X-Git-Url: http://git.nikiroo.be/?a=blobdiff_plain;f=src%2Fbe%2Fnikiroo%2Futils%2FReplaceInputStream.java;fp=src%2Fbe%2Fnikiroo%2Futils%2FReplaceInputStream.java;h=5ce9ef32d3692619c4018cc1a26c25ef69e0a070;hb=6ef54b36380b9d123bbdb6b4056cf64b7489225e;hp=0000000000000000000000000000000000000000;hpb=33895a7b06d1a8a7c3555da06b215ab1085ac4df;p=nikiroo-utils.git

diff --git a/src/be/nikiroo/utils/ReplaceInputStream.java b/src/be/nikiroo/utils/ReplaceInputStream.java
new file mode 100644
index 0000000..5ce9ef3
--- /dev/null
+++ b/src/be/nikiroo/utils/ReplaceInputStream.java
@@ -0,0 +1,68 @@
+package be.nikiroo.utils;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UnsupportedEncodingException;
+
+public class ReplaceInputStream extends BufferedInputStream {
+	private byte[] from;
+	private byte[] to;
+
+	private byte[] source;
+	private int spos;
+	private int slen;
+
+	public ReplaceInputStream(InputStream in, String from, String to) {
+		this(in, bytes(from), bytes(to));
+	}
+
+	public ReplaceInputStream(InputStream in, byte[] from, byte[] to) {
+		super(in);
+		this.from = from;
+		this.to = to;
+
+		source = new byte[4096];
+		spos = 0;
+		slen = 0;
+	}
+
+	@Override
+	protected int read(InputStream in, byte[] buffer) throws IOException {
+		if (buffer.length < to.length) {
+			throw new IOException(
+					"Underlaying buffer is too small to contain the replace String");
+		}
+
+		if (spos >= slen) {
+			spos = 0;
+			slen = in.read(source);
+		}
+
+		// Note: very simple, not efficient implementation, sorry.
+		int count = 0;
+		int i = spos;
+		while (i < slen && count < buffer.length - to.length) {
+			if (from.length > 0 && startsWith(from, source, spos)) {
+				System.arraycopy(to, 0, buffer, spos, to.length);
+				count += to.length;
+				i += to.length;
+				spos += to.length;
+			} else {
+				buffer[count++] = source[i++];
+				spos++;
+			}
+		}
+
+		return count;
+	}
+
+	static private byte[] bytes(String str) {
+		try {
+			return str.getBytes("UTF-8");
+		} catch (UnsupportedEncodingException e) {
+			// All conforming JVM must support UTF-8
+			e.printStackTrace();
+			return null;
+		}
+	}
+}