--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.base/share/native/libjimage/imageDecompressor.hpp Fri Sep 04 10:11:43 2015 -0300
@@ -0,0 +1,162 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef LIBJIMAGE_IMAGEDECOMPRESSOR_HPP
+#define LIBJIMAGE_IMAGEDECOMPRESSOR_HPP
+
+#include <assert.h>
+#include <string.h>
+
+#include "imageFile.hpp"
+#include "inttypes.hpp"
+#include "jni.h"
+
+/*
+ * Compressed resources located in image have an header.
+ * This header contains:
+ * - _magic: A magic u4, required to retrieved the header in the compressed content
+ * - _size: The size of the compressed resource.
+ * - _uncompressed_size: The uncompressed size of the compressed resource.
+ * - _decompressor_name_offset: The ImageDecompressor instance name StringsTable offset.
+ * - _decompressor_config_offset: StringsTable offset of configuration that could be needed by
+ * the decompressor in order to decompress.
+ * - _is_terminal: 1: the compressed content is terminal. Uncompressing it would
+ * create the actual resource. 0: the compressed content is not terminal. Uncompressing it
+ * will result in a compressed content to be decompressed (This occurs when a stack of compressors
+ * have been used to compress the resource.
+ */
+struct ResourceHeader {
+ /* Length of header, needed to retrieve content offset */
+ static const u1 resource_header_length = 21;
+ /* magic bytes that identifies a compressed resource header*/
+ static const u4 resource_header_magic = 0xCAFEFAFA;
+ u4 _magic; // Resource header
+ u4 _size; // Resource size
+ u4 _uncompressed_size; // Expected uncompressed size
+ u4 _decompressor_name_offset; // Strings table decompressor offset
+ u4 _decompressor_config_offset; // Strings table config offset
+ u1 _is_terminal; // Last decompressor 1, otherwise 0.
+};
+
+/*
+ * Resources located in jimage file can be compressed. Compression occurs at
+ * jimage file creation time. When compressed a resource is added an header that
+ * contains the name of the compressor that compressed it.
+ * Various compression strategies can be applied to compress a resource.
+ * The same resource can even be compressed multiple time by a stack of compressors.
+ * At runtime, a resource is decompressed in a loop until there is no more header
+ * meaning that the resource is equivalent to the not compressed resource.
+ * In each iteration, the name of the compressor located in the current header
+ * is used to retrieve the associated instance of ImageDecompressor.
+ * For example “zip” is the name of the compressor that compresses resources
+ * using the zip algorithm. The ZipDecompressor class name is also “zip”.
+ * ImageDecompressor instances are retrieved from a static array in which
+ * they are registered.
+ */
+class ImageDecompressor {
+
+private:
+ const char* _name;
+
+ /*
+ * Array of concrete decompressors. This array is used to retrieve the decompressor
+ * that can handle resource decompression.
+ */
+ static ImageDecompressor** _decompressors;
+ /**
+ * Num of decompressors
+ */
+ static int _decompressors_num;
+ /*
+ * Identifier of a decompressor. This name is the identification key to retrieve
+ * decompressor from a resource header.
+ */
+ inline const char* get_name() const { return _name; }
+
+
+protected:
+ ImageDecompressor(const char* name) : _name(name) {
+ }
+ virtual void decompress_resource(u1* data, u1* uncompressed,
+ ResourceHeader* header, const ImageStrings* strings) = 0;
+
+public:
+ static void image_decompressor_init();
+ static void image_decompressor_close();
+ static ImageDecompressor* get_decompressor(const char * decompressor_name) ;
+ static void decompress_resource(u1* compressed, u1* uncompressed,
+ u4 uncompressed_size, const ImageStrings* strings);
+};
+
+/**
+ * Zip decompressor.
+ */
+class ZipDecompressor : public ImageDecompressor {
+public:
+ ZipDecompressor(const char* sym) : ImageDecompressor(sym) { }
+ void decompress_resource(u1* data, u1* uncompressed, ResourceHeader* header,
+ const ImageStrings* strings);
+ static jboolean decompress(void *in, u8 inSize, void *out, u8 outSize, char **pmsg);
+};
+
+/*
+ * Shared Strings decompressor. This decompressor reconstruct the class
+ * constant pool UTF_U entries by retrieving strings stored in jimage strings table.
+ * In addition, if the UTF_8 entry is a descriptor, the descriptor has to be rebuilt,
+ * all java type having been removed from the descriptor and added to the sting table.
+ * eg: "(Ljava/lang/String;I)V" ==> "(L;I)V" and "java/lang", "String"
+ * stored in string table. offsets to the 2 strings are compressed and stored in the
+ * constantpool entry.
+ */
+class SharedStringDecompressor : public ImageDecompressor {
+private:
+ // the constant pool tag for UTF8 string located in strings table
+ static const int externalized_string = 23;
+ // the constant pool tag for UTF8 descriptors string located in strings table
+ static const int externalized_string_descriptor = 25;
+ // the constant pool tag for UTF8
+ static const int constant_utf8 = 1;
+ // the constant pool tag for long
+ static const int constant_long = 5;
+ // the constant pool tag for double
+ static const int constant_double = 6;
+ // array index is the constant pool tag. value is size.
+ // eg: array[5] = 8; means size of long is 8 bytes.
+ static const u1 sizes[];
+ // bit 5 and 6 are used to store the length of the compressed integer.
+ // size can be 1 (01), 2 (10), 3 (11).
+ // 0x60 ==> 0110000
+ static const int compressed_index_size_mask = 0x60;
+ /*
+ * mask the length bits (5 and 6) and move to the right 5 bits.
+ */
+ inline static int get_compressed_length(char c) { return ((char) (c & compressed_index_size_mask) >> 5); }
+ inline static bool is_compressed(signed char b1) { return b1 < 0; }
+ static int decompress_int(unsigned char*& value);
+public:
+ SharedStringDecompressor(const char* sym) : ImageDecompressor(sym){}
+ void decompress_resource(u1* data, u1* uncompressed, ResourceHeader* header,
+ const ImageStrings* strings);
+};
+#endif // LIBJIMAGE_IMAGEDECOMPRESSOR_HPP