ByteProcessor shouldn't throw checked exception (#10767)

Motivation:
There is no need for ByteProcessor to throw a checked exception.
The declared checked exception causes unnecessary code complications just to propagate it.
This can be cleaned up.

Modification:
ByteProcessor.process no longer declares to throw a checked exception, and all the places that were trying to cope with the checked exception have been simplified.

Result:
Simpler code.

buffer/src/main/java/io/netty/buffer/AbstractByteBuf.java

@@ -1262,58 +1262,37 @@ public abstract class AbstractByteBuf extends ByteBuf {
     @Override
     public int forEachByte(ByteProcessor processor) {
         ensureAccessible();
-        try {
+        return forEachByteAsc0(readerIndex, writerIndex, processor);
-            return forEachByteAsc0(readerIndex, writerIndex, processor);
-        } catch (Exception e) {
-            PlatformDependent.throwException(e);
-            return -1;
-        }
     }
 
     @Override
     public int forEachByte(int index, int length, ByteProcessor processor) {
         checkIndex(index, length);
-        try {
+        return forEachByteAsc0(index, index + length, processor);
-            return forEachByteAsc0(index, index + length, processor);
-        } catch (Exception e) {
-            PlatformDependent.throwException(e);
-            return -1;
-        }
     }
 
-    int forEachByteAsc0(int start, int end, ByteProcessor processor) throws Exception {
+    int forEachByteAsc0(int start, int end, ByteProcessor processor) {
         for (; start < end; ++start) {
             if (!processor.process(_getByte(start))) {
                 return start;
             }
         }
-
         return -1;
     }
 
     @Override
     public int forEachByteDesc(ByteProcessor processor) {
         ensureAccessible();
-        try {
+        return forEachByteDesc0(writerIndex - 1, readerIndex, processor);
-            return forEachByteDesc0(writerIndex - 1, readerIndex, processor);
-        } catch (Exception e) {
-            PlatformDependent.throwException(e);
-            return -1;
-        }
     }
 
     @Override
     public int forEachByteDesc(int index, int length, ByteProcessor processor) {
         checkIndex(index, length);
-        try {
+        return forEachByteDesc0(index + length - 1, index, processor);
-            return forEachByteDesc0(index + length - 1, index, processor);
-        } catch (Exception e) {
-            PlatformDependent.throwException(e);
-            return -1;
-        }
     }
 
-    int forEachByteDesc0(int rStart, final int rEnd, ByteProcessor processor) throws Exception {
+    int forEachByteDesc0(int rStart, final int rEnd, ByteProcessor processor) {
         for (; rStart >= rEnd; --rStart) {
             if (!processor.process(_getByte(rStart))) {
                 return rStart;

buffer/src/main/java/io/netty/buffer/CompositeByteBuf.java

@@ -660,7 +660,7 @@ public class CompositeByteBuf extends AbstractReferenceCountedByteBuf implements
     }
 
     @Override
-    protected int forEachByteAsc0(int start, int end, ByteProcessor processor) throws Exception {
+    protected int forEachByteAsc0(int start, int end, ByteProcessor processor) {
         if (end <= start) {
             return -1;
         }
@@ -686,7 +686,7 @@ public class CompositeByteBuf extends AbstractReferenceCountedByteBuf implements
     }
 
     @Override
-    protected int forEachByteDesc0(int rStart, int rEnd, ByteProcessor processor) throws Exception {
+    protected int forEachByteDesc0(int rStart, int rEnd, ByteProcessor processor) {
         if (rEnd > rStart) { // rStart *and* rEnd are inclusive
             return -1;
         }

buffer/src/test/java/io/netty/buffer/AbstractByteBufTest.java

@@ -2284,7 +2284,7 @@ public abstract class AbstractByteBufTest {
             int i = CAPACITY / 4;
 
             @Override
-            public boolean process(byte value) throws Exception {
+            public boolean process(byte value) {
                 assertThat(value, is((byte) (i + 1)));
                 lastIndex.set(i);
                 i ++;
@@ -2307,7 +2307,7 @@ public abstract class AbstractByteBufTest {
             int i = CAPACITY / 3;
 
             @Override
-            public boolean process(byte value) throws Exception {
+            public boolean process(byte value) {
                 assertThat(value, is((byte) (i + 1)));
                 if (i == stop) {
                     return false;
@@ -4608,7 +4608,7 @@ public abstract class AbstractByteBufTest {
                 private int index = bytes.length - 1;
 
                 @Override
-                public boolean process(byte value) throws Exception {
+                public boolean process(byte value) {
                     bytes[index--] = value;
                     return true;
                 }
@@ -4631,7 +4631,7 @@ public abstract class AbstractByteBufTest {
                 private int index;
 
                 @Override
-                public boolean process(byte value) throws Exception {
+                public boolean process(byte value) {
                     bytes[index++] = value;
                     return true;
                 }
@@ -4804,7 +4804,7 @@ public abstract class AbstractByteBufTest {
 
     private static final class TestByteProcessor implements ByteProcessor {
         @Override
-        public boolean process(byte value) throws Exception {
+        public boolean process(byte value) {
             return true;
         }
     }

codec-http/src/main/java/io/netty/handler/codec/http/DefaultHttpHeaders.java

@@ -24,7 +24,6 @@ import io.netty.handler.codec.HeadersUtils;
 import io.netty.handler.codec.ValueConverter;
 import io.netty.util.AsciiString;
 import io.netty.util.ByteProcessor;
-import io.netty.util.internal.PlatformDependent;
 
 import java.util.ArrayList;
 import java.util.Calendar;
@@ -50,14 +49,10 @@ public class DefaultHttpHeaders extends HttpHeaders {
     };
     static final NameValidator<CharSequence> HttpNameValidator = name -> {
         if (name == null || name.length() == 0) {
-            throw new IllegalArgumentException("empty headers are not allowed [" + name + "]");
+            throw new IllegalArgumentException("empty headers are not allowed [" + name + ']');
         }
         if (name instanceof AsciiString) {
-            try {
+            ((AsciiString) name).forEachByte(HEADER_NAME_VALIDATOR);
-                ((AsciiString) name).forEachByte(HEADER_NAME_VALIDATOR);
-            } catch (Exception e) {
-                PlatformDependent.throwException(e);
-            }
         } else {
             // Go through each character in the name
             for (int index = 0; index < name.length(); ++index) {
@@ -73,7 +68,7 @@ public class DefaultHttpHeaders extends HttpHeaders {
     }
 
     /**
-     * <b>Warning!</b> Setting <code>validate</code> to <code>false</code> will mean that Netty won't
+     * <b>Warning!</b> Setting {@code validate} to {@code false} will mean that Netty won't
      * validate & protect against user-supplied header values that are malicious.
      * This can leave your server implementation vulnerable to
      * <a href="https://cwe.mitre.org/data/definitions/113.html">

codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectDecoder.java

@@ -936,7 +936,7 @@ public abstract class HttpObjectDecoder extends ByteToMessageDecoder {
         }
 
         @Override
-        public boolean process(byte value) throws Exception {
+        public boolean process(byte value) {
             char nextByte = (char) (value & 0xFF);
             if (nextByte == HttpConstants.LF) {
                 int len = seq.length();
@@ -983,7 +983,7 @@ public abstract class HttpObjectDecoder extends ByteToMessageDecoder {
         }
 
         @Override
-        public boolean process(byte value) throws Exception {
+        public boolean process(byte value) {
             if (currentState == State.SKIP_CONTROL_CHARS) {
                 char c = (char) (value & 0xFF);
                 if (Character.isISOControl(c) || Character.isWhitespace(c)) {

codec-http/src/main/java/io/netty/handler/codec/http/multipart/HttpPostStandardRequestDecoder.java

@@ -706,7 +706,7 @@ public class HttpPostStandardRequestDecoder implements InterfaceHttpPostRequestD
 
     private static final class UrlEncodedDetector implements ByteProcessor {
         @Override
-        public boolean process(byte value) throws Exception {
+        public boolean process(byte value) {
             return value != '%' && value != '+';
         }
     }

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/Utf8Validator.java

@@ -84,7 +84,7 @@ final class Utf8Validator implements ByteProcessor {
     }
 
     @Override
-    public boolean process(byte b) throws Exception {
+    public boolean process(byte b) {
         byte type = TYPES[b & 0xFF];
 
         codep = state != UTF8_ACCEPT ? b & 0x3f | codep << 6 : 0xff >> type & b;

codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2Headers.java

@@ -38,18 +38,7 @@ public class DefaultHttp2Headers
                     "empty headers are not allowed [%s]", name));
         }
         if (name instanceof AsciiString) {
-            final int index;
+            int index = ((AsciiString) name).forEachByte(HTTP2_NAME_VALIDATOR_PROCESSOR);
-            try {
-                index = ((AsciiString) name).forEachByte(HTTP2_NAME_VALIDATOR_PROCESSOR);
-            } catch (Http2Exception e) {
-                PlatformDependent.throwException(e);
-                return;
-            } catch (Throwable t) {
-                PlatformDependent.throwException(connectionError(PROTOCOL_ERROR, t,
-                        "unexpected error. invalid header name [%s]", name));
-                return;
-            }
-
             if (index != -1) {
                 PlatformDependent.throwException(connectionError(PROTOCOL_ERROR,
                         "invalid header name [%s]", name));
@@ -109,7 +98,7 @@ public class DefaultHttp2Headers
 
     @Override
     public Http2Headers clear() {
-        this.firstNonPseudo = head;
+        firstNonPseudo = head;
         return super.clear();
     }
 

codec-http2/src/main/java/io/netty/handler/codec/http2/HpackHuffmanEncoder.java

@@ -70,11 +70,9 @@ final class HpackHuffmanEncoder {
         requireNonNull(out, "out");
         if (data instanceof AsciiString) {
             AsciiString string = (AsciiString) data;
+            encodeProcessor.out = out;
             try {
-                encodeProcessor.out = out;
                 string.forEachByte(encodeProcessor);
-            } catch (Exception e) {
-                PlatformDependent.throwException(e);
             } finally {
                 encodeProcessor.end();
             }
@@ -118,14 +116,9 @@ final class HpackHuffmanEncoder {
     int getEncodedLength(CharSequence data) {
         if (data instanceof AsciiString) {
             AsciiString string = (AsciiString) data;
-            try {
+            encodedLengthProcessor.reset();
-                encodedLengthProcessor.reset();
+            string.forEachByte(encodedLengthProcessor);
-                string.forEachByte(encodedLengthProcessor);
+            return encodedLengthProcessor.length();
-                return encodedLengthProcessor.length();
-            } catch (Exception e) {
-                PlatformDependent.throwException(e);
-                return -1;
-            }
         } else {
             return getEncodedLengthSlowPath(data);
         }

codec-http2/src/main/java/io/netty/handler/codec/http2/HttpConversionUtil.java

@@ -427,23 +427,17 @@ public final class HttpConversionUtil {
 
         while (valuesIter.hasNext()) {
             AsciiString lowerCased = AsciiString.of(valuesIter.next()).toLowerCase();
-            try {
+            int index = lowerCased.forEachByte(FIND_COMMA);
-                int index = lowerCased.forEachByte(FIND_COMMA);
+            if (index != -1) {
-                if (index != -1) {
+                int start = 0;
-                    int start = 0;
+                do {
-                    do {
+                    result.add(lowerCased.subSequence(start, index, false).trim(), EMPTY_STRING);
-                        result.add(lowerCased.subSequence(start, index, false).trim(), EMPTY_STRING);
+                    start = index + 1;
-                        start = index + 1;
+                } while (start < lowerCased.length() &&
-                    } while (start < lowerCased.length() &&
+                         (index = lowerCased.forEachByte(start, lowerCased.length() - start, FIND_COMMA)) != -1);
-                             (index = lowerCased.forEachByte(start, lowerCased.length() - start, FIND_COMMA)) != -1);
+                result.add(lowerCased.subSequence(start, lowerCased.length(), false).trim(), EMPTY_STRING);
-                    result.add(lowerCased.subSequence(start, lowerCased.length(), false).trim(), EMPTY_STRING);
+            } else {
-                } else {
+                result.add(lowerCased.trim(), EMPTY_STRING);
-                    result.add(lowerCased.trim(), EMPTY_STRING);
-                }
-            } catch (Exception e) {
-                // This is not expect to happen because FIND_COMMA never throws but must be caught
-                // because of the ByteProcessor interface.
-                throw new IllegalStateException(e);
             }
         }
         return result;
@@ -489,27 +483,21 @@ public final class HttpConversionUtil {
                     AsciiString value = AsciiString.of(entry.getValue());
                     // split up cookies to allow for better compression
                     // https://tools.ietf.org/html/rfc7540#section-8.1.2.5
-                    try {
+                    int index = value.forEachByte(FIND_SEMI_COLON);
-                        int index = value.forEachByte(FIND_SEMI_COLON);
+                    if (index != -1) {
-                        if (index != -1) {
+                        int start = 0;
-                            int start = 0;
+                        do {
-                            do {
+                            out.add(COOKIE, value.subSequence(start, index, false));
-                                out.add(COOKIE, value.subSequence(start, index, false));
+                            // skip 2 characters "; " (see https://tools.ietf.org/html/rfc6265#section-4.2.1)
-                                // skip 2 characters "; " (see https://tools.ietf.org/html/rfc6265#section-4.2.1)
+                            start = index + 2;
-                                start = index + 2;
+                        } while (start < value.length() &&
-                            } while (start < value.length() &&
+                                 (index = value.forEachByte(start, value.length() - start, FIND_SEMI_COLON)) != -1);
-                                    (index = value.forEachByte(start, value.length() - start, FIND_SEMI_COLON)) != -1);
+                        if (start >= value.length()) {
-                            if (start >= value.length()) {
+                            throw new IllegalArgumentException("cookie value is of unexpected format: " + value);
-                                throw new IllegalArgumentException("cookie value is of unexpected format: " + value);
-                            }
-                            out.add(COOKIE, value.subSequence(start, value.length(), false));
-                        } else {
-                            out.add(COOKIE, value);
                         }
-                    } catch (Exception e) {
+                        out.add(COOKIE, value.subSequence(start, value.length(), false));
-                        // This is not expect to happen because FIND_SEMI_COLON never throws but must be caught
+                    } else {
-                        // because of the ByteProcessor interface.
+                        out.add(COOKIE, value);
-                        throw new IllegalStateException(e);
                     }
                 } else {
                     out.add(aName, entry.getValue());

codec-redis/src/main/java/io/netty/handler/codec/redis/RedisDecoder.java

@@ -311,7 +311,7 @@ public final class RedisDecoder extends ByteToMessageDecoder {
         private long result;
 
         @Override
-        public boolean process(byte value) throws Exception {
+        public boolean process(byte value) {
             if (value < '0' || value > '9') {
                 throw new RedisCodecException("bad byte in number: " + value);
             }

codec-stomp/src/main/java/io/netty/handler/codec/stomp/StompSubframeDecoder.java

@@ -274,7 +274,7 @@ public class StompSubframeDecoder extends ReplayingDecoder<State> {
         }
 
         @Override
-        public boolean process(byte nextByte) throws Exception {
+        public boolean process(byte nextByte) {
             if (nextByte == StompConstants.CR) {
                 ++lineLength;
                 return true;
@@ -353,7 +353,7 @@ public class StompSubframeDecoder extends ReplayingDecoder<State> {
         }
 
         @Override
-        public boolean process(byte nextByte) throws Exception {
+        public boolean process(byte nextByte) {
             if (nextByte == StompConstants.COLON) {
                 if (name == null) {
                     AppendableCharSequence charSeq = charSequence();

codec/src/main/java/io/netty/handler/codec/base64/Base64.java

@@ -331,7 +331,7 @@ public final class Base64 {
         }
 
         @Override
-        public boolean process(byte value) throws Exception {
+        public boolean process(byte value) {
             if (value > 0) {
                 byte sbiDecode = decodabet[value];
                 if (sbiDecode >= WHITE_SPACE_ENC) { // White space, Equals sign or better

common/src/main/java/io/netty/util/AsciiString.java

@@ -255,7 +255,7 @@ public final class AsciiString implements CharSequence, Comparable<CharSequence>
      * @return {@code -1} if the processor iterated to or beyond the end of the readable bytes.
      *         The last-visited index If the {@link ByteProcessor#process(byte)} returned {@code false}.
      */
-    public int forEachByte(ByteProcessor visitor) throws Exception {
+    public int forEachByte(ByteProcessor visitor) {
         return forEachByte0(0, length(), visitor);
     }
 
@@ -266,7 +266,7 @@ public final class AsciiString implements CharSequence, Comparable<CharSequence>
      * @return {@code -1} if the processor iterated to or beyond the end of the specified area.
      *         The last-visited index If the {@link ByteProcessor#process(byte)} returned {@code false}.
      */
-    public int forEachByte(int index, int length, ByteProcessor visitor) throws Exception {
+    public int forEachByte(int index, int length, ByteProcessor visitor) {
         if (isOutOfBounds(index, length, length())) {
             throw new IndexOutOfBoundsException("expected: " + "0 <= index(" + index + ") <= start + length(" + length
                     + ") <= " + "length(" + length() + ')');
@@ -274,7 +274,7 @@ public final class AsciiString implements CharSequence, Comparable<CharSequence>
         return forEachByte0(index, length, visitor);
     }
 
-    private int forEachByte0(int index, int length, ByteProcessor visitor) throws Exception {
+    private int forEachByte0(int index, int length, ByteProcessor visitor) {
         final int len = offset + index + length;
         for (int i = offset + index; i < len; ++i) {
             if (!visitor.process(value[i])) {
@@ -290,7 +290,7 @@ public final class AsciiString implements CharSequence, Comparable<CharSequence>
      * @return {@code -1} if the processor iterated to or beyond the beginning of the readable bytes.
      *         The last-visited index If the {@link ByteProcessor#process(byte)} returned {@code false}.
      */
-    public int forEachByteDesc(ByteProcessor visitor) throws Exception {
+    public int forEachByteDesc(ByteProcessor visitor) {
         return forEachByteDesc0(0, length(), visitor);
     }
 
@@ -301,7 +301,7 @@ public final class AsciiString implements CharSequence, Comparable<CharSequence>
      * @return {@code -1} if the processor iterated to or beyond the beginning of the specified area.
      *         The last-visited index If the {@link ByteProcessor#process(byte)} returned {@code false}.
      */
-    public int forEachByteDesc(int index, int length, ByteProcessor visitor) throws Exception {
+    public int forEachByteDesc(int index, int length, ByteProcessor visitor) {
         if (isOutOfBounds(index, length, length())) {
             throw new IndexOutOfBoundsException("expected: " + "0 <= index(" + index + ") <= start + length(" + length
                     + ") <= " + "length(" + length() + ')');
@@ -309,7 +309,7 @@ public final class AsciiString implements CharSequence, Comparable<CharSequence>
         return forEachByteDesc0(index, length, visitor);
     }
 
-    private int forEachByteDesc0(int index, int length, ByteProcessor visitor) throws Exception {
+    private int forEachByteDesc0(int index, int length, ByteProcessor visitor) {
         final int end = offset + index;
         for (int i = offset + index + length - 1; i >= end; --i) {
             if (!visitor.process(value[i])) {

common/src/main/java/io/netty/util/ByteProcessor.java

@@ -124,5 +124,5 @@ public interface ByteProcessor {
      * @return {@code true} if the processor wants to continue the loop and handle the next byte in the buffer.
      *         {@code false} if the processor wants to stop handling bytes and abort the loop.
      */
-    boolean process(byte value) throws Exception;
+    boolean process(byte value);
 }

common/src/test/java/io/netty/util/AsciiStringMemoryTest.java

@@ -78,13 +78,13 @@ public class AsciiStringMemoryTest {
     }
 
     @Test
-    public void forEachTest() throws Exception {
+    public void forEachTest() {
         final AtomicReference<Integer> aCount = new AtomicReference<>(0);
         final AtomicReference<Integer> bCount = new AtomicReference<>(0);
         aAsciiString.forEachByte(new ByteProcessor() {
             int i;
             @Override
-            public boolean process(byte value) throws Exception {
+            public boolean process(byte value) {
                 assertEquals("failed at index: " + i, value, bAsciiString.byteAt(i++));
                 aCount.set(aCount.get() + 1);
                 return true;
@@ -93,7 +93,7 @@ public class AsciiStringMemoryTest {
         bAsciiString.forEachByte(new ByteProcessor() {
             int i;
             @Override
-            public boolean process(byte value) throws Exception {
+            public boolean process(byte value) {
                 assertEquals("failed at index: " + i, value, aAsciiString.byteAt(i++));
                 bCount.set(bCount.get() + 1);
                 return true;
@@ -104,25 +104,25 @@ public class AsciiStringMemoryTest {
     }
 
     @Test
-    public void forEachWithIndexEndTest() throws Exception {
+    public void forEachWithIndexEndTest() {
         assertNotEquals(-1, aAsciiString.forEachByte(aAsciiString.length() - 1,
                 1, new IndexOfProcessor(aAsciiString.byteAt(aAsciiString.length() - 1))));
     }
 
     @Test
-    public void forEachWithIndexBeginTest() throws Exception {
+    public void forEachWithIndexBeginTest() {
         assertNotEquals(-1, aAsciiString.forEachByte(0,
                 1, new IndexOfProcessor(aAsciiString.byteAt(0))));
     }
 
     @Test
-    public void forEachDescTest() throws Exception {
+    public void forEachDescTest() {
         final AtomicReference<Integer> aCount = new AtomicReference<>(0);
         final AtomicReference<Integer> bCount = new AtomicReference<>(0);
         aAsciiString.forEachByteDesc(new ByteProcessor() {
             int i = 1;
             @Override
-            public boolean process(byte value) throws Exception {
+            public boolean process(byte value) {
                 assertEquals("failed at index: " + i, value, bAsciiString.byteAt(bAsciiString.length() - (i++)));
                 aCount.set(aCount.get() + 1);
                 return true;
@@ -131,7 +131,7 @@ public class AsciiStringMemoryTest {
         bAsciiString.forEachByteDesc(new ByteProcessor() {
             int i = 1;
             @Override
-            public boolean process(byte value) throws Exception {
+            public boolean process(byte value) {
                 assertEquals("failed at index: " + i, value, aAsciiString.byteAt(aAsciiString.length() - (i++)));
                 bCount.set(bCount.get() + 1);
                 return true;
@@ -142,13 +142,13 @@ public class AsciiStringMemoryTest {
     }
 
     @Test
-    public void forEachDescWithIndexEndTest() throws Exception {
+    public void forEachDescWithIndexEndTest() {
         assertNotEquals(-1, bAsciiString.forEachByteDesc(bAsciiString.length() - 1,
                 1, new IndexOfProcessor(bAsciiString.byteAt(bAsciiString.length() - 1))));
     }
 
     @Test
-    public void forEachDescWithIndexBeginTest() throws Exception {
+    public void forEachDescWithIndexBeginTest() {
         assertNotEquals(-1, bAsciiString.forEachByteDesc(0,
                 1, new IndexOfProcessor(bAsciiString.byteAt(0))));
     }