream.ImageInputSt
import java.sql.Connection;
import javax.sql.DataSource;
import org.apache.sis.util.Classes;
+import org.apache.sis.util.ArraysExt;
import org.apache.sis.util.ArgumentChecks;
import org.apache.sis.util.resources.Errors;
import org.apache.sis.internal.storage.IOUtilities;
@@ -118,13 +119,6 @@ public class DataStoreConnection impleme
private transient Map<Class<?>, Object> views;
/**
- * If an {@link ImageInputStream} vie exists, then the stream position at
the time the view has been initialized.
- * This is usually zero, but could be different if the {@link #storage}
provided by the users is already an instance
- * of {@code ImageInputStream}.
- */
- private transient long streamOrigin;
-
- /**
* The options, created only when first needed.
*
* @see #getOption(OptionKey)
@@ -234,11 +228,11 @@ public class DataStoreConnection impleme
* The default implementation accepts the following types:
*
* <ul>
- * <li><p>{@link ByteBuffer}:
+ * <li><p>{@link ByteBuffer} -
* A read-only view of the first bytes of the input stream, or
{@code null} if unavailable.
* If non-null, then the buffer can be used for a quick check of
file magic number.</p></li>
*
- * <li><p>{@link DataInput}:
+ * <li><p>{@link DataInput} -
* Performs the following choice based on the type of the
{@linkplain #getStorage() storage} object:
* <ul>
* <li>If the storage is already an instance of {@link DataInput}
(including the {@link ImageInputStream}
@@ -255,7 +249,7 @@ public class DataStoreConnection impleme
* <li>Otherwise this method returns {@code null}.</li>
* </ul></p></li>
*
- * <li><p>{@link Connection}:
+ * <li><p>{@link Connection} -
* Performs the following choice based on the type of the
{@linkplain #getStorage() storage} object:
* <ul>
* <li>If the storage is already an instance of {@link
Connection}, then it is returned unchanged.</li>
@@ -267,9 +261,11 @@ public class DataStoreConnection impleme
* </ul></p></li>
* </ul>
*
- * Callers shall not close the stream or database connection returned by
this method. Multiple invocations
- * of this method on the same {@code DataStoreConnection} instance will
try to return the same instance on
- * a <cite>best effort</cite> basis.
+ * Multiple invocations of this method on the same {@code
DataStoreConnection} instance will try
+ * to return the same instance on a <cite>best effort</cite> basis.
Consequently, implementations
+ * of {@link DataStoreProvider#canOpen(DataStoreConnection)} methods shall
not close the stream or
+ * database connection returned by this method. In addition, those {@code
canOpen(DataStoreConnection)}
+ * methods are responsible for restoring the stream or byte buffer to its
original position on return.
*
* @param <T> The compile-time type of the {@code type} argument.
* @param type The desired type as one of {@code ByteBuffer}, {@code
DataInput}, {@code Connection}
@@ -320,8 +316,9 @@ public class DataStoreConnection impleme
/**
* Creates a view for the input as a {@link DataInput} if possible. This
method performs the choice
- * documented in the {@link #openAs(Class)} method for the {@code
DataInput} case, and create the
- * {@code ByteBuffer} in same time if possible.
+ * documented in the {@link #openAs(Class)} method for the {@code
DataInput} case. Opening the data
+ * input may imply creating a {@link ByteBuffer}, in which case the buffer
will be stored under the
+ * {@code ByteBuffer.class} key together with the {@code DataInput.class}
case.
*
* @throws IOException If an error occurred while opening a stream for the
input.
*/
@@ -338,12 +335,11 @@ public class DataStoreConnection impleme
*/
final ReadableByteChannel channel = IOUtilities.open(storage,
getOption(OptionKey.URL_ENCODING));
if (channel != null) {
- ByteBuffer buffer = getView(ByteBuffer.class);
+ ByteBuffer buffer = getOption(OptionKey.BYTE_BUFFER);
if (buffer == null) {
- buffer = getOption(OptionKey.BYTE_BUFFER);
- if (buffer == null) {
- buffer = ByteBuffer.allocate(DEFAULT_BUFFER_SIZE);
- }
+ buffer = ByteBuffer.allocate(DEFAULT_BUFFER_SIZE);
+ // TODO: we do not create direct buffer yet, but this is
something
+ // we may want to consider in a future SIS version.
}
asDataInput = new ChannelImageInputStream(getStorageName(),
channel, buffer, false);
asByteBuffer = buffer.asReadOnlyBuffer();
@@ -351,8 +347,24 @@ public class DataStoreConnection impleme
asDataInput = ImageIO.createImageInputStream(storage);
}
}
- if (asDataInput instanceof ImageInputStream) {
- streamOrigin = ((ImageInputStream)
asDataInput).getStreamPosition();
+ /*
+ * If an ImageInputStream has been created without buffer, read an
arbitrary amount of bytes now
+ * so we can provide a ByteBuffer in case some user wants it. This may
be a unnecessary overhead
+ * since maybe no user will want to look at a ByteBuffer, but this
case is presumed rare enough
+ * for not being worth a more complex "lazy instantiation" mechanism.
We read only a small amount
+ * of bytes because, at the contrary of the buffer created in the
above block, the buffer created
+ * here is unlikely to be used for the reading process after the
recognition of the file format.
+ */
+ if (asByteBuffer == null && asDataInput instanceof ImageInputStream) {
+ final ImageInputStream in = (ImageInputStream) asDataInput;
+ in.mark();
+ final byte[] buffer = new byte[256];
+ final int n = in.read(buffer);
+ in.reset();
+ if (n >= 1) {
+ asByteBuffer = ByteBuffer.wrap(ArraysExt.resize(buffer, n))
+ .asReadOnlyBuffer().order(in.getByteOrder());
+ }
}
addView(ByteBuffer.class, asByteBuffer);
addView(DataInput.class, asDataInput);
@@ -405,38 +417,6 @@ public class DataStoreConnection impleme
}
/**
- * Rewinds the {@link DataInput} and {@link ByteBuffer} to the beginning
of the stream.
- * This method is invoked when more than one {@link DataStore} instance is
tried in search
- * for a data store that accept this {@code DataStoreInput} instance.
- *
- * @throws DataStoreException If the stream is open but can not be
rewinded.
- */
- public void rewind() throws DataStoreException {
- if (views != null) {
- /*
- * Restores the ImageInputStream to its original position if
possible. Note that in
- * the ChannelImageInputStream, this may reload the buffer content
if necessary.
- */
- final DataInput asDataInput = getView(DataInput.class);
- if (asDataInput instanceof ImageInputStream) try {
- ((ImageInputStream) asDataInput).seek(streamOrigin);
- } catch (IOException | IndexOutOfBoundsException e) {
- throw new
DataStoreException(Errors.format(Errors.Keys.StreamIsForwardOnly_1,
getStorageName()), e);
- }
- /*
- * Copy the position and limits from the buffer. Note that this
copy must be performed after the
- * above 'seek', because the seek operation may have modified the
buffer position and limit.
- */
- final ByteBuffer asByteBuffer = getView(ByteBuffer.class);
- if (asByteBuffer != null && asDataInput instanceof
ChannelImageInputStream) {
- final ByteBuffer buffer = ((ChannelImageInputStream)
asDataInput).buffer;
-
asByteBuffer.clear().limit(buffer.limit()).position(buffer.position());
- asByteBuffer.order(buffer.order());
- }
- }
- }
-
- /**
* Closes all streams and connections created by this {@code
DataStoreConnection} except the given view.
* This method closes all objects created by the {@link #openAs(Class)}
method, leaving only {@code view} open.
* If {@code view} is {@code null}, then this method closes everything
including the {@linkplain #getStorage()
Modified:
sis/branches/JDK7/storage/sis-storage/src/test/java/org/apache/sis/storage/DataStoreConnectionTest.java
URL:
http://svn.apache.org/viewvc/sis/branches/JDK7/storage/sis-storage/src/test/java/org/apache/sis/storage/DataStoreConnectionTest.java?rev=1488774&r1=1488773&r2=1488774&view=diff
==============================================================================
---
sis/branches/JDK7/storage/sis-storage/src/test/java/org/apache/sis/storage/DataStoreConnectionTest.java
[UTF-8] (original)
+++
sis/branches/JDK7/storage/sis-storage/src/test/java/org/apache/sis/storage/DataStoreConnectionTest.java
[UTF-8] Sun Jun 2 19:35:55 2013
@@ -20,6 +20,7 @@ import java.io.DataInput;
import java.io.IOException;
import java.nio.channels.ReadableByteChannel;
import org.apache.sis.internal.storage.ChannelImageInputStream;
+import org.apache.sis.test.DependsOn;
import org.apache.sis.test.TestCase;
import org.junit.Test;
@@ -34,6 +35,7 @@ import static org.opengis.test.Assert.*;
* @version 0.3
* @module
*/
+@DependsOn(org.apache.sis.internal.storage.ChannelImageInputStreamTest.class)
public final strictfp class DataStoreConnectionTest extends TestCase {
/**
* The magic number of Java class files, used for verifying the content of
our test file.
