implement Inflater and InflaterInputStream

classpath/java/util/zip/InflaterInputStream.java

@@ -2,19 +2,64 @@ package java.util.zip;
 
 import java.io.InputStream;
 import java.io.IOException;
+import java.io.EOFException;
 
 public class InflaterInputStream extends InputStream {
   private final InputStream in;
+  private final Inflater inflater;
+  private final byte[] buffer;
+
+  public InflaterInputStream(InputStream in, Inflater inflater, int bufferSize)
+  {
+    this.in = in;
+    this.inflater = inflater;
+    this.buffer = new byte[bufferSize];
+  }
+
+  public InflaterInputStream(InputStream in, Inflater inflater) {
+    this(in, inflater, 4 * 1024);
+  }
 
   public InflaterInputStream(InputStream in) {
-    this.in = in;
+    this(in, new Inflater());
   }
 
   public int read() throws IOException {
-    throw new IOException("not implemented");
+    byte[] buffer = new byte[1];
+    int c = read(buffer);
+    return (c < 0 ? c : (buffer[0] & 0xFF));
+  }
+
+  public int read(byte[] b, int offset, int length) throws IOException {
+    if (inflater.finished()) {
+      return -1;
+    }
+
+    while (true) {
+      if (inflater.needsInput()) {
+        int count = in.read(buffer);
+        if (count > 0) {
+          inflater.setInput(buffer, 0, count);
+        } else {
+          throw new EOFException();
+        }
+      }
+
+      try {
+        int count = inflater.inflate(b, offset, length);
+        if (count > 0) {
+          return count;
+        } else if (inflater.needsDictionary()) {
+          throw new IOException("missing dictionary");
+        }
+      } catch (DataFormatException e) {
+        throw new IOException(e);
+      }
+    }
   }
 
   public void close() throws IOException {
     in.close();
+    inflater.dispose();
   }
 }