(#42) HtHead can be broken.

yegor256 · Feb 21, 2019 · 89c7a77 · 89c7a77
1 parent 9f10348
commit 89c7a77
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Showing 2 changed files with 88 additions and 65 deletions.
diff --git a/src/main/java/org/cactoos/http/HtHead.java b/src/main/java/org/cactoos/http/HtHead.java
@@ -25,9 +25,9 @@
 package org.cactoos.http;
 
 import java.io.InputStream;
-import java.io.SequenceInputStream;
+import java.nio.charset.Charset;
+import java.util.Scanner;
 import org.cactoos.Input;
-import org.cactoos.io.DeadInputStream;
 import org.cactoos.io.InputStreamOf;
 
 /**
@@ -38,9 +38,14 @@
 public final class HtHead implements Input {
 
     /**
-     * Buffer length.
+     * Header separator.
      */
-    private static final int LENGTH = 16384;
+    private static final String DELIMITER = "\r\n\r\n";
+
+    /**
+     * Charset that is used to read headers.
+     */
+    private static final Charset CHARSET = Charset.defaultCharset();
 
     /**
      * Response.
@@ -56,50 +61,14 @@ public HtHead(final Input rsp) {
     }
 
     @Override
-    @SuppressWarnings("PMD.AvoidInstantiatingObjectsInLoops")
     public InputStream stream() throws Exception {
-        final InputStream stream = this.response.stream();
-        final byte[] buf = new byte[HtHead.LENGTH];
-        InputStream head = new DeadInputStream();
-        while (true) {
-            final int len = stream.read(buf);
-            if (len < 0) {
-                break;
-            }
-            final int tail = HtHead.findEnd(buf, len);
-            final byte[] temp = new byte[tail];
-            System.arraycopy(buf, 0, temp, 0, tail);
-            head = new SequenceInputStream(head, new InputStreamOf(temp));
-            if (tail != len) {
-                break;
-            }
+        try (final Scanner scanner = new Scanner(
+            this.response.stream(),
+            HtHead.CHARSET.name()
+        )) {
+            scanner.useDelimiter(HtHead.DELIMITER);
+            return new InputStreamOf(scanner.next());
         }
-        return head;
-    }
-
-    /**
-     * Find header end.
-     * @param buf Buffer where to search
-     * @param len Size of the buffer
-     * @return End of the header
-     */
-    private static int findEnd(final byte[] buf, final int len) {
-        final byte[] end = {'\r', '\n', '\r', '\n'};
-        int tail = end.length - 1;
-        while (tail < len) {
-            boolean found = true;
-            for (int num = 0; num < end.length; ++num) {
-                if (end[num] != buf[tail - end.length + 1 + num]) {
-                    found = false;
-                    break;
-                }
-            }
-            if (found) {
-                tail = tail - end.length + 1;
-                break;
-            }
-            ++tail;
-        }
-        return tail;
     }
 }
+
diff --git a/src/test/java/org/cactoos/http/HtHeadTest.java b/src/test/java/org/cactoos/http/HtHeadTest.java
@@ -23,15 +23,20 @@
  */
 package org.cactoos.http;
 
-import java.io.IOException;
 import java.util.Random;
+import org.cactoos.Text;
 import org.cactoos.io.BytesOf;
 import org.cactoos.io.InputOf;
 import org.cactoos.text.JoinedText;
+import org.cactoos.text.RepeatedText;
+import org.cactoos.text.ReplacedText;
 import org.cactoos.text.TextOf;
-import org.hamcrest.MatcherAssert;
 import org.hamcrest.Matchers;
+import org.hamcrest.core.IsEqual;
 import org.junit.Test;
+import org.llorllale.cactoos.matchers.Assertion;
+import org.llorllale.cactoos.matchers.EndsWith;
+import org.llorllale.cactoos.matchers.StartsWith;
 import org.llorllale.cactoos.matchers.TextHasString;
 
 /**
@@ -45,9 +50,10 @@
 public final class HtHeadTest {
 
     @Test
-    public void takesHeadOutOfHttpResponse() throws IOException {
-        MatcherAssert.assertThat(
-            new TextOf(
+    public void takesHeadOutOfHttpResponse() {
+        new Assertion<>(
+            "Header does not have 'text/plain'",
+            () -> new TextOf(
                 new HtHead(
                     new InputOf(
                         new JoinedText(
@@ -59,15 +65,16 @@ public void takesHeadOutOfHttpResponse() throws IOException {
                         )
                     )
                 )
-            ).asString(),
-            Matchers.endsWith("text/plain")
-        );
+            ),
+            new EndsWith("text/plain")
+        ).affirm();
     }
 
     @Test
-    public void emptyHeadOfHttpResponse() throws IOException {
-        MatcherAssert.assertThat(
-            new TextOf(
+    public void emptyHeadOfHttpResponse()  {
+        new Assertion<>(
+            "Text does not have an empty string",
+            () -> new TextOf(
                 new HtHead(
                     new InputOf(
                         new JoinedText(
@@ -80,16 +87,17 @@ public void emptyHeadOfHttpResponse() throws IOException {
                 )
             ),
             new TextHasString("")
-        );
+        ).affirm();
     }
 
     @Test
-    public void largeText() throws IOException {
+    public void largeText() {
         //@checkstyle MagicNumberCheck (1 lines)
         final byte[] bytes = new byte[18000];
         new Random().nextBytes(bytes);
-        MatcherAssert.assertThat(
-            new TextOf(
+        new Assertion<>(
+            "Header does not have text/plain header",
+            () -> new TextOf(
                 new HtHead(
                     new InputOf(
                         new JoinedText(
@@ -101,9 +109,55 @@ public void largeText() throws IOException {
                         )
                     )
                 )
-            ).asString(),
-            Matchers.endsWith("text/plain")
-        );
+            ),
+            new EndsWith("text/plain")
+        ).affirm();
     }
 
+    @Test
+    public void edgeOfTheBlockTearing() throws Exception {
+        final int size = 16384;
+        final Text header = new JoinedText(
+            "\r\n",
+            "HTTP/1.1 200 OK",
+            "Referer: http://en.wikipedia.org/wiki/Main_Page#\0",
+            "Content-type: text/plain",
+            ""
+        );
+        final Text block = new ReplacedText(
+            header,
+            "\0",
+            new RepeatedText(
+                "x",
+                size - header.asString().length() + 1
+            ).asString()
+        );
+        new Assertion<>(
+            "make sure the constructed block is exact size",
+            () -> block.asString().length(),
+            new IsEqual<>(
+                size
+            )
+        ).affirm();
+        new Assertion<>(
+            String.format("Edge of the block tearing for size: %s", size),
+            () -> new TextOf(
+                new HtHead(
+                    new InputOf(
+                        new JoinedText(
+                            "\r\n",
+                            block.asString(),
+                            "",
+                            "body here"
+                        )
+                    )
+                )
+            ),
+            Matchers.allOf(
+                new StartsWith("HTTP"),
+                new TextHasString("OK\r\nReferer"),
+                new EndsWith("text/plain")
+            )
+        ).affirm();
+    }
 }