Export backupV2 using actual desired file format.

core-util/src/main/java/org/signal/core/util/ContentResolverExtensions.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2023 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.signal.core.util
+
+import android.content.ContentResolver
+import android.net.Uri
+import android.provider.OpenableColumns
+import okio.IOException
+
+@Throws(IOException::class)
+fun ContentResolver.getLength(uri: Uri): Long? {
+  return this.query(uri, arrayOf(OpenableColumns.SIZE), null, null, null)?.use { cursor ->
+    if (cursor.moveToFirst()) {
+      cursor.requireLongOrNull(OpenableColumns.SIZE)
+    } else {
+      null
+    }
+  } ?: openInputStream(uri)?.use { it.readLength() }
+}

core-util/src/main/java/org/signal/core/util/InputStreamExtensions.kt

@@ -1,38 +0,0 @@
-/*
- * Copyright 2023 Signal Messenger, LLC
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-package org.signal.core.util
-
-import java.io.IOException
-import java.io.InputStream
-import kotlin.jvm.Throws
-
-/**
- * Reads the entire stream into a [ByteArray].
- */
-@Throws(IOException::class)
-fun InputStream.readFully(): ByteArray {
-  return StreamUtil.readFully(this)
-}
-
-/**
- * Fills reads data from the stream into the [buffer] until it is full.
- * Throws an [IOException] if the stream doesn't have enough data to fill the buffer.
- */
-@Throws(IOException::class)
-fun InputStream.readFully(buffer: ByteArray) {
-  return StreamUtil.readFully(this, buffer)
-}
-
-/**
- * Reads the specified number of bytes from the stream and returns it as a [ByteArray].
- * Throws an [IOException] if the stream doesn't have that many bytes.
- */
-@Throws(IOException::class)
-fun InputStream.readNBytesOrThrow(length: Int): ByteArray {
-  val buffer: ByteArray = ByteArray(length)
-  this.readFully(buffer)
-  return buffer
-}

core-util/src/main/java/org/signal/core/util/StreamUtil.java

@@ -1,104 +0,0 @@
-package org.signal.core.util;
-
-import androidx.annotation.Nullable;
-
-import org.signal.core.util.logging.Log;
-
-import java.io.ByteArrayOutputStream;
-import java.io.Closeable;
-import java.io.EOFException;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-
-/**
- * Utility methods for input and output streams.
- */
-public final class StreamUtil {
-
-  private static final String TAG = Log.tag(StreamUtil.class);
-
-  private StreamUtil() {}
-
-  public static void close(@Nullable Closeable closeable) {
-    if (closeable == null) return;
-
-    try {
-      closeable.close();
-    } catch (IOException e) {
-      Log.w(TAG, e);
-    }
-  }
-
-  public static long getStreamLength(InputStream in) throws IOException {
-    byte[] buffer    = new byte[4096];
-    int    totalSize = 0;
-
-    int read;
-
-    while ((read = in.read(buffer)) != -1) {
-      totalSize += read;
-    }
-
-    return totalSize;
-  }
-
-  public static void readFully(InputStream in, byte[] buffer) throws IOException {
-    readFully(in, buffer, buffer.length);
-  }
-
-  public static void readFully(InputStream in, byte[] buffer, int len) throws IOException {
-    int offset = 0;
-
-    for (;;) {
-      int read = in.read(buffer, offset, len - offset);
-      if (read == -1) throw new EOFException("Stream ended early, offset: " + offset + " len: " + len);
-
-      if (read + offset < len) offset += read;
-      else                		 return;
-    }
-  }
-
-  public static byte[] readFully(InputStream in) throws IOException {
-    return readFully(in, Integer.MAX_VALUE);
-  }
-
-  public static byte[] readFully(InputStream in, int maxBytes) throws IOException {
-    ByteArrayOutputStream bout      = new ByteArrayOutputStream();
-    byte[]                buffer    = new byte[4096];
-    int                   totalRead = 0;
-    int                   read;
-
-    while ((read = in.read(buffer)) != -1) {
-      bout.write(buffer, 0, read);
-      totalRead += read;
-      if (totalRead > maxBytes) {
-        throw new IOException("Stream size limit exceeded");
-      }
-    }
-
-    in.close();
-
-    return bout.toByteArray();
-  }
-
-  public static String readFullyAsString(InputStream in) throws IOException {
-    return new String(readFully(in));
-  }
-
-  public static long copy(InputStream in, OutputStream out) throws IOException {
-    byte[] buffer = new byte[64 * 1024];
-    int read;
-    long total = 0;
-
-    while ((read = in.read(buffer)) != -1) {
-      out.write(buffer, 0, read);
-      total += read;
-    }
-
-    in.close();
-    out.close();
-
-    return total;
-  }
-}

core-util/src/test/java/org/signal/core/util/InputStreamExtensionTests.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2023 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.signal.core.util
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import kotlin.random.Random
+
+class InputStreamExtensionTests {
+
+  @Test
+  fun `when I call readLength, it returns the correct length`() {
+    for (i in 1..10) {
+      val bytes = ByteArray(Random.nextInt(from = 512, until = 8092))
+      val length = bytes.inputStream().readLength()
+      assertEquals(bytes.size.toLong(), length)
+    }
+  }
+}