1 files changed, 92 insertions, 0 deletions
diff --git a/mobile/android/services/src/main/java/org/mozilla/gecko/sync/net/GzipNonChunkedCompressingEntity.java b/mobile/android/services/src/main/java/org/mozilla/gecko/sync/net/GzipNonChunkedCompressingEntity.java
new file mode 100644
index 000000000..1e238c022
--- /dev/null
+++ b/mobile/android/services/src/main/java/org/mozilla/gecko/sync/net/GzipNonChunkedCompressingEntity.java
@@ -0,0 +1,92 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.sync.net;
+
+import ch.boye.httpclientandroidlib.HttpEntity;
+import ch.boye.httpclientandroidlib.client.entity.GzipCompressingEntity;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+/**
+ * Wrapping entity that compresses content when {@link #writeTo writing}.
+ *
+ * This differs from {@link GzipCompressingEntity} in that it does not chunk
+ * the sent data, therefore replacing the "Transfer-Encoding" HTTP header with
+ * the "Content-Length" header required by some servers.
+ *
+ * However, to measure the content length, the gzipped content will be temporarily
+ * stored in memory so be careful what content you send!
+ */
+public class GzipNonChunkedCompressingEntity extends GzipCompressingEntity {
+    final int MAX_BUFFER_SIZE_BYTES = 10 * 1000 * 1000; // 10 MB.
+
+    private byte[] gzippedContent;
+
+    public GzipNonChunkedCompressingEntity(final HttpEntity entity) {
+        super(entity);
+    }
+
+    /**
+     * @return content length for gzipped content or -1 if there is an error
+     */
+    @Override
+    public long getContentLength() {
+        try {
+            initBuffer();
+        } catch (final IOException e) {
+            // GzipCompressingEntity always returns -1 in which case a 'Content-Length' header is omitted.
+            // Presumably, without it the request will fail (either client-side or server-side).
+            return -1;
+        }
+        return gzippedContent.length;
+    }
+
+    @Override
+    public boolean isChunked() {
+        // "Content-Length" & chunked encoding are mutually exclusive:
+        //   https://en.wikipedia.org/wiki/Chunked_transfer_encoding
+        return false;
+    }
+
+    @Override
+    public InputStream getContent() throws IOException {
+        initBuffer();
+        return new ByteArrayInputStream(gzippedContent);
+    }
+
+    @Override
+    public void writeTo(final OutputStream outstream) throws IOException {
+        initBuffer();
+        outstream.write(gzippedContent);
+    }
+
+    private void initBuffer() throws IOException {
+        if (gzippedContent != null) {
+            return;
+        }
+
+        final long unzippedContentLength = wrappedEntity.getContentLength();
+        if (unzippedContentLength > MAX_BUFFER_SIZE_BYTES) {
+            throw new IOException(
+                    "Wrapped entity content length, " + unzippedContentLength + " bytes, exceeds max: " + MAX_BUFFER_SIZE_BYTES);
+        }
+
+        // The buffer size needed by the gzipped content should be smaller than this,
+        // but it's more efficient just to allocate one larger buffer than allocate
+        // twice if the gzipped content is too large for the default buffer.
+        final ByteArrayOutputStream s = new ByteArrayOutputStream((int) unzippedContentLength);
+        try {
+            super.writeTo(s);
+        } finally {
+            s.close();
+        }
+
+        gzippedContent = s.toByteArray();
+    }
+}