exifinterface/exifinterface/src/main/java/androidx/exifinterface/media/ExifInterfaceUtils.java

/*
 * Copyright 2020 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package androidx.exifinterface.media;

import static androidx.exifinterface.media.ExifInterface.IMAGE_TYPE_JPEG;
import static androidx.exifinterface.media.ExifInterface.IMAGE_TYPE_PNG;
import static androidx.exifinterface.media.ExifInterface.IMAGE_TYPE_WEBP;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

class ExifInterfaceUtils {
    private static final String TAG = "ExifInterfaceUtils";

    private ExifInterfaceUtils() {
        // Prevent instantiation
    }
    /**
     * Copies all of the bytes from {@code in} to {@code out}. Neither stream is closed.
     * Returns the total number of bytes transferred.
     */
    static int copy(InputStream in, OutputStream out) throws IOException {
        int total = 0;
        byte[] buffer = new byte[8192];
        int c;
        while ((c = in.read(buffer)) != -1) {
            total += c;
            out.write(buffer, 0, c);
        }
        return total;
    }

    /**
     * Copies the given number of the bytes from {@code in} to {@code out}. Neither stream is
     * closed.
     */
    static void copy(InputStream in, OutputStream out, int numBytes) throws IOException {
        int remainder = numBytes;
        byte[] buffer = new byte[8192];
        while (remainder > 0) {
            int bytesToRead = Math.min(remainder, 8192);
            int bytesRead = in.read(buffer, 0, bytesToRead);
            if (bytesRead != bytesToRead) {
                throw new IOException("Failed to copy the given amount of bytes from the input"
                        + "stream to the output stream.");
            }
            remainder -= bytesRead;
            out.write(buffer, 0, bytesRead);
        }
    }

    /**
     * Convert given int[] to long[]. If long[] is given, just return it.
     * Return null for other types of input.
     */
    static long[] convertToLongArray(Object inputObj) {
        if (inputObj instanceof int[]) {
            int[] input = (int[]) inputObj;
            long[] result = new long[input.length];
            for (int i = 0; i < input.length; i++) {
                result[i] = input[i];
            }
            return result;
        } else if (inputObj instanceof long[]) {
            return (long[]) inputObj;
        }
        return null;
    }

    static boolean startsWith(byte[] cur, byte[] val) {
        if (cur == null || val == null) {
            return false;
        }
        if (cur.length < val.length) {
            return false;
        }
        for (int i = 0; i < val.length; i++) {
            if (cur[i] != val[i]) {
                return false;
            }
        }
        return true;
    }

    static boolean isSupportedFormatForSavingAttributes(int mimeType) {
        if (mimeType == IMAGE_TYPE_JPEG || mimeType == IMAGE_TYPE_PNG
                || mimeType == IMAGE_TYPE_WEBP) {
            return true;
        }
        return false;
    }

    static String byteArrayToHexString(byte[] bytes) {
        StringBuilder sb = new StringBuilder(bytes.length * 2);
        for (int i = 0; i < bytes.length; i++) {
            sb.append(String.format("%02x", bytes[i]));
        }
        return sb.toString();
    }

    static long parseSubSeconds(String subSec) {
        try {
            final int len = Math.min(subSec.length(), 3);
            long sub = Long.parseLong(subSec.substring(0, len));
            for (int i = len; i < 3; i++) {
                sub *= 10;
            }
            return sub;
        } catch (NumberFormatException e) {
            // Ignored
        }
        return 0L;
    }
}