--- a/hotspot/src/share/vm/classfile/imageFile.hpp Fri Sep 18 14:21:34 2015 -0700
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,602 +0,0 @@
-/*
- * Copyright (c) 2014, 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_CLASSFILE_IMAGEFILE_HPP
-#define SHARE_VM_CLASSFILE_IMAGEFILE_HPP
-
-#include "classfile/classLoader.hpp"
-#include "memory/allocation.hpp"
-#include "memory/allocation.inline.hpp"
-#include "utilities/endian.hpp"
-#include "utilities/globalDefinitions.hpp"
-#include "utilities/growableArray.hpp"
-
-// Image files are an alternate file format for storing classes and resources. The
-// goal is to supply file access which is faster and smaller than the jar format.
-// It should be noted that unlike jars, information stored in an image is in native
-// endian format. This allows the image to be mapped into memory without endian
-// translation. This also means that images are platform dependent.
-//
-// Image files are structured as three sections;
-//
-// +-----------+
-// | Header |
-// +-----------+
-// | |
-// | Index |
-// | |
-// +-----------+
-// | |
-// | |
-// | Resources |
-// | |
-// | |
-// +-----------+
-//
-// The header contains information related to identification and description of
-// contents.
-//
-// +-------------------------+
-// | Magic (0xCAFEDADA) |
-// +------------+------------+
-// | Major Vers | Minor Vers |
-// +------------+------------+
-// | Flags |
-// +-------------------------+
-// | Resource Count |
-// +-------------------------+
-// | Table Length |
-// +-------------------------+
-// | Attributes Size |
-// +-------------------------+
-// | Strings Size |
-// +-------------------------+
-//
-// Magic - means of identifying validity of the file. This avoids requiring a
-// special file extension.
-// Major vers, minor vers - differences in version numbers indicate structural
-// changes in the image.
-// Flags - various image wide flags (future).
-// Resource count - number of resources in the file.
-// Table length - the length of lookup tables used in the index.
-// Attributes size - number of bytes in the region used to store location attribute
-// streams.
-// Strings size - the size of the region used to store strings used by the
-// index and meta data.
-//
-// The index contains information related to resource lookup. The algorithm
-// used for lookup is "A Practical Minimal Perfect Hashing Method"
-// (http://homepages.dcc.ufmg.br/~nivio/papers/wea05.pdf). Given a path string
-// in the form /<module>/<package>/<base>.<extension> return the resource location
-// information;
-//
-// redirectIndex = hash(path, DEFAULT_SEED) % table_length;
-// redirect = redirectTable[redirectIndex];
-// if (redirect == 0) return not found;
-// locationIndex = redirect < 0 ? -1 - redirect : hash(path, redirect) % table_length;
-// location = locationTable[locationIndex];
-// if (!verify(location, path)) return not found;
-// return location;
-//
-// Note: The hash function takes an initial seed value. A different seed value
-// usually returns a different result for strings that would otherwise collide with
-// other seeds. The verify function guarantees the found resource location is
-// indeed the resource we are looking for.
-//
-// The following is the format of the index;
-//
-// +-------------------+
-// | Redirect Table |
-// +-------------------+
-// | Attribute Offsets |
-// +-------------------+
-// | Attribute Data |
-// +-------------------+
-// | Strings |
-// +-------------------+
-//
-// Redirect Table - Array of 32-bit signed values representing actions that
-// should take place for hashed strings that map to that
-// value. Negative values indicate no hash collision and can be
-// quickly converted to indices into attribute offsets. Positive
-// values represent a new seed for hashing an index into attribute
-// offsets. Zero indicates not found.
-// Attribute Offsets - Array of 32-bit unsigned values representing offsets into
-// attribute data. Attribute offsets can be iterated to do a
-// full survey of resources in the image. Offset of zero
-// indicates no attributes.
-// Attribute Data - Bytes representing compact attribute data for locations. (See
-// comments in ImageLocation.)
-// Strings - Collection of zero terminated UTF-8 strings used by the index and
-// image meta data. Each string is accessed by offset. Each string is
-// unique. Offset zero is reserved for the empty string.
-//
-// Note that the memory mapped index assumes 32 bit alignment of each component
-// in the index.
-//
-// Endianness of an image.
-// An image booted by hotspot is always in native endian. However, it is possible
-// to read (by the JDK) in alternate endian format. Primarily, this is during
-// cross platform scenarios. Ex, where javac needs to read an embedded image
-// to access classes for crossing compilation.
-//
-
-class ImageFileReader; // forward declaration
-
-// Manage image file string table.
-class ImageStrings VALUE_OBJ_CLASS_SPEC {
-private:
- u1* _data; // Data bytes for strings.
- u4 _size; // Number of bytes in the string table.
-public:
- enum {
- // Not found result from find routine.
- NOT_FOUND = -1,
- // Prime used to generate hash for Perfect Hashing.
- HASH_MULTIPLIER = 0x01000193
- };
-
- ImageStrings(u1* data, u4 size) : _data(data), _size(size) {}
-
- // Return the UTF-8 string beginning at offset.
- inline const char* get(u4 offset) const {
- guarantee(offset < _size, "offset exceeds string table size");
- return (const char*)(_data + offset);
- }
-
- // Compute the Perfect Hashing hash code for the supplied UTF-8 string.
- inline static u4 hash_code(const char* string) {
- return hash_code(string, HASH_MULTIPLIER);
- }
-
- // Compute the Perfect Hashing hash code for the supplied string, starting at seed.
- static s4 hash_code(const char* string, s4 seed);
-
- // Match up a string in a perfect hash table. Result still needs validation
- // for precise match.
- static s4 find(Endian* endian, const char* name, s4* redirect, u4 length);
-
- // Test to see if UTF-8 string begins with the start UTF-8 string. If so,
- // return non-NULL address of remaining portion of string. Otherwise, return
- // NULL. Used to test sections of a path without copying from image string
- // table.
- static const char* starts_with(const char* string, const char* start);
-
- // Test to see if UTF-8 string begins with start char. If so, return non-NULL
- // address of remaining portion of string. Otherwise, return NULL. Used
- // to test a character of a path without copying.
- inline static const char* starts_with(const char* string, const char ch) {
- return *string == ch ? string + 1 : NULL;
- }
-};
-
-// Manage image file location attribute data. Within an image, a location's
-// attributes are compressed into a stream of bytes. An attribute stream is
-// composed of individual attribute sequences. Each attribute sequence begins with
-// a header byte containing the attribute 'kind' (upper 5 bits of header) and the
-// 'length' less 1 (lower 3 bits of header) of bytes that follow containing the
-// attribute value. Attribute values present as most significant byte first.
-//
-// Ex. Container offset (ATTRIBUTE_OFFSET) 0x33562 would be represented as 0x22
-// (kind = 4, length = 3), 0x03, 0x35, 0x62.
-//
-// An attribute stream is terminated with a header kind of ATTRIBUTE_END (header
-// byte of zero.)
-//
-// ImageLocation inflates the stream into individual values stored in the long
-// array _attributes. This allows an attribute value can be quickly accessed by
-// direct indexing. Unspecified values default to zero.
-//
-// Notes:
-// - Even though ATTRIBUTE_END is used to mark the end of the attribute stream,
-// streams will contain zero byte values to represent lesser significant bits.
-// Thus, detecting a zero byte is not sufficient to detect the end of an attribute
-// stream.
-// - ATTRIBUTE_OFFSET represents the number of bytes from the beginning of the region
-// storing the resources. Thus, in an image this represents the number of bytes
-// after the index.
-// - Currently, compressed resources are represented by having a non-zero
-// ATTRIBUTE_COMPRESSED value. This represents the number of bytes stored in the
-// image, and the value of ATTRIBUTE_UNCOMPRESSED represents number of bytes of the
-// inflated resource in memory. If the ATTRIBUTE_COMPRESSED is zero then the value
-// of ATTRIBUTE_UNCOMPRESSED represents both the number of bytes in the image and
-// in memory. In the future, additional compression techniques will be used and
-// represented differently.
-// - Package strings include trailing slash and extensions include prefix period.
-//
-class ImageLocation VALUE_OBJ_CLASS_SPEC {
-public:
- enum {
- ATTRIBUTE_END, // End of attribute stream marker
- ATTRIBUTE_MODULE, // String table offset of module name
- ATTRIBUTE_PARENT, // String table offset of resource path parent
- ATTRIBUTE_BASE, // String table offset of resource path base
- ATTRIBUTE_EXTENSION, // String table offset of resource path extension
- ATTRIBUTE_OFFSET, // Container byte offset of resource
- ATTRIBUTE_COMPRESSED, // In image byte size of the compressed resource
- ATTRIBUTE_UNCOMPRESSED, // In memory byte size of the uncompressed resource
- ATTRIBUTE_COUNT // Number of attribute kinds
- };
-
-private:
- // Values of inflated attributes.
- u8 _attributes[ATTRIBUTE_COUNT];
-
- // Return the attribute value number of bytes.
- inline static u1 attribute_length(u1 data) {
- return (data & 0x7) + 1;
- }
-
- // Return the attribute kind.
- inline static u1 attribute_kind(u1 data) {
- u1 kind = data >> 3;
- guarantee(kind < ATTRIBUTE_COUNT, "invalid attribute kind");
- return kind;
- }
-
- // Return the attribute length.
- inline static u8 attribute_value(u1* data, u1 n) {
- guarantee(0 < n && n <= 8, "invalid attribute value length");
- u8 value = 0;
- // Most significant bytes first.
- for (u1 i = 0; i < n; i++) {
- value <<= 8;
- value |= data[i];
- }
- return value;
- }
-
-public:
- ImageLocation() {
- clear_data();
- }
-
- ImageLocation(u1* data) {
- clear_data();
- set_data(data);
- }
-
- // Inflates the attribute stream into individual values stored in the long
- // array _attributes. This allows an attribute value to be quickly accessed by
- // direct indexing. Unspecified values default to zero.
- void set_data(u1* data);
-
- // Zero all attribute values.
- void clear_data();
-
- // Retrieve an attribute value from the inflated array.
- inline u8 get_attribute(u1 kind) const {
- guarantee(ATTRIBUTE_END < kind && kind < ATTRIBUTE_COUNT, "invalid attribute kind");
- return _attributes[kind];
- }
-
- // Retrieve an attribute string value from the inflated array.
- inline const char* get_attribute(u4 kind, const ImageStrings& strings) const {
- return strings.get((u4)get_attribute(kind));
- }
-};
-
-//
-// NOTE: needs revision.
-// Each loader requires set of module meta data to identify which modules and
-// packages are managed by that loader. Currently, there is one image file per
-// builtin loader, so only one module meta data resource per file.
-//
-// Each element in the module meta data is a native endian 4 byte integer. Note
-// that entries with zero offsets for string table entries should be ignored (
-// padding for hash table lookup.)
-//
-// Format:
-// Count of package to module entries
-// Count of module to package entries
-// Perfect Hash redirect table[Count of package to module entries]
-// Package to module entries[Count of package to module entries]
-// Offset to package name in string table
-// Offset to module name in string table
-// Perfect Hash redirect table[Count of module to package entries]
-// Module to package entries[Count of module to package entries]
-// Offset to module name in string table
-// Count of packages in module
-// Offset to first package in packages table
-// Packages[]
-// Offset to package name in string table
-//
-// Manage the image module meta data.
-class ImageModuleData : public CHeapObj<mtClass> {
- class Header VALUE_OBJ_CLASS_SPEC {
- private:
- u4 _ptm_count; // Count of package to module entries
- u4 _mtp_count; // Count of module to package entries
- public:
- inline u4 ptm_count(Endian* endian) const { return endian->get(_ptm_count); }
- inline u4 mtp_count(Endian* endian) const { return endian->get(_mtp_count); }
- };
-
- // Hashtable entry
- class HashData VALUE_OBJ_CLASS_SPEC {
- private:
- u4 _name_offset; // Name offset in string table
- public:
- inline s4 name_offset(Endian* endian) const { return endian->get(_name_offset); }
- };
-
- // Package to module hashtable entry
- class PTMData : public HashData {
- private:
- u4 _module_name_offset; // Module name offset in string table
- public:
- inline s4 module_name_offset(Endian* endian) const { return endian->get(_module_name_offset); }
- };
-
- // Module to package hashtable entry
- class MTPData : public HashData {
- private:
- u4 _package_count; // Number of packages in module
- u4 _package_offset; // Offset in package list
- public:
- inline u4 package_count(Endian* endian) const { return endian->get(_package_count); }
- inline u4 package_offset(Endian* endian) const { return endian->get(_package_offset); }
- };
-
- const ImageFileReader* _image_file; // Source image file
- Endian* _endian; // Endian handler
- ImageStrings _strings; // Image file strings
- u1* _data; // Module data resource data
- u8 _data_size; // Size of resource data
- Header* _header; // Module data header
- s4* _ptm_redirect; // Package to module hashtable redirect
- PTMData* _ptm_data; // Package to module data
- s4* _mtp_redirect; // Module to packages hashtable redirect
- MTPData* _mtp_data; // Module to packages data
- s4* _mtp_packages; // Package data (name offsets)
-
- // Return a string from the string table.
- inline const char* get_string(u4 offset) {
- return _strings.get(offset);
- }
-
- inline u4 mtp_package(u4 index) {
- return _endian->get(_mtp_packages[index]);
- }
-
-public:
- ImageModuleData(const ImageFileReader* image_file, const char* module_data_name);
- ~ImageModuleData();
-
- // Return the name of the module data resource.
- static void module_data_name(char* buffer, const char* image_file_name);
-
- // Return the module in which a package resides. Returns NULL if not found.
- const char* package_to_module(const char* package_name);
-
- // Returns all the package names in a module. Returns NULL if module not found.
- GrowableArray<const char*>* module_to_packages(const char* module_name);
-};
-
-// Image file header, starting at offset 0.
-class ImageHeader VALUE_OBJ_CLASS_SPEC {
-private:
- u4 _magic; // Image file marker
- u4 _version; // Image file major version number
- u4 _flags; // Image file flags
- u4 _resource_count; // Number of resources in file
- u4 _table_length; // Number of slots in index tables
- u4 _locations_size; // Number of bytes in attribute table
- u4 _strings_size; // Number of bytes in string table
-
-public:
- u4 magic() const { return _magic; }
- u4 magic(Endian* endian) const { return endian->get(_magic); }
- void set_magic(Endian* endian, u4 magic) { return endian->set(_magic, magic); }
-
- u4 major_version(Endian* endian) const { return endian->get(_version) >> 16; }
- u4 minor_version(Endian* endian) const { return endian->get(_version) & 0xFFFF; }
- void set_version(Endian* endian, u4 major_version, u4 minor_version) {
- return endian->set(_version, major_version << 16 | minor_version);
- }
-
- u4 flags(Endian* endian) const { return endian->get(_flags); }
- void set_flags(Endian* endian, u4 value) { return endian->set(_flags, value); }
-
- u4 resource_count(Endian* endian) const { return endian->get(_resource_count); }
- void set_resource_count(Endian* endian, u4 count) { return endian->set(_resource_count, count); }
-
- u4 table_length(Endian* endian) const { return endian->get(_table_length); }
- void set_table_length(Endian* endian, u4 count) { return endian->set(_table_length, count); }
-
- u4 locations_size(Endian* endian) const { return endian->get(_locations_size); }
- void set_locations_size(Endian* endian, u4 size) { return endian->set(_locations_size, size); }
-
- u4 strings_size(Endian* endian) const { return endian->get(_strings_size); }
- void set_strings_size(Endian* endian, u4 size) { return endian->set(_strings_size, size); }
-};
-
-// Max path length limit independent of platform. Windows max path is 1024,
-// other platforms use 4096. The JCK fails several tests when 1024 is used.
-#define IMAGE_MAX_PATH 4096
-
-// Manage the image file.
-// ImageFileReader manages the content of an image file.
-// Initially, the header of the image file is read for validation. If valid,
-// values in the header are used calculate the size of the image index. The
-// index is then memory mapped to allow load on demand and sharing. The
-// -XX:+MemoryMapImage flag determines if the entire file is loaded (server use.)
-// An image can be used by Hotspot and multiple reference points in the JDK, thus
-// it is desirable to share a reader. To accomodate sharing, a share table is
-// defined (see ImageFileReaderTable in imageFile.cpp) To track the number of
-// uses, ImageFileReader keeps a use count (_use). Use is incremented when
-// 'opened' by reference point and decremented when 'closed'. Use of zero
-// leads the ImageFileReader to be actually closed and discarded.
-class ImageFileReader : public CHeapObj<mtClass> {
-private:
- // Manage a number of image files such that an image can be shared across
- // multiple uses (ex. loader.)
- static GrowableArray<ImageFileReader*>* _reader_table;
-
- char* _name; // Name of image
- s4 _use; // Use count
- int _fd; // File descriptor
- Endian* _endian; // Endian handler
- u8 _file_size; // File size in bytes
- ImageHeader _header; // Image header
- size_t _index_size; // Total size of index
- u1* _index_data; // Raw index data
- s4* _redirect_table; // Perfect hash redirect table
- u4* _offsets_table; // Location offset table
- u1* _location_bytes; // Location attributes
- u1* _string_bytes; // String table
-
- ImageFileReader(const char* name, bool big_endian);
- ~ImageFileReader();
-
- // Compute number of bytes in image file index.
- inline u8 index_size() {
- return sizeof(ImageHeader) +
- table_length() * sizeof(u4) * 2 + locations_size() + strings_size();
- }
-
-public:
- enum {
- // Image file marker.
- IMAGE_MAGIC = 0xCAFEDADA,
- // Endian inverted Image file marker.
- IMAGE_MAGIC_INVERT = 0xDADAFECA,
- // Image file major version number.
- MAJOR_VERSION = 1,
- // Image file minor version number.
- MINOR_VERSION = 0
- };
-
- // Open an image file, reuse structure if file already open.
- static ImageFileReader* open(const char* name, bool big_endian = Endian::is_big_endian());
-
- // Close an image file if the file is not in use elsewhere.
- static void close(ImageFileReader *reader);
-
- // Return an id for the specifed ImageFileReader.
- static u8 readerToID(ImageFileReader *reader);
-
- // Validate the image id.
- static bool idCheck(u8 id);
-
- // Return an id for the specifed ImageFileReader.
- static ImageFileReader* idToReader(u8 id);
-
- // Open image file for read access.
- bool open();
-
- // Close image file.
- void close();
-
- // Read directly from the file.
- bool read_at(u1* data, u8 size, u8 offset) const;
-
- inline Endian* endian() const { return _endian; }
-
- // Retrieve name of image file.
- inline const char* name() const {
- return _name;
- }
-
- // Retrieve size of image file.
- inline u8 file_size() const {
- return _file_size;
- }
-
- // Return first address of index data.
- inline u1* get_index_address() const {
- return _index_data;
- }
-
- // Return first address of resource data.
- inline u1* get_data_address() const {
- return _index_data + _index_size;
- }
-
- // Get the size of the index data.
- size_t get_index_size() const {
- return _index_size;
- }
-
- inline u4 table_length() const {
- return _header.table_length(_endian);
- }
-
- inline u4 locations_size() const {
- return _header.locations_size(_endian);
- }
-
- inline u4 strings_size()const {
- return _header.strings_size(_endian);
- }
-
- inline u4* offsets_table() const {
- return _offsets_table;
- }
-
- // Increment use count.
- inline void inc_use() {
- _use++;
- }
-
- // Decrement use count.
- inline bool dec_use() {
- return --_use == 0;
- }
-
- // Return a string table accessor.
- inline const ImageStrings get_strings() const {
- return ImageStrings(_string_bytes, _header.strings_size(_endian));
- }
-
- // Return location attribute stream at offset.
- inline u1* get_location_offset_data(u4 offset) const {
- guarantee((u4)offset < _header.locations_size(_endian),
- "offset exceeds location attributes size");
- return offset != 0 ? _location_bytes + offset : NULL;
- }
-
- // Return location attribute stream for location i.
- inline u1* get_location_data(u4 index) const {
- guarantee((u4)index < _header.table_length(_endian),
- "index exceeds location count");
- u4 offset = _endian->get(_offsets_table[index]);
-
- return get_location_offset_data(offset);
- }
-
- // Find the location attributes associated with the path. Returns true if
- // the location is found, false otherwise.
- bool find_location(const char* path, ImageLocation& location) const;
-
- // Assemble the location path.
- void location_path(ImageLocation& location, char* path, size_t max) const;
-
- // Verify that a found location matches the supplied path.
- bool verify_location(ImageLocation& location, const char* path) const;
-
- // Return the resource for the supplied path.
- void get_resource(ImageLocation& location, u1* uncompressed_data) const;
-};
-#endif // SHARE_VM_CLASSFILE_IMAGEFILE_HPP