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authorFredrik Gustafsson <[email protected]>2013-02-13 15:09:45 +0100
committerFredrik Gustafsson <[email protected]>2013-02-13 15:09:45 +0100
commit14254702c27e9010f65cab69cd2829b00012d7ff (patch)
tree655e03f7a4f79bddfc3de193974fbfda7896d981 /lib/jinterface/java_src/com
parente55aff9434072dc9ba45b610d2e5110b0d537692 (diff)
parent283569b8ede00003c24776961e77051f37dc5594 (diff)
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Merge branch 'nk/jinterface_dont_compress_if_size_increased/OTP-10822'
* nk/jinterface_dont_compress_if_size_increased/OTP-10822: jinterface, OtpOutputStream: add a write_compressed(object, level) method jinterface: fix a memory leak jinterface: new limited OutputStream implementation without the need to resize jinterface: don't return compressed external term if bigger than uncompressed jinterface: don't compress small erlang terms < 5 bytes jinterface, OtpOutputStream: properly override the three write() methods to ensure our growth strategy jinterface: fix typo in error message if encoding fails jinterface: don't need another FilterOutputStream wrapper
Diffstat (limited to 'lib/jinterface/java_src/com')
-rw-r--r--lib/jinterface/java_src/com/ericsson/otp/erlang/OtpOutputStream.java138
1 files changed, 111 insertions, 27 deletions
diff --git a/lib/jinterface/java_src/com/ericsson/otp/erlang/OtpOutputStream.java b/lib/jinterface/java_src/com/ericsson/otp/erlang/OtpOutputStream.java
index 47ec3cc052..78f47aa32f 100644
--- a/lib/jinterface/java_src/com/ericsson/otp/erlang/OtpOutputStream.java
+++ b/lib/jinterface/java_src/com/ericsson/otp/erlang/OtpOutputStream.java
@@ -26,6 +26,7 @@ import java.math.BigDecimal;
import java.math.BigInteger;
import java.text.DecimalFormat;
import java.util.Arrays;
+import java.util.zip.Deflater;
/**
* Provides a stream for encoding Erlang terms to external format, for
@@ -48,6 +49,8 @@ public class OtpOutputStream extends ByteArrayOutputStream {
private static final BigDecimal ten = new BigDecimal(10.0);
private static final BigDecimal one = new BigDecimal(1.0);
+ private int fixedSize = Integer.MAX_VALUE;
+
/**
* Create a stream with the default initial size (2048 bytes).
*/
@@ -101,10 +104,16 @@ public class OtpOutputStream extends ByteArrayOutputStream {
* the storage of an <tt>OtpOutputStream</tt> instance.
*/
public void trimToSize() {
- if (super.count < super.buf.length) {
- final byte[] tmp = new byte[super.count];
- System.arraycopy(super.buf, 0, tmp, 0, super.count);
+ resize(super.count);
+ }
+
+ private void resize(int size) {
+ if (size < super.buf.length) {
+ final byte[] tmp = new byte[size];
+ System.arraycopy(super.buf, 0, tmp, 0, size);
super.buf = tmp;
+ } else if (size > super.buf.length) {
+ ensureCapacity(size);
}
}
@@ -116,6 +125,9 @@ public class OtpOutputStream extends ByteArrayOutputStream {
* @param minCapacity the desired minimum capacity
*/
public void ensureCapacity(int minCapacity) {
+ if (minCapacity > fixedSize) {
+ throw new IllegalArgumentException("Trying to increase fixed-size buffer");
+ }
int oldCapacity = super.buf.length;
if (minCapacity > oldCapacity) {
int newCapacity = (oldCapacity * 3)/2 + 1;
@@ -123,6 +135,7 @@ public class OtpOutputStream extends ByteArrayOutputStream {
newCapacity = oldCapacity + defaultIncrement;
if (newCapacity < minCapacity)
newCapacity = minCapacity;
+ newCapacity = Math.min(fixedSize, newCapacity);
// minCapacity is usually close to size, so this is a win:
final byte[] tmp = new byte[newCapacity];
System.arraycopy(super.buf, 0, tmp, 0, super.count);
@@ -142,19 +155,37 @@ public class OtpOutputStream extends ByteArrayOutputStream {
super.buf[super.count++] = b;
}
- /**
- * Write an array of bytes to the stream.
- *
- * @param buf
- * the array of bytes to write.
- *
+ /* (non-Javadoc)
+ * @see java.io.ByteArrayOutputStream#write(byte[])
*/
-
@Override
public void write(final byte[] buf) {
- ensureCapacity(super.count + buf.length);
- System.arraycopy(buf, 0, super.buf, super.count, buf.length);
- super.count += buf.length;
+ // don't assume that super.write(byte[]) calls write(buf, 0, buf.length)
+ write(buf, 0, buf.length);
+ }
+
+ /* (non-Javadoc)
+ * @see java.io.ByteArrayOutputStream#write(int)
+ */
+ @Override
+ public synchronized void write(int b) {
+ ensureCapacity(super.count + 1);
+ super.buf[super.count] = (byte) b;
+ count += 1;
+ }
+
+ /* (non-Javadoc)
+ * @see java.io.ByteArrayOutputStream#write(byte[], int, int)
+ */
+ @Override
+ public synchronized void write(byte[] b, int off, int len) {
+ if ((off < 0) || (off > b.length) || (len < 0)
+ || ((off + len) - b.length > 0)) {
+ throw new IndexOutOfBoundsException();
+ }
+ ensureCapacity(super.count + len);
+ System.arraycopy(b, off, super.buf, super.count, len);
+ super.count += len;
}
/**
@@ -819,24 +850,77 @@ public class OtpOutputStream extends ByteArrayOutputStream {
/**
* Write an arbitrary Erlang term to the stream in compressed format.
- *
+ *
* @param o
- * the Erlang tem to write.
+ * the Erlang term to write.
*/
public void write_compressed(final OtpErlangObject o) {
+ write_compressed(o, Deflater.DEFAULT_COMPRESSION);
+ }
+
+ /**
+ * Write an arbitrary Erlang term to the stream in compressed format.
+ *
+ * @param o
+ * the Erlang term to write.
+ * @param level
+ * the compression level (<tt>0..9</tt>)
+ */
+ public void write_compressed(final OtpErlangObject o, int level) {
final OtpOutputStream oos = new OtpOutputStream(o);
- write1(OtpExternal.compressedTag);
- write4BE(oos.size());
- final java.io.FilterOutputStream fos = new java.io.FilterOutputStream(
- this);
- final java.util.zip.DeflaterOutputStream dos = new java.util.zip.DeflaterOutputStream(
- fos);
- try {
- oos.writeTo(dos);
- dos.close();
- } catch (final IOException e) {
- throw new java.lang.IllegalArgumentException(
- "Intremediate stream failed for Erlang object " + o);
+ /*
+ * similar to erts_term_to_binary() in external.c:
+ * We don't want to compress if compression actually increases the size.
+ * Since compression uses 5 extra bytes (COMPRESSED tag + size), don't
+ * compress if the original term is smaller.
+ */
+ if (oos.size() < 5) {
+ // fast path for small terms
+ try {
+ oos.writeTo(this);
+ // if the term is written as a compressed term, the output
+ // stream is closed, so we do this here, too
+ this.close();
+ } catch (IOException e) {
+ throw new java.lang.IllegalArgumentException(
+ "Intermediate stream failed for Erlang object " + o);
+ }
+ } else {
+ int startCount = super.count;
+ // we need destCount bytes for an uncompressed term
+ // -> if compression uses more, use the uncompressed term!
+ int destCount = startCount + oos.size();
+ this.fixedSize = destCount;
+ Deflater def = new Deflater(level);
+ final java.util.zip.DeflaterOutputStream dos = new java.util.zip.DeflaterOutputStream(
+ this, def);
+ try {
+ write1(OtpExternal.compressedTag);
+ write4BE(oos.size());
+ oos.writeTo(dos);
+ dos.close(); // note: closes this, too!
+ } catch (final IllegalArgumentException e) {
+ // discard further un-compressed data
+ // -> if not called, there may be memory leaks!
+ def.end();
+ // could not make the value smaller than originally
+ // -> reset to starting count, write uncompressed
+ super.count = startCount;
+ try {
+ oos.writeTo(this);
+ // if the term is written as a compressed term, the output
+ // stream is closed, so we do this here, too
+ this.close();
+ } catch (IOException e2) {
+ throw new java.lang.IllegalArgumentException(
+ "Intermediate stream failed for Erlang object " + o);
+ }
+ } catch (final IOException e) {
+ throw new java.lang.IllegalArgumentException(
+ "Intermediate stream failed for Erlang object " + o);
+ } finally {
+ this.fixedSize = Integer.MAX_VALUE;
+ }
}
}