add etagv2

src/main/java/com/qiniu/util/EtagV2.java

@@ -0,0 +1,132 @@
+package com.qiniu.util;
+
+import java.io.*;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
+
+public class EtagV2 {
+    private EtagV2() {
+    }
+
+    public static String data(byte[] data, int offset, int length, long blockSize) {
+        try {
+            return stream(new ByteArrayInputStream(data, offset, length), length, blockSize);
+        } catch (IOException e) {
+            throw new AssertionError(e);
+        }
+    }
+
+    public static String data(byte[] data, long blockSize) {
+        return data(data, 0, data.length, blockSize);
+    }
+
+    public static String data(byte[] data, int offset, int length, long[] parts) {
+        try {
+            return stream(new ByteArrayInputStream(data, offset, length), length, parts);
+        } catch (IOException e) {
+            throw new AssertionError(e);
+        }
+    }
+
+    public static String data(byte[] data, long[] parts) {
+        return data(data, 0, data.length, parts);
+    }
+
+    public static String file(String filePath, long blockSize) throws IOException {
+        return file(new File(filePath), blockSize);
+    }
+
+    public static String file(String filePath, long[] parts) throws IOException {
+        return file(new File(filePath), parts);
+    }
+
+    public static String file(File file, long blockSize) throws IOException {
+        FileInputStream fi = null;
+        try {
+            fi = new FileInputStream(file);
+            return stream(fi, file.length(), blockSize);
+        } finally {
+            if (fi != null) {
+                try {
+                    fi.close();
+                } catch (Throwable t) {
+                }
+            }
+        }
+    }
+
+    public static String file(File file, long[] parts) throws IOException {
+        FileInputStream fi = null;
+        try {
+            fi = new FileInputStream(file);
+            return stream(fi, file.length(), parts);
+        } finally {
+            if (fi != null) {
+                try {
+                    fi.close();
+                } catch (Throwable t) {
+                }
+            }
+        }
+    }
+
+
+    public static String stream(InputStream in, long len, long blockSize) throws IOException {
+        // // 和 is4MBParts(new long[]{len}) 实质一样，只有一个 part 的简化版 // //
+        if (blockSize == 1024 * 1024 * 4 || (len <= blockSize && len <= 1024 * 1024 * 4)) {
+            return Etag.stream(in, len);
+        }
+        int size = (int) ((len + blockSize - 1) / blockSize);
+        long[] parts = new long[size];
+        Arrays.fill(parts, 0, size - 1, blockSize);
+        parts[size - 1] = len % blockSize;
+
+        return etagV2NoCheck(in, len, parts);
+    }
+
+    public static String stream(InputStream in, long len, long[] parts) throws IOException {
+        if (is4MBParts(parts)) {
+            return Etag.stream(in, len);
+        }
+        long partSize = 0;
+        for (long part : parts) {
+            partSize += part;
+        }
+        if (len != partSize) {
+            throw new IOException("etag calc failed: size not equal with part size");
+        }
+        return etagV2NoCheck(in, len, parts);
+    }
+
+    private static boolean is4MBParts(long[] parts) {
+        int idx = 0;
+        int last = parts.length - 1;
+        for (long part : parts) {
+            if (idx != last && part != 1024 * 1024 * 4 || part > 1024 * 1024 * 4) {
+                return false;
+            }
+            idx += 1;
+        }
+        return true;
+    }
+
+    private static String etagV2NoCheck(InputStream in, long len, long[] parts) throws IOException {
+        MessageDigest sha1;
+        try {
+            sha1 = MessageDigest.getInstance("sha-1");
+        } catch (NoSuchAlgorithmException e) {
+            throw new AssertionError(e);
+        }
+        for (long part : parts) {
+            String partEtag = Etag.stream(in, part);
+            byte[] bytes = UrlSafeBase64.decode(partEtag);
+            sha1.update(bytes, 1, bytes.length - 1);
+        }
+        byte[] digest = sha1.digest();
+        byte[] ret = new byte[digest.length + 1];
+        ret[0] = (byte) 0x9e;
+        System.arraycopy(digest, 0, ret, 1, digest.length);
+        return UrlSafeBase64.encodeToString(ret);
+    }
+}