From 34b6fa7d6b22439f5c703bf7e82de5c40c77994a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?M=C3=A1rton=20Elek?= <elek@apache.org>
Date: Wed, 21 Nov 2018 17:59:20 +0100
Subject: [PATCH] HDDS-732. Add read method which takes offset and length in
 SignedChunkInputStream. Contributed by chencan.

---
 .../ozone/s3/SignedChunksInputStream.java     | 40 +++++++++++++++++++
 .../ozone/s3/TestSignedChunksInputStream.java | 30 ++++++++++++++
 2 files changed, 70 insertions(+)

diff --git a/hadoop-ozone/s3gateway/src/main/java/org/apache/hadoop/ozone/s3/SignedChunksInputStream.java b/hadoop-ozone/s3gateway/src/main/java/org/apache/hadoop/ozone/s3/SignedChunksInputStream.java
index a35133f965..b0dfce64ff 100644
--- a/hadoop-ozone/s3gateway/src/main/java/org/apache/hadoop/ozone/s3/SignedChunksInputStream.java
+++ b/hadoop-ozone/s3gateway/src/main/java/org/apache/hadoop/ozone/s3/SignedChunksInputStream.java
@@ -65,6 +65,46 @@ public int read() throws IOException {
     }
   }
 
+  @Override
+  public int read(byte b[], int off, int len) throws IOException {
+    if (b == null) {
+      throw new NullPointerException();
+    } else if (off < 0 || len < 0 || len > b.length - off) {
+      throw new IndexOutOfBoundsException();
+    } else if (len == 0) {
+      return 0;
+    }
+    int currentOff = off;
+    int currentLen = len;
+    int totalReadBytes = 0;
+    int realReadLen = 0;
+    int maxReadLen = 0;
+    do {
+      if (remainingData > 0) {
+        maxReadLen = Math.min(remainingData, currentLen);
+        realReadLen = originalStream.read(b, currentOff, maxReadLen);
+        if (realReadLen == -1) {
+          break;
+        }
+        currentOff += realReadLen;
+        currentLen -= realReadLen;
+        totalReadBytes += realReadLen;
+        remainingData -= realReadLen;
+        if (remainingData == 0) {
+          //read the "\r\n" at the end of the data section
+          originalStream.read();
+          originalStream.read();
+        }
+      } else {
+        remainingData = readHeader();
+        if (remainingData == -1) {
+          break;
+        }
+      }
+    } while (currentLen > 0);
+    return totalReadBytes > 0 ? totalReadBytes : -1;
+  }
+
   private int readHeader() throws IOException {
     int prev = -1;
     int curr = 0;
diff --git a/hadoop-ozone/s3gateway/src/test/java/org/apache/hadoop/ozone/s3/TestSignedChunksInputStream.java b/hadoop-ozone/s3gateway/src/test/java/org/apache/hadoop/ozone/s3/TestSignedChunksInputStream.java
index f1af7cb378..3599c059b1 100644
--- a/hadoop-ozone/s3gateway/src/test/java/org/apache/hadoop/ozone/s3/TestSignedChunksInputStream.java
+++ b/hadoop-ozone/s3gateway/src/test/java/org/apache/hadoop/ozone/s3/TestSignedChunksInputStream.java
@@ -49,32 +49,62 @@ public void emptyfile() throws IOException {
 
   @Test
   public void singlechunk() throws IOException {
+    //test simple read()
     InputStream is = fileContent("0A;chunk-signature"
         +
         "=23abb2bd920ddeeaac78a63ed808bc59fa6e7d3ef0e356474b82cdc2f8c93c40\r"
         + "\n1234567890\r\n");
     String result = IOUtils.toString(is, Charset.forName("UTF-8"));
     Assert.assertEquals("1234567890", result);
+
+    //test read(byte[],int,int)
+    is = fileContent("0A;chunk-signature"
+        +
+        "=23abb2bd920ddeeaac78a63ed808bc59fa6e7d3ef0e356474b82cdc2f8c93c40\r"
+        + "\n1234567890\r\n");
+    byte[] bytes = new byte[10];
+    IOUtils.read(is, bytes, 0, 10);
+    Assert.assertEquals("1234567890", new String(bytes));
   }
 
   @Test
   public void singlechunkwithoutend() throws IOException {
+    //test simple read()
     InputStream is = fileContent("0A;chunk-signature"
         +
         "=23abb2bd920ddeeaac78a63ed808bc59fa6e7d3ef0e356474b82cdc2f8c93c40\r"
         + "\n1234567890");
     String result = IOUtils.toString(is, Charset.forName("UTF-8"));
     Assert.assertEquals("1234567890", result);
+
+    //test read(byte[],int,int)
+    is = fileContent("0A;chunk-signature"
+        +
+        "=23abb2bd920ddeeaac78a63ed808bc59fa6e7d3ef0e356474b82cdc2f8c93c40\r"
+        + "\n1234567890");
+    byte[] bytes = new byte[10];
+    IOUtils.read(is, bytes, 0, 10);
+    Assert.assertEquals("1234567890", new String(bytes));
   }
 
   @Test
   public void multichunks() throws IOException {
+    //test simple read()
     InputStream is = fileContent("0a;chunk-signature=signature\r\n"
         + "1234567890\r\n"
         + "05;chunk-signature=signature\r\n"
         + "abcde\r\n");
     String result = IOUtils.toString(is, Charset.forName("UTF-8"));
     Assert.assertEquals("1234567890abcde", result);
+
+    //test read(byte[],int,int)
+    is = fileContent("0a;chunk-signature=signature\r\n"
+        + "1234567890\r\n"
+        + "05;chunk-signature=signature\r\n"
+        + "abcde\r\n");
+    byte[] bytes = new byte[15];
+    IOUtils.read(is, bytes, 0, 15);
+    Assert.assertEquals("1234567890abcde", new String(bytes));
   }
 
   private InputStream fileContent(String content) {