This is an automated email from the ASF dual-hosted git repository.
desruisseaux pushed a commit to branch geoapi-4.0
in repository https://gitbox.apache.org/repos/asf/sis.git
commit c14f9c667295ff317fdfb8d10b70a809a2888372
Author: Martin Desruisseaux <martin.desruisse...@geomatys.com>
AuthorDate: Thu Jan 6 04:53:31 2022 +0100
Provide a safer alternative to the possibly infinite loops over
`Markable.reset()`.
---
.../sis/internal/storage/io/ChannelData.java | 26 ++++++++++++++++++++--
.../internal/storage/io/InputStreamAdapter.java | 26 +++++++++++++++++++++-
.../apache/sis/internal/storage/io/Markable.java | 12 +++++++++-
.../internal/storage/io/OutputStreamAdapter.java | 15 +++++++++++--
.../org/apache/sis/storage/DataStoreProvider.java | 3 +--
.../internal/storage/xml/stream/StaxDataStore.java | 14 ++++--------
6 files changed, 78 insertions(+), 18 deletions(-)
diff --git
a/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/ChannelData.java
b/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/ChannelData.java
index 36a1caf..adab367 100644
---
a/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/ChannelData.java
+++
b/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/ChannelData.java
@@ -32,8 +32,8 @@ import static
org.apache.sis.util.ArgumentChecks.ensureBetween;
* querying or modifying the stream position. This class does not define any
read or write operations.
*
* @author Martin Desruisseaux (Geomatys)
- * @version 1.1
- * @since 0.5 (derived from 0.3)
+ * @version 1.2
+ * @since 0.3
* @module
*/
public abstract class ChannelData implements Markable {
@@ -332,6 +332,28 @@ public abstract class ChannelData implements Markable {
}
/**
+ * Moves to the given position in the stream and discards all marks at or
after that position.
+ * If a mark exists at the given position, the bit offset is also restored.
+ *
+ * @param position position where to seek.
+ * @throws IOException if this stream can not move to the specified mark
position.
+ */
+ @Override
+ public final void reset(final long position) throws IOException {
+ Mark lastValid = null;
+ while (mark != null && mark.position >= position) {
+ final boolean found = mark.position == position;
+ if (found) lastValid = mark;
+ mark = mark.next; // Discard all marks after the
specified position.
+ if (found) break;
+ }
+ seek(position);
+ if (lastValid != null) {
+ setBitOffset(lastValid.bitOffset);
+ }
+ }
+
+ /**
* Invoked when an operation between the channel and the buffer
transferred no byte. Note that this is unrelated
* to end-of-file, in which case {@link
java.nio.channels.ReadableByteChannel#read(ByteBuffer)} returns -1.
* A return value of 0 happen for example if the channel is a socket in
non-blocking mode and the socket buffer
diff --git
a/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/InputStreamAdapter.java
b/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/InputStreamAdapter.java
index 76ee111..c9fd626 100644
---
a/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/InputStreamAdapter.java
+++
b/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/InputStreamAdapter.java
@@ -20,6 +20,7 @@ import java.io.InputStream;
import java.io.IOException;
import java.io.UncheckedIOException;
import javax.imageio.stream.ImageInputStream;
+import org.apache.sis.io.InvalidSeekException;
import org.apache.sis.internal.storage.Resources;
@@ -181,7 +182,7 @@ public final class InputStreamAdapter extends InputStream
implements Markable {
* were created by {@link #mark()} or {@link #mark(int)}, except that all
marks created by
* {@link #mark(int)} are ignored except the most recent one.
*
- * <p>Implementations of {@code reset()} if Java I/O package does not
discard the mark.
+ * <p>Implementations of {@code reset()} in Java I/O package does not
discard the mark.
* The implementation in this {@code InputStreamAdapter} class does not
discard the mark
* neither if the mark done by a call to {@link #mark(int)} is the only
mark remaining.
* Some code depends on the ability to do many {@code reset()} for the
same mark.</p>
@@ -204,6 +205,29 @@ public final class InputStreamAdapter extends InputStream
implements Markable {
}
/**
+ * Moves to the given position in the stream and discards all marks at or
after that position.
+ * This convolved method exists because of the attempt to conciliate two
different APIs in this class
+ * (see {@link #reset()}). This method does not simply call {@link
ImageInputStream#seek(long)}
+ * because we need to keep track of the marks.
+ *
+ * @param mark position where to seek.
+ * @throws IOException if this stream can not move to the specified mark
position.
+ */
+ @Override
+ public synchronized void reset(final long mark) throws IOException {
+ long p;
+ int n;
+ do {
+ n = nestedMarks;
+ reset();
+ p = input.getStreamPosition();
+ } while (p > mark && n > 0);
+ if (p != mark) {
+ throw new InvalidSeekException();
+ }
+ }
+
+ /**
* Returns the current byte position of the stream.
*
* @return the position of the stream.
diff --git
a/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/Markable.java
b/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/Markable.java
index 044df5d..2d90ee0 100644
---
a/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/Markable.java
+++
b/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/Markable.java
@@ -35,7 +35,7 @@ import java.io.IOException;
* </div>
*
* @author Martin Desruisseaux (Geomatys)
- * @version 0.8
+ * @version 1.2
*
* @see Readable
*
@@ -82,4 +82,14 @@ public interface Markable {
* @see org.apache.sis.io.InvalidSeekException
*/
void reset() throws IOException;
+
+ /**
+ * Resets the stream position to the mark at the given position. Invoking
this method is similar to
+ * invoking {@code seek(mark)} except that it may work on non-seekable
stream if a mark has been set
+ * on that position.
+ *
+ * @param mark position where to seek. Should be a position where a mark
has been created.
+ * @throws IOException if this stream can not move to the specified mark
position.
+ */
+ void reset(long mark) throws IOException;
}
diff --git
a/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/OutputStreamAdapter.java
b/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/OutputStreamAdapter.java
index 5942685..d58b138 100644
---
a/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/OutputStreamAdapter.java
+++
b/storage/sis-storage/src/main/java/org/apache/sis/internal/storage/io/OutputStreamAdapter.java
@@ -24,7 +24,7 @@ import java.io.IOException;
* Wraps a {@link ChannelDataOutput} as a standard {@link OutputStream}.
*
* @author Martin Desruisseaux (Geomatys)
- * @version 0.8
+ * @version 1.2
*
* @see InputStreamAdapter
*
@@ -95,7 +95,7 @@ final class OutputStreamAdapter extends OutputStream
implements Markable {
}
/**
- * Repositions this stream to the position at the time the {@code mark}
method was last called.
+ * Resets this stream to the position at the time the {@code mark} method
was last called.
*
* @throws IOException if this stream can not move to the last mark
position.
*/
@@ -105,6 +105,17 @@ final class OutputStreamAdapter extends OutputStream
implements Markable {
}
/**
+ * Moves to the given position in the stream and discards all marks at or
after that position.
+ *
+ * @param mark position where to seek.
+ * @throws IOException if this stream can not move to the specified mark
position.
+ */
+ @Override
+ public void reset(final long mark) throws IOException {
+ output.reset(mark);
+ }
+
+ /**
* Returns the current byte position of the stream.
*
* @return the position of the stream.
diff --git
a/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStoreProvider.java
b/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStoreProvider.java
index 02bdeb3..fb6bab3 100644
---
a/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStoreProvider.java
+++
b/storage/sis-storage/src/main/java/org/apache/sis/storage/DataStoreProvider.java
@@ -379,8 +379,7 @@ public abstract class DataStoreProvider {
final long position = stream.getStreamPosition();
stream.mark();
result = prober.test(input);
- do stream.reset();
- while (stream.getStreamPosition() != position);
+ stream.reset(position);
} else if (input instanceof ImageInputStream) {
/*
* `ImageInputStream` supports an arbitrary number of
marks as well,
diff --git
a/storage/sis-xmlstore/src/main/java/org/apache/sis/internal/storage/xml/stream/StaxDataStore.java
b/storage/sis-xmlstore/src/main/java/org/apache/sis/internal/storage/xml/stream/StaxDataStore.java
index 2a7b7ac..4c2295c 100644
---
a/storage/sis-xmlstore/src/main/java/org/apache/sis/internal/storage/xml/stream/StaxDataStore.java
+++
b/storage/sis-xmlstore/src/main/java/org/apache/sis/internal/storage/xml/stream/StaxDataStore.java
@@ -268,16 +268,10 @@ public abstract class StaxDataStore extends URIDataStore {
private boolean reset() throws IOException {
if (streamPosition >= 0) try {
final Markable m = (Markable) stream;
- long p;
- do {
- m.reset();
- p = m.getStreamPosition();
- } while (p > streamPosition);
- if (p == streamPosition) {
- m.mark();
- state = START;
- return true;
- }
+ m.reset(streamPosition);
+ m.mark();
+ state = START;
+ return true;
} catch (InvalidSeekException e) {
listeners.warning(e);
}
