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authorSam Whited <sam@samwhited.com>2014-10-22 15:44:55 -0400
committerSam Whited <sam@samwhited.com>2014-10-22 15:47:11 -0400
commit281ce3105fad5f012471cf3e5062a4032dfbc7a6 (patch)
tree63f9e37c2104609a9ace4724b5e10c3539a7feb4 /src/main/java/eu/siacs/conversations/utils/zlib
parent07b47172a08c01c248c6f69bae48d9e60695a14b (diff)
Make conversations the root project
Diffstat (limited to 'src/main/java/eu/siacs/conversations/utils/zlib')
-rw-r--r--src/main/java/eu/siacs/conversations/utils/zlib/ZLibInputStream.java54
-rw-r--r--src/main/java/eu/siacs/conversations/utils/zlib/ZLibOutputStream.java95
2 files changed, 149 insertions, 0 deletions
diff --git a/src/main/java/eu/siacs/conversations/utils/zlib/ZLibInputStream.java b/src/main/java/eu/siacs/conversations/utils/zlib/ZLibInputStream.java
new file mode 100644
index 00000000..b777c10c
--- /dev/null
+++ b/src/main/java/eu/siacs/conversations/utils/zlib/ZLibInputStream.java
@@ -0,0 +1,54 @@
+package eu.siacs.conversations.utils.zlib;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.zip.Inflater;
+import java.util.zip.InflaterInputStream;
+
+/**
+ * ZLibInputStream is a zlib and input stream compatible version of an
+ * InflaterInputStream. This class solves the incompatibility between
+ * {@link InputStream#available()} and {@link InflaterInputStream#available()}.
+ */
+public class ZLibInputStream extends InflaterInputStream {
+
+ /**
+ * Construct a ZLibInputStream, reading data from the underlying stream.
+ *
+ * @param is
+ * The {@code InputStream} to read data from.
+ * @throws IOException
+ * If an {@code IOException} occurs.
+ */
+ public ZLibInputStream(InputStream is) throws IOException {
+ super(is, new Inflater(), 512);
+ }
+
+ /**
+ * Provide a more InputStream compatible version of available. A return
+ * value of 1 means that it is likly to read one byte without blocking, 0
+ * means that the system is known to block for more input.
+ *
+ * @return 0 if no data is available, 1 otherwise
+ * @throws IOException
+ */
+ @Override
+ public int available() throws IOException {
+ /*
+ * This is one of the funny code blocks. InflaterInputStream.available
+ * violates the contract of InputStream.available, which breaks kXML2.
+ *
+ * I'm not sure who's to blame, oracle/sun for a broken api or the
+ * google guys for mixing a sun bug with a xml reader that can't handle
+ * it....
+ *
+ * Anyway, this simple if breaks suns distorted reality, but helps to
+ * use the api as intended.
+ */
+ if (inf.needsInput()) {
+ return 0;
+ }
+ return super.available();
+ }
+
+}
diff --git a/src/main/java/eu/siacs/conversations/utils/zlib/ZLibOutputStream.java b/src/main/java/eu/siacs/conversations/utils/zlib/ZLibOutputStream.java
new file mode 100644
index 00000000..8b3f5e68
--- /dev/null
+++ b/src/main/java/eu/siacs/conversations/utils/zlib/ZLibOutputStream.java
@@ -0,0 +1,95 @@
+package eu.siacs.conversations.utils.zlib;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.security.NoSuchAlgorithmException;
+import java.util.zip.Deflater;
+import java.util.zip.DeflaterOutputStream;
+
+/**
+ * <p>
+ * Android 2.2 includes Java7 FLUSH_SYNC option, which will be used by this
+ * Implementation, preferable via reflection. The @hide was remove in API level
+ * 19. This class might thus go away in the future.
+ * </p>
+ * <p>
+ * Please use {@link ZLibOutputStream#SUPPORTED} to check for flush
+ * compatibility.
+ * </p>
+ */
+public class ZLibOutputStream extends DeflaterOutputStream {
+
+ /**
+ * The reflection based flush method.
+ */
+
+ private final static Method method;
+ /**
+ * SUPPORTED is true if a flush compatible method exists.
+ */
+ public final static boolean SUPPORTED;
+
+ /**
+ * Static block to initialize {@link #SUPPORTED} and {@link #method}.
+ */
+ static {
+ Method m = null;
+ try {
+ m = Deflater.class.getMethod("deflate", byte[].class, int.class,
+ int.class, int.class);
+ } catch (SecurityException e) {
+ } catch (NoSuchMethodException e) {
+ }
+ method = m;
+ SUPPORTED = (method != null);
+ }
+
+ /**
+ * Create a new ZLib compatible output stream wrapping the given low level
+ * stream. ZLib compatiblity means we will send a zlib header.
+ *
+ * @param os
+ * OutputStream The underlying stream.
+ * @throws IOException
+ * In case of a lowlevel transfer problem.
+ * @throws NoSuchAlgorithmException
+ * In case of a {@link Deflater} error.
+ */
+ public ZLibOutputStream(OutputStream os) throws IOException,
+ NoSuchAlgorithmException {
+ super(os, new Deflater(Deflater.BEST_COMPRESSION));
+ }
+
+ /**
+ * Flush the given stream, preferring Java7 FLUSH_SYNC if available.
+ *
+ * @throws IOException
+ * In case of a lowlevel exception.
+ */
+ @Override
+ public void flush() throws IOException {
+ if (!SUPPORTED) {
+ super.flush();
+ return;
+ }
+ try {
+ int count = 0;
+ do {
+ count = (Integer) method.invoke(def, buf, 0, buf.length, 3);
+ if (count > 0) {
+ out.write(buf, 0, count);
+ }
+ } while (count > 0);
+ } catch (IllegalArgumentException e) {
+ throw new IOException("Can't flush");
+ } catch (IllegalAccessException e) {
+ throw new IOException("Can't flush");
+ } catch (InvocationTargetException e) {
+ throw new IOException("Can't flush");
+ }
+ super.flush();
+ }
+
+}