Preliminary GZIP implementation (no CRC32 and ISIZE checksum yet)

src/main/java/org/jboss/netty/handler/codec/compression/ZlibDecoder.java

@@ -47,7 +47,7 @@ public class ZlibDecoder extends OneToOneDecoder {
      */
     public ZlibDecoder() {
         synchronized (z) {
-            int resultCode = z.inflateInit();
+            int resultCode = z.inflateInit(JZlib.W_ZLIB);
             if (resultCode != JZlib.Z_OK) {
                 ZlibUtil.fail(z, "initialization failure", resultCode);
             }
@@ -66,7 +66,7 @@ public class ZlibDecoder extends OneToOneDecoder {
 
         synchronized (z) {
             int resultCode;
-            resultCode = z.inflateInit();
+            resultCode = z.inflateInit(JZlib.W_ZLIB);
             if (resultCode != JZlib.Z_OK) {
                 ZlibUtil.fail(z, "initialization failure", resultCode);
             } else {

src/main/java/org/jboss/netty/handler/codec/compression/ZlibEncoder.java

@@ -223,7 +223,7 @@ public class ZlibEncoder extends OneToOneEncoder {
                 z.avail_in = 0;
 
                 // Configure output.
-                byte[] out = new byte[8]; // Minimum room for ADLER32 + ZLIB header
+                byte[] out = new byte[32]; // room for ADLER32 + ZLIB / CRC32 + GZIP header
                 z.next_out = out;
                 z.next_out_index = 0;
                 z.avail_out = out.length;

src/main/java/org/jboss/netty/util/internal/jzlib/CRC32.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2009 Red Hat, Inc.
+ *
+ * Red Hat licenses this file to you under the Apache License, version 2.0
+ * (the "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at:
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+package org.jboss.netty.util.internal.jzlib;
+
+final class CRC32 {
+    static long crc32(long crc32, byte[] buf, int index, int len) {
+        // TODO implement me
+        return crc32;
+    }
+}

src/main/java/org/jboss/netty/util/internal/jzlib/Deflate.java

@@ -1378,6 +1378,7 @@ final class Deflate {
         wroteTrailer = false;
         status = wrapperType == WrapperType.NONE? BUSY_STATE : INIT_STATE;
         strm.adler = Adler32.adler32(0, null, 0, 0);
+        strm.crc32 = CRC32.crc32(0, null, 0, 0);
 
         last_flush = JZlib.Z_NO_FLUSH;
 
@@ -1490,6 +1491,8 @@ final class Deflate {
 
         // Write the zlib header
         if (status == INIT_STATE) {
+            switch (wrapperType) {
+            case ZLIB:
                 int header = JZlib.Z_DEFLATED + (w_bits - 8 << 4) << 8;
                 int level_flags = (level - 1 & 0xff) >> 1;
 
@@ -1502,7 +1505,6 @@ final class Deflate {
                 }
                 header += 31 - header % 31;
 
-            status = BUSY_STATE;
                 putShortMSB(header);
 
                 // Save the adler32 of the preset dictionary:
@@ -1511,6 +1513,40 @@ final class Deflate {
                     putShortMSB((int) (strm.adler & 0xffff));
                 }
                 strm.adler = Adler32.adler32(0, null, 0, 0);
+                break;
+            case GZIP:
+                // Identification
+                put_byte((byte) 0x1f);
+                put_byte((byte) 0x8b);
+                // Compression method: DEFLATE
+                put_byte((byte) 8);
+                // Flags
+                put_byte((byte) 0);
+                // MTIME
+                put_byte((byte) 0);
+                put_byte((byte) 0);
+                put_byte((byte) 0);
+                put_byte((byte) 0);
+                // XFL
+                switch (config_table[level].func) {
+                case FAST:
+                    put_byte((byte) 4);
+                    break;
+                case SLOW:
+                    put_byte((byte) 2);
+                    break;
+                default:
+                    put_byte((byte) 0);
+                    break;
+                }
+                // OS
+                put_byte((byte) 255);
+
+                strm.crc32 = CRC32.crc32(0, null, 0, 0);
+                break;
+            }
+
+            status = BUSY_STATE;
         }
 
         // Flush as much pending output as possible
@@ -1605,11 +1641,23 @@ final class Deflate {
             return JZlib.Z_STREAM_END;
         }
 
+        switch (wrapperType) {
+        case ZLIB:
             // Write the zlib trailer (adler32)
             putShortMSB((int) (strm.adler >>> 16));
             putShortMSB((int) (strm.adler & 0xffff));
-        strm.flush_pending();
+            break;
+        case GZIP:
+            // Write the gzip trailer (crc32)
+            putShortMSB((int) (strm.crc32 >>> 16));
+            putShortMSB((int) (strm.crc32 & 0xffff));
+            // FIXME implement me
+            putShortMSB(0); // ISIZE 1
+            putShortMSB(0); // ISIZE 2
+            break;
+        }
 
+        strm.flush_pending();
         // If avail_out is zero, the application will call deflate again
         // to flush the rest.
         wroteTrailer = true; // write the trailer only once!

src/main/java/org/jboss/netty/util/internal/jzlib/Inflate.java

@@ -67,6 +67,26 @@ final class Inflate {
     private static final int DONE = 12; // finished check, done
     private static final int BAD = 13; // got an error--stay here
 
+    private static final int GZIP_CHECK8 = 14;
+    private static final int GZIP_CHECK7 = 15;
+    private static final int GZIP_CHECK6 = 16;
+    private static final int GZIP_CHECK5 = 17;
+    private static final int GZIP_CHECK4 = 18;
+    private static final int GZIP_CHECK3 = 19;
+    private static final int GZIP_CHECK2 = 20;
+    private static final int GZIP_CHECK1 = 21;
+
+    private static final int GZIP_ID1 = 22;
+    private static final int GZIP_ID2 = 23;
+    private static final int GZIP_CM = 24;
+    private static final int GZIP_FLG = 25;
+    private static final int GZIP_MTIME_XFL_OS = 26;
+    private static final int GZIP_XLEN = 27;
+    private static final int GZIP_FEXTRA = 28;
+    private static final int GZIP_FNAME = 29;
+    private static final int GZIP_FCOMMENT = 30;
+    private static final int GZIP_FHCRC = 31;
+
     private int mode; // current inflate mode
     // mode dependent information
     private int method; // if FLAGS, method byte
@@ -79,6 +99,9 @@ final class Inflate {
     private WrapperType wrapperType;
     private int wbits; // log2(window size)  (8..15, defaults to 15)
     private InfBlocks blocks; // current inflate_blocks state
+    private int gzipFlag;
+    private int gzipBytesToRead;
+    private int gzipXLen;
 
     private int inflateReset(ZStream z) {
         if (z == null || z.istate == null) {
@@ -87,7 +110,17 @@ final class Inflate {
 
         z.total_in = z.total_out = 0;
         z.msg = null;
-        z.istate.mode = z.istate.wrapperType == WrapperType.NONE? BLOCKS : METHOD;
+        switch (wrapperType) {
+        case NONE:
+            z.istate.mode = BLOCKS;
+            break;
+        case ZLIB:
+            z.istate.mode = METHOD;
+            break;
+        case GZIP:
+            z.istate.mode = GZIP_ID1;
+            break;
+        }
         z.istate.blocks.reset(z, null);
         return JZlib.Z_OK;
     }
@@ -254,8 +287,12 @@ final class Inflate {
                 if (z.istate.wrapperType == WrapperType.NONE) {
                     z.istate.mode = DONE;
                     break;
-                }
+                } else if (z.istate.wrapperType == WrapperType.ZLIB) {
                     z.istate.mode = CHECK4;
+                } else {
+                    z.istate.mode = GZIP_CHECK8;
+                    break;
+                }
             case CHECK4:
 
                 if (z.avail_in == 0) {
@@ -312,6 +349,218 @@ final class Inflate {
                 return JZlib.Z_STREAM_END;
             case BAD:
                 return JZlib.Z_DATA_ERROR;
+            case GZIP_ID1:
+                if (z.avail_in == 0) {
+                    return r;
+                }
+                r = f;
+                z.avail_in --;
+                z.total_in ++;
+
+                if ((z.next_in[z.next_in_index ++] & 0xff) != 31) {
+                    z.istate.mode = BAD;
+                    z.msg = "not a gzip stream";
+                    z.istate.marker = 5; // can't try inflateSync
+                    break;
+                }
+                z.istate.mode = GZIP_ID2;
+            case GZIP_ID2:
+                if (z.avail_in == 0) {
+                    return r;
+                }
+                r = f;
+                z.avail_in --;
+                z.total_in ++;
+
+                if ((z.next_in[z.next_in_index ++] & 0xff) != 139) {
+                    z.istate.mode = BAD;
+                    z.msg = "not a gzip stream";
+                    z.istate.marker = 5; // can't try inflateSync
+                    break;
+                }
+                z.istate.mode = GZIP_CM;
+            case GZIP_CM:
+                if (z.avail_in == 0) {
+                    return r;
+                }
+                r = f;
+                z.avail_in --;
+                z.total_in ++;
+
+                if ((z.next_in[z.next_in_index ++] & 0xff) != JZlib.Z_DEFLATED) {
+                    z.istate.mode = BAD;
+                    z.msg = "unknown compression method";
+                    z.istate.marker = 5; // can't try inflateSync
+                    break;
+                }
+                z.istate.mode = GZIP_FLG;
+            case GZIP_FLG:
+                if (z.avail_in == 0) {
+                    return r;
+                }
+                r = f;
+                z.avail_in --;
+                z.total_in ++;
+                gzipFlag = z.next_in[z.next_in_index ++] & 0xff;
+                gzipBytesToRead = 6;
+                z.istate.mode = GZIP_MTIME_XFL_OS;
+            case GZIP_MTIME_XFL_OS:
+                while (gzipBytesToRead > 0) {
+                    if (z.avail_in == 0) {
+                        return r;
+                    }
+                    r = f;
+                    z.avail_in --;
+                    z.total_in ++;
+                    z.next_in_index ++;
+                    gzipBytesToRead --;
+                }
+                z.istate.mode = GZIP_XLEN;
+                gzipXLen = 0;
+                gzipBytesToRead = 2;
+            case GZIP_XLEN:
+                if ((gzipFlag & 4) != 0) {
+                    while (gzipBytesToRead > 0) {
+                        if (z.avail_in == 0) {
+                            return r;
+                        }
+                        r = f;
+                        z.avail_in --;
+                        z.total_in ++;
+                        gzipXLen = gzipXLen << 8 | z.next_in[z.next_in_index ++] & 0xff;
+                        gzipBytesToRead --;
+                    }
+                    gzipBytesToRead = gzipXLen;
+                    z.istate.mode = GZIP_FEXTRA;
+                } else {
+                    z.istate.mode = GZIP_FNAME;
+                    break;
+                }
+            case GZIP_FEXTRA:
+                while (gzipBytesToRead > 0) {
+                    if (z.avail_in == 0) {
+                        return r;
+                    }
+                    r = f;
+                    z.avail_in --;
+                    z.total_in ++;
+                    z.next_in_index ++;
+                    gzipBytesToRead --;
+                }
+                z.istate.mode = GZIP_FNAME;
+            case GZIP_FNAME:
+                if ((gzipFlag & 8) != 0) {
+                    do {
+                        if (z.avail_in == 0) {
+                            return r;
+                        }
+                        r = f;
+                        z.avail_in --;
+                        z.total_in ++;
+                    } while (z.next_in[z.next_in_index ++] == 0);
+                }
+                z.istate.mode = GZIP_FCOMMENT;
+            case GZIP_FCOMMENT:
+                if ((gzipFlag & 16) != 0) {
+                    do {
+                        if (z.avail_in == 0) {
+                            return r;
+                        }
+                        r = f;
+                        z.avail_in --;
+                        z.total_in ++;
+                    } while (z.next_in[z.next_in_index ++] == 0);
+                }
+                gzipBytesToRead = 2;
+                z.istate.mode = GZIP_FHCRC;
+            case GZIP_FHCRC:
+                if ((gzipFlag & 2) != 0) {
+                    while (gzipBytesToRead > 0) {
+                        if (z.avail_in == 0) {
+                            return r;
+                        }
+                        r = f;
+                        z.avail_in --;
+                        z.total_in ++;
+                        z.next_in_index ++;
+                        gzipBytesToRead --;
+                    }
+                }
+                z.istate.mode = BLOCKS;
+                break;
+            case GZIP_CHECK8:
+                if (z.avail_in == 0) {
+                    return r;
+                }
+                r = f;
+                z.avail_in --;
+                z.total_in ++;
+                z.istate.need = (z.next_in[z.next_in_index ++] & 0xff) << 24 & 0xff000000L;
+                z.istate.mode = GZIP_CHECK7;
+            case GZIP_CHECK7:
+                if (z.avail_in == 0) {
+                    return r;
+                }
+                r = f;
+                z.avail_in --;
+                z.total_in ++;
+                z.istate.need = (z.next_in[z.next_in_index ++] & 0xff) << 24 & 0xff000000L;
+                z.istate.mode = GZIP_CHECK6;
+            case GZIP_CHECK6:
+                if (z.avail_in == 0) {
+                    return r;
+                }
+                r = f;
+                z.avail_in --;
+                z.total_in ++;
+                z.istate.need = (z.next_in[z.next_in_index ++] & 0xff) << 24 & 0xff000000L;
+                z.istate.mode = GZIP_CHECK5;
+            case GZIP_CHECK5:
+                if (z.avail_in == 0) {
+                    return r;
+                }
+                r = f;
+                z.avail_in --;
+                z.total_in ++;
+                z.istate.need = (z.next_in[z.next_in_index ++] & 0xff) << 24 & 0xff000000L;
+                z.istate.mode = GZIP_CHECK4;
+            case GZIP_CHECK4:
+                if (z.avail_in == 0) {
+                    return r;
+                }
+                r = f;
+                z.avail_in --;
+                z.total_in ++;
+                z.istate.need = (z.next_in[z.next_in_index ++] & 0xff) << 24 & 0xff000000L;
+                z.istate.mode = GZIP_CHECK3;
+            case GZIP_CHECK3:
+                if (z.avail_in == 0) {
+                    return r;
+                }
+                r = f;
+                z.avail_in --;
+                z.total_in ++;
+                z.istate.need = (z.next_in[z.next_in_index ++] & 0xff) << 24 & 0xff000000L;
+                z.istate.mode = GZIP_CHECK2;
+            case GZIP_CHECK2:
+                if (z.avail_in == 0) {
+                    return r;
+                }
+                r = f;
+                z.avail_in --;
+                z.total_in ++;
+                z.istate.need = (z.next_in[z.next_in_index ++] & 0xff) << 24 & 0xff000000L;
+                z.istate.mode = GZIP_CHECK1;
+            case GZIP_CHECK1:
+                if (z.avail_in == 0) {
+                    return r;
+                }
+                r = f;
+                z.avail_in --;
+                z.total_in ++;
+                z.istate.need = (z.next_in[z.next_in_index ++] & 0xff) << 24 & 0xff000000L;
+                z.istate.mode = DONE;
+                break;
             default:
                 return JZlib.Z_STREAM_ERROR;
             }

src/main/java/org/jboss/netty/util/internal/jzlib/ZStream.java

@@ -65,6 +65,7 @@ public final class ZStream {
     Inflate istate;
     int data_type; // best guess about the data type: ascii or binary
     long adler;
+    long crc32;
 
     public int inflateInit() {
         return inflateInit(JZlib.DEF_WBITS);
@@ -214,9 +215,15 @@ public final class ZStream {
 
         avail_in -= len;
 
-        if (dstate.wrapperType == WrapperType.ZLIB) {
+        switch (dstate.wrapperType) {
+        case ZLIB:
             adler = Adler32.adler32(adler, next_in, next_in_index, len);
+            break;
+        case GZIP:
+            crc32 = CRC32.crc32(crc32, next_in, next_in_index, len);
+            break;
         }
+
         System.arraycopy(next_in, next_in_index, buf, start, len);
         next_in_index += len;
         total_in += len;