Initial libarchive simple support

native/src/main/java/com/hippo/UriArchiveAccessor.java

@@ -0,0 +1,79 @@
+package com.hippo;
+
+import android.content.Context;
+import android.net.Uri;
+import android.os.ParcelFileDescriptor;
+import android.system.ErrnoException;
+import android.system.Os;
+import android.system.OsConstants;
+
+import java.io.Closeable;
+import java.io.FileDescriptor;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.OutputStream;
+
+public class UriArchiveAccessor implements Closeable {
+    public static int OPEN_OK = 1;
+    public static int OPEN_ERR = 2;
+    private final OsReadableFile osf;
+
+    public UriArchiveAccessor(Context ctx, Uri uri) throws FileNotFoundException {
+        osf = new OsReadableFile(ctx, uri);
+    }
+
+    public int open() {
+        return openArchive(osf);
+    }
+
+    public void extractTargetIndexToOutputStream(int index, OutputStream os) {
+        extracttoOutputStream(osf, index, os);
+    }
+
+    private native int openArchive(OsReadableFile osf);
+    private native int extracttoOutputStream(OsReadableFile osf, int index, OutputStream os);
+
+    @Override
+    public void close() throws IOException {
+        osf.close();
+    }
+
+    static class OsReadableFile {
+        ParcelFileDescriptor pfd;
+        FileDescriptor fd;
+
+        public OsReadableFile(Context ctx, Uri uri) throws FileNotFoundException {
+            pfd = ctx.getContentResolver().openFileDescriptor(uri, "r");
+            fd = pfd.getFileDescriptor();
+        }
+
+        public int read(byte[] b, int off, int len) throws IOException, ErrnoException {
+            return Os.read(fd, b, off, len);
+        }
+
+        public int read(byte[] b) throws IOException, ErrnoException {
+            return read(b, 0, b.length);
+        }
+
+        public long length() throws IOException, ErrnoException {
+            return Os.fstat(fd).st_size;
+        }
+
+        public void seek(long pos) throws IOException, ErrnoException {
+            Os.lseek(fd, pos, OsConstants.SEEK_SET);
+        }
+
+        public void rewind() throws IOException, ErrnoException {
+            Os.lseek(fd, 0, OsConstants.SEEK_SET);
+        }
+
+        public void close() throws IOException {
+            pfd.close();
+            try {
+                Os.close(fd);
+            } catch (ErrnoException e) {
+                throw new IOException("An ErrnoException occurs", e);
+            }
+        }
+    }
+}