1 /*

     2  * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 

    25 #include "precompiled.hpp"

    26 #include "runtime/thread.inline.hpp"

    27 #include "classfile/imageDecompressor.hpp"

    28 #include "runtime/thread.hpp"

    29 #include "utilities/bytes.hpp"

    30 

    31 /*

    32  * Allocate in C Heap not in resource area, otherwise JVM crashes.

    33  * This array life time is the VM life time. Array is never freed and

    34  * is not expected to contain more than few references.

    35  */

    36 GrowableArray<ImageDecompressor*>* ImageDecompressor::_decompressors =

    37   new(ResourceObj::C_HEAP, mtInternal) GrowableArray<ImageDecompressor*>(2, true);

    38 

    39 static Symbol* createSymbol(const char* str) {

    40   Thread* THREAD = Thread::current();

    41   Symbol* sym = SymbolTable::lookup(str, (int) strlen(str), THREAD);

    42   if (HAS_PENDING_EXCEPTION) {

    43     warning("can't create symbol\n");

    44     CLEAR_PENDING_EXCEPTION;

    45     return NULL;

    46   }

    47   return sym;

    48 }

    49 

    50 /*

    51  * Initialize the array of decompressors.

    52  */

    53 bool image_decompressor_init() {

    54   Symbol* zipSymbol = createSymbol("zip");

    55   if (zipSymbol == NULL) {

    56     return false;

    57   }

    58   ImageDecompressor::add_decompressor(new ZipDecompressor(zipSymbol));

    59 

    60   return true;

    61 }

    62 

    63 /*

    64  * Decompression entry point. Called from ImageFileReader::get_resource.

    65  */

    66 void ImageDecompressor::decompress_resource(u1* compressed, u1* uncompressed,

    67         u4 uncompressed_size, const ImageStrings* strings, bool is_C_heap) {

    68   bool has_header = false;

    69   u1* decompressed_resource = compressed;

    70   u1* compressed_resource = compressed;

    71 

    72   // Resource could have been transformed by a stack of decompressors.

    73   // Iterate and decompress resources until there is no more header.

    74   do {

    75     ResourceHeader _header;

    76     memcpy(&_header, compressed_resource, sizeof (ResourceHeader));

    77     has_header = _header._magic == ResourceHeader::resource_header_magic;

    78     if (has_header) {

    79       // decompressed_resource array contains the result of decompression

    80       // when a resource content is terminal, it means that it is an actual resource,

    81       // not an intermediate not fully uncompressed content. In this case

    82       // the resource is allocated as an mtClass, otherwise as an mtOther

    83       decompressed_resource = is_C_heap && _header._is_terminal ?

    84               NEW_C_HEAP_ARRAY(u1, _header._uncompressed_size, mtClass) :

    85               NEW_C_HEAP_ARRAY(u1, _header._uncompressed_size, mtOther);

    86       // Retrieve the decompressor name

    87       const char* decompressor_name = strings->get(_header._decompressor_name_offset);

    88       if (decompressor_name == NULL) warning("image decompressor not found\n");

    89       guarantee(decompressor_name, "image decompressor not found");

    90       // Retrieve the decompressor instance

    91       ImageDecompressor* decompressor = get_decompressor(decompressor_name);

    92       if (decompressor == NULL) {

    93         warning("image decompressor %s not found\n", decompressor_name);

    94       }

    95       guarantee(decompressor, "image decompressor not found");

    96       u1* compressed_resource_base = compressed_resource;

    97       compressed_resource += ResourceHeader::resource_header_length;

    98       // Ask the decompressor to decompress the compressed content

    99       decompressor->decompress_resource(compressed_resource, decompressed_resource,

   100         &_header, strings);

   101       if (compressed_resource_base != compressed) {

   102         FREE_C_HEAP_ARRAY(char, compressed_resource_base);

   103       }

   104       compressed_resource = decompressed_resource;

   105     }

   106   } while (has_header);

   107   memcpy(uncompressed, decompressed_resource, uncompressed_size);

   108 }

   109 

   110 // Zip decompressor

   111 

   112 void ZipDecompressor::decompress_resource(u1* data, u1* uncompressed,

   113         ResourceHeader* header, const ImageStrings* strings) {

   114   char* msg = NULL;

   115   jboolean res = ClassLoader::decompress(data, header->_size, uncompressed,

   116           header->_uncompressed_size, &msg);

   117   if (!res) warning("decompression failed due to %s\n", msg);

   118   guarantee(res, "decompression failed");

   119 }

   120 

   121 // END Zip Decompressor