/*

 * Copyright (c) 2003, 2017, 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 SHARE_VM_MEMORY_FILEMAP_HPP

#define SHARE_VM_MEMORY_FILEMAP_HPP

#include "classfile/classLoader.hpp"

#include "memory/metaspaceShared.hpp"

#include "memory/metaspace.hpp"

#include "memory/universe.hpp"

#include "utilities/align.hpp"

// Layout of the file:

//  header: dump of archive instance plus versioning info, datestamp, etc.

//   [magic # = 0xF00BABA2]

//  ... padding to align on page-boundary

//  read-write space

//  read-only space

//  misc data (block offset table, string table, symbols, dictionary, etc.)

//  tag(666)

static const int JVM_IDENT_MAX = 256;

class SharedClassPathEntry VALUE_OBJ_CLASS_SPEC {

protected:

  bool   _is_dir;

  time_t _timestamp;          // jar/jimage timestamp,  0 if is directory or other

  long   _filesize;           // jar/jimage file size, -1 if is directory, -2 if other

  Array<char>* _name;

  Array<u1>*   _manifest;

public:

  void init(const char* name, TRAPS);

  void metaspace_pointers_do(MetaspaceClosure* it);

  bool validate();

  // The _timestamp only gets set for jar files and "modules" jimage.

  bool is_jar_or_bootimage() {

    return _timestamp != 0;

  }

  bool is_dir() { return _is_dir; }

  bool is_jrt() { return ClassLoader::is_jrt(name()); }

  time_t timestamp() const { return _timestamp; }

  long   filesize()  const { return _filesize; }

  const char* name() const { return _name->data(); }

  const char* manifest() const {

    return (_manifest == NULL) ? NULL : (const char*)_manifest->data();

  }

  int manifest_size() const {

    return (_manifest == NULL) ? 0 : _manifest->length();

  }

};

class FileMapInfo : public CHeapObj<mtInternal> {

private:

  friend class ManifestStream;

  enum {

    _invalid_version = -1,

    _current_version = 3

  };

  bool  _file_open;

  int   _fd;

  size_t  _file_offset;

private:

  static Array<u8>*            _classpath_entry_table;

  static int                   _classpath_entry_table_size;

  static size_t                _classpath_entry_size;

  static bool                  _validating_classpath_entry_table;

  // FileMapHeader describes the shared space data in the file to be

  // mapped.  This structure gets written to a file.  It is not a class, so

  // that the compilers don't add any compiler-private data to it.

public:

  struct FileMapHeaderBase : public CHeapObj<mtClass> {

    virtual bool validate() = 0;

    virtual void populate(FileMapInfo* info, size_t alignment) = 0;

  };

  struct FileMapHeader : FileMapHeaderBase {

    // Use data() and data_size() to memcopy to/from the FileMapHeader. We need to

    // avoid read/writing the C++ vtable pointer.

    static size_t data_size();

    char* data() {

      return ((char*)this) + sizeof(FileMapHeaderBase);

    }

    int    _magic;                    // identify file type.

    int    _crc;                      // header crc checksum.

    int    _version;                  // (from enum, above.)

    size_t _alignment;                // how shared archive should be aligned

    int    _obj_alignment;            // value of ObjectAlignmentInBytes

    int    _narrow_oop_shift;         // compressed oop encoding shift

    bool   _compact_strings;          // value of CompactStrings

    uintx  _max_heap_size;            // java max heap size during dumping

    Universe::NARROW_OOP_MODE _narrow_oop_mode; // compressed oop encoding mode

    int     _narrow_klass_shift;      // save narrow klass base and shift

    address _narrow_klass_base;

    char*   _misc_data_patching_start;

    char*   _read_only_tables_start;

    address _cds_i2i_entry_code_buffers;

    size_t  _cds_i2i_entry_code_buffers_size;

    size_t  _core_spaces_size;        // number of bytes allocated by the core spaces

                                      // (mc, md, ro, rw and od).

    struct space_info {

      int    _crc;           // crc checksum of the current space

      size_t _file_offset;   // sizeof(this) rounded to vm page size

      union {

        char*  _base;        // copy-on-write base address

        intx   _offset;      // offset from the compressed oop encoding base, only used

                             // by string space

      } _addr;

      size_t _used;          // for setting space top on read

      bool   _read_only;     // read only space?

      bool   _allow_exec;    // executable code in space?

    } _space[MetaspaceShared::n_regions];

    // The following fields are all sanity checks for whether this archive

    // will function correctly with this JVM and the bootclasspath it's

    // invoked with.

    char  _jvm_ident[JVM_IDENT_MAX];      // identifier for jvm

    // The _paths_misc_info is a variable-size structure that records "miscellaneous"

    // information during dumping. It is generated and validated by the

    // SharedPathsMiscInfo class. See SharedPathsMiscInfo.hpp and sharedClassUtil.hpp for

    // detailed description.

    //

    // The _paths_misc_info data is stored as a byte array in the archive file header,

    // immediately after the _header field. This information is used only when

    // checking the validity of the archive and is deallocated after the archive is loaded.

    //

    // Note that the _paths_misc_info does NOT include information for JAR files

    // that existed during dump time. Their information is stored in _classpath_entry_table.

    int _paths_misc_info_size;

    // The following is a table of all the class path entries that were used

    // during dumping. At run time, we require these files to exist and have the same

    // size/modification time, or else the archive will refuse to load.

    //

    // All of these entries must be JAR files. The dumping process would fail if a non-empty

    // directory was specified in the classpaths. If an empty directory was specified

    // it is checked by the _paths_misc_info as described above.

    //

    // FIXME -- if JAR files in the tail of the list were specified but not used during dumping,

    // they should be removed from this table, to save space and to avoid spurious

    // loading failures during runtime.

    int _classpath_entry_table_size;

    size_t _classpath_entry_size;

    Array<u8>* _classpath_entry_table;

    char* region_addr(int idx);

    virtual bool validate();

    virtual void populate(FileMapInfo* info, size_t alignment);

    int compute_crc();

  };

  FileMapHeader * _header;

  const char* _full_path;

  char* _paths_misc_info;

  static FileMapInfo* _current_info;

  bool  init_from_file(int fd);

  void  align_file_position();

  bool  validate_header_impl();

  static void metaspace_pointers_do(MetaspaceClosure* it);

public:

  FileMapInfo();

  ~FileMapInfo();

  static int current_version()        { return _current_version; }

  int    compute_header_crc()         { return _header->compute_crc(); }

  void   set_header_crc(int crc)      { _header->_crc = crc; }

  void   populate_header(size_t alignment);

  bool   validate_header();

  void   invalidate();

  int    version()                    { return _header->_version; }

  size_t alignment()                  { return _header->_alignment; }

  Universe::NARROW_OOP_MODE narrow_oop_mode() { return _header->_narrow_oop_mode; }

  int    narrow_oop_shift()           { return _header->_narrow_oop_shift; }

  uintx  max_heap_size()              { return _header->_max_heap_size; }

  address narrow_klass_base() const   { return _header->_narrow_klass_base; }

  int     narrow_klass_shift() const  { return _header->_narrow_klass_shift; }

  struct FileMapHeader* header()      { return _header; }

  char* misc_data_patching_start()            { return _header->_misc_data_patching_start; }

  void set_misc_data_patching_start(char* p)  { _header->_misc_data_patching_start = p; }

  char* read_only_tables_start()              { return _header->_read_only_tables_start; }

  void set_read_only_tables_start(char* p)    { _header->_read_only_tables_start = p; }

  address cds_i2i_entry_code_buffers() {

    return _header->_cds_i2i_entry_code_buffers;

  }

  void set_cds_i2i_entry_code_buffers(address addr) {

    _header->_cds_i2i_entry_code_buffers = addr;

  }

  size_t cds_i2i_entry_code_buffers_size() {

    return _header->_cds_i2i_entry_code_buffers_size;

  }

  void set_cds_i2i_entry_code_buffers_size(size_t s) {

    _header->_cds_i2i_entry_code_buffers_size = s;

  }

  void set_core_spaces_size(size_t s)    {  _header->_core_spaces_size = s; }

  size_t core_spaces_size()              { return _header->_core_spaces_size; }

  static FileMapInfo* current_info() {

    CDS_ONLY(return _current_info;)

    NOT_CDS(return NULL;)

  }

  static void assert_mark(bool check);

  // File manipulation.

  bool  initialize() NOT_CDS_RETURN_(false);

  bool  open_for_read();

  void  open_for_write();

  void  write_header();

  void  write_region(int region, char* base, size_t size,

                     bool read_only, bool allow_exec);

  size_t write_archive_heap_regions(GrowableArray<MemRegion> *heap_mem,

                                    int first_region_id, int max_num_regions);

  void  write_bytes(const void* buffer, int count);

  void  write_bytes_aligned(const void* buffer, int count);

  char* map_region(int i);

  void  map_heap_regions() NOT_CDS_JAVA_HEAP_RETURN;

  void  fixup_mapped_heap_regions() NOT_CDS_JAVA_HEAP_RETURN;

  void  unmap_region(int i);

  bool  verify_region_checksum(int i);

  void  close();

  bool  is_open() { return _file_open; }

  ReservedSpace reserve_shared_memory();

  // JVM/TI RedefineClasses() support:

  // Remap the shared readonly space to shared readwrite, private.

  bool  remap_shared_readonly_as_readwrite();

  // Errors.

  static void fail_stop(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2);

  static void fail_continue(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2);

  // Return true if given address is in the mapped shared space.

  bool is_in_shared_space(const void* p) NOT_CDS_RETURN_(false);

  bool is_in_shared_region(const void* p, int idx) NOT_CDS_RETURN_(false);

  void print_shared_spaces() NOT_CDS_RETURN;

  // Stop CDS sharing and unmap CDS regions.

  static void stop_sharing_and_unmap(const char* msg);

  static void allocate_classpath_entry_table();

  bool validate_classpath_entry_table();

  static SharedClassPathEntry* shared_classpath(int index) {

    if (index < 0) {

      return NULL;

    }

    assert(index < _classpath_entry_table_size, "sanity");

    char* p = (char*)_classpath_entry_table->data();

    p += _classpath_entry_size * index;

    return (SharedClassPathEntry*)p;

  }

  static const char* shared_classpath_name(int index) {

    assert(index >= 0, "Sanity");

    return shared_classpath(index)->name();

  }

  static int get_number_of_share_classpaths() {

    return _classpath_entry_table_size;

  }

 private:

  bool  map_heap_data(MemRegion **heap_mem, int first, int max, int* num,

                      bool is_open = false) NOT_CDS_JAVA_HEAP_RETURN_(false);

  bool  verify_mapped_heap_regions(int first, int num) NOT_CDS_JAVA_HEAP_RETURN_(false);

  void  dealloc_archive_heap_regions(MemRegion* regions, int num) NOT_CDS_JAVA_HEAP_RETURN;

};

#endif // SHARE_VM_MEMORY_FILEMAP_HPP