From a6d0f962e89ea0188620eac1c71439d43ba6c1e9 Mon Sep 17 00:00:00 2001
From: Chris Lu <chris.lu@gmail.com>
Date: Wed, 29 Jul 2020 20:10:04 -0700
Subject: [PATCH] add buffered seaweed input stream

---
 .../hdfs/BufferedSeaweedInputStream.java      | 49 +++++++++++++++++++
 .../java/seaweed/hdfs/SeaweedFileSystem.java  |  4 +-
 2 files changed, 51 insertions(+), 2 deletions(-)
 create mode 100644 other/java/hdfs2/src/main/java/seaweed/hdfs/BufferedSeaweedInputStream.java

diff --git a/other/java/hdfs2/src/main/java/seaweed/hdfs/BufferedSeaweedInputStream.java b/other/java/hdfs2/src/main/java/seaweed/hdfs/BufferedSeaweedInputStream.java
new file mode 100644
index 000000000..0bee6e43f
--- /dev/null
+++ b/other/java/hdfs2/src/main/java/seaweed/hdfs/BufferedSeaweedInputStream.java
@@ -0,0 +1,49 @@
+package seaweed.hdfs;
+
+import org.apache.hadoop.fs.PositionedReadable;
+import org.apache.hadoop.fs.Seekable;
+
+import java.io.BufferedInputStream;
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+class BufferedSeaweedInputStream extends FilterInputStream implements Seekable, PositionedReadable {
+
+    SeaweedInputStream t;
+
+    protected BufferedSeaweedInputStream(InputStream in, int bufferSize) {
+        super(new BufferedInputStream(in, bufferSize));
+        t = (SeaweedInputStream)in;
+    }
+
+    @Override
+    public int read(long position, byte[] buffer, int offset, int length) throws IOException {
+        return this.t.read(position,buffer,offset,length);
+    }
+
+    @Override
+    public void readFully(long position, byte[] buffer, int offset, int length) throws IOException {
+        this.t.readFully(position,buffer,offset,length);
+    }
+
+    @Override
+    public void readFully(long position, byte[] buffer) throws IOException {
+        this.t.readFully(position,buffer);
+    }
+
+    @Override
+    public void seek(long pos) throws IOException {
+        this.t.seek(pos);
+    }
+
+    @Override
+    public long getPos() throws IOException {
+        return this.t.getPos();
+    }
+
+    @Override
+    public boolean seekToNewSource(long targetPos) throws IOException {
+        return this.t.seekToNewSource(targetPos);
+    }
+}
diff --git a/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedFileSystem.java b/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedFileSystem.java
index 2341d335d..35cc54309 100644
--- a/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedFileSystem.java
+++ b/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedFileSystem.java
@@ -1,11 +1,11 @@
 package seaweed.hdfs;
 
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.*;
 import org.apache.hadoop.fs.permission.AclEntry;
 import org.apache.hadoop.fs.permission.AclStatus;
 import org.apache.hadoop.fs.permission.FsPermission;
-import org.apache.hadoop.security.AccessControlException;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.util.Progressable;
 import org.slf4j.Logger;
@@ -76,7 +76,7 @@ public class SeaweedFileSystem extends FileSystem {
 
         try {
             InputStream inputStream = seaweedFileSystemStore.openFileForRead(path, statistics, bufferSize);
-            return new FSDataInputStream(inputStream);
+            return new FSDataInputStream(new BufferedSeaweedInputStream(inputStream, 16 * 1024 * 1024));
         } catch (Exception ex) {
             LOG.warn("open path: {} bufferSize:{}", path, bufferSize, ex);
             return null;