| /* |
| * Copyright 1997-2005 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| * CA 95054 USA or visit www.sun.com if you need additional information or |
| * have any questions. |
| * |
| */ |
| |
| // A symbolOop is a canonicalized string. |
| // All symbolOops reside in global symbolTable. |
| // See oopFactory::new_symbol for how to allocate a symbolOop |
| |
| class symbolOopDesc : public oopDesc { |
| friend class VMStructs; |
| private: |
| unsigned short _length; // number of UTF8 characters in the symbol |
| jbyte _body[1]; |
| |
| enum { |
| // max_symbol_length is constrained by type of _length |
| max_symbol_length = (1 << 16) -1 |
| }; |
| public: |
| |
| // Low-level access (used with care, since not GC-safe) |
| jbyte* base() { return &_body[0]; } |
| |
| |
| // Returns the largest size symbol we can safely hold. |
| static int max_length() { |
| return max_symbol_length; |
| } |
| |
| static int object_size(int length) { |
| int size = header_size() + (sizeof(unsigned short) + length + HeapWordSize - 1) / HeapWordSize; |
| return align_object_size(size); |
| } |
| |
| int object_size() { return object_size(utf8_length()); } |
| |
| int byte_at(int index) const { |
| assert(index >=0 && index < _length, "symbol index overflow"); |
| return ((symbolOopDesc*)this)->base()[index]; |
| } |
| |
| void byte_at_put(int index, int value) { |
| assert(index >=0 && index < _length, "symbol index overflow"); |
| ((symbolOopDesc*)this)->base()[index] = value; |
| } |
| |
| jbyte* bytes() { return base(); } |
| |
| int utf8_length() const { return _length; } |
| |
| void set_utf8_length(int len) { _length = len; } |
| |
| // Compares the symbol with a string |
| bool equals(const char* str, int len) const; |
| |
| // Three-way compare for sorting; returns -1/0/1 if receiver is </==/> than arg |
| // note that the ordering is not alfabetical |
| inline int fast_compare(symbolOop other) const; |
| |
| // Returns receiver converted to null-terminated UTF-8 string; string is |
| // allocated in resource area, or in the char buffer provided by caller. |
| char* as_C_string() const; |
| char* as_C_string(char* buf, int size) const; |
| // Use buf if needed buffer length is <= size. |
| char* as_C_string_flexible_buffer(Thread* t, char* buf, int size) const; |
| |
| |
| // Returns a null terminated utf8 string in a resource array |
| char* as_utf8() const { return as_C_string(); } |
| char* as_utf8_flexible_buffer(Thread* t, char* buf, int size) const { |
| return as_C_string_flexible_buffer(t, buf, size); |
| } |
| |
| jchar* as_unicode(int& length) const; |
| |
| // Treating this symbol as a class name, returns the Java name for the class. |
| // String is allocated in resource area if buffer is not provided. |
| // See Klass::external_name() |
| const char* as_klass_external_name() const; |
| const char* as_klass_external_name(char* buf, int size) const; |
| |
| bool object_is_parsable() const { |
| return (utf8_length() > 0 || (oop)this == Universe::emptySymbol()); |
| } |
| |
| // Printing |
| void print_symbol_on(outputStream* st = NULL); |
| }; |
| |
| |
| // Note: this comparison is used for vtable sorting only; it doesn't matter |
| // what order it defines, as long as it is a total, time-invariant order |
| // Since symbolOops are in permSpace, their relative order in memory never changes, |
| // so use address comparison for speed |
| int symbolOopDesc::fast_compare(symbolOop other) const { |
| return (((uintptr_t)this < (uintptr_t)other) ? -1 |
| : ((uintptr_t)this == (uintptr_t) other) ? 0 : 1); |
| } |