rev 15130 : imported patch 8162343

   1 /*
   2  * Copyright (c) 2015, 2016 Oracle and/or its affiliates. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  *   - Redistributions of source code must retain the above copyright
   9  *     notice, this list of conditions and the following disclaimer.
  10  *
  11  *   - Redistributions in binary form must reproduce the above copyright
  12  *     notice, this list of conditions and the following disclaimer in the
  13  *     documentation and/or other materials provided with the distribution.
  14  *
  15  *   - Neither the name of Oracle nor the names of its
  16  *     contributors may be used to endorse or promote products derived
  17  *     from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  20  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31 
  32 #ifndef LIBJIMAGE_IMAGEDECOMPRESSOR_HPP
  33 #define LIBJIMAGE_IMAGEDECOMPRESSOR_HPP
  34 
  35 #include <assert.h>
  36 #include <string.h>
  37 
  38 #include "imageFile.hpp"
  39 #include "inttypes.hpp"
  40 #include "jni.h"
  41 
  42 /*
  43  * Compressed resources located in image have an header.
  44  * This header contains:
  45  * - _magic: A magic u4, required to retrieved the header in the compressed content
  46  * - _size: The size of the compressed resource.
  47  * - _uncompressed_size: The uncompressed size of the compressed resource.
  48  * - _decompressor_name_offset: The ImageDecompressor instance name StringsTable offset.
  49  * - _decompressor_config_offset: StringsTable offset of configuration that could be needed by
  50  *   the decompressor in order to decompress.
  51  * - _is_terminal: 1: the compressed content is terminal. Uncompressing it would
  52  *   create the actual resource. 0: the compressed content is not terminal. Uncompressing it
  53  *   will result in a compressed content to be decompressed (This occurs when a stack of compressors
  54  *   have been used to compress the resource.
  55  */
  56 struct ResourceHeader {
  57     /* magic bytes that identifies a compressed resource header*/
  58     static const u4 resource_header_magic = 0xCAFEFAFA;
  59     u4 _magic; // Resource header
  60     u8 _size;    // Resource size
  61     u8 _uncompressed_size;  // Expected uncompressed size
  62     u4 _decompressor_name_offset;    // Strings table decompressor offset
  63     u4 _decompressor_config_offset; // Strings table config offset
  64     u1 _is_terminal; // Last decompressor 1, otherwise 0.
  65 };
  66 
  67 /*
  68  * Resources located in jimage file can be compressed. Compression occurs at
  69  * jimage file creation time. When compressed a resource is added an header that
  70  * contains the name of the compressor that compressed it.
  71  * Various compression strategies can be applied to compress a resource.
  72  * The same resource can even be compressed multiple time by a stack of compressors.
  73  * At runtime, a resource is decompressed in a loop until there is no more header
  74  * meaning that the resource is equivalent to the not compressed resource.
  75  * In each iteration, the name of the compressor located in the current header
  76  * is used to retrieve the associated instance of ImageDecompressor.
  77  * For example “zip” is the name of the compressor that compresses resources
  78  * using the zip algorithm. The ZipDecompressor class name is also “zip”.
  79  * ImageDecompressor instances are retrieved from a static array in which
  80  * they are registered.
  81  */
  82 class ImageDecompressor {
  83 
  84 private:
  85     const char* _name;
  86 
  87     /*
  88      * Array of concrete decompressors. This array is used to retrieve the decompressor
  89      * that can handle resource decompression.
  90      */
  91     static ImageDecompressor** _decompressors;
  92     /**
  93      * Num of decompressors
  94      */
  95     static int _decompressors_num;
  96     /*
  97      * Identifier of a decompressor. This name is the identification key to retrieve
  98      * decompressor from a resource header.
  99      */
 100     inline const char* get_name() const { return _name; }
 101 
 102     static u8 getU8(u1* ptr, Endian *endian);
 103     static u4 getU4(u1* ptr, Endian *endian);
 104 
 105 protected:
 106     ImageDecompressor(const char* name) : _name(name) {
 107     }
 108     virtual void decompress_resource(u1* data, u1* uncompressed,
 109         ResourceHeader* header, const ImageStrings* strings) = 0;
 110 
 111 public:
 112     static void image_decompressor_init();
 113     static void image_decompressor_close();
 114     static ImageDecompressor* get_decompressor(const char * decompressor_name) ;
 115     static void decompress_resource(u1* compressed, u1* uncompressed,
 116         u8 uncompressed_size, const ImageStrings* strings, Endian* _endian);
 117 };
 118 
 119 /**
 120  * Zip decompressor.
 121  */
 122 class ZipDecompressor : public ImageDecompressor {
 123 public:
 124     ZipDecompressor(const char* sym) : ImageDecompressor(sym) { }
 125     void decompress_resource(u1* data, u1* uncompressed, ResourceHeader* header,
 126         const ImageStrings* strings);
 127     static jboolean decompress(void *in, u8 inSize, void *out, u8 outSize, char **pmsg);
 128 };
 129 
 130 /*
 131  * Shared Strings decompressor. This decompressor reconstruct the class
 132  * constant pool UTF_U entries by retrieving strings stored in jimage strings table.
 133  * In addition, if the UTF_8 entry is a descriptor, the descriptor has to be rebuilt,
 134  * all java type having been removed from the descriptor and added to the sting table.
 135  * eg: "(Ljava/lang/String;I)V" ==> "(L;I)V" and "java/lang", "String"
 136  * stored in string table. offsets to the 2 strings are compressed and stored in the
 137  * constantpool entry.
 138  */
 139 class SharedStringDecompressor : public ImageDecompressor {
 140 private:
 141     // the constant pool tag for UTF8 string located in strings table
 142     static const int externalized_string = 23;
 143     // the constant pool tag for UTF8 descriptors string located in strings table
 144     static const int externalized_string_descriptor = 25;
 145     // the constant pool tag for UTF8
 146     static const int constant_utf8 = 1;
 147     // the constant pool tag for long
 148     static const int constant_long = 5;
 149     // the constant pool tag for double
 150     static const int constant_double = 6;
 151     // array index is the constant pool tag. value is size.
 152     // eg: array[5]  = 8; means size of long is 8 bytes.
 153     static const u1 sizes[];
 154     // bit 5 and 6 are used to store the length of the compressed integer.
 155     // size can be 1 (01), 2 (10), 3 (11).
 156     // 0x60 ==> 0110000
 157     static const int compressed_index_size_mask = 0x60;
 158     /*
 159      * mask the length bits (5 and 6) and move to the right 5 bits.
 160      */
 161     inline static int get_compressed_length(char c) {
 162         return ((char) (c & compressed_index_size_mask) >> 5);
 163     }
 164     inline static bool is_compressed(signed char b1) { return b1 < 0; }
 165     static int decompress_int(unsigned char*& value);
 166 public:
 167     SharedStringDecompressor(const char* sym) : ImageDecompressor(sym){}
 168     void decompress_resource(u1* data, u1* uncompressed, ResourceHeader* header,
 169     const ImageStrings* strings);
 170 };
 171 #endif // LIBJIMAGE_IMAGEDECOMPRESSOR_HPP
--- EOF ---