优化

2022-12-20 19:18:04 +08:00
parent 6797894f1c
commit ee28484b02
17 changed files with 1339 additions and 51 deletions
@@ -0,0 +1,102 @@
+package me.ag2s.base;
+
+import static me.ag2s.base.ThrowableUtils.rethrowAsIOException;
+
+import android.os.ParcelFileDescriptor;
+import android.system.ErrnoException;
+import android.system.OsConstants;
+
+import java.io.EOFException;
+import java.io.IOException;
+
+/**
+ * 读取ParcelFileDescriptor的工具类
+ */
+@SuppressWarnings("unused")
+public final class PfdHelper {
+
+    /**
+     * 读取基本类型的buffer
+     */
+    private static final byte[] readBuffer = new byte[8];
+
+    public static void seek(ParcelFileDescriptor pfd, long pos) throws IOException {
+        try {
+            android.system.Os.lseek(pfd.getFileDescriptor(), pos, OsConstants.SEEK_SET);
+        } catch (ErrnoException e) {
+            throw rethrowAsIOException(e);
+        }
+
+    }
+
+    public static long getFilePointer(ParcelFileDescriptor pfd) throws IOException {
+        try {
+            return android.system.Os.lseek(pfd.getFileDescriptor(), 0, OsConstants.SEEK_CUR);
+        } catch (ErrnoException e) {
+            throw rethrowAsIOException(e);
+        }
+    }
+
+    public static long length(ParcelFileDescriptor pfd) throws IOException {
+        try {
+            return android.system.Os.lseek(pfd.getFileDescriptor(), 0, OsConstants.SEEK_END);
+        } catch (ErrnoException e) {
+            throw rethrowAsIOException(e);
+        }
+    }
+
+    private static int readBytes(ParcelFileDescriptor pfd, byte[] b, int off, int len) throws IOException {
+        try {
+            return android.system.Os.read(pfd.getFileDescriptor(), b, off, len);
+        } catch (ErrnoException e) {
+            throw rethrowAsIOException(e);
+        }
+    }
+
+    public static int read(ParcelFileDescriptor pfd) throws IOException {
+        return (read(pfd, readBuffer, 0, 1) != -1) ? readBuffer[0] & 0xff : -1;
+    }
+
+    public static int read(ParcelFileDescriptor pfd, byte[] b, int off, int len) throws IOException {
+        return readBytes(pfd, b, off, len);
+    }
+
+    public static int read(ParcelFileDescriptor pfd, byte[] b) throws IOException {
+        return readBytes(pfd, b, 0, b.length);
+    }
+
+    public static void readFully(ParcelFileDescriptor pfd, byte[] b) throws IOException {
+        readFully(pfd, b, 0, b.length);
+    }
+
+    public static void readFully(ParcelFileDescriptor pfd, byte[] b, int off, int len) throws IOException {
+        int n = 0;
+        do {
+            int count = read(pfd, b, off + n, len - n);
+            if (count < 0)
+                throw new EOFException();
+            n += count;
+        } while (n < len);
+    }
+
+
+    public static int skipBytes(ParcelFileDescriptor pfd, int n) throws IOException {
+        long pos;
+        long len;
+        long newpos;
+
+        if (n <= 0) {
+            return 0;
+        }
+        pos = getFilePointer(pfd);
+        len = length(pfd);
+        newpos = pos + n;
+        if (newpos > len) {
+            newpos = len;
+        }
+        seek(pfd, newpos);
+
+        /* return the actual number of bytes skipped */
+        return (int) (newpos - pos);
+    }
+}